Software Technology for “Carpal tunnel syndrome treated with injection of the flexor retinaculum

Medical Device – John M. Agee, Ben C. Goss, Francis C. King, Jeffrey Woodhouse, JOHN M AGEE AND KAREN K AGEE TRUSTEES OF JOHN M AGEE TRUST

Abstract for “Carpal tunnel syndrome treated with injection of the flexor retinaculum

“An apparatus and a method for identifying the carpal tunnel’s flexor retinaculum, injecting an appropriate amount of agent into at most a portion of the tissue or tissue thereto. The agent is designed to weaken the flexibility retinaculum. This system may also include hand exercises that increase the tensile stress of the flexor retinaculum after injection. This will weaken its structural integrity, and decrease pressure in the carpal tunnel.

Background for “Carpal tunnel syndrome treated with injection of the flexor retinaculum

“1. “1.

“The invention relates generally to the treatment of carpal tunnel syndrome and, more specifically, to a method and apparatus to treat it by injecting a biological substance into flexor retinaculum.”

“2. “2.

“The carpal tunnel, an area of the hand that is adjacent to the wrist, is made by an arch of eight wrist bones and is spanned by the flexor retinaculum on its palmar surface. The flexor retinaculum functions as a pulley. Nine flexor tendon with synovial membranes, four muscles of the lumbrical region, and the median nerve pass through the carpal tunnel. The flexor retinaculum is missing, which causes the flexor tendon to bowstring. This results in loss of strength and dexterity in the wrist and hands, which the carpal tunnel tendons control.

Carpal tunnel syndrome (CTS), is a condition that results in a rise in pressure inside the carpal tunnel. This disease is characterized by pain, numbness and tingling due to the increased pressure on the median nerve. It is currently the most common occupational health risk in the industrialized world. It costs billions of dollars each year to treat, diagnose and prevent this syndrome from becoming a serious problem.

“Intracarpal pressure can be dynamic and affected by many factors. These factors include disease, injury, wrist position and hand use, compliance with the flexor retinaculum, lumbrical muscle, externally applied force, finger position, and compliance of the flexor muscles. Pressure dynamics are also affected by the geometry of the carpal tunnel. It is difficult to measure intracarpal tunnel pressure accurately due to the complexity of the geometry and interactions among these factors. Pressure measurement also depends on the type and extent of pressure changes introduced by the measurement device.

“Active hand usage produces the largest range of pressures in the carpal tunnel. Patients with carpal tunnel syndrome (CTS) were included in most studies that measured intracarpal tunnel pressure while active hand use. None of these studies measured hand use during pressure measurement. Intracarpal tunnel pressure is also a function the location of pressure measurements. Therefore, any analysis of intracarpal pressure dynamics should include a profile within the carpal canal. Although others have described the pressure profile from the carpal canal’s proximal to distal, only one included pressure measurements during active use. But, it was not possible to quantify hand use.

Although the cause of CTS remains unknown, treatment is well-established. To temporarily relieve symptoms, non-operative treatments such as splinting and anti-inflammatory medication, cortisone injections in the carpal tunnel, and cortisone injections are sometimes used. CTS can be treated with surgical division of the retinaculum if other treatments fail. The surgical division of the flexor retinaculum results in a decrease of pressure in the carpal tunnel, which allows normal blood flow to the median nervous to return. This relieves the symptoms and signs of CTS. There are many methods to release the flexor retinaculum. The most common ones are endoscopic and open.

An open release involves a longitudinal incision through the skin of the palm of your hand. This is carried down through the palmar fascia, subcutaneous fat, palmaris brvis muscle and finally the flexor retinaculum. After the flexor retinaculum has been released, the skin can be sutured. The wrist is often splinted until it heals. The typical outpatient procedure takes approximately 15-30 minutes.

There are many devices that can perform an endoscopic release of the flexor retinaculum. A video endoscope is one device. Another includes a handpiece that holds a disposable knife assembly. The device is inserted via a small incision made in the wrist flexion crease. The device’s tip is seen through a window at its tip. Next, the blade is raised to make the longitudinal cut while the device is being withdrawn from the carpal tube. The device is then used to check the length of the incision through flexor retinaculum, and if necessary, perform any additional cutting. The entry wound can be closed once the incision is complete. Endoscopic release can be performed outpatient and takes approximately the same time as open release.

“While complete surgical divisions of the flexor retinaculum are promoted as the standard of care for patients with CTS,”

“(a) The arch of the carpal bones could be altered to affect the functional biomechanics and hand function.”

“(b) The pulley effect of the flexor corneaculum might be lost or compromised, which could cause the median nerve and digital flexor tendon to sublux palmarwardly in between the cut edges. Power grip and pinch will be affected until the flexor retinaculum heals sufficiently to allow the carpal tunnel to function as a pulley for nine digital flexor tendon.

“(c) The exposed edges of the flexor retinaculum allow scar tissue to heal in the longer position. This can increase the risk of post-operative morbidity, pain, weakness, and even lead to greater complication rates.”

“(d) A complete ligament division can affect the time it takes for a patient’s activities of daily living to resume their work and other activities.

“(e) Some surgical techniques require that an operation room procedure be performed rather than an office procedure or clinic procedure.

“(f) Following the complete division of flexor retinaculum portions of the hypothenar and thenar muscle groups become unstable. This causes pain and weakness in pinching and gripping during healing of flexor retinaculum.

“To avoid potential problems associated with current surgical techniques, an object in the present invention is a method or apparatus that weakens structural integrity of flexor retinaculum sans using a surgical cut or surgically dividing portions of the retinaculum. The following description will meet at least some of these objectives.

“The invention provides a system and method for altering the stiffness in the flexor retinaculum to make it more flexible. This causes the circumference to expand, and decreases pressure on the contents of carpal tunnel. It is similar to what happens after surgical division of flexor retinaculum. This allows the pressure in the carpal tunnel, which is responsible for the relief of CTS symptoms, to return to a normal level.

“According to one aspect of the invention, an apparatus is provided for identifying and injecting a drug into the carpal tunnel. “An apparatus and method for identifying the flexor retinaculum of the carpal tunnel and injecting a drug into it is provided. The apparatus may include: (a) a drug that can weaken collagen’s structural integrity; (b) an imaging device for identifying the flexible retinaculum; c) a detector frame that attaches to the palm of the hands that holds and positions the detector; (d), an injection needle that injects the drug; and (e). a needle guide that attaches to the imaging detector or integrates with it that positions, guides, and holds the needle.

“Any drug that reduces the structural integrity collagen can be used. Collagenase is a preferred method. Collagenase, an enzyme that digests collagen by breaking down the collagen protein’s peptide bonds, is a preferred embodiment.

“Collagen fibers in the flexor retinaculum (carpal tunnel) are susceptible to being broken down by collagenase. The methods and systems of this invention are significantly better than current surgical procedures. They inject collagenase into any part or tissue adjacent to the flexor retinaculum. This weakens the structural integrity and increases the tensile stress within the flexor. It causes the ligament to grow in length and decreases pressure on the median nerve.

“The present invention could include a combination collagenase and a liquid carrier in an effective dose for injection into or near to the flexor retinaculum to weaken collagen’s structural integrity.”

“The ?structural integrity? The structural integrity of collagen can be defined as its ability to withstand tensile loads. The threshold for tensile loading drops once collagenase weakens the structural integrity collagen. This means that collagen fibers can no longer withstand the same tensile loads as they did before the injection. Individual collagen fibers become structurally unsound when tensile loads exceed this threshold. This is due to the breakdown of collagen protein bonds. Initial failure of collagen fibers is microscopic. As the tensile loads increase, the collagen structure begins to fail.

