Consumer Products – Robert E. Grove, Mark V. Weckwerth, Tobin C. Island, Channel Investments LLC
Abstract for “Self-contained, eye-safe hair-regrowth-inhibition apparatus and method”
“A dermatologic hair-regrowth-inhibiting apparatus is disclosed which is cordless and sufficiently compact as to be hand-held. A self-contained housing is configured for gripping by a person’s hand for cordless manipulation in a hair-regrowth-inhibiting procedure. The housing contains a light source and an electrical circuit. One or more batteries are used to energize the light source and produce light pulses. An aperture is located within the housing that allows for the transmission of eye-safe light pulses out of the housing. These light pulses have sufficient properties to inhibit hair-regrowth at most temporary levels. To reduce the integrated radiation to an eye-safe level, a diffuser is placed along the light path.
Background for “Self-contained, eye-safe hair-regrowth-inhibition apparatus and method”
“Field of Invention”
“The invention relates to a hair-regrowth-inhibiting apparatus and method, and particularly to a self-contained, cordless and hand-held apparatus that is light-based, yet eye-safe, and upon dermatologic application, at least temporarily inhibits hair regrowth.”
“Description of Related Art”
“The 1996 introduction of specialized lasers for doctor-performed epilation (and IPL sources shortly afterwards) marked the first significant advancement in the treatment and prevention of unwanted hairs since electrolysis was invented in the late 1800’s. These devices have been safe and effective. They also allow for multiple hair treatment at once, which is a significant improvement on electrolysis.
“Light-based epilation using lasers is sometimes called “laser hair removal?”, but this is only true when the follicles are sufficiently damaged to prevent new hair growth (permanent hair loss?). Hair-regrowth inhibition is a procedure that causes hair regrowth to be delayed by thermal damage to follicles.
Methods and devices for light-based epilation have become very popular and are used by approximately three million people around the world. Because of the inconvenience and high cost of physician-based devices and procedures, this is a small portion of the market. There is a demand for smaller, cheaper devices that can be used to lower the cost of physician-based procedures and ultimately help create salons and consumer markets. Devices with improved eye safety are also desired.
Star Medical introduced the LightSheer Diode Laser System in 1997 to inhibit hair-regrowth and then for permanent hair loss. This was the start of one of the most popular aesthetic laser applications for dermatologists. These and other similar devices have been widely used worldwide and their safety and efficacy are well-established. The Palomar Medical Technologies SLP 1000 (LC100) diode-laser, the Apex 800 diode-laser of IRIDEX Corporation, as well as the Opus Medical, Inc F1 diode beam laser are all examples of such devices.
The radiant exposure to the skin (often referred as “fluence”, expressed in joules/square centimeter) is usually in the 10-40 J/cm2 region at a wavelength nominally 800 nanometers. Initial research believed that pulse durations of 5-30 ms were optimal. However, later studies revealed that longer pulses (often in the 10-40 J/cm2 range) can achieve hair-regrowth inhibition and reduce epidermal heat for a given fluence (e.g. by placing a sapphire output window in contact with the skin).
“The small size and high efficiency of these semiconductor diode lasers allows for the production of compact systems, typically 1-3 cubic feet in volume and simple 115 VAC operation. The systems are typically 25-100 lbs in weight and retail for $40,000-$90,000. This popular procedure would be more accessible if it were cheaper and could be carried around.
Dermatologists are increasingly accepting lasers and intense light sources for the effective treatment of a variety of conditions, including hair-regrowth inhibition, permanent hair reduction, removal tattoos, treatment birthmarks and facial resurfacing. Medical professionals are well aware that these light sources can cause serious eye damage and blindness. The fluence of light-based dermatologic procedures such as the reduction of unwanted hair and destruction of small blood vessels must exceed 1 J/cm2 to achieve acceptable efficacy. The fluence of these devices at the eye is often greater than the maximum allowed exposure. This can make them and their treatments extremely dangerous if they are not properly used. This procedure requires that safety precautions are taken to protect not only the eyes of the patient but also the operator of the laser and other personnel who may be present in the same vicinity. See, for instance, IEC Technical Report 60825-8 Safety of laser products?Guideline to the safe use medical laser equipment. The IEC report states that some medical lasers can expose the retina to a higher irradiance than what is incident on the skin or cornea. This is due to the focusing action.
Eye damage can be reduced by taking proper safety precautions such as safety glasses and training personnel. In medical settings, eye injuries are very rare. Eye injury remains a concern.
A contact sensor, which allows the device to operate only when it is in direct contact with a surface such as skin, can increase the safety of light-based dermatologic devices. The light source, such as a laser, light-emitting device, flashlamp, or other light source, can be placed within a housing. A housing with one open end through which light propagates can be used. However, a contact sensor located at the open end of the housing can only allow operation of the device if it is placed against a contacted surface. This ensures that light cannot propagate through or into the surface on which it is placed. However, any sensor that is added to eye safety can cause complications and even failure. The ideal dermatologic treatment method and device would not depend on electronic circuitry, or user compliance with safety glasses for safe use.
It is therefore highly desirable that any light-based medical device be designed to minimize eye damage at a certain level of output fluence, or therapeutic benefit. This will increase the inherent eye safety. Laser hair reduction devices such as those used today are more dangerous than necessary for the eyes because they have a high directional output and can be easily focused by the eyes. Their output could be made more divergent or less coherent to reduce the risk of injury to the eye. This would not result in a significant loss of effectiveness.
U.S. Pat. explains “Examples for office-based, light based systems dermatological treatment Nos. Nos. 2002/0005475 and published PCT Application no. WO 03/049633. The published application ‘5475 uses a contact sensor to enable laser pulses only when the handpiece comes in contact with the skin of a patient. The problem with using such a device in a self-care or home use setting is that small children or people trying to treat their eye brows or eye lashes with it may inadvertently shine laser pulses into their eyes, potentially causing permanent vision damage. Similar eye safety issues would occur in home care, self-care applications of the devices described above.
“The published application ‘49633 addresses the eye-safety problem by providing a diffuser unit. The device is too heavy, complicated, and costly to be used at home. It includes a non-portable laser floor unit, an extensible handpiece and a long beam delivery guide. This device also has other safety concerns. A home-use, self-care device may not be able to deal with the safety issues posed by a device drawing high current from a wall outlet. The invention in the patent addresses eye safety with collimated laser beams, convergent beams, concentrated multiple beams, or fiber guided beams. It also includes monochromatic sources. Divergent light sources, however, can be made eye-safe significantly easier, as described in accordance to the present invention.
“The patents ‘029, ‘020 describe devices that produce fluences greater than 100 J/cm2. These fluences are too large to be safe for the eyes and epidermis in self-care settings. These fluences can cause corneal fluences that are potentially higher than the Maximum Permissible Exposition (MPE), which is described below. They may also likely cause epidermal burns. These fluence levels cannot be produced in a self contained apparatus such as a handheld and battery-powered device that is used for home and self-care.
“Furthermore the device described in the ?029 and the ?020 patents has a very small spot of between 2 and 5 millimeters diameter, which corresponds to 0.03 to 0.0.2 square centimeters. This small spot means that one hair can be treated at a given time. In fact, some visual targeting is required to make sure that the spot covers even one target follicle. A small spot, such as 0.03 to 0.2 square cms, implies very low coverage rates. For a given area of skin with unwanted hairs, the treatment time will be longer if the spot size is smaller. A small spot size can be advantageous because it allows for low fluence (since energy is divided by area). However, the fluence at a certain depth within the skin, such as where the target cells are, can be significantly reduced by scattering. The effective decrease in fluence at depth relative with fluence at the surface is greater the smaller the spot size (especially below 0.5 cm2). In other words, too small a spot, such as the one described in the ?029 and the ?020 patents can result in either burning the epidermis (to get enough fluence) or poor efficacy due insufficient fluence at depth. Both of these outcomes are clearly undesirable.
“CURRENT STATE of THE ART”
The two main types of devices currently on the market can be used to describe the current state of light-based epilation. Devices that are sold to physicians make up one market segment. The LightSheer diode-laser system, now manufactured by Lumenis Ltd. and the SLP-1000 fiber?coupled diode laser manufactured by Palomar Medical Technologies Inc. are all representative products. Also, Altus Inc.’s CoolGlide Excel YAG Laser and Quantum flash lamps are also manufactured by Lumenis Ltd. The FDA cleared physician devices have (a) proven efficacy, (b), practical coverage rate, and (c) high price. They also feature a physical design that attaches a handpiece to a console and (e) severe eye hazards due to their output fluences. These devices are light-based epilation devices that provide effective and practical light-based epilation. They generally have a peak optical power of 50 W, an output fluence greater than 10 J/cm2, spot sizes greater than 0.5 cm2, a coverage rate greater then 10 cm2/min, and a maximum optical power greater than 50W. These office-based devices can be found in the patent literature, which is cited above. Additional examples are available in other references.
“The second market segment consists of a limited number consumer light-based epilation device. There are currently no personal light-based epilators on the American market. The most developed market for consumer-light-based devices at the moment is Asia and Japan. There are many products on the Japanese market. Ya-Man Ltd.’s devices are a good example of the current state of these products in Japan. These consumer devices have a low peak power (1 W) and a small spot size (0.1 cm2 or less), a low coverage rate and low cost.
