Software Technology for “Body-worn mobile medical patient monitor”

Medical Device – Ammar Al-Ali, Masimo Corp

Abstract for “Body-worn mobile medical patient monitor”

A body-worn mobile medical monitoring device that minimizes the need for cable wiring by placing one or more sensors communication ports. A body-worn mobile medical monitoring system includes a housing that can be secured to the lower arm and display of a patient. The sensor communication port is located on the side of the housing. It can face the lower arm and face the patient’s hand when the mobile medical monitor device is attached to it. The sensor communication port allows wired communication with the pulse oximetry sensor attached at a patient’s digit. It is located on the side housing so that the path from the port to the patient’s digit is shorter than any other route from the housing to the other digit.

Background for “Body-worn mobile medical patient monitor”

“Patient vital signs monitoring may include measurements such as blood oxygen, blood pressure and respiratory gas. These physiological parameters require a sensor that is in direct contact with the patient and a cable to connect it to a monitor device. FIGS. FIGS. 1-2 show a conventional pulse-oximetry system 100 that is used to measure blood oxygen. FIG. FIG. 1 shows a pulse oximetry device that includes a sensor 110 and a patient cable 140 as well as a monitor 160. As shown, the sensor 110 is usually attached to a finger 10. The plug 118 of the sensor 110 can be inserted into a socket 142 for patient cables. The socket 162 on the monitor 160 accepts a patient-cable plug 144. The patient cable 140 transmits a LED drive signal 252 to the monitor 160 (FIG. 2) From the monitor 160 to sensor 110, a resulting detector sign 254 (FIG. 2) From the sensor 110 to monitor 160. Monitor 160 processes the detected signal 254 (FIG. 2) to provide, usually, a numerical reading of patient’s oxygen saturation and pulse rate as well as an audible indicator (or?beep?). This is done in response to each arterial pulse.

“As shown at FIG. 2 The sensor 110 includes both infrared and red LED emitters (212) and a photodiode detection (214). Monitor 160 includes a sensor interface 271, an output driver 276, a controller 273, and a signal processor 273. As is well-known, the monitor 160 calculates oxygen saturation by computing differential absorption by arterial blood for the two wavelengths emitted from the sensor emitters. The sensor interface 271 supplies LED drive current 252, which alternately activates IR and red LED emitters 212. The photodiode detector 214, generates a signal 254 that corresponds to the infrared and red light energy, attenuated by transmission through patient finger 10 (FIG. 1). The input circuitry of the sensor interface 271 allows for the amplification, filtering, and digitization 254 of the detected signal. Based on the ratio of red and infrared intensities detected, the signal processor 273 computes an arterial oxygen saturation value. The controller 275 is a hardware and software interface that manages the audible indicator 278, keypad 278, and display. The controller 275 provides hardware and software interfaces for managing the display and audible indicators 278 and keypad 279. The keypad 279 allows you to set alarm thresholds, enable alarms, and select display options.

The patient cable connection between the monitor and sensor limits conventional physiological measurement systems. The monitor must be in close proximity to the patient. Relocating a patient requires disconnection of the monitoring equipment, resulting in a loss of measurements and/or awkward simultaneous movements of cables and equipment. Many devices have been developed or implemented to allow wireless communication between monitors and sensors, which frees patients from the patient’s cable tether. However, these devices are not compatible with existing sensors and monitors, so caregivers and institutions will need to upgrade their wireless networks. It is therefore desirable to offer a communications adapter, which is compatible with existing sensors and monitors, and that replaces the patient’s cable wirelessly.

“A physiological measurement communications adapter is a device that allows for the reception of sensor signals. The transmitter modulates the first baseband signal that is responsive to the sensor signal to create a transmit signal. A receiver demodulates the receive signal that corresponds to the transmit signal in order to generate a second baseband sign. A monitor interface can also be configured to transmit a waveform to a sensor port on a monitor that is responsive to the second-baseband signal. The waveform is adaptable to the monitor so that measurements taken by the monitor using the waveform are equivalent to those derived from the sensor signal. A signal processor may be included in the communications adapter. This processor can operate to determine a parameter from the sensor signal. The first baseband signal will also be responsive to this parameter. The parameter could correspond to at most one of measured oxygen saturation or a pulse rate.