Direct injection of drug to a portion of or adjacent the flexor retinaculum may be possible by only visual and palpation methods of a skilled physician who is familiar with the anatomy of the hand. An imaging device is recommended because the flexor retinaculum lies below the palmar surface and is not visible or palpable. An imaging device is also required in order to identify the flexorreticulum.

“The imaging device can be any noninvasive imaging detector that is commonly used to guide injection needles. The preferred embodiment of the imaging detector uses an ultrasound transducer. You can use any standard, commercially available ultrasound transmitter with both hardware- and software capabilities to create high quality images of anatomy of the wrist or hand. The physician can adjust the position of the imaging detector by holding it against the palmar skin. This will allow the doctor to view acceptable images of the flexor retinaculum as well as other vital anatomic features. The hook of the Hamate is an anatomic attachment to the stiffest part of the Flexor retinaculum. Ultrasound can also be used to identify it. This is where the median nerve in the carpal tunnel is compressed the most. The images allow for visual identification of the flexor retinaculum and the calculation of its palmar to-dorsal distance relative to a reference position. Real-time images of an injection needle relative to the anatomy of the carpal tube allow for more precise and repeatable injections at specific locations.

While the doctor can manually hold and position the imaging detector, it is helpful to have a frame that assists in this task. The preferred embodiment of the detector frame is attached to the patient’s hand. The detector frame holds the imaging sensor and allows for rotational and translational positioning. A detector frame allows for greater freedom in the hands of the physician, provides stable images of the anatomy and can be used to guide an injection needle.

An injection needle can be directed to the flexor retinaculum if it is identified and its depth relative to the palmar surface. A standard hypodermic needle can be used to dispense a dose of drug. It should be of the appropriate length, diameter, and syringe. The tip of an injection needle can either be inserted into the flexor retinaculum or a segment adjacent.

Although the physician can manually hold, position, and guide the injection needle, it is more efficient to use a needle guidance device. The preferred embodiment has a needle guide attached to the imaging detector. This guides the needle along a path that allows the physician to insert the tip of its needle into the desired area. The physician can then give the drug at the appropriate dosage.

After the drug has been deposited into the flexor, or near it, it might be necessary for the patient to increase the tensile stress within the flexor. This will result in the weakening of collagen fibers, which can either cause them to fail abruptly or increase in length. The physician might recommend a hand exercise program to provide the required increase in tensile stresses in the weak collagen fibers.

“Accordingly, a portion of the invention is a method of treating a patient suffering from carpal tunnel syndrome. It involves: identifying the location of the patient?s flexor retinaculum that can be treated; injecting an agent in the location of said flexor retinaculum in one to more doses so as to weaken the structural integrity.

“In one embodiment, flexor retinaculum also includes the transverse ligament and/or its attachments to the bones.

“Another embodiment of the agent consists: one or more doses collagenase, a Corticosteroid or both.”

“A further embodiment involves locating a suitable treatment site for the patient?s flexor retinaculum by positioning an imaging detector near a region in the patient?s hand, the region being associated to the flexor, and then generating an image from the patient?s hand. An imaging detector could include ultrasound imaging, Xray imaging, Magnetic Resonance imaging, or other similar methods.

“In one embodiment of the present invention, the method for generating an image is to position an ultrasound transducer near the patient’s hand and generate an ultrasound image.”

“In an alternative embodiment, the method also includes increasing the tension in the flexor retinaculum after injecting the agent. Pressure within the carpal tunnel may cause an increase in tensile strain. This pressure can be created by the following: having the patient use one to three digits of their hand; having them grip the object with one or two fingers; having them flex one or both fingers into the palm of their hand and having them pinch one or several fingers together. The object could be a dynamometer and be placed in the palm or heel.

“In another embodiment, the method also includes measuring pressure in the carpal tunnel.”

“In addition to injecting an agent, the method might also include the cutting of the flexor retinaculum using a blade.”

“In one embodiment, the procedure of identifying the treatment location for the patient’s palmar-to?dorsal distance from the palm of the hands to the flexor is further simplified by computing the palmar?to?dorsal thickness. The agent is then injected via a needle at the computed palmer?to?dorsal height along an axis substantially parallel with the imaging surface of a detector or the longitudinal axis to the flexor.

“In another embodiment, the agent may be delivered to a central part of the flexor retinaculum.”

“A further embodiment of the method might include inserting a guidetube into the hand near the flexor corneaculum and then accessing the flexor at the distal end. The current mode may also include the advancement of a pressure sensor within the guide tube to the treatment location and measurement at that location. The method could also include cutting tissue associated to the flexor retinaculum and advancing a cutting probe inside said guide tube.

“Another aspect of the system is one for treating a patient suffering from carpal tunnel syndrome. It comprises: a needle guide; an injectable needle; the needle guided comprising a guide hole for receiving the injection; and an agent that is to be delivered within said injection to a region of tissue associated with the flexorreticulum of the patient. The agent is designed to weaken the structural integrity the flexorreticulum.

“In one embodiment, the system comprises a clamp that is coupled to a needle guide. The reference surface allows for patient positioning at the palm of the hand. The needle guide is then slideably coupled with the clamp so that the needle can be adjusted relative to the reference surface. Preferably, the guide hole’s longitudinal axis is substantially parallel with the reference surface.

“In another embodiment of the present invention, the system includes an imaging device that is used to image the carpal tunnel during injection. The clamp is designed to hold the imaging device. To obtain transverse and longitudinal images of the carpal tunnel, the imaging device can be pivotably connected to the clamp.

“In another configuration, the imaging device includes an imaging surface. The imaging surface is substantially parallel with the longitudinal axis the needle guide’s guide hole. The needle guide can be set up to allow for adjustments in a palmar-dorsal manner, while the guide hole is maintained substantially parallel to the imaging surface. A needle guide and clamp may include an indicator that indicates the depth of needle insertion relative to the reference surface.

“Another embodiment of the system comprises a guide tube that is placed within the guide hole. The guide tube can be inserted into the hand near the flexor retinaculum. A central channel in the guide tube allows for delivery of an instrument to the region. A delivery instrument could include a pressure sensor that is sized to fit within the guide tube and deliver the tissue to it. The pressure sensor or cutting probe may also be included.

“In another embodiment, the clamp is secured to the patient’s hand by a linkage. The linkage includes a first joint that allows the clamp to rotate with respect to the patient’s hand. The first joint allows rotation of the clamp with respect to the patient’s hands in a flexion/extension direction. A second joint may be included in the linkage. This second joint allows rotation of the clamp with respect to patient’s hand in a radial to ulnar direction.

“In another embodiment, a linkage system allows for translational and rotational adjustments to the imaging detector and needle/probe guides relative to the patient’s hands. The current embodiment uses a linkage system to establish a fixed point distal of the imaging detector around which the longitudinal axis is of a contact line connecting a patient’s long fingers and his ring.

“Another aspect of an apparatus for treating patients with carpal tunnel syndrome includes: a needle guided; an injection needle; the guide hole for receiving the injections needle; a clamp coupled with the needle guidance; wherein a reference surface is provided for positioning the needle at the palm of the patient’s hands; wherein a slideable coupling allows the needle to be moved with respect to this surface; and an imaging system for imaging the carpal tunnel during injection. The clamp is designed to hold the imaging device.