“The inventors of the embodiment of the invention recognized that it would be beneficial to have a device and method that can provide effective and convenient epilation in a completely handheld and cordless device. The term “cordless” and “handheld” is preferred to mean that the device is portable and can be used by one person. This handheld and cordless device is significantly easier than handpiece and console devices. It allows the operator to position the device in the most convenient orientation to treat the desired area of skin. It is portable and can be used without the need for electricity. To be an effective and useful treatment device, it must have a peak optical output power of 10 W, a fluence of more than 4 J/cm2, spot sizes larger than 0.25 cm2, and coverage rates greater that 10 cm2/min.
While there are other light sources that can be used to inhibit hair-regrowth, such as intense pulsed or laser light, diode laser systems are the most popular. These devices often include laser diode bars that operate at approximately 800 nm wavelength. These systems have a peak optical power of approximately 90 watts up to almost 3,000 watts.
“Discrete laser diodes have a peak power of about one watt. This low power is sufficient to treat individual hairs (like the Ya-Man device made in Japan), but for treatment of large areas of hair, peak optical powers of approximately 25 watts and more are required. These diode-based office products include diode beam bars rather than individual diode devices. These laser diode bar hair-regrowth inhibitor systems, which are used in offices by nurses and doctors, have been a huge success. This has led to interest in home-use devices. Devices that can be safely used at home without the need to visit the doctor’s offices are also becoming more popular due to the inconvenience of having multiple appointments. This device should be small, portable, and powered by batteries. It would also incorporate proven laser diode-bar technology. Because of the high current requirement (40 A) for laser diode bar technology, it is not recommended that such devices be powered by batteries. Instead, they should be powered by an electrical cord connected to a wall outlet.
U.S. Pat. explains “Examples for other dermatologic devices” No. No. 2003/0004499, 2002/0097587 and other references incorporated herein.
“The U.S. Patent is potentially safe for the eyes, but it does not protect the eye. No. 6,533,775 describes a mechanical hair removal device, and not a light-based hair-regrowth-inhibition apparatus. In order to decrease the time it takes for the device to become active, the patent ‘775 describes a light source that reacts with skin cream. The mechanical hair removal device does not produce heat to cause thermal damage to hair follicles. It is intended to prevent regrowth. The cream is not intended to penetrate the cream and cause any thermal injury to the dermis targets.
“The ‘97587 patent describes a device that has variable current control. This device is not intended for medical purposes. This reference does not have any output fluences, wavelengths, or pulse lengths that could possibly cause the fluence at an individual’s eye to fall below the MPE. This device would need to be modified to make it safe for home use, and effective for dermatologic treatment of hair-regrowth inhibition.
“The ‘4499 patent describes a device that is said to be designed to prevent hair regrowth. Its procedure is called bio-stimulation in order to produce bio-inhibition. In any case, it’s non-thermal. This is a wholly separate field from hair-regrowth-inhibiting devices that operate by causing thermal damage to hair follicles. For hair-regrowth inhibition, the ‘4499 reference uses lower fluences or intensities than what would be effective for thermal damage to hair follicles.
“Designing a handheld device to inhibit hair-regrowth requires clever circuit design. Implementing a dermatologic treatment device that is effective and safe for the eyes requires novel optical design. Therefore it has appeared up to now that the creation of a low-cost, light-based dermatologic treatment device, such as a home-use hair-regrowth-inhibiting device that is effective, compact, battery-powered, and incorporates a diode laser or other light source, is an unachievable goal. Recent advances in light technology and microelectronics make it possible to create dermatologic devices that are both effective and affordable for the average consumer. These devices may be small enough to be carried around and powered by a battery. These devices can also be used for dermatologic procedures and are safe for the eyes. These devices are the subject of the present invention and are described below.
“Therefore, in view of and in accordance with the above, a dermatologic hair-regrowth-inhibiting apparatus is provided that is cordless and sufficiently compact as to be hand-held. A self-contained housing is configured for gripping with a person’s hand for cordless manipulation in a hair-regrowth-inhibiting procedure. The housing contains a light source and an electrical circuit. One or more batteries are used to energize the light source and produce light pulses. An aperture is located within the housing that allows for the transmission of eye-safe light pulses out of the housing. These light pulses have sufficient properties to inhibit hair-regrowth at most temporary levels. To reduce the integrated radiation to an eye-safe level, an optical diffuser is placed along the light path.
The cordless apparatus is lightweight at no more than 1 kg. The cordless apparatus also occupies a volume of no more than 1500 cm3. The preferred embodiment weighs less than 700g and takes up 700 cm3 volume. In use, the hair-regrowth-inhibiting apparatus produces a light pulse having a fluence on the skin surface that is sufficient to at least temporarily inhibit hair regrowth and having an integrated radiance insufficient to cause eye damage.”
“In addition to the features described above, light pulses can also be generated by a diode light source. They emit light at a repetition rate of 0.1 Hz to 2 Hz, have peak power between 10 and 120 watts, have a spot area between 0.25 cm2 – 5 cm2. Further, the light source may include one or more flashlamps and LEDs.
“A hair-regrowth-inhibiting device in accordance with various combinations of the above aspects may include any combination of the following further features. The heatsink can be used to contact the epidermis region of the person while the device is being used. Preferably, the heatsink has one or more thermal properties that remove enough heat from the epidermis to prevent or reduce epidermal damage. The heatsink temperature can be lower than or higher than a normal temperature. Normal skin temperature refers to the temperature of the skin without the device. A sapphire output window may be included in the heatsink.
A contact sensor can be used to allow light pulses to propagate from the housing when there is substantial contact between the sensor and the surface being contacted, such as the skin of a person. When the contact sensor is in contact with the surface to be contacted, a light pulse can be generated automatically.
“The light source could include a diode-laser light source. One or more diode light sources may be included in such a diode source. If possible, two or more diode beams are used. Multiple laser diode emitters would be included in each diode laser bar. One or more laser diode bar may be thermally connected to a fan-cooled heatsink.
“The light source could include a divergent source like a diode laser or flashlamp source or an alternative source like an LED or flashlamp.
The bandwidth of the output light pulses could be greater than 2 nm and less than 40 nm. Pulse durations can be as short as 10 milliseconds to 1 second. Pulse durations can be as short as 200 milliseconds and as long at 600 milliseconds.
The electrical circuit could include a supercapacitor to energize the light source. It is preferable that the electrical circuit contains a direct drive circuit to energize the light source. Direct drive circuits are best without storage capacitors, transformers, or both.
The optical diffuser can be either reflective or transmissive. To distribute light uniformly at the aperture, a mixer can be placed along the light path. The diffuser’s normal may not coincide with the principal optical axis of light from the source. The light source could include one or more laser beam diode bar lasers that have a principal optical direction that is not parallel to the normal surface of the diffuser. Alternatively, the principal optical path of the laser diode bar lasers may be parallel to that of the diffuser’s normal surface, but the laser diode light may be redirected by a mirror so that the light strikes the diffuser at a different angle than the diffuser surface. An audible feedback component may be included in the apparatus.
“A hair-regrowth-inhibiting method for cordlessly inhibiting hair regrowth is also provided. A self-contained housing assembly of a hair-regrowth-inhibiting device is gripped in a person’s hand. The housing assembly is placed so that the output window component contacts an epidermis region of another person. To produce light pulses, the light source is powered by an electrical circuit that includes one or more batteries. The light pulses from the light source are transmitted through a housing that includes an aperture through which light pulses with eye-safe properties are propagated. To reduce the integrated radiation to an eye-safe level, the light pulses are diffused along a light path. The hand-held, dermatologic device is then cordlessly manipulated in a hair-regrowth-inhibiting procedure. The hair-regrowth-inhibiting device thus produces a fluence on the skin surface that is sufficient to at least temporarily inhibit hair regrowth and that has an integrated radiance insufficient to cause eye damage.”
“The preferred method involves the use of an apparatus that conforms to at least one of the features above, as well as any other aspects. To reduce or prevent epidermal damage, heat can be extracted from the epidermis. A heat sink may be used to remove the heat generated by laser diode bar lasers.
“The energizing can involve either partial discharge of a capacitor for energizing the light source or direct drive energy. Direct drive energizing is a method where current pulses are generated by one or more batteries and pass through the light source without the need to discharge a storage capacitor. In order to generate light pulses, the energizing can also include current pulses that are generated without the need for a transformer.
The cordless manipulation may be performed by the same person who applied the light pulses to the skin. Or it may be another person. A switch can be used to reduce the fluence.
“In another aspect, light pulses are emitted at repetition rates between 0.1 Hz to 2 Hz. Each light pulse has a peak power of 10 watts or 120 watts and a spot size of 0.25 cm2 to 5 cm2. This cordless apparatus has a weight limit of 1 kg and a volume of 1500 cm3. Energizing can be done by energizing a divergent source of light, such as a diode-laser light source, flashlamp light source, or light emitting diode (light emitting diode) light source.
“First Embodiment”
“A first embodiment describes a device and a method that allow light-based dermatologic treatments with a handheld, self-contained device. This device is a combination of a battery-powered electrical circuit design and a self-contained housing mechanic design. It also includes a light source, optical design, and a light source. This allows for effective and practical dermatologic treatments in a handheld and cordless manner.