One embodiment could also include a waveform generator, which synthesizes waveforms from predetermined shapes. The waveform generator synthesizes a waveform at a frequency that is generally equal to the pulse rate. The waveform can have a first and second amplitude. The generator may adjust the amplitudes to ensure that the monitor’s measurements are equivalent to measured oxygen saturation.

“Another embodiment of the sensor interface can be used to generate a plethysmograph output signal from the sensor signal. The first baseband signal is responsive the the plethysmograph signals. The waveform modulator in this embodiment modifies the decoded signal that is responsive to the second-baseband signal to produce the waveform. A waveform modulator could include a demodulator, which separates a first and a secondary signal from the decoded signals, an amplifier that adjusts the amplitudes to generate a first adjusted and second signal, and a modator that combines both the first- and second adjusted signals into a waveform. The monitor and sensor may have predetermined calibration data that will affect the amplitudes and frequency of the first and second signals.

A physiological measurement communications adapter process includes the following steps: Input a sensor signal at patient location, transmit patient data between patient location and monitor location, construct a waveform at monitor location responsive to sensor signal and provide the waveform via a sensor port to a monitor. The waveform is designed so that the monitor can calculate a parameter which is generally equivalent to the measurement derivable by the sensor signal.

“In one embodiment, communication may include the substeps deriving a condition signal from the sensor signals, computing a parameter signal using the conditioned signal, then transmitting that parameter signal to the monitor location. The substep of synthesizing a waveform from the parameter signals may be included in the constructing step. Alternately, the communicating step could include the substeps that derivate a condition signal from said sensor signals and transmit the condition signal from the patient to the monitor location. The substeps of demodulating and remodulating the condition signal to create the waveform may be included in the constructing step. Substeps may include input of a monitor signal from the LED drive output of a sensor port, modulation of the waveform in response, and output of the waveform to a detector input of a sensor port.

A physiological measurement communications adapter also includes a sensor interface for inputting a signal and outputting it as a condition signal, a transmitter for transmitting data and a receiver for receiving that data. A waveform processor is used to construct a waveform using the data. This allows for measurements to be derived from the waveform by a monitor to be roughly equivalent to those derived from the sensor signal. A signal processor may be included in the communications adapter to deduce a parameter signal using the conditioned signal. The data must include the parameter signal. The waveform processor may include a method for synthesizing waveforms from the parameter signal. The data could include the conditioned signals, and the waveform processing means may be used to modulate the conditioned signals in response to the monitor.

“Overview”

“FIG. “FIG. FIGS. FIGS. 4-5 show physical configurations of a communications adapter. Particularly, FIGS. FIGS. 5A-C show configurations of monitor modules. FIGS. FIGS. 6-14 show communications adapter functions. Particularly, FIGS. FIGS. 6-7 show the general functions of a sensor module or a monitor module. FIGS. FIGS. 8-9 illustrate functionally a communications adapter in which derived pulse oxygen parameters such as saturation or pulse rate, are transmitted between a monitor module and a sensor module. Also, FIGS. FIGS. 10-12 show a communication adapter that transmits a plethysmograph between a sensor module, and a monitor module. FIGS. FIGS. 13-14 show a multi-parameter communication adapter functionally.

“FIG. 3. An illustration of a communications adapter 300 with a sensor module 400, and a monitor module 500. The communications adapter 300 transmits patient data from a sensor module 400 to the monitor module 500. This sensor module is located close to a patient 20. The wireless link 340 connects the sensor module 400 to the monitor module 500. It replaces the traditional patient cable 140, which is a pulse oximetry patient cabling 140 (FIG. 1). The sensor module 400 can be used in conjunction with the 310. The sensor connector 318 connects to sensor module 400 in the same way as a patient cable. The sensor module 400 outputs the drive signal to the sensor 318 and receives the sensor signal from the sensor 311. This is in a similar manner to a traditional monitor 360. The 400-watt sensor module can be either battery powered or externally charged. External power can be used to recharge internal batteries, power the module during operation, or both.

“As illustrated in FIG. 3. The monitor module 500 can be used with a standard monitor 360. The monitor module 500’s sensor port 362 is connected to the monitor module 500 in the same way as a patient cable (FIG. 1). The monitor module 500 also inputs a drive signals from the monitor 360, and outputs the corresponding sensor signal to that monitor 360 in the same manner as a traditional sensor 310. The combination sensor module 400 with monitor module 500 provides a plug-compatible wireless replacement to a patient cable. It adapts an existing wired physiological measuring system into a wireless one. The monitor module 500 can be powered by a battery, from the monitor, using current from the monitor’s LED drive or from an external AC or DC power source.