“The apparatus includes a device that allows the delivery of an agent within the injection needle to a region of tissue associated with the patient’s flexor retinaculum; the agent is designed to weaken the structural integrity the flexor. The guide hole should be substantially parallel to the reference surface.

“In one embodiment, an apparatus also includes a linkage attached the clamp. The linkage is designed to secure to patients’ hands and has first- and second-joints that allow rotation in the clamp with respect the hand. The first joint allows rotation in a direction of flexion-extension with respect the patient’s arm; the second joint allows rotation in a direction of radial-ulnar with respect the patient’s wrist.

“Another aspect of the apparatus is for treating a patient suffering from carpal tunnel syndrome. It comprises: a base that supports a patient’s hand and forearm; a first surface for supporting the hand and a second surface for supporting the hand; a pivotable arms coupled to this base; wherein a needle guide is supported by the pivotable Arm; the needle guided comprising a guide hole for receiving an injection needle; and a clamp connecting the pivotable and needle guides. The clamp allows the needle

“In a preferred embodiment of the apparatus, an agent is delivered within the injection needle to a tissue area associated with the patient’s flexor retinaculum; said agent is designed to weaken the structural integrity the flexor.

“In another embodiment, an imaging device is included that can be used to image the carpal tunnel during injection. The clamp is designed to hold the imaging device.

“In another embodiment, the guide holes are substantially parallel to each other surface. The needle guide can be adjusted in a palmar direction, while the guide hole remains parallel to the second. The needle guide and clamp include an indicator that indicates the depth of needle insertion relative to the reference surface. The pivotable arm also allows rotation and translation of the needle guide relative to the second surface.

“Another aspect is the treatment of a patient suffering from carpal tunnel syndrome. This involves injecting a drug into the flexor eye in one or more doses that weaken the structure of the flexor. Also, increasing the tensile stress within the flexor. You can also measure the pressure in the carpal tunnel. The flexor retinaculum can also be cut using a blade. An imaging method is used to show the flexor retinaculum on an LCD monitor.

“Another aspect is a percutaneous injectable device for use with medical imaging detectors. It comprises: a clamp for attaching to the imaging scanner; a needle-guide for attaching to the clamp; and an injection tool for inserting through the needle. The needle guide has a longitudinal axis that is substantially parallel the imaging surface of an imaging detector.

“Another aspect is the invention, which includes an imaging detector; an imaging clamp that couples with the imaging detector; an adjustable guide that attaches and is adjustable along an angle that is substantially parallel the longitudinal axis; a probe with an cutting blade whose longaxis is substantially parallel the imaging surface of imaging detector when inserted through guide; and a pressure measuring device to measure pressure in the carpal tunnel.

“Another aspect is a device to use as a medical imaging sensor. It includes a clamp to attach to an imaging detector; probe guide to attach to that clamp; a probe with cutting blade whose long edge is substantially parallel the imaging surface of that detector when it is inserted through the probe guidance; and a linkage system that attaches the clamp to the patient’s hands.

“Another aspect is the invention, which consists of an imaging detector; an adjustable guide that is integrated with the imaging device and adjusts along an axis substantially parallel to that of the imaging scanner; and a probe that has a cutting blade whose longitudinal line is substantially parallel with that of the imaging sensor when it is inserted through the guide.

“Further aspects will be revealed in the following sections of the specification. The detailed description is intended to fully disclose preferred embodiments without imposing limitations on them.”

“BRIEF DESCRIPTION ABOUT THE VIEWS OF MANY DRAWINGS”

“The invention can be better understood by referring to the following drawings, which are only for illustration purposes:

“FIG. “FIG.

“FIG. “FIG.

“FIG. “FIG. 1. However, the injection needle has been replaced by other devices to measure and treat carpal tunnel syndrome.

“FIG. “FIG.

“FIG. FIG. 5 shows an anterior-posterior view showing the injection apparatus. 4.”

“FIG. “FIG. 4 but the injection needle has been replaced by an alternate device for measuring and treating carpal tunnel syndrome.

“FIG. “FIG. 6. However, the alternative devices for measuring and treating carpal tunnel syndrome are shown palmar to the retinaculum.

“FIG. “FIG.8 is an anterior-posterior shot of an injection device according to the invention, similar to that in FIG. 4 but with a detector clamp which allows rotation of the imaging sensor to obtain different image views.”

“FIG. “FIG.

“FIG. FIG. 10 shows an anterior-posterior view showing the injection apparatus. 9.”

“FIG. “FIG. 11. This is a view from the top of a standard grip-dynamometer with data acquisition module and display module.”

“FIG. 12 is a perspective of a standard pinch-dynamometer with data acquisition module and display module.”

“FIG. 13 shows a hand with the indicated measurement locations selected and standardized using a DWC?HH measurement.

“FIG. 14 shows the placement of a pressure sensor that has been confirmed by fluoroscopy.

“FIG. “FIG.15 illustrates measurements of maximum grip force (MGF) on a patient’s hands.

“FIG. “FIG.16 illustrates the testing of a patient’s hand to determine maximum pulp pinch force (MPF).

“FIG. “FIG.17 illustrates the testing of a patient’s hand to determine maximum key pinch force (MKF)

“FIG. “FIG.

“FIG. “FIG.

“FIG. 20 is a graph that compares intracarpal pressures adjacent to HH before and following the release of transverse carpal ligament.

“Referring to the drawings more specifically, the present invention is embodied as the apparatus generally shown at FIG. 1. through FIG. 20. You will appreciate that the configuration and details of the parts may differ from those described herein. The steps and sequences may also vary without departing significantly from the fundamental concepts.

“FIGS. “FIGS. One aspect of CTS is the injection of a drug at a level that can cause enough structural damage to the collagen fibers in the flexor retinaculum. Second, induce enough tensile stress to weaken the collagen fibers. This will cause them to either burst or increase in length due to fiber growth.

“In a preferred embodiment, an agent that contains collagenase can be used to weaken the structural integrity collagen fibers. Collagenase, which is naturally produced by the body, is vital for normal remodeling of collagen-rich tissues. A particular injectable collagenase, clostridium mytolyticum (Xiaflex), can be injected into or near the flexor.

A single injection of up 0.9 mg collagenase may be used to treat CTS. The total volume of the collagenase injected must not exceed 0.5 ml. A single injection may not be sufficient to weaken collagen enough to cause fibrous cords to fail. Four additional injections of upto 0.9 mg may be required.

Corticosteroids, or any drug that weakens collagen’s structural integrity, may also be used. Corticosteroids can temporarily relieve symptoms for patients suffering from CTS. However, they are typically injected into the synovium surrounding the contents of the carpal canal, and not directly into the flexor retinaculum, as described in the system of this invention.

Corticosteroids can also be used to treat painful soft tissue injuries such as tendonitis, medial epicondylitis, and plantar fasciitis. The corticosteroid often weakens collagen fibers in tendon or ligaments after multiple injections. When the weak collagen fibers are subject to tensile loads from active muscle, this causes a sudden rupture of tendon along its length, or at its origin or entry into bone. To weaken its structural integrity, the corticosteroids in various dosages and concentrations are commonly used to treat these soft tissue injuries.

“In one embodiment, a combination of collagenase as well as corticosteroids are injected near or at the flexor retinaculum to treat patients with CTS. A combination of collagenase and corticosteroids may offer better relief due to the anti-inflammatory effects of corticosteroids. Inflammation is one of the most common side effects of collagenase injections. The corticosteroid can be mixed with the collagenase or administered separately. The corticosteroid may be administered separately, either before, during, or after the collagenase injection. The corticosteroid may be administered separately into the carpal tunnel synovium, the flexor or adjacent to the flexor retinaculum.