“The light source could be, for instance, one or more semiconductor diode bars that emit pulses of infrared radiation. The device emits light through the epidermis, which is absorbed into the hair shaft and follicle to inhibit hair-regrowth. The resultant temperature rise temporarily disables the follicle, slowing down hair regrowth. You can pulse the device at a rate of up to 0.25 Hz.
Effective dermatologic treatment (e.g., hair regrowth inhibition) can be achieved with standard output fluences (10-40 J/cm2), but with extremely long pulse durations (upto 1000 ms). This eliminates the need to use very high peak laser power. For example, 20 J/cm2 can be produced in 350 ms using a 9 mm x 9 mm output area. However, an optical peak power of 46 watts is required. This allows for battery operation and reduces the peak power requirement. This device can be carried around with the above parameters.
FIG. 1. Light source 10, mixer 12, output windows 14, heat-removal and electrical elements 16, 18, and housing 20 are the elements shown. Other mechanical, optical, and electrical elements are not shown, but they are involved in the operation. These include a trigger, drive circuitry, indicators, and sensors. FIG. FIG. 1 is intended to only introduce the preferred first embodiment, which will be described in greater detail later.
The user must charge the battery 18 by placing it in a charging station that provides an electrical charge from a wall outlet. After the battery has been charged, the user will press an aperture or output window 14 against the skin surface to be treated. Because of its high thermal conductivity, sapphire is preferred for the aperture or window 14 that comes in contact with skin. However, the output aperture, or window 14, may only be an opening or aperture. The window component 14 that touches the skin of the individual may be a frame. The heat-removal component 16 draws heat from the light source 10. It may also draw heat from the skin through conduction through window 14, and mixer 12. The heat-removal device 16 could be a thermoelectric heat exchanging unit that heats the surrounding air using a fan and finned heat sink. It may also draw heat from the skin through conduction through window 14 and mixer 12. As described below. By pressing a trigger button, the user activates a pulse of light from the source 10. Alternately, an electrical circuit could be designed in such a way that the light source 10 contacts the skin of the person being treated. A contact sensor near the output aperture detects enough contact between the output window 14 and the skin to activate one or more pulses. The light pulse is sent to the mixer 12, which distributes light uniformly onto the output windows 14 and into the skin. The output window 14 connects to the heat-removal device 16 via mixer 12. This serves as an additional heat sink for skin.
The preferred device has a fixed, mid range output fluence setting of nominally 20, J/cm2 with a nominally 300-350 ms pulse duration. This simplifies operation. Alternately, the output fluence could be either continuously adjustable or discretely adjustable. Below are details about the electrical circuit design.
“Additional details of a preferred embodiment of a light-based hair-regrowth-inhibition apparatus are shown in FIGS. 6-8. These figures show schematically the exterior of the unit housing. FIG. FIG. 6 shows a front view, and the output window (420) is illustrated. The trigger buttons 430 that initiate laser pulses are also displayed. They can be easily depressed by either a left- or a right-handed self-care person. Also visible are vent louvers, or openings 440. The charging base 450 is shown here with a power cord of 460 to recharge the apparatus.
FIG. 7 shows the output window, 420 along with vent louvers 440 and an on-off switch 460. FIG. 2 shows the indicator lights 470 in greater detail. 8. Examples include a battery indicator 472, an on/off indication 474, and a ready indicator 469.
“The volume of the primary components of the apparatus should be less than 2000 cm3, more preferably less that 1000 cm3, and less than one kilogram. The apparatus can have a volume of 700 cm3 or less and a weight of 700 grams, which is even more preferable. This allows the apparatus to be held in one’s hand and can be controlled with a firm grip. FIGS. FIGS. 6-7 show that the apparatus measures 400 cm3 in volume and weighs 500 grams in a self-contained, cordless device. When the term cordless appears in this document, it means that the unit is powered by a battery and is not connected to an external power source or outlet. The term “self-contained” is also used to mean that the unit does not need to be physically connected to any base unit or other unit. It can be freely manipulated without the use of wires or couplings. A self-contained housing, such as the one shown in FIGS. The housing 6-7 contains the light source and batteries. It is not attached to any light guide or electrical cable that protrudes from the housing 410. However, a wireless control or other wireless coupling or the charging base (450) cannot be included components in a unit that has the self-contained housing of FIGS. However, the housing 410 does not have any externally protruding physical couplings like control wires or optical cables.
The preferred embodiment of a handheld device is efficient, self-contained, and user-friendly, even allowing maximum electrical, thermal and optical inefficiencies. The output parameters of this device prove that it is practical and efficient in use.
“In this section, we provide additional information regarding the preferred method of using the apparatus. The charging of the apparatus requires that it be placed in a charging base (450 as shown in FIG. 6. Usually, this is done over night. The charging of the device can be done easily by plugging it into an AC outlet and then placing the device in the charging stand 450. The unit should be returned to its charger 450 after each use so it can be fully charged for the next one. You can leave the unit in the charger 450 for extended times without causing any damage to it.
“During charging, left indicator light 472(FIGS. 7-8) flashes green. This light will stop flashing when the battery is fully charged and stay green.
To ensure maximum comfort, you should first trim the skin. Next, use a damp, cool cloth to wipe the treated area. The unit is dependent on light absorption by the hair shaft beneath the skin. This means that the hair should not be removed by waxing or plucking. Treatment should be delayed if either of these procedures were used recently.
After the unit is fully charged, turn it on by pressing and releasing ON-OFF button (460 in FIG. 7. The center indicator light 474 in FIG. 8 will be illuminated.
The right indicator light 476 might flash briefly after power has been turned on. This indicates that the unit is nearing the?ready? state. state. When the right indicator light 476 is steady green, it indicates that the device has been ready. It will emit a light pulse if either of the trigger buttons 430 are depressed (provided the output window 420 touches skin). To allow comfortable use of the device, two triggers 430 have been provided.
The output window 420 should be placed against the area of the skin to be treated. Press the trigger 430 and release the trigger. When the laser pulse has completed, a beep is preferably heard. A particular embodiment will produce a sound that is either a tone or a beep when the laser pulse is complete. This indicates that the contacts sensors around the window (420) are in contact with skin, and the pulse can be propagated from the housing 410. The self-care user will be able to tell that the unit won’t generate a pulse unless good contact has been established and the tone heard. Another embodiment will emit a tone and/or a beep if the output window 420 moves away from good contact. This is an indication to the user that the housing 410 will not allow a pulse to propagate until the contact is restored. The output window 420 should be moved to another area after the pulse-completed sound is heard. There should be approximately fifty percent overlap. The tip should be moved approximately one-half of the distance from the skin. The trigger need not be held down during the pulse. However, it is important to keep the trigger in full contact with the skin for the duration of the pulse. The output window 420 should not be lifted from the skin before the laser pulse is completed. A distinct tone will sound to alert the user and the area should then be treated with another pulse.
“The unit’s maximum repetition rate is between one pulse per second and one pulse per four seconds. There may be a delay of a few seconds before the next beep is heard.
“All the sounds above can be used as feedback and aids in using the device.
“Second, Third Embodiments”
Alternative embodiments of a dermatologic therapy device and method include an optical diffuser. This is to increase the safety of the device’s eyes while minimizing any adverse effects on its efficacy. An optical diffuser is added to the apparatus to increase the divergence and reduce the spatial coherence. This allows it to be classified as a Class 1 Laser Device according to the U.S. Food and Drug Administration Center for Devices and Radiological Health guidelines. This allows the user to use the apparatus without the need for safety glasses or goggles. It also eliminates the possibility of injury to the eyes if any other safety measures, such as the contact sensors, fail.
“Accordingly, a device for dermatologic treatment is provided in a second or third embodiments that are eye-safe. The device and method can be used to treat various dermatologic conditions. The fluence produced at the skin’s surface is greater than one joule per centimeter. However, the fluence can be aimed directly at the eyes from any distance and still produce a fluence that is below the maximum permissible exposure (MPE), as determined by the American National Standards Institute and the International Electrotechnical Commission. The MPE value is essentially the equivalent to the Exposure Limit (EL), published by the International Commission on Non-ionizing Radiation Protection.
“Dermal treatment is not a high-directed beam application, as it is rare for many other applications of lasers or light sources. It is not necessary for the light to reach the skin at normal incidence. This means that the light must be contained within an applicator or handpiece before it can enter the skin. Because the skin is highly scattering, any light rays that enter the skin at normal incidence are scattered very close to the surface by epidermal cells and redirected into every angle. This diffuser allows light rays to spread before entering the skin. Although it has very little effect on efficacy, it greatly increases eye safety. Due to the eye’s focusing ability and the intensification of light onto the retina, simply increasing the divergence from a coherent source like a laser is not enough to ensure eye safety.
“It should be noted that the devices in the second and third embodiments can easily accommodate the essential elements from the first embodiment. The embodiments below can be used to create the eye-safe devices. The devices described below can also be corded so that they can be used from a standard wall outlet. The second and third embodiments are basically the same as the first.
“FIG. 2A schematically illustrates a dermatologic device, such as a light-based hair-regrowth-inhibition device, incorporating a transmissive diffuser in accordance with the second embodiment of the invention. A transmissive diffuser can be described as an element that is integrated into a light path. It has an input surface where light strikes first and an output surface from which it propagates. The diffuser’s material is able to separate these output and input surfaces.