“A communications adapter 300 is described in this document with respect to a pulse-oximetry sensor. However, an ordinary skilled person will know that a communications connector may be used to provide a plug compatible wireless replacement for a patient cable. This adapter can connect any physiological sensor or monitor. A communications adapter 300 could be used to connect a biopotential sensor to non-invasive blood pressure sensors (NIBP), a respiratory rate sensor to measure glucose and the corresponding monitors.

“Sensor Module Physical Configurations”

“FIGS. 4A-B show physical embodiments for a sensor module 400. FIG. FIG. 4A shows a wrist-mounted module (410), which includes a strap 411, a case 412, and an auxiliary cable 442 The case 412 houses the electronic components of the sensor module electronics. These are described in detail with reference to FIG. 6, below. The case 412 attaches to the wrist strap 411 which connects the wrist-mounted module (410) to patient 20. A 420 auxiliary cable connects to a connector 318 and a connector 414. This provides a wired connection between a wrist-mounted module (410) and a conventional sensor. Alternativly, the auxiliary cables 420 can be directly connected to the sensor module 400. A display 415 may be included on the wrist-mounted module. This displays sensor status, sensor measurements, and other visual indicators such as monitor status. Keys (not shown), or other input mechanisms may be used to control the module’s operational mode and characteristics. Alternately, the sensor 310 could have a tail (not illustrated) that connects directly with the wrist-mounted module. This eliminates the need for the auxiliary cable.

“FIG. “FIG. Clip 461 attaches clip-on module460 to patient clothing and objects, such as a bed frame. The auxiliary connector 470 is a mate to the sensor connector 318, and performs the same functions as the auxiliary cables 420 (FIG. 4A) of wrist-mounted module (FIG. 4A, as described above. The clip-on module460 could have a display 463 or keys 464, as in the wrist-mounted module module 410 (FIG. 4A). 4A.

“Monitor Module Physical Configurations”

“FIGS. 5A-C show physical embodiments for a 500-watt monitor module. FIG. FIG. 5A shows a direct-connect module510 with a case 512, and integrated monitor connector 514. The monitor module electronics are contained in the case 512. These electronic components will be described functionally with reference to FIG. 7, below. The monitor connector 514 is similar to the monitor end of a patient cables, such as a pulse-oximetry patient cable 140 (FIG. 1) and connects the monitor module 514 to the monitor 360 via its sensor port 362 (electrically and mechanically).

“FIG. 5B shows a cable-connect Module 540 with a case 542, and an auxiliary Cable 550. The case 542 functions the same as the direct-connect module (FIG. 5A, described above. The cable-connect module540 is not wired directly to the monitor 360. Instead, it uses the auxiliary cable550. This mimics the monitor end a patient cable such as the pulse oximetry patient cables 140 (FIG. 1.) and connects the cable connector module 540 to monitor sensor port 362 by using an electrical connection.

“FIG. “FIG. The plug-in casing 572 is mechanically compatible to the multiparameter monitor’s plug-in chassis 370. It may or not be electrically connected to the chassis backplane. The auxiliary cable 580 is a replica of a patient cable. It electrically connects to the sensor port 372 on another plug-in device. Direct-connect module (FIG. 5A or a cable connector module 540 (FIG. 5B) can also be used in conjunction with a multiparameter display 370.

“In a multiparameter configuration, such as the one described in FIGS. 13-14, below, a single monitor module 500 can be connected to multiple plug-in devices on a multiparameter display 370. For example, a cable-connect module 540 (FIG. 5B may include multiple auxiliary cables (FIG.550). 5B) connects to multiple plug-in device installed within a multiparameter chassis. A plug-in module 570 could also have one or more auxiliary cable 580 with multiple connectors to attach to the sensor ports 372 and multiple plug-in devices.

“Communications Adapter Functions.”