“Another embodiment may see the injection of a corticosteroid or collagenase into the synovium surrounding the contents of the carpal tube. This is similar to a standard steroid injection. The intention is not to damage the structure of the flexor retinaculum. It is intended to alleviate the symptoms of carpal tunnel syndrome.

“The invention relates to an injection/agent delivery system that allows for the safe and accurate injection of an agent at locations desired, either directly into or adjacent to the flexor retinaculum. FIG. FIG. 1 illustrates one embodiment of the injection device 10. It is used to identify the flexor retinaculum in the carpal tunnel by using ultrasound imaging, and to inject a drug in any area of the flexor retinaculum. The injection device 10 shown in the illustration includes an imaging detector 12 with a clamp 14, a needle guidance 16 and an injection needle 18. A syringe 20 contains the drug 34.

“The imaging means 12 could be any noninvasive imaging device that is used to guide injection needles. The preferred embodiment uses an existing commercially available ultrasound transducer that is connected via cable 37 to an ultrasonic imaging monitor 39. This device can produce high-quality images of the flexor retinaculum 22, and any associated anatomy, as well as the hand and wrist. The image monitor 39 can be found far from the imaging detector in a standard ultrasound system. It may be beneficial to position the image monitor 39 near the hand being imaged in order to make it easier to inject while imaging.

The physician can adjust the position of the imaging detector 12 to view acceptable images of the palmar skin 24, the flexor retinaculum 22, and other vital anatomic features. The hook of 32 can also be identified by ultrasound. This is the anatomic attachment to the stiffest part of the flexible retinaculum. This is where the median nerve in the carpal tunnel is most compressed. The images show the flexor retinaculum 22, which can be visually identified. It can also be computed to determine its palmar-to?dorsal depth relative to a reference position. Real-time images of an injection needle relative to the anatomy of the carpal canal allow for more precise and repeatable injections.

To aid in the guidance of the injection needle, other standard imaging devices, such as MRI or X-ray, can be used. Ultrasound imaging has certain advantages. It provides real-time images of the flexor retinaculum 22 and the injection needle 18 and 34, and there is no radiation exposure to patients. The needle guide 16 can be integrated with the housing for the imaging detector 12.

The physician can hold the injection device 10, and the imaging surface 38, of the imaging detector 12, on the patient’s palm. 1. Or rotate 90 degrees around the imaging detector ZD’s longitudinal axis to obtain a transverse position. 2.”

“Alternatively, you can have two imaging detectors (not illustrated) contained in one clamp 14 or separately. One is oriented to give a longitudinal image, the other is oriented to show the transverse anatomy of the patient’s wrist. Two imaging detectors may be identical or different in their physical dimensions and/or performance abilities. This arrangement allows for two images of the carpal tunnel anatomy to be displayed simultaneously on one image monitor.

“In another embodiment, an imaging detector 12 can be combined with software (not illustrated) in the image monitor 39. This allows for three-dimensional images to be provided using mechanical or electronic switching. It scans longitudinally and transversely.

To enhance the acoustic quality and make it easier to position the imaging detector 12, a standard, commercially available, aqueous ultrasound Gel or another suitable material for conducting sound is applied to the patient’s palm 24 before imaging. Once the desired image of flexor retinaculum 22 has been obtained, the needle 16 is adjusted in a palmar direction YP?D along the needle guide’s axis AN?G to align the injection site 18 with the desired location. The needle guide AN-G is adjusted along the same axis as the ZD longitudinal axis.

“Needle guide 16 can be slideably connected to clamp 14 by a dovetail joint35 (see FIG. This allows for controlled translation of needle guide 16 relative to clamp 14 in the YP/D direction. The image monitor displays ultrasound depth information. This is used to calculate the palmar-dorsal distance from the hand’s palm to the flexor retinaculum 22, The indicator marks 28 are used to determine the desired depth. They represent the palmar-dorsal position 16-16 of the clamp 14.

Summary for “Carpal tunnel syndrome treated with injection of the flexor retinaculum

“1. “1.

“The invention relates generally to the treatment of carpal tunnel syndrome and, more specifically, to a method and apparatus to treat it by injecting a biological substance into flexor retinaculum.”

“2. “2.

“The carpal tunnel, an area of the hand that is adjacent to the wrist, is made by an arch of eight wrist bones and is spanned by the flexor retinaculum on its palmar surface. The flexor retinaculum functions as a pulley. Nine flexor tendon with synovial membranes, four muscles of the lumbrical region, and the median nerve pass through the carpal tunnel. The flexor retinaculum is missing, which causes the flexor tendon to bowstring. This results in loss of strength and dexterity in the wrist and hands, which the carpal tunnel tendons control.

Carpal tunnel syndrome (CTS), is a condition that results in a rise in pressure inside the carpal tunnel. This disease is characterized by pain, numbness and tingling due to the increased pressure on the median nerve. It is currently the most common occupational health risk in the industrialized world. It costs billions of dollars each year to treat, diagnose and prevent this syndrome from becoming a serious problem.

“Intracarpal pressure can be dynamic and affected by many factors. These factors include disease, injury, wrist position and hand use, compliance with the flexor retinaculum, lumbrical muscle, externally applied force, finger position, and compliance of the flexor muscles. Pressure dynamics are also affected by the geometry of the carpal tunnel. It is difficult to measure intracarpal tunnel pressure accurately due to the complexity of the geometry and interactions among these factors. Pressure measurement also depends on the type and extent of pressure changes introduced by the measurement device.

“Active hand usage produces the largest range of pressures in the carpal tunnel. Patients with carpal tunnel syndrome (CTS) were included in most studies that measured intracarpal tunnel pressure while active hand use. None of these studies measured hand use during pressure measurement. Intracarpal tunnel pressure is also a function the location of pressure measurements. Therefore, any analysis of intracarpal pressure dynamics should include a profile within the carpal canal. Although others have described the pressure profile from the carpal canal’s proximal to distal, only one included pressure measurements during active use. But, it was not possible to quantify hand use.

Although the cause of CTS remains unknown, treatment is well-established. To temporarily relieve symptoms, non-operative treatments such as splinting and anti-inflammatory medication, cortisone injections in the carpal tunnel, and cortisone injections are sometimes used. CTS can be treated with surgical division of the retinaculum if other treatments fail. The surgical division of the flexor retinaculum results in a decrease of pressure in the carpal tunnel, which allows normal blood flow to the median nervous to return. This relieves the symptoms and signs of CTS. There are many methods to release the flexor retinaculum. The most common ones are endoscopic and open.

An open release involves a longitudinal incision through the skin of the palm of your hand. This is carried down through the palmar fascia, subcutaneous fat, palmaris brvis muscle and finally the flexor retinaculum. After the flexor retinaculum has been released, the skin can be sutured. The wrist is often splinted until it heals. The typical outpatient procedure takes approximately 15-30 minutes.

There are many devices that can perform an endoscopic release of the flexor retinaculum. A video endoscope is one device. Another includes a handpiece that holds a disposable knife assembly. The device is inserted via a small incision made in the wrist flexion crease. The device’s tip is seen through a window at its tip. Next, the blade is raised to make the longitudinal cut while the device is being withdrawn from the carpal tube. The device is then used to check the length of the incision through flexor retinaculum, and if necessary, perform any additional cutting. The entry wound can be closed once the incision is complete. Endoscopic release can be performed outpatient and takes approximately the same time as open release.