The figure schematically shows the device in contact with skin 150. It incorporates the use a diffusing medium 120 through which light passes before reaching the apparatus via an output window (or simply an aperture) 100. A light source 140 is contained within the source chamber 130. It emits pulses with many advantages. One or more laser diode bars are preferred. Light source 140 could be used to treat a dermatological condition.
“The diffuser 120 is placed above an aperture in the source chamber 130. Diffusing material 120 is placed over an aperture in source chamber 130. Diffuser 120 increases the diffuser 120’s light output and reduces the spatial coherence. The diffuser 120 can be made from a material that scatters light passing through it, such an opalized substrate. In a section that describes component details, you will find information about the appropriate optical diffuser designs. A variation of this embodiment would see the inner walls 130 of the source chamber coated with a non-absorbing material at therapeutic wavelengths. It is possible to have a source chamber that isn’t substantially absorbent. However, for the same power delivered the skin would need to be used, an intense light source 140 would be required. Because energy efficiency is at a premium, it is not desirable to require additional power, especially in a cordless, hand held, self-care device.
A mixing chamber 110 may increase the spatial uniformity of light. This may simply be a hollow tube with side walls that are substantially non-absorbing. The light would then propagate through the chamber before it leaves the apparatus via the output window 100. The mixer can be removed if the diffuser’s spatial uniformity is sufficient for the treatment. In this case, the diffuser 120 could be directly in contact with the skin, and the output window 100 may be used instead. Alternately, the diffuser 120 can be placed at the location shown in FIG. 2A, even though sufficient uniformity can be achieved without the use of the mixing chamber 110. However, it is important that the diffuser 120 be not placed too close to the light source 140. This will prevent substantial non-uniformity from occurring because the light source has not sufficiently diverged before it impedes upon the diffuser 120.
“FIG. 2B schematically illustrates a dermatologic device, such as a light-based hair-regrowth-inhibition device, incorporating a reflective diffuser in accordance with the third embodiment of the invention. Refer to FIG. FIG. 2B shows that the term reflective diffuser refers to an element integrated into a light path. This first surface is where the light strikes initially. However, unlike a transmissive diffuser this surface also acts as the output surface. Further, the term “reflective” is used to refer to reflected light. It is also important to note that the term “reflective” can be used in this context to refer to reflected light. This means that the diffuser can scatter or refract light.
“In FIG. 2B, a light-based hair-regrowth-inhibition device is illustrated in contact with skin 155 that incorporates the use of a diffusing material 125 which diffuses light from source or sources 145 before the light leaves the apparatus though output window (or simply an open aperture) 105. The chamber 115 contains a light source (or sources 145) that emits pulses with many advantages. The light source or sources 145 could be used to treat a dermatological condition, such as unwanted hair, by using laser diode bars.
“The diffuser material 125 should be placed in chamber 115 at a location that is generally against the skin. The diffuser 125 is illuminated by the light source or sources 145, although it does not have to be uniformly lit. Diffuser 125 can be used to increase the diffuser’s light output from sources or light sources 145, and reduce the spatial coherence between the source or sources. The diffuser 125 can be made of highly scattering materials such as Teflon or PTFE. In a section that describes component details, you will find information about the appropriate optical diffuser designs. A variation of this embodiment would see the chamber 115’s inner walls coated with or otherwise constructed from a material that is not absorbent at therapeutic wavelengths emitted from source(s) 145. Chamber 115 may be used as a mixer to increase the spatial uniformity of light. It may simply be a hollow tube with side walls that are substantially non-absorbing. The light would then propagate through the chamber before it leaves the apparatus via output window 100. Further, FIG. FIG. 2B shows an example of a reflective diffuser. In this embodiment, light from the source or sources (145) is directed initially away from the skin 155 before striking diffuser 125. FIG. Alternately, 2B could be constructed so that light from source or sources 140 initially propagates toward the skin. However, before striking the skin such light is redirected to the diffuser 125 by a mirror.
“Component Design”
“Light Source”
“With reference to FIG. 1. The light source 10 is preferably two diode-laser bars with a nominal wavelength around 800 nm. For example, operating specifications could include a 20 J/cm2 output fluence with 350 ms pulse duration and a 0.8 cm2 spot size (output opening) and a 0.5 Hz pulse repeat rate. These parameters correspond to an optical peak of 46 W and a duty circle of approximately 18%. The resulting optical power into the light source is around 23 W (8 W of average optical power emitted and 15 W of wasted heat). The light source’s volume and weight are approximately 1 cm3 and 10 grams.
“Skin Contact Sensor”
“A skin contact sensor is preferred to be incorporated into the tip or the preferred dermatologic treatment device in order to prevent accidental output of light pulses from the device. A ring of tiny?membrane switch? may be included in the sensor. The preferred sapphire window’s circumference is covered by a ring of membrane switches. The membrane switches signal that the device is not in contact with skin or any other contact surface will prevent it from firing. Alternately, the trigger can be removed and one or more membrane switches closed to activate light pulses. As mentioned above, an audible or other sensor indication is provided when contact is established. The output window must be moved from a contact position on the skin of the user so that firing can be disabled until contact is restored. A pulse indication should include an audible indication or another sensory indication at the end to inform the user that the apparatus can be moved to a different location before the next pulse.
“Charging Base”
“Between the uses of the dermatologic therapy apparatus of the preferred embodiment it is preferably placed into a charging base (see FIG. 6). It may look similar to the charging bases used with phones, shavers, and electric toothbrushes. The charging base can be connected to an AC outlet and charged overnight.
“As stated above, the second and third embodiments of the apparatus may be corded so that it can be used from a standard outlet, eliminating the need to charge a base.
“Mixer”
FIG. 1. The mixer 12 is used to: (a) mix the light emitted by the diode lasers to create a uniform beam profile at output window 14, (b), provide a low temperature path between output window 14 and heat-removal 16 and (c) minimize thermal loads on device due to light absorption from back reflected or back-scattered sunlight.”
“An alternative embodiment of the mixer may include an inner mixer such as a sheet made of polished metal for reflecting light from the source towards the output window 14, and an outer metal surface such as a copper barrel or aluminum barrel to conduct heat from the output window 14 to the heat-removal elements 16. The inner mixer can be made from solid transparent materials such as acrylic or glass. The light coming from the light source would then be reflected towards the output window 14 through total internal reflection in the acrylic or glass.
“Optical Diffuser”
“The term “diffuser” is used. “Optical diffuser” or?diffuser? This patent application refers to all conventional elements, such as the “optical disk diffuser” Flashed opal type, Stratford, Conn. Oriel Instruments Model 48010) and more generally any element that, when incorporated in a light-emitting apparatus having a given radiant expose or fluence, significantly reduces the integrated radiance (brightness). The device. Diffusers are generally used to increase the spatial coherence and divergence of light incident on them.
“With reference to FIG. 2A, diffuser 120 could be made from a material that scatters light. This would be the optical disk diffuser (Oriel) mentioned above. Diffuser 120 could be made of a transparent substrate with a roughened surface to scatter incident light through reflection. Diffuser 120 could be bulk scattering diffuser made from, for example, opal glass or PTFE. It may also be made from thin (e.g. Spectralon sheet, or combinations thereof. Alternately, the diffuser 120 could have a body or refractive surface; or a diffusing surface with random surface irregularities. These diffusers can be made from ground glass, sandblasted or plastic or molded materials created by a randomly-textured mold or combinations thereof. Diffuser 120 could also have a patterned body or surface, such as a Fresnel or holographic pattern.
FIG. 2B can be made of a scattering material like PTFE or a commercial material like Spectralon (available at LabSphere, Inc.). Diffuser 125 could also contain Duraflect, a scattering material that can be applied to the chamber 115, opposite the skin 155. You can also make diffuser 125 by simply roughening the chamber 115 against the skin 155. However, the preferred embodiment will include a diffusing material like Spectralon or an applied coating such Duraflect due to their low absorption. Diffuser 125 could also be made from a material that scatters light, such as an opalized substrate made by Spectra-Physics. This is then backed with a highly reflective mirror. A transmissive diffuser can be used to diffuse the light.
“FIG. 3A shows an example of a diffuser 120 with transparent screens of the fine structure or lenticular types. FIG. 3A shows transmissive sheets with machined or molded refractive and diffractive elements. FIG. 3B illustrates concentric microgrooves in the diffuser 120. 3B.”
“The diffuser (125) of FIG. 2B could include only roughened interior surfaces of passageways through which light is scattered before exiting the device. 3C, which is discussed in relation to FIG. 3E in more detail below.”
A small light source that is approximately the size of a “point source” can be used to achieve very low integrated radiation for a given output fluence of a device according to embodiments of this invention. Projecting into a mixer with mirrored walls, such as the one illustrated in FIG. 3D.”
“FIG. 3E illustrates an embodiment of the present invention in contact with skin 250. It incorporates the diffusing surface 220 from FIG. 3C shows the light striking the apparatus through the output window 200. Source chamber 230 houses light source 240. Instead of using a diffusing material to direct the light, a diffusing layer 220 is placed relative to source 240 so that the light hits surface 220 before it leaves the device. Diffusing surface 220 could be a roughened surface, such as sand-blasted aluminium, that diffuses the light. Or diffusing surface 220-may be a surface coated in a bulk diffuser like an opalized material from part #48010 made by Spectra-Physics. The entire surface 220 does not have to be applied to the inner wall of source chamber 233, but only enough to provide sufficient beam divergence and spatial coherence. The preferred embodiment of surface 220 would be a material that is not substantially absorbent at therapeutic wavelengths emitted from source 240.