“FIGS. FIGS. 6-7 show functional embodiments for a communications adapter. FIG. FIG. 6 shows a sensor module 400 with a sensor interface610, a signal processor630, an encoder640, a transmitter650, and a transmitting radio 670. An input sensor signal 612 is provided by a physiological sensor 310 at the sensor connector 313. The sensor module 400 can provide one or more drives signals 618 depending on the sensor. The sensor interface610 inputs the sensor signal 612 to generate a conditioned 614. The transmitter 650 may receive the conditioned signal 614, or it can be further processed by a signal processing 630. A signal processor 630 is used to generate a parameter signal 632 that responds to the sensor signal 612. This is then coupled with the transmitter 650. The transmitter 650 receives a baseband signal 642 which is responsive to the sensor signals 612. To generate a transmit signal 654, the transmitter 650 modifies the baseband signal 642 using a carrier. As is well-known in the art, there are many ways to generate the transmit signal 654: it can be generated using different amplitudes, frequencies, or phase modulation schemes. The transmit signal 654 is connected to the transmit antenna 670 which transmits wirelessly to a corresponding receiver antenna 770 (FIG. 7), as described below.”

“As shown at FIG. 6. The sensor interface 610 digitizes and conditions the sensor signal 612 in order to create the conditioned signal 614. The sensor signal conditioning can be done in either the analog or digital domains, or both. It may include filtering, buffering, and data rate modification in digital domain. The resulting conditioned signals 614 are responsive to the sensor signal 602 and can be used to calculate, or derive, a parameter signal 632.

“Further illustrated in FIG. 6. The signal processor 630 processes the conditioned signal 614 and generates the parameter signal 632. Signal processing can include smoothing, buffering, digital filtering or smoothing. The parameter signal 632 can be used to calculate or derive measurements from the conditioned signal. This includes oxygen saturation, pulse rate and blood glucose. The parameter signal 632 could also be an intermediate result that can be used to calculate or derive the previously mentioned measurements.

“The sensor interface 610, as described above, performs mixed analog-digit pre-processing on an analog sensor signal and then provides a digital out signal to the signal processing unit 630. The front-end processor output is then processed digitally by the signal processor 630. Alternate embodiments allow for the input sensor signal 612 or the output conditioned sign 614 to be analog or digital. The front-end processing can be purely or purely digital and the back-end may be purely or mixed digital or analog.

“In addition, FIG. FIG. 6 also shows an encoder 642, which converts a serial bit stream or digital word into baseband signal 642. This is well-known to the art. The baseband signal 642 is the symbol stream that drives transmit signal 654 modulation. It may be one signal or multiple related signal elements, such as quadrature and in-phase signals. Data compression and redundancy are also possible in encoder 640, which is well-known in this art.

“FIG. 7 shows a monitor module 500 with a receive antenna 710, a receiver 710 and a decoder 730. A monitor interface 750 is also included. The receive signal 712 is connected to the antenna 770. This provides wireless communications with a 670 corresponding transmit antenna (FIG. 6), as described above. The receiver 710 receives the 712-bit transmit signal, which corresponds with the FIG. 6). Receiver 710 demodulates the received signal to create a baseband signal 714. The decoder 710 converts the symbols from the demodulated baseband signals 714 to a decoded 724. This can be a digital word stream, bit stream, or digital word stream. The waveform processor 730 receives the decoded 724 signal and creates a constructed 732. Monitor interface 750 can transmit the constructed signal 732 from a monitor 360 to a sensor port 362. Monitor 360 may output a sensor driver signal 754, which is input by the monitor interface 754 to the waveform processor 730. This signal can be used as a monitor drive sign 734. The monitor drive signal 734 may be used by the waveform processor 730 to generate the constructed sign 732. The monitor interface 758 may also provide 758 characterization information to the waveform process 730. This information could relate to the monitor 360, sensor 310, or both.

“The constructed signal 732 has been adapted to monitor 360 to ensure that measurements derived from the built signal 732 by the monitor 360 are roughly equivalent to those derived from sensor signal 612 (FIG. 6). The sensor 310 (FIG. The monitor 360 may not be compatible with the sensor 310 (FIG. The sensor 310 (FIG. If the sensor 310 (FIG. 6). The sensor 310 (FIG. If the sensor 310 (FIG. 6) with a compatible monitor.

“Wireless Pulse Oximetry.”

“FIGS. 8-11 show embodiments of a communications connector that pulse oximeters. FIGS. FIGS. 8-9 show a sensor module as well as a monitor module that are configured to transmit measured pulse oximeter parameters. FIG. FIG. 10-11 shows a sensor module (or monitor module) that can communicate a plethysmograph signals.