“While complete surgical divisions of the flexor retinaculum are promoted as the standard of care for patients with CTS,”

“(a) The arch of the carpal bones could be altered to affect the functional biomechanics and hand function.”

“(b) The pulley effect of the flexor corneaculum might be lost or compromised, which could cause the median nerve and digital flexor tendon to sublux palmarwardly in between the cut edges. Power grip and pinch will be affected until the flexor retinaculum heals sufficiently to allow the carpal tunnel to function as a pulley for nine digital flexor tendon.

“(c) The exposed edges of the flexor retinaculum allow scar tissue to heal in the longer position. This can increase the risk of post-operative morbidity, pain, weakness, and even lead to greater complication rates.”

“(d) A complete ligament division can affect the time it takes for a patient’s activities of daily living to resume their work and other activities.

“(e) Some surgical techniques require that an operation room procedure be performed rather than an office procedure or clinic procedure.

“(f) Following the complete division of flexor retinaculum portions of the hypothenar and thenar muscle groups become unstable. This causes pain and weakness in pinching and gripping during healing of flexor retinaculum.

“To avoid potential problems associated with current surgical techniques, an object in the present invention is a method or apparatus that weakens structural integrity of flexor retinaculum sans using a surgical cut or surgically dividing portions of the retinaculum. The following description will meet at least some of these objectives.

“The invention provides a system and method for altering the stiffness in the flexor retinaculum to make it more flexible. This causes the circumference to expand, and decreases pressure on the contents of carpal tunnel. It is similar to what happens after surgical division of flexor retinaculum. This allows the pressure in the carpal tunnel, which is responsible for the relief of CTS symptoms, to return to a normal level.

“According to one aspect of the invention, an apparatus is provided for identifying and injecting a drug into the carpal tunnel. “An apparatus and method for identifying the flexor retinaculum of the carpal tunnel and injecting a drug into it is provided. The apparatus may include: (a) a drug that can weaken collagen’s structural integrity; (b) an imaging device for identifying the flexible retinaculum; c) a detector frame that attaches to the palm of the hands that holds and positions the detector; (d), an injection needle that injects the drug; and (e). a needle guide that attaches to the imaging detector or integrates with it that positions, guides, and holds the needle.

“Any drug that reduces the structural integrity collagen can be used. Collagenase is a preferred method. Collagenase, an enzyme that digests collagen by breaking down the collagen protein’s peptide bonds, is a preferred embodiment.

“Collagen fibers in the flexor retinaculum (carpal tunnel) are susceptible to being broken down by collagenase. The methods and systems of this invention are significantly better than current surgical procedures. They inject collagenase into any part or tissue adjacent to the flexor retinaculum. This weakens the structural integrity and increases the tensile stress within the flexor. It causes the ligament to grow in length and decreases pressure on the median nerve.

“The present invention could include a combination collagenase and a liquid carrier in an effective dose for injection into or near to the flexor retinaculum to weaken collagen’s structural integrity.”

“The ?structural integrity? The structural integrity of collagen can be defined as its ability to withstand tensile loads. The threshold for tensile loading drops once collagenase weakens the structural integrity collagen. This means that collagen fibers can no longer withstand the same tensile loads as they did before the injection. Individual collagen fibers become structurally unsound when tensile loads exceed this threshold. This is due to the breakdown of collagen protein bonds. Initial failure of collagen fibers is microscopic. As the tensile loads increase, the collagen structure begins to fail.

Direct injection of drug to a portion of or adjacent the flexor retinaculum may be possible by only visual and palpation methods of a skilled physician who is familiar with the anatomy of the hand. An imaging device is recommended because the flexor retinaculum lies below the palmar surface and is not visible or palpable. An imaging device is also required in order to identify the flexorreticulum.

“The imaging device can be any noninvasive imaging detector that is commonly used to guide injection needles. The preferred embodiment of the imaging detector uses an ultrasound transducer. You can use any standard, commercially available ultrasound transmitter with both hardware- and software capabilities to create high quality images of anatomy of the wrist or hand. The physician can adjust the position of the imaging detector by holding it against the palmar skin. This will allow the doctor to view acceptable images of the flexor retinaculum as well as other vital anatomic features. The hook of the Hamate is an anatomic attachment to the stiffest part of the Flexor retinaculum. Ultrasound can also be used to identify it. This is where the median nerve in the carpal tunnel is compressed the most. The images allow for visual identification of the flexor retinaculum and the calculation of its palmar to-dorsal distance relative to a reference position. Real-time images of an injection needle relative to the anatomy of the carpal tube allow for more precise and repeatable injections at specific locations.

While the doctor can manually hold and position the imaging detector, it is helpful to have a frame that assists in this task. The preferred embodiment of the detector frame is attached to the patient’s hand. The detector frame holds the imaging sensor and allows for rotational and translational positioning. A detector frame allows for greater freedom in the hands of the physician, provides stable images of the anatomy and can be used to guide an injection needle.

An injection needle can be directed to the flexor retinaculum if it is identified and its depth relative to the palmar surface. A standard hypodermic needle can be used to dispense a dose of drug. It should be of the appropriate length, diameter, and syringe. The tip of an injection needle can either be inserted into the flexor retinaculum or a segment adjacent.

Although the physician can manually hold, position, and guide the injection needle, it is more efficient to use a needle guidance device. The preferred embodiment has a needle guide attached to the imaging detector. This guides the needle along a path that allows the physician to insert the tip of its needle into the desired area. The physician can then give the drug at the appropriate dosage.

After the drug has been deposited into the flexor, or near it, it might be necessary for the patient to increase the tensile stress within the flexor. This will result in the weakening of collagen fibers, which can either cause them to fail abruptly or increase in length. The physician might recommend a hand exercise program to provide the required increase in tensile stresses in the weak collagen fibers.

“Accordingly, a portion of the invention is a method of treating a patient suffering from carpal tunnel syndrome. It involves: identifying the location of the patient?s flexor retinaculum that can be treated; injecting an agent in the location of said flexor retinaculum in one to more doses so as to weaken the structural integrity.

“In one embodiment, flexor retinaculum also includes the transverse ligament and/or its attachments to the bones.

“Another embodiment of the agent consists: one or more doses collagenase, a Corticosteroid or both.”

“A further embodiment involves locating a suitable treatment site for the patient?s flexor retinaculum by positioning an imaging detector near a region in the patient?s hand, the region being associated to the flexor, and then generating an image from the patient?s hand. An imaging detector could include ultrasound imaging, Xray imaging, Magnetic Resonance imaging, or other similar methods.

“In one embodiment of the present invention, the method for generating an image is to position an ultrasound transducer near the patient’s hand and generate an ultrasound image.”

“In an alternative embodiment, the method also includes increasing the tension in the flexor retinaculum after injecting the agent. Pressure within the carpal tunnel may cause an increase in tensile strain. This pressure can be created by the following: having the patient use one to three digits of their hand; having them grip the object with one or two fingers; having them flex one or both fingers into the palm of their hand and having them pinch one or several fingers together. The object could be a dynamometer and be placed in the palm or heel.

“In another embodiment, the method also includes measuring pressure in the carpal tunnel.”

“In addition to injecting an agent, the method might also include the cutting of the flexor retinaculum using a blade.”

“In one embodiment, the procedure of identifying the treatment location for the patient’s palmar-to?dorsal distance from the palm of the hands to the flexor is further simplified by computing the palmar?to?dorsal thickness. The agent is then injected via a needle at the computed palmer?to?dorsal height along an axis substantially parallel with the imaging surface of a detector or the longitudinal axis to the flexor.