“Other designs can be understood by those skilled and provided in the literature incorporated herein. i.e. these are only examples.
“Output Window”
“Heat Removal Element”
Summary for “Self-contained, eye-safe hair-regrowth-inhibition apparatus and method”
“Field of Invention”
“The invention relates to a hair-regrowth-inhibiting apparatus and method, and particularly to a self-contained, cordless and hand-held apparatus that is light-based, yet eye-safe, and upon dermatologic application, at least temporarily inhibits hair regrowth.”
“Description of Related Art”
“The 1996 introduction of specialized lasers for doctor-performed epilation (and IPL sources shortly afterwards) marked the first significant advancement in the treatment and prevention of unwanted hairs since electrolysis was invented in the late 1800’s. These devices have been safe and effective. They also allow for multiple hair treatment at once, which is a significant improvement on electrolysis.
“Light-based epilation using lasers is sometimes called “laser hair removal?”, but this is only true when the follicles are sufficiently damaged to prevent new hair growth (permanent hair loss?). Hair-regrowth inhibition is a procedure that causes hair regrowth to be delayed by thermal damage to follicles.
Methods and devices for light-based epilation have become very popular and are used by approximately three million people around the world. Because of the inconvenience and high cost of physician-based devices and procedures, this is a small portion of the market. There is a demand for smaller, cheaper devices that can be used to lower the cost of physician-based procedures and ultimately help create salons and consumer markets. Devices with improved eye safety are also desired.
Star Medical introduced the LightSheer Diode Laser System in 1997 to inhibit hair-regrowth and then for permanent hair loss. This was the start of one of the most popular aesthetic laser applications for dermatologists. These and other similar devices have been widely used worldwide and their safety and efficacy are well-established. The Palomar Medical Technologies SLP 1000 (LC100) diode-laser, the Apex 800 diode-laser of IRIDEX Corporation, as well as the Opus Medical, Inc F1 diode beam laser are all examples of such devices.
The radiant exposure to the skin (often referred as “fluence”, expressed in joules/square centimeter) is usually in the 10-40 J/cm2 region at a wavelength nominally 800 nanometers. Initial research believed that pulse durations of 5-30 ms were optimal. However, later studies revealed that longer pulses (often in the 10-40 J/cm2 range) can achieve hair-regrowth inhibition and reduce epidermal heat for a given fluence (e.g. by placing a sapphire output window in contact with the skin).
“The small size and high efficiency of these semiconductor diode lasers allows for the production of compact systems, typically 1-3 cubic feet in volume and simple 115 VAC operation. The systems are typically 25-100 lbs in weight and retail for $40,000-$90,000. This popular procedure would be more accessible if it were cheaper and could be carried around.
Dermatologists are increasingly accepting lasers and intense light sources for the effective treatment of a variety of conditions, including hair-regrowth inhibition, permanent hair reduction, removal tattoos, treatment birthmarks and facial resurfacing. Medical professionals are well aware that these light sources can cause serious eye damage and blindness. The fluence of light-based dermatologic procedures such as the reduction of unwanted hair and destruction of small blood vessels must exceed 1 J/cm2 to achieve acceptable efficacy. The fluence of these devices at the eye is often greater than the maximum allowed exposure. This can make them and their treatments extremely dangerous if they are not properly used. This procedure requires that safety precautions are taken to protect not only the eyes of the patient but also the operator of the laser and other personnel who may be present in the same vicinity. See, for instance, IEC Technical Report 60825-8 Safety of laser products?Guideline to the safe use medical laser equipment. The IEC report states that some medical lasers can expose the retina to a higher irradiance than what is incident on the skin or cornea. This is due to the focusing action.
Eye damage can be reduced by taking proper safety precautions such as safety glasses and training personnel. In medical settings, eye injuries are very rare. Eye injury remains a concern.
A contact sensor, which allows the device to operate only when it is in direct contact with a surface such as skin, can increase the safety of light-based dermatologic devices. The light source, such as a laser, light-emitting device, flashlamp, or other light source, can be placed within a housing. A housing with one open end through which light propagates can be used. However, a contact sensor located at the open end of the housing can only allow operation of the device if it is placed against a contacted surface. This ensures that light cannot propagate through or into the surface on which it is placed. However, any sensor that is added to eye safety can cause complications and even failure. The ideal dermatologic treatment method and device would not depend on electronic circuitry, or user compliance with safety glasses for safe use.
It is therefore highly desirable that any light-based medical device be designed to minimize eye damage at a certain level of output fluence, or therapeutic benefit. This will increase the inherent eye safety. Laser hair reduction devices such as those used today are more dangerous than necessary for the eyes because they have a high directional output and can be easily focused by the eyes. Their output could be made more divergent or less coherent to reduce the risk of injury to the eye. This would not result in a significant loss of effectiveness.
U.S. Pat. explains “Examples for office-based, light based systems dermatological treatment Nos. Nos. 2002/0005475 and published PCT Application no. WO 03/049633. The published application ‘5475 uses a contact sensor to enable laser pulses only when the handpiece comes in contact with the skin of a patient. The problem with using such a device in a self-care or home use setting is that small children or people trying to treat their eye brows or eye lashes with it may inadvertently shine laser pulses into their eyes, potentially causing permanent vision damage. Similar eye safety issues would occur in home care, self-care applications of the devices described above.
“The published application ‘49633 addresses the eye-safety problem by providing a diffuser unit. The device is too heavy, complicated, and costly to be used at home. It includes a non-portable laser floor unit, an extensible handpiece and a long beam delivery guide. This device also has other safety concerns. A home-use, self-care device may not be able to deal with the safety issues posed by a device drawing high current from a wall outlet. The invention in the patent addresses eye safety with collimated laser beams, convergent beams, concentrated multiple beams, or fiber guided beams. It also includes monochromatic sources. Divergent light sources, however, can be made eye-safe significantly easier, as described in accordance to the present invention.
“The patents ‘029, ‘020 describe devices that produce fluences greater than 100 J/cm2. These fluences are too large to be safe for the eyes and epidermis in self-care settings. These fluences can cause corneal fluences that are potentially higher than the Maximum Permissible Exposition (MPE), which is described below. They may also likely cause epidermal burns. These fluence levels cannot be produced in a self contained apparatus such as a handheld and battery-powered device that is used for home and self-care.
“Furthermore the device described in the ?029 and the ?020 patents has a very small spot of between 2 and 5 millimeters diameter, which corresponds to 0.03 to 0.0.2 square centimeters. This small spot means that one hair can be treated at a given time. In fact, some visual targeting is required to make sure that the spot covers even one target follicle. A small spot, such as 0.03 to 0.2 square cms, implies very low coverage rates. For a given area of skin with unwanted hairs, the treatment time will be longer if the spot size is smaller. A small spot size can be advantageous because it allows for low fluence (since energy is divided by area). However, the fluence at a certain depth within the skin, such as where the target cells are, can be significantly reduced by scattering. The effective decrease in fluence at depth relative with fluence at the surface is greater the smaller the spot size (especially below 0.5 cm2). In other words, too small a spot, such as the one described in the ?029 and the ?020 patents can result in either burning the epidermis (to get enough fluence) or poor efficacy due insufficient fluence at depth. Both of these outcomes are clearly undesirable.
“CURRENT STATE of THE ART”
The two main types of devices currently on the market can be used to describe the current state of light-based epilation. Devices that are sold to physicians make up one market segment. The LightSheer diode-laser system, now manufactured by Lumenis Ltd. and the SLP-1000 fiber?coupled diode laser manufactured by Palomar Medical Technologies Inc. are all representative products. Also, Altus Inc.’s CoolGlide Excel YAG Laser and Quantum flash lamps are also manufactured by Lumenis Ltd. The FDA cleared physician devices have (a) proven efficacy, (b), practical coverage rate, and (c) high price. They also feature a physical design that attaches a handpiece to a console and (e) severe eye hazards due to their output fluences. These devices are light-based epilation devices that provide effective and practical light-based epilation. They generally have a peak optical power of 50 W, an output fluence greater than 10 J/cm2, spot sizes greater than 0.5 cm2, a coverage rate greater then 10 cm2/min, and a maximum optical power greater than 50W. These office-based devices can be found in the patent literature, which is cited above. Additional examples are available in other references.
“The second market segment consists of a limited number consumer light-based epilation device. There are currently no personal light-based epilators on the American market. The most developed market for consumer-light-based devices at the moment is Asia and Japan. There are many products on the Japanese market. Ya-Man Ltd.’s devices are a good example of the current state of these products in Japan. These consumer devices have a low peak power (1 W) and a small spot size (0.1 cm2 or less), a low coverage rate and low cost.
“The inventors of the embodiment of the invention recognized that it would be beneficial to have a device and method that can provide effective and convenient epilation in a completely handheld and cordless device. The term “cordless” and “handheld” is preferred to mean that the device is portable and can be used by one person. This handheld and cordless device is significantly easier than handpiece and console devices. It allows the operator to position the device in the most convenient orientation to treat the desired area of skin. It is portable and can be used without the need for electricity. To be an effective and useful treatment device, it must have a peak optical output power of 10 W, a fluence of more than 4 J/cm2, spot sizes larger than 0.25 cm2, and coverage rates greater that 10 cm2/min.