“In another embodiment, the agent may be delivered to a central part of the flexor retinaculum.”

“A further embodiment of the method might include inserting a guidetube into the hand near the flexor corneaculum and then accessing the flexor at the distal end. The current mode may also include the advancement of a pressure sensor within the guide tube to the treatment location and measurement at that location. The method could also include cutting tissue associated to the flexor retinaculum and advancing a cutting probe inside said guide tube.

“Another aspect of the system is one for treating a patient suffering from carpal tunnel syndrome. It comprises: a needle guide; an injectable needle; the needle guided comprising a guide hole for receiving the injection; and an agent that is to be delivered within said injection to a region of tissue associated with the flexorreticulum of the patient. The agent is designed to weaken the structural integrity the flexorreticulum.

“In one embodiment, the system comprises a clamp that is coupled to a needle guide. The reference surface allows for patient positioning at the palm of the hand. The needle guide is then slideably coupled with the clamp so that the needle can be adjusted relative to the reference surface. Preferably, the guide hole’s longitudinal axis is substantially parallel with the reference surface.

“In another embodiment of the present invention, the system includes an imaging device that is used to image the carpal tunnel during injection. The clamp is designed to hold the imaging device. To obtain transverse and longitudinal images of the carpal tunnel, the imaging device can be pivotably connected to the clamp.

“In another configuration, the imaging device includes an imaging surface. The imaging surface is substantially parallel with the longitudinal axis the needle guide’s guide hole. The needle guide can be set up to allow for adjustments in a palmar-dorsal manner, while the guide hole is maintained substantially parallel to the imaging surface. A needle guide and clamp may include an indicator that indicates the depth of needle insertion relative to the reference surface.

“Another embodiment of the system comprises a guide tube that is placed within the guide hole. The guide tube can be inserted into the hand near the flexor retinaculum. A central channel in the guide tube allows for delivery of an instrument to the region. A delivery instrument could include a pressure sensor that is sized to fit within the guide tube and deliver the tissue to it. The pressure sensor or cutting probe may also be included.

“In another embodiment, the clamp is secured to the patient’s hand by a linkage. The linkage includes a first joint that allows the clamp to rotate with respect to the patient’s hand. The first joint allows rotation of the clamp with respect to the patient’s hands in a flexion/extension direction. A second joint may be included in the linkage. This second joint allows rotation of the clamp with respect to patient’s hand in a radial to ulnar direction.

“In another embodiment, a linkage system allows for translational and rotational adjustments to the imaging detector and needle/probe guides relative to the patient’s hands. The current embodiment uses a linkage system to establish a fixed point distal of the imaging detector around which the longitudinal axis is of a contact line connecting a patient’s long fingers and his ring.

“Another aspect of an apparatus for treating patients with carpal tunnel syndrome includes: a needle guided; an injection needle; the guide hole for receiving the injections needle; a clamp coupled with the needle guidance; wherein a reference surface is provided for positioning the needle at the palm of the patient’s hands; wherein a slideable coupling allows the needle to be moved with respect to this surface; and an imaging system for imaging the carpal tunnel during injection. The clamp is designed to hold the imaging device.

“The apparatus includes a device that allows the delivery of an agent within the injection needle to a region of tissue associated with the patient’s flexor retinaculum; the agent is designed to weaken the structural integrity the flexor. The guide hole should be substantially parallel to the reference surface.

“In one embodiment, an apparatus also includes a linkage attached the clamp. The linkage is designed to secure to patients’ hands and has first- and second-joints that allow rotation in the clamp with respect the hand. The first joint allows rotation in a direction of flexion-extension with respect the patient’s arm; the second joint allows rotation in a direction of radial-ulnar with respect the patient’s wrist.

“Another aspect of the apparatus is for treating a patient suffering from carpal tunnel syndrome. It comprises: a base that supports a patient’s hand and forearm; a first surface for supporting the hand and a second surface for supporting the hand; a pivotable arms coupled to this base; wherein a needle guide is supported by the pivotable Arm; the needle guided comprising a guide hole for receiving an injection needle; and a clamp connecting the pivotable and needle guides. The clamp allows the needle

“In a preferred embodiment of the apparatus, an agent is delivered within the injection needle to a tissue area associated with the patient’s flexor retinaculum; said agent is designed to weaken the structural integrity the flexor.

“In another embodiment, an imaging device is included that can be used to image the carpal tunnel during injection. The clamp is designed to hold the imaging device.

“In another embodiment, the guide holes are substantially parallel to each other surface. The needle guide can be adjusted in a palmar direction, while the guide hole remains parallel to the second. The needle guide and clamp include an indicator that indicates the depth of needle insertion relative to the reference surface. The pivotable arm also allows rotation and translation of the needle guide relative to the second surface.

“Another aspect is the treatment of a patient suffering from carpal tunnel syndrome. This involves injecting a drug into the flexor eye in one or more doses that weaken the structure of the flexor. Also, increasing the tensile stress within the flexor. You can also measure the pressure in the carpal tunnel. The flexor retinaculum can also be cut using a blade. An imaging method is used to show the flexor retinaculum on an LCD monitor.

“Another aspect is a percutaneous injectable device for use with medical imaging detectors. It comprises: a clamp for attaching to the imaging scanner; a needle-guide for attaching to the clamp; and an injection tool for inserting through the needle. The needle guide has a longitudinal axis that is substantially parallel the imaging surface of an imaging detector.

“Another aspect is the invention, which includes an imaging detector; an imaging clamp that couples with the imaging detector; an adjustable guide that attaches and is adjustable along an angle that is substantially parallel the longitudinal axis; a probe with an cutting blade whose longaxis is substantially parallel the imaging surface of imaging detector when inserted through guide; and a pressure measuring device to measure pressure in the carpal tunnel.

“Another aspect is a device to use as a medical imaging sensor. It includes a clamp to attach to an imaging detector; probe guide to attach to that clamp; a probe with cutting blade whose long edge is substantially parallel the imaging surface of that detector when it is inserted through the probe guidance; and a linkage system that attaches the clamp to the patient’s hands.

“Another aspect is the invention, which consists of an imaging detector; an adjustable guide that is integrated with the imaging device and adjusts along an axis substantially parallel to that of the imaging scanner; and a probe that has a cutting blade whose longitudinal line is substantially parallel with that of the imaging sensor when it is inserted through the guide.

“Further aspects will be revealed in the following sections of the specification. The detailed description is intended to fully disclose preferred embodiments without imposing limitations on them.”

“BRIEF DESCRIPTION ABOUT THE VIEWS OF MANY DRAWINGS”

“The invention can be better understood by referring to the following drawings, which are only for illustration purposes:

“FIG. “FIG.

“FIG. “FIG.

“FIG. “FIG. 1. However, the injection needle has been replaced by other devices to measure and treat carpal tunnel syndrome.

“FIG. “FIG.

“FIG. FIG. 5 shows an anterior-posterior view showing the injection apparatus. 4.”

“FIG. “FIG. 4 but the injection needle has been replaced by an alternate device for measuring and treating carpal tunnel syndrome.

“FIG. “FIG. 6. However, the alternative devices for measuring and treating carpal tunnel syndrome are shown palmar to the retinaculum.

“FIG. “FIG.8 is an anterior-posterior shot of an injection device according to the invention, similar to that in FIG. 4 but with a detector clamp which allows rotation of the imaging sensor to obtain different image views.”

“FIG. “FIG.

“FIG. FIG. 10 shows an anterior-posterior view showing the injection apparatus. 9.”