While there are other light sources that can be used to inhibit hair-regrowth, such as intense pulsed or laser light, diode laser systems are the most popular. These devices often include laser diode bars that operate at approximately 800 nm wavelength. These systems have a peak optical power of approximately 90 watts up to almost 3,000 watts.
“Discrete laser diodes have a peak power of about one watt. This low power is sufficient to treat individual hairs (like the Ya-Man device made in Japan), but for treatment of large areas of hair, peak optical powers of approximately 25 watts and more are required. These diode-based office products include diode beam bars rather than individual diode devices. These laser diode bar hair-regrowth inhibitor systems, which are used in offices by nurses and doctors, have been a huge success. This has led to interest in home-use devices. Devices that can be safely used at home without the need to visit the doctor’s offices are also becoming more popular due to the inconvenience of having multiple appointments. This device should be small, portable, and powered by batteries. It would also incorporate proven laser diode-bar technology. Because of the high current requirement (40 A) for laser diode bar technology, it is not recommended that such devices be powered by batteries. Instead, they should be powered by an electrical cord connected to a wall outlet.
U.S. Pat. explains “Examples for other dermatologic devices” No. No. 2003/0004499, 2002/0097587 and other references incorporated herein.
“The U.S. Patent is potentially safe for the eyes, but it does not protect the eye. No. 6,533,775 describes a mechanical hair removal device, and not a light-based hair-regrowth-inhibition apparatus. In order to decrease the time it takes for the device to become active, the patent ‘775 describes a light source that reacts with skin cream. The mechanical hair removal device does not produce heat to cause thermal damage to hair follicles. It is intended to prevent regrowth. The cream is not intended to penetrate the cream and cause any thermal injury to the dermis targets.
“The ‘97587 patent describes a device that has variable current control. This device is not intended for medical purposes. This reference does not have any output fluences, wavelengths, or pulse lengths that could possibly cause the fluence at an individual’s eye to fall below the MPE. This device would need to be modified to make it safe for home use, and effective for dermatologic treatment of hair-regrowth inhibition.
“The ‘4499 patent describes a device that is said to be designed to prevent hair regrowth. Its procedure is called bio-stimulation in order to produce bio-inhibition. In any case, it’s non-thermal. This is a wholly separate field from hair-regrowth-inhibiting devices that operate by causing thermal damage to hair follicles. For hair-regrowth inhibition, the ‘4499 reference uses lower fluences or intensities than what would be effective for thermal damage to hair follicles.
“Designing a handheld device to inhibit hair-regrowth requires clever circuit design. Implementing a dermatologic treatment device that is effective and safe for the eyes requires novel optical design. Therefore it has appeared up to now that the creation of a low-cost, light-based dermatologic treatment device, such as a home-use hair-regrowth-inhibiting device that is effective, compact, battery-powered, and incorporates a diode laser or other light source, is an unachievable goal. Recent advances in light technology and microelectronics make it possible to create dermatologic devices that are both effective and affordable for the average consumer. These devices may be small enough to be carried around and powered by a battery. These devices can also be used for dermatologic procedures and are safe for the eyes. These devices are the subject of the present invention and are described below.
“Therefore, in view of and in accordance with the above, a dermatologic hair-regrowth-inhibiting apparatus is provided that is cordless and sufficiently compact as to be hand-held. A self-contained housing is configured for gripping with a person’s hand for cordless manipulation in a hair-regrowth-inhibiting procedure. The housing contains a light source and an electrical circuit. One or more batteries are used to energize the light source and produce light pulses. An aperture is located within the housing that allows for the transmission of eye-safe light pulses out of the housing. These light pulses have sufficient properties to inhibit hair-regrowth at most temporary levels. To reduce the integrated radiation to an eye-safe level, an optical diffuser is placed along the light path.
The cordless apparatus is lightweight at no more than 1 kg. The cordless apparatus also occupies a volume of no more than 1500 cm3. The preferred embodiment weighs less than 700g and takes up 700 cm3 volume. In use, the hair-regrowth-inhibiting apparatus produces a light pulse having a fluence on the skin surface that is sufficient to at least temporarily inhibit hair regrowth and having an integrated radiance insufficient to cause eye damage.”
“In addition to the features described above, light pulses can also be generated by a diode light source. They emit light at a repetition rate of 0.1 Hz to 2 Hz, have peak power between 10 and 120 watts, have a spot area between 0.25 cm2 – 5 cm2. Further, the light source may include one or more flashlamps and LEDs.
“A hair-regrowth-inhibiting device in accordance with various combinations of the above aspects may include any combination of the following further features. The heatsink can be used to contact the epidermis region of the person while the device is being used. Preferably, the heatsink has one or more thermal properties that remove enough heat from the epidermis to prevent or reduce epidermal damage. The heatsink temperature can be lower than or higher than a normal temperature. Normal skin temperature refers to the temperature of the skin without the device. A sapphire output window may be included in the heatsink.
A contact sensor can be used to allow light pulses to propagate from the housing when there is substantial contact between the sensor and the surface being contacted, such as the skin of a person. When the contact sensor is in contact with the surface to be contacted, a light pulse can be generated automatically.
“The light source could include a diode-laser light source. One or more diode light sources may be included in such a diode source. If possible, two or more diode beams are used. Multiple laser diode emitters would be included in each diode laser bar. One or more laser diode bar may be thermally connected to a fan-cooled heatsink.
“The light source could include a divergent source like a diode laser or flashlamp source or an alternative source like an LED or flashlamp.
The bandwidth of the output light pulses could be greater than 2 nm and less than 40 nm. Pulse durations can be as short as 10 milliseconds to 1 second. Pulse durations can be as short as 200 milliseconds and as long at 600 milliseconds.
The electrical circuit could include a supercapacitor to energize the light source. It is preferable that the electrical circuit contains a direct drive circuit to energize the light source. Direct drive circuits are best without storage capacitors, transformers, or both.
The optical diffuser can be either reflective or transmissive. To distribute light uniformly at the aperture, a mixer can be placed along the light path. The diffuser’s normal may not coincide with the principal optical axis of light from the source. The light source could include one or more laser beam diode bar lasers that have a principal optical direction that is not parallel to the normal surface of the diffuser. Alternatively, the principal optical path of the laser diode bar lasers may be parallel to that of the diffuser’s normal surface, but the laser diode light may be redirected by a mirror so that the light strikes the diffuser at a different angle than the diffuser surface. An audible feedback component may be included in the apparatus.
“A hair-regrowth-inhibiting method for cordlessly inhibiting hair regrowth is also provided. A self-contained housing assembly of a hair-regrowth-inhibiting device is gripped in a person’s hand. The housing assembly is placed so that the output window component contacts an epidermis region of another person. To produce light pulses, the light source is powered by an electrical circuit that includes one or more batteries. The light pulses from the light source are transmitted through a housing that includes an aperture through which light pulses with eye-safe properties are propagated. To reduce the integrated radiation to an eye-safe level, the light pulses are diffused along a light path. The hand-held, dermatologic device is then cordlessly manipulated in a hair-regrowth-inhibiting procedure. The hair-regrowth-inhibiting device thus produces a fluence on the skin surface that is sufficient to at least temporarily inhibit hair regrowth and that has an integrated radiance insufficient to cause eye damage.”
“The preferred method involves the use of an apparatus that conforms to at least one of the features above, as well as any other aspects. To reduce or prevent epidermal damage, heat can be extracted from the epidermis. A heat sink may be used to remove the heat generated by laser diode bar lasers.
“The energizing can involve either partial discharge of a capacitor for energizing the light source or direct drive energy. Direct drive energizing is a method where current pulses are generated by one or more batteries and pass through the light source without the need to discharge a storage capacitor. In order to generate light pulses, the energizing can also include current pulses that are generated without the need for a transformer.
The cordless manipulation may be performed by the same person who applied the light pulses to the skin. Or it may be another person. A switch can be used to reduce the fluence.
“In another aspect, light pulses are emitted at repetition rates between 0.1 Hz to 2 Hz. Each light pulse has a peak power of 10 watts or 120 watts and a spot size of 0.25 cm2 to 5 cm2. This cordless apparatus has a weight limit of 1 kg and a volume of 1500 cm3. Energizing can be done by energizing a divergent source of light, such as a diode-laser light source, flashlamp light source, or light emitting diode (light emitting diode) light source.
“First Embodiment”
“A first embodiment describes a device and a method that allow light-based dermatologic treatments with a handheld, self-contained device. This device is a combination of a battery-powered electrical circuit design and a self-contained housing mechanic design. It also includes a light source, optical design, and a light source. This allows for effective and practical dermatologic treatments in a handheld and cordless manner.
“The light source could be, for instance, one or more semiconductor diode bars that emit pulses of infrared radiation. The device emits light through the epidermis, which is absorbed into the hair shaft and follicle to inhibit hair-regrowth. The resultant temperature rise temporarily disables the follicle, slowing down hair regrowth. You can pulse the device at a rate of up to 0.25 Hz.
Effective dermatologic treatment (e.g., hair regrowth inhibition) can be achieved with standard output fluences (10-40 J/cm2), but with extremely long pulse durations (upto 1000 ms). This eliminates the need to use very high peak laser power. For example, 20 J/cm2 can be produced in 350 ms using a 9 mm x 9 mm output area. However, an optical peak power of 46 watts is required. This allows for battery operation and reduces the peak power requirement. This device can be carried around with the above parameters.
FIG. 1. Light source 10, mixer 12, output windows 14, heat-removal and electrical elements 16, 18, and housing 20 are the elements shown. Other mechanical, optical, and electrical elements are not shown, but they are involved in the operation. These include a trigger, drive circuitry, indicators, and sensors. FIG. FIG. 1 is intended to only introduce the preferred first embodiment, which will be described in greater detail later.
The user must charge the battery 18 by placing it in a charging station that provides an electrical charge from a wall outlet. After the battery has been charged, the user will press an aperture or output window 14 against the skin surface to be treated. Because of its high thermal conductivity, sapphire is preferred for the aperture or window 14 that comes in contact with skin. However, the output aperture, or window 14, may only be an opening or aperture. The window component 14 that touches the skin of the individual may be a frame. The heat-removal component 16 draws heat from the light source 10. It may also draw heat from the skin through conduction through window 14, and mixer 12. The heat-removal device 16 could be a thermoelectric heat exchanging unit that heats the surrounding air using a fan and finned heat sink. It may also draw heat from the skin through conduction through window 14 and mixer 12. As described below. By pressing a trigger button, the user activates a pulse of light from the source 10. Alternately, an electrical circuit could be designed in such a way that the light source 10 contacts the skin of the person being treated. A contact sensor near the output aperture detects enough contact between the output window 14 and the skin to activate one or more pulses. The light pulse is sent to the mixer 12, which distributes light uniformly onto the output windows 14 and into the skin. The output window 14 connects to the heat-removal device 16 via mixer 12. This serves as an additional heat sink for skin.
The preferred device has a fixed, mid range output fluence setting of nominally 20, J/cm2 with a nominally 300-350 ms pulse duration. This simplifies operation. Alternately, the output fluence could be either continuously adjustable or discretely adjustable. Below are details about the electrical circuit design.
“Additional details of a preferred embodiment of a light-based hair-regrowth-inhibition apparatus are shown in FIGS. 6-8. These figures show schematically the exterior of the unit housing. FIG. FIG. 6 shows a front view, and the output window (420) is illustrated. The trigger buttons 430 that initiate laser pulses are also displayed. They can be easily depressed by either a left- or a right-handed self-care person. Also visible are vent louvers, or openings 440. The charging base 450 is shown here with a power cord of 460 to recharge the apparatus.
FIG. 7 shows the output window, 420 along with vent louvers 440 and an on-off switch 460. FIG. 2 shows the indicator lights 470 in greater detail. 8. Examples include a battery indicator 472, an on/off indication 474, and a ready indicator 469.
“The volume of the primary components of the apparatus should be less than 2000 cm3, more preferably less that 1000 cm3, and less than one kilogram. The apparatus can have a volume of 700 cm3 or less and a weight of 700 grams, which is even more preferable. This allows the apparatus to be held in one’s hand and can be controlled with a firm grip. FIGS. FIGS. 6-7 show that the apparatus measures 400 cm3 in volume and weighs 500 grams in a self-contained, cordless device. When the term cordless appears in this document, it means that the unit is powered by a battery and is not connected to an external power source or outlet. The term “self-contained” is also used to mean that the unit does not need to be physically connected to any base unit or other unit. It can be freely manipulated without the use of wires or couplings. A self-contained housing, such as the one shown in FIGS. The housing 6-7 contains the light source and batteries. It is not attached to any light guide or electrical cable that protrudes from the housing 410. However, a wireless control or other wireless coupling or the charging base (450) cannot be included components in a unit that has the self-contained housing of FIGS. However, the housing 410 does not have any externally protruding physical couplings like control wires or optical cables.
The preferred embodiment of a handheld device is efficient, self-contained, and user-friendly, even allowing maximum electrical, thermal and optical inefficiencies. The output parameters of this device prove that it is practical and efficient in use.
“In this section, we provide additional information regarding the preferred method of using the apparatus. The charging of the apparatus requires that it be placed in a charging base (450 as shown in FIG. 6. Usually, this is done over night. The charging of the device can be done easily by plugging it into an AC outlet and then placing the device in the charging stand 450. The unit should be returned to its charger 450 after each use so it can be fully charged for the next one. You can leave the unit in the charger 450 for extended times without causing any damage to it.
“During charging, left indicator light 472(FIGS. 7-8) flashes green. This light will stop flashing when the battery is fully charged and stay green.
To ensure maximum comfort, you should first trim the skin. Next, use a damp, cool cloth to wipe the treated area. The unit is dependent on light absorption by the hair shaft beneath the skin. This means that the hair should not be removed by waxing or plucking. Treatment should be delayed if either of these procedures were used recently.
After the unit is fully charged, turn it on by pressing and releasing ON-OFF button (460 in FIG. 7. The center indicator light 474 in FIG. 8 will be illuminated.
The right indicator light 476 might flash briefly after power has been turned on. This indicates that the unit is nearing the?ready? state. state. When the right indicator light 476 is steady green, it indicates that the device has been ready. It will emit a light pulse if either of the trigger buttons 430 are depressed (provided the output window 420 touches skin). To allow comfortable use of the device, two triggers 430 have been provided.
The output window 420 should be placed against the area of the skin to be treated. Press the trigger 430 and release the trigger. When the laser pulse has completed, a beep is preferably heard. A particular embodiment will produce a sound that is either a tone or a beep when the laser pulse is complete. This indicates that the contacts sensors around the window (420) are in contact with skin, and the pulse can be propagated from the housing 410. The self-care user will be able to tell that the unit won’t generate a pulse unless good contact has been established and the tone heard. Another embodiment will emit a tone and/or a beep if the output window 420 moves away from good contact. This is an indication to the user that the housing 410 will not allow a pulse to propagate until the contact is restored. The output window 420 should be moved to another area after the pulse-completed sound is heard. There should be approximately fifty percent overlap. The tip should be moved approximately one-half of the distance from the skin. The trigger need not be held down during the pulse. However, it is important to keep the trigger in full contact with the skin for the duration of the pulse. The output window 420 should not be lifted from the skin before the laser pulse is completed. A distinct tone will sound to alert the user and the area should then be treated with another pulse.
“The unit’s maximum repetition rate is between one pulse per second and one pulse per four seconds. There may be a delay of a few seconds before the next beep is heard.
“All the sounds above can be used as feedback and aids in using the device.
“Second, Third Embodiments”
Alternative embodiments of a dermatologic therapy device and method include an optical diffuser. This is to increase the safety of the device’s eyes while minimizing any adverse effects on its efficacy. An optical diffuser is added to the apparatus to increase the divergence and reduce the spatial coherence. This allows it to be classified as a Class 1 Laser Device according to the U.S. Food and Drug Administration Center for Devices and Radiological Health guidelines. This allows the user to use the apparatus without the need for safety glasses or goggles. It also eliminates the possibility of injury to the eyes if any other safety measures, such as the contact sensors, fail.
“Accordingly, a device for dermatologic treatment is provided in a second or third embodiments that are eye-safe. The device and method can be used to treat various dermatologic conditions. The fluence produced at the skin’s surface is greater than one joule per centimeter. However, the fluence can be aimed directly at the eyes from any distance and still produce a fluence that is below the maximum permissible exposure (MPE), as determined by the American National Standards Institute and the International Electrotechnical Commission. The MPE value is essentially the equivalent to the Exposure Limit (EL), published by the International Commission on Non-ionizing Radiation Protection.
“Dermal treatment is not a high-directed beam application, as it is rare for many other applications of lasers or light sources. It is not necessary for the light to reach the skin at normal incidence. This means that the light must be contained within an applicator or handpiece before it can enter the skin. Because the skin is highly scattering, any light rays that enter the skin at normal incidence are scattered very close to the surface by epidermal cells and redirected into every angle. This diffuser allows light rays to spread before entering the skin. Although it has very little effect on efficacy, it greatly increases eye safety. Due to the eye’s focusing ability and the intensification of light onto the retina, simply increasing the divergence from a coherent source like a laser is not enough to ensure eye safety.
“It should be noted that the devices in the second and third embodiments can easily accommodate the essential elements from the first embodiment. The embodiments below can be used to create the eye-safe devices. The devices described below can also be corded so that they can be used from a standard wall outlet. The second and third embodiments are basically the same as the first.
“FIG. 2A schematically illustrates a dermatologic device, such as a light-based hair-regrowth-inhibition device, incorporating a transmissive diffuser in accordance with the second embodiment of the invention. A transmissive diffuser can be described as an element that is integrated into a light path. It has an input surface where light strikes first and an output surface from which it propagates. The diffuser’s material is able to separate these output and input surfaces.
The figure schematically shows the device in contact with skin 150. It incorporates the use a diffusing medium 120 through which light passes before reaching the apparatus via an output window (or simply an aperture) 100. A light source 140 is contained within the source chamber 130. It emits pulses with many advantages. One or more laser diode bars are preferred. Light source 140 could be used to treat a dermatological condition.