“FIG. “FIG. 11. This is a view from the top of a standard grip-dynamometer with data acquisition module and display module.”

“FIG. 12 is a perspective of a standard pinch-dynamometer with data acquisition module and display module.”

“FIG. 13 shows a hand with the indicated measurement locations selected and standardized using a DWC?HH measurement.

“FIG. 14 shows the placement of a pressure sensor that has been confirmed by fluoroscopy.

“FIG. “FIG.15 illustrates measurements of maximum grip force (MGF) on a patient’s hands.

“FIG. “FIG.16 illustrates the testing of a patient’s hand to determine maximum pulp pinch force (MPF).

“FIG. “FIG.17 illustrates the testing of a patient’s hand to determine maximum key pinch force (MKF)

“FIG. “FIG.

“FIG. “FIG.

“FIG. 20 is a graph that compares intracarpal pressures adjacent to HH before and following the release of transverse carpal ligament.

“Referring to the drawings more specifically, the present invention is embodied as the apparatus generally shown at FIG. 1. through FIG. 20. You will appreciate that the configuration and details of the parts may differ from those described herein. The steps and sequences may also vary without departing significantly from the fundamental concepts.

“FIGS. “FIGS. One aspect of CTS is the injection of a drug at a level that can cause enough structural damage to the collagen fibers in the flexor retinaculum. Second, induce enough tensile stress to weaken the collagen fibers. This will cause them to either burst or increase in length due to fiber growth.

“In a preferred embodiment, an agent that contains collagenase can be used to weaken the structural integrity collagen fibers. Collagenase, which is naturally produced by the body, is vital for normal remodeling of collagen-rich tissues. A particular injectable collagenase, clostridium mytolyticum (Xiaflex), can be injected into or near the flexor.

A single injection of up 0.9 mg collagenase may be used to treat CTS. The total volume of the collagenase injected must not exceed 0.5 ml. A single injection may not be sufficient to weaken collagen enough to cause fibrous cords to fail. Four additional injections of upto 0.9 mg may be required.

Corticosteroids, or any drug that weakens collagen’s structural integrity, may also be used. Corticosteroids can temporarily relieve symptoms for patients suffering from CTS. However, they are typically injected into the synovium surrounding the contents of the carpal canal, and not directly into the flexor retinaculum, as described in the system of this invention.

Corticosteroids can also be used to treat painful soft tissue injuries such as tendonitis, medial epicondylitis, and plantar fasciitis. The corticosteroid often weakens collagen fibers in tendon or ligaments after multiple injections. When the weak collagen fibers are subject to tensile loads from active muscle, this causes a sudden rupture of tendon along its length, or at its origin or entry into bone. To weaken its structural integrity, the corticosteroids in various dosages and concentrations are commonly used to treat these soft tissue injuries.

“In one embodiment, a combination of collagenase as well as corticosteroids are injected near or at the flexor retinaculum to treat patients with CTS. A combination of collagenase and corticosteroids may offer better relief due to the anti-inflammatory effects of corticosteroids. Inflammation is one of the most common side effects of collagenase injections. The corticosteroid can be mixed with the collagenase or administered separately. The corticosteroid may be administered separately, either before, during, or after the collagenase injection. The corticosteroid may be administered separately into the carpal tunnel synovium, the flexor or adjacent to the flexor retinaculum.

“Another embodiment may see the injection of a corticosteroid or collagenase into the synovium surrounding the contents of the carpal tube. This is similar to a standard steroid injection. The intention is not to damage the structure of the flexor retinaculum. It is intended to alleviate the symptoms of carpal tunnel syndrome.

“The invention relates to an injection/agent delivery system that allows for the safe and accurate injection of an agent at locations desired, either directly into or adjacent to the flexor retinaculum. FIG. FIG. 1 illustrates one embodiment of the injection device 10. It is used to identify the flexor retinaculum in the carpal tunnel by using ultrasound imaging, and to inject a drug in any area of the flexor retinaculum. The injection device 10 shown in the illustration includes an imaging detector 12 with a clamp 14, a needle guidance 16 and an injection needle 18. A syringe 20 contains the drug 34.

“The imaging means 12 could be any noninvasive imaging device that is used to guide injection needles. The preferred embodiment uses an existing commercially available ultrasound transducer that is connected via cable 37 to an ultrasonic imaging monitor 39. This device can produce high-quality images of the flexor retinaculum 22, and any associated anatomy, as well as the hand and wrist. The image monitor 39 can be found far from the imaging detector in a standard ultrasound system. It may be beneficial to position the image monitor 39 near the hand being imaged in order to make it easier to inject while imaging.

The physician can adjust the position of the imaging detector 12 to view acceptable images of the palmar skin 24, the flexor retinaculum 22, and other vital anatomic features. The hook of 32 can also be identified by ultrasound. This is the anatomic attachment to the stiffest part of the flexible retinaculum. This is where the median nerve in the carpal tunnel is most compressed. The images show the flexor retinaculum 22, which can be visually identified. It can also be computed to determine its palmar-to?dorsal depth relative to a reference position. Real-time images of an injection needle relative to the anatomy of the carpal canal allow for more precise and repeatable injections.

To aid in the guidance of the injection needle, other standard imaging devices, such as MRI or X-ray, can be used. Ultrasound imaging has certain advantages. It provides real-time images of the flexor retinaculum 22 and the injection needle 18 and 34, and there is no radiation exposure to patients. The needle guide 16 can be integrated with the housing for the imaging detector 12.

The physician can hold the injection device 10, and the imaging surface 38, of the imaging detector 12, on the patient’s palm. 1. Or rotate 90 degrees around the imaging detector ZD’s longitudinal axis to obtain a transverse position. 2.”

“Alternatively, you can have two imaging detectors (not illustrated) contained in one clamp 14 or separately. One is oriented to give a longitudinal image, the other is oriented to show the transverse anatomy of the patient’s wrist. Two imaging detectors may be identical or different in their physical dimensions and/or performance abilities. This arrangement allows for two images of the carpal tunnel anatomy to be displayed simultaneously on one image monitor.

“In another embodiment, an imaging detector 12 can be combined with software (not illustrated) in the image monitor 39. This allows for three-dimensional images to be provided using mechanical or electronic switching. It scans longitudinally and transversely.

To enhance the acoustic quality and make it easier to position the imaging detector 12, a standard, commercially available, aqueous ultrasound Gel or another suitable material for conducting sound is applied to the patient’s palm 24 before imaging. Once the desired image of flexor retinaculum 22 has been obtained, the needle 16 is adjusted in a palmar direction YP?D along the needle guide’s axis AN?G to align the injection site 18 with the desired location. The needle guide AN-G is adjusted along the same axis as the ZD longitudinal axis.

“Needle guide 16 can be slideably connected to clamp 14 by a dovetail joint35 (see FIG. This allows for controlled translation of needle guide 16 relative to clamp 14 in the YP/D direction. The image monitor displays ultrasound depth information. This is used to calculate the palmar-dorsal distance from the hand’s palm to the flexor retinaculum 22, The indicator marks 28 are used to determine the desired depth. They represent the palmar-dorsal position 16-16 of the clamp 14.

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What is a software medical device?

The FDA can refer to software functions that include ” Software As a Medical Device” and “Software in a Medical Device(SiMD)”, which are software functions that are integral to (embedded in a) a medical device.

Section 201(h),?21 U.S.C. 321(h),(1) defines a medical device to be?an apparatus, implements, machine, contrivances, implant, in vitro regulator, or other similar or related articles, as well as a component or accessory. . . (b) is intended for diagnosis or treatment of disease or other conditions in humans or animals. (c) Is intended to alter the structure or function of human bodies or animals. To be considered a medical device, and thus subject to FDA regulation, the software must meet at least one of these criteria:

• It must be used in diagnosing and treating patients.
• It must not be designed to alter the structure or function of the body.

If your software is designed to be used by healthcare professionals to diagnose, treat, or manage patient information in hospitals, the FDA will likely consider such software to be medical devices that are subject to regulatory review.

Is Your Software a Medical Device?

FDA’s current oversight, which puts more emphasis on the functionality of the software than the platform, will ensure that FDA does not regulate medical devices with functionality that could be dangerous to patient safety. Examples of Device Software and Mobile Medical Apps FDA is focused on

• Software functions that aid patients with diagnosed mental disorders (e.g., depression, anxiety, and post-traumatic stress disorder (PTSD), etc.) by providing “Skill of the Day”, a behavioral technique, or audio messages, that the user can access when they are experiencing anxiety.
• Software functions that offer periodic reminders, motivational guidance, and educational information to patients who are recovering from addiction or smokers trying to quit;
• Software functions that use GPS location data to alert asthmatics when they are near high-risk locations (substance abusers), or to alert them of potential environmental conditions that could cause symptoms.
• Software that uses video and games to encourage patients to exercise at home.
• Software functions that prompt users to choose which herb or drug they wish to take simultaneously. They also provide information about interactions and give a summary of the type of interaction reported.
• Software functions that take into account patient characteristics, such as gender, age, and risk factors, to offer patient-specific counseling, screening, and prevention recommendations from established and well-respected authorities.
• Software functions that use a list of common symptoms and signs to give advice about when to see a doctor and what to do next.
• Software functions that help users to navigate through a questionnaire about symptoms and to make a recommendation on the best type of healthcare facility for them.
• These mobile apps allow users to make pre-specified nurse calls or emergency calls using broadband or cell phone technology.
• Apps that allow patients or caregivers to send emergency notifications to first responders via mobile phones
• Software that tracks medications and provides user-configured reminders to improve medication adherence.
• Software functions that give patients access to their health information. This includes historical trending and comparisons of vital signs (e.g. body temperature, heart rate or blood pressure).
• Software functions that display trends in personal healthcare incidents (e.g. hospitalization rates or alert notification rate)
• Software functions allow users to electronically or manually enter blood pressure data, and to share it via e-mail, track it and trend it, and upload it to an electronic or personal health record.
• Apps that offer mobile apps for tracking and reminders about oral health or tools to track users suffering from gum disease.
• Apps that offer mobile guidance and tools for prediabetes patients;
• Apps that allow users to display images and other messages on their mobile devices, which can be used by substance abusers who want to quit addictive behaviors.
• Software functions that provide drug interaction and safety information (side effects and drug interactions, active ingredient, active ingredient) in a report based upon demographic data (age and gender), current diagnosis (current medications), and clinical information (current treatment).
• Software functions that allow the surgeon to determine the best intraocular lens powers for the patient and the axis of implantation. This information is based on the surgeon’s inputs (e.g., expected surgically induced astigmatism and patient’s axial length, preoperative corneal astigmatism etc.).
• Software, usually mobile apps, converts a mobile platform into a regulated medical device.
• Software that connects with a mobile platform via a sensor or lead to measure and display electrical signals from the heart (electrocardiograph; ECG).
• Software that attaches a sensor or other tools to the mobile platform to view, record and analyze eye movements to diagnose balance disorders
• Software that collects information about potential donors and transmits it to a blood collection facility. This software determines if a donor is eligible to collect blood or other components.
• Software that connects to an existing device type in order to control its operation, function, or energy source.
• Software that alters or disables the functions of an infusion pump
• Software that controls the inflation or deflation of a blood pressure cuff
• Software that calibrates hearing aids and assesses sound intensity characteristics and electroacoustic frequency of hearing aids.

What does it mean if your software/SaaS is classified as a medical device?

SaaS founders need to be aware of the compliance risks that medical devices pose. Data breaches are one of the biggest risks. Medical devices often contain sensitive patient data, which is why they are subject to strict regulations. This data could lead to devastating consequences if it were to become unprotected. SaaS companies who develop medical devices need to take extra precautions to ensure their products are safe.

So who needs to apply for FDA clearance? The FDA defines a ?mobile medical app manufacturer? is any person or entity who initiates specifications, designs, labels, or creates a software system or application for a regulated medical device in whole or from multiple software components. This term does not include persons who exclusively distribute mobile medical apps without engaging in manufacturing functions; examples of such distributors may include the app stores.

Software As Medical Device Patenting Considerations

The good news is that investors like medical device companies which have double exclusivity obtained through FDA and US Patent and Trademark Office (USPTO) approvals. As such, the exit point for many medical device companies is an acquisition by cash rich medical public companies. This approach enables medical devices to skip the large and risky go-to-market (GTM) spend and work required to put products in the hands of consumers.

Now that we have discussed the FDA review process, we will discuss IP issues for software medical device companies. Typically, IP includes Patents, Trademarks, Copyrights, and Trade secrets. All of these topics matter and should be considered carefully. However, we will concentrate on patents to demonstrate how careless drafting and lack of planning can lead to problems, namely unplanned disclosures of your design that can then be used as prior art against your patent application.

In general, you should file patent application(s) as soon as practicable to get the earliest priority dates. This will help you when you talk to investors, FDA consultants, prototyping firms, and government agencies, among others. Compliance or other documents filed with any government agency may be considered disclosure to third parties and could make the document public. In general, disclosures to third parties or public availability of an invention trigger a one year statutory bar during which you must file your patent application. Failure to file your application within the required time frame could result in you losing your right to protect your invention.

The information from your FDA application may find its way into FDA databases, including DeNovo, PMA and 510k databases and FDA summaries of orders, decisions, and other documents on products and devices currently being evaluated by the FDA. Your detailed information may be gleaned from Freedom of Information Act requests on your application. This risk mandates that you patent your invention quickly.

When you patent your medical device invention, have a global picture of FDA regulatory framework when you draft your patent application. Be mindful of whether your software/SaaS application discusses the diagnosing and treating patients or affecting the structure or function of the body and add language to indicate that such description in the patent application relates to only one embodiment and not to other embodiments. That way you have flexibility in subsequent discussions with the FDA if you want to avoid classification of your software/SaaS/software as a medical device. In this way, if you wish to avoid FDA registration and oversight, you have the flexibility to do so.

An experienced attorney can assist you in navigating the regulatory landscape and ensure that you comply with all applicable laws. This area of law is complex and constantly changing. It is important that you seek legal advice if you have any questions about whether or not your software should be registered with FDA.

Patent PC is an intellectual property and business law firm that was built to speed startups. We have internally developed AI tools to assist our patent workflow and to guide us in navigating through government agencies. Our business and patent lawyers are experienced in software, SaaS, and medical device technology. For a flat fee, we offer legal services to startups, businesses, and intellectual property. Our lawyers do not have to track time as there is no hourly billing and no charges for calls or emails. We just focus on getting you the best legal work for your needs.

Our expertise ranges from advising established businesses on regulatory and intellectual property issues to helping startups in their early years. Our lawyers are familiar with helping entrepreneurs and fast-moving companies in need of legal advice regarding company formation, liability, equity issuing, venture financing, IP asset security, infringement resolution, litigation, and equity issuance. For a confidential consultation, contact us at 800-234-3032 or make an appointment here.