“The diffuser 120 is placed above an aperture in the source chamber 130. Diffusing material 120 is placed over an aperture in source chamber 130. Diffuser 120 increases the diffuser 120’s light output and reduces the spatial coherence. The diffuser 120 can be made from a material that scatters light passing through it, such an opalized substrate. In a section that describes component details, you will find information about the appropriate optical diffuser designs. A variation of this embodiment would see the inner walls 130 of the source chamber coated with a non-absorbing material at therapeutic wavelengths. It is possible to have a source chamber that isn’t substantially absorbent. However, for the same power delivered the skin would need to be used, an intense light source 140 would be required. Because energy efficiency is at a premium, it is not desirable to require additional power, especially in a cordless, hand held, self-care device.
A mixing chamber 110 may increase the spatial uniformity of light. This may simply be a hollow tube with side walls that are substantially non-absorbing. The light would then propagate through the chamber before it leaves the apparatus via the output window 100. The mixer can be removed if the diffuser’s spatial uniformity is sufficient for the treatment. In this case, the diffuser 120 could be directly in contact with the skin, and the output window 100 may be used instead. Alternately, the diffuser 120 can be placed at the location shown in FIG. 2A, even though sufficient uniformity can be achieved without the use of the mixing chamber 110. However, it is important that the diffuser 120 be not placed too close to the light source 140. This will prevent substantial non-uniformity from occurring because the light source has not sufficiently diverged before it impedes upon the diffuser 120.
“FIG. 2B schematically illustrates a dermatologic device, such as a light-based hair-regrowth-inhibition device, incorporating a reflective diffuser in accordance with the third embodiment of the invention. Refer to FIG. FIG. 2B shows that the term reflective diffuser refers to an element integrated into a light path. This first surface is where the light strikes initially. However, unlike a transmissive diffuser this surface also acts as the output surface. Further, the term “reflective” is used to refer to reflected light. It is also important to note that the term “reflective” can be used in this context to refer to reflected light. This means that the diffuser can scatter or refract light.
“In FIG. 2B, a light-based hair-regrowth-inhibition device is illustrated in contact with skin 155 that incorporates the use of a diffusing material 125 which diffuses light from source or sources 145 before the light leaves the apparatus though output window (or simply an open aperture) 105. The chamber 115 contains a light source (or sources 145) that emits pulses with many advantages. The light source or sources 145 could be used to treat a dermatological condition, such as unwanted hair, by using laser diode bars.
“The diffuser material 125 should be placed in chamber 115 at a location that is generally against the skin. The diffuser 125 is illuminated by the light source or sources 145, although it does not have to be uniformly lit. Diffuser 125 can be used to increase the diffuser’s light output from sources or light sources 145, and reduce the spatial coherence between the source or sources. The diffuser 125 can be made of highly scattering materials such as Teflon or PTFE. In a section that describes component details, you will find information about the appropriate optical diffuser designs. A variation of this embodiment would see the chamber 115’s inner walls coated with or otherwise constructed from a material that is not absorbent at therapeutic wavelengths emitted from source(s) 145. Chamber 115 may be used as a mixer to increase the spatial uniformity of light. It may simply be a hollow tube with side walls that are substantially non-absorbing. The light would then propagate through the chamber before it leaves the apparatus via output window 100. Further, FIG. FIG. 2B shows an example of a reflective diffuser. In this embodiment, light from the source or sources (145) is directed initially away from the skin 155 before striking diffuser 125. FIG. Alternately, 2B could be constructed so that light from source or sources 140 initially propagates toward the skin. However, before striking the skin such light is redirected to the diffuser 125 by a mirror.
“Component Design”
“Light Source”
“With reference to FIG. 1. The light source 10 is preferably two diode-laser bars with a nominal wavelength around 800 nm. For example, operating specifications could include a 20 J/cm2 output fluence with 350 ms pulse duration and a 0.8 cm2 spot size (output opening) and a 0.5 Hz pulse repeat rate. These parameters correspond to an optical peak of 46 W and a duty circle of approximately 18%. The resulting optical power into the light source is around 23 W (8 W of average optical power emitted and 15 W of wasted heat). The light source’s volume and weight are approximately 1 cm3 and 10 grams.
“Skin Contact Sensor”
“A skin contact sensor is preferred to be incorporated into the tip or the preferred dermatologic treatment device in order to prevent accidental output of light pulses from the device. A ring of tiny?membrane switch? may be included in the sensor. The preferred sapphire window’s circumference is covered by a ring of membrane switches. The membrane switches signal that the device is not in contact with skin or any other contact surface will prevent it from firing. Alternately, the trigger can be removed and one or more membrane switches closed to activate light pulses. As mentioned above, an audible or other sensor indication is provided when contact is established. The output window must be moved from a contact position on the skin of the user so that firing can be disabled until contact is restored. A pulse indication should include an audible indication or another sensory indication at the end to inform the user that the apparatus can be moved to a different location before the next pulse.
“Charging Base”
“Between the uses of the dermatologic therapy apparatus of the preferred embodiment it is preferably placed into a charging base (see FIG. 6). It may look similar to the charging bases used with phones, shavers, and electric toothbrushes. The charging base can be connected to an AC outlet and charged overnight.
“As stated above, the second and third embodiments of the apparatus may be corded so that it can be used from a standard outlet, eliminating the need to charge a base.
“Mixer”
FIG. 1. The mixer 12 is used to: (a) mix the light emitted by the diode lasers to create a uniform beam profile at output window 14, (b), provide a low temperature path between output window 14 and heat-removal 16 and (c) minimize thermal loads on device due to light absorption from back reflected or back-scattered sunlight.”
“An alternative embodiment of the mixer may include an inner mixer such as a sheet made of polished metal for reflecting light from the source towards the output window 14, and an outer metal surface such as a copper barrel or aluminum barrel to conduct heat from the output window 14 to the heat-removal elements 16. The inner mixer can be made from solid transparent materials such as acrylic or glass. The light coming from the light source would then be reflected towards the output window 14 through total internal reflection in the acrylic or glass.
“Optical Diffuser”
“The term “diffuser” is used. “Optical diffuser” or?diffuser? This patent application refers to all conventional elements, such as the “optical disk diffuser” Flashed opal type, Stratford, Conn. Oriel Instruments Model 48010) and more generally any element that, when incorporated in a light-emitting apparatus having a given radiant expose or fluence, significantly reduces the integrated radiance (brightness). The device. Diffusers are generally used to increase the spatial coherence and divergence of light incident on them.
“With reference to FIG. 2A, diffuser 120 could be made from a material that scatters light. This would be the optical disk diffuser (Oriel) mentioned above. Diffuser 120 could be made of a transparent substrate with a roughened surface to scatter incident light through reflection. Diffuser 120 could be bulk scattering diffuser made from, for example, opal glass or PTFE. It may also be made from thin (e.g. Spectralon sheet, or combinations thereof. Alternately, the diffuser 120 could have a body or refractive surface; or a diffusing surface with random surface irregularities. These diffusers can be made from ground glass, sandblasted or plastic or molded materials created by a randomly-textured mold or combinations thereof. Diffuser 120 could also have a patterned body or surface, such as a Fresnel or holographic pattern.
FIG. 2B can be made of a scattering material like PTFE or a commercial material like Spectralon (available at LabSphere, Inc.). Diffuser 125 could also contain Duraflect, a scattering material that can be applied to the chamber 115, opposite the skin 155. You can also make diffuser 125 by simply roughening the chamber 115 against the skin 155. However, the preferred embodiment will include a diffusing material like Spectralon or an applied coating such Duraflect due to their low absorption. Diffuser 125 could also be made from a material that scatters light, such as an opalized substrate made by Spectra-Physics. This is then backed with a highly reflective mirror. A transmissive diffuser can be used to diffuse the light.
“FIG. 3A shows an example of a diffuser 120 with transparent screens of the fine structure or lenticular types. FIG. 3A shows transmissive sheets with machined or molded refractive and diffractive elements. FIG. 3B illustrates concentric microgrooves in the diffuser 120. 3B.”
“The diffuser (125) of FIG. 2B could include only roughened interior surfaces of passageways through which light is scattered before exiting the device. 3C, which is discussed in relation to FIG. 3E in more detail below.”
A small light source that is approximately the size of a “point source” can be used to achieve very low integrated radiation for a given output fluence of a device according to embodiments of this invention. Projecting into a mixer with mirrored walls, such as the one illustrated in FIG. 3D.”
“FIG. 3E illustrates an embodiment of the present invention in contact with skin 250. It incorporates the diffusing surface 220 from FIG. 3C shows the light striking the apparatus through the output window 200. Source chamber 230 houses light source 240. Instead of using a diffusing material to direct the light, a diffusing layer 220 is placed relative to source 240 so that the light hits surface 220 before it leaves the device. Diffusing surface 220 could be a roughened surface, such as sand-blasted aluminium, that diffuses the light. Or diffusing surface 220-may be a surface coated in a bulk diffuser like an opalized material from part #48010 made by Spectra-Physics. The entire surface 220 does not have to be applied to the inner wall of source chamber 233, but only enough to provide sufficient beam divergence and spatial coherence. The preferred embodiment of surface 220 would be a material that is not substantially absorbent at therapeutic wavelengths emitted from source 240.
“Other designs can be understood by those skilled and provided in the literature incorporated herein. i.e. these are only examples.
“Output Window”
“Heat Removal Element”
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