“Parameter Transmission”

“FIG. 8 shows a pulse-oximetry sensor module 800 with a signal processor 830 and encoder 840. It also has a sensor interface 810 and a transmitter 850, transmitting an 870, and controller 890. As shown in FIG. 2, the sensor interface 810 and signal processor 830, as well as controller 890, work according to the following description. 2, above. The sensor interface 810 communicates to a standard pulseoximetry sensor 310. It provides an LED drive signal 818 for the LED emitters 312, and receives a sensor signal 812 back from the detector 314 as a response. The sensor interface 810 performs front-end processing for the sensor signal 812. It also provides a plethysmograph signals 814 to signal processor 830. The signal processor 830 then generates a parameter signal 832, which includes a real-time measurement of oxygen saturation as well as pulse rate. Other parameters may be included in the parameter signal 832, including measurements of signal quality and perfusion index. One embodiment of the signal processor uses an MS-5 or MS-7 board, which can be purchased from Masimo Corporation, Irvine (Calif.).

“As shown at FIG. “As shown in FIG. 8. The encoder 840 and transmitter 850 function as described in FIG. 6, above. The parameter signal 832 could be, for example, a digital word stream serialized into a bitstream and encoded into the baseband signal 842. For example, the baseband signal 842 could be two bit symbols that drive a quadrature Phase Shif Keyed (QPSK), modulator in transmitter 850. As mentioned above, there are many other encodings or modulations that can be used. The transmitter 850 receives the baseband signal 842, and generates a transmit message 854 which is a modulated carrier with a frequency that can be used for short-range transmissions, such as in a hospital, doctor’s office or emergency vehicle. The transmit signal 854 is connected to the transmit antenna 870 which allows wireless communication to a corresponding receiver antenna 970 (FIG. 9), as described below.”

“FIG. 9. illustrates a monitor 900 with a receiver 970, a receiver 920, and a waveform generator 930. An interface cable 950 is also included. As shown in FIG. 9, the receive antenna 970 and receiver 910, as well as decoder 9920, function according to the following: 7, above. The receive signal 912 is mainly coupled to the receive antenna 970. This provides wireless communications to the corresponding transmit antenna 870 (FIG. 8). The receiver 910 receives the 912 signal, which corresponds with the 854 transmit signal (FIG. 8). The receiver 810 modifies the receive signal 912 to produce a baseband signal 914. The baseband signal 914, which does not account for transmission errors (FIG. 8), which is a symbol stream with two bits each. The baseband signal 914 is converted by the decoder 920 into a parameter signal 924. This may include a sequence digital words that correspond to oxygen saturation or pulse rate. The monitor module parameter signals 924 and 832 correspond to each other, but this time transmission errors are not taken into account. 8), which is derived from the signal processor 830. (FIG. 8).”

“Also seen in FIG. “Also shown in FIG. 9 is the waveform generator 930, which is an embodiment of the waveform processor 730 (FIG. 7) as described above. The waveform generator 930 creates a synthesized 932 waveform that the pulse monitor 360 can process in order to calculate SpO2 or pulse rate values, or exception messages. The waveform generator output is not a physiological waveform in the present embodiment. The synthesized waveform, which is not physiological data from sensor module 800, is instead a waveform that is synthesized using predetermined waveform data. This allows the monitor 360 calculate oxygen saturation and pulse rate equal to, or generally equivalent (within the clinical significance) to the one calculated by signal processor 830 (FIG. 8). FIG. 314 shows the actual intensity signal received from the patient by the detector 314 (FIG. In the present embodiment, the monitor 360 is not provided with the intensity signal from the patient (FIG. The waveform that is provided to the monitor 360 does not usually resemble a plethysmographic or other physiological data of the patient for whom the sensor module 800 was attached (FIG. Attached is a number 8.

“The drive signal input 934 modulates the synthesized waveform 932. The pulse oximeter monitor360 expects to be able to detect a red or IR modulated intensity signal from a detector. 1-2, above. Waveform generator 930 creates the synthesized waves 932 according to a predetermined form, such as a triangular and sawtooth waveform that is stored in waveform memory or generated by a waveform generation algorithm. The drive input 934 modulates the waveform synchronously. The first and second amplitudes are used in the monitor 360 to process the red and IR portions. The frequency and second amplitudes of the pulse oximeter monitor360 are adjusted to make sure that the oxygen saturation and pulse rates are equivalent to those derived from the signal processor 830 (FIG. 8), as described above. U.S. Patent Application No. 930 describes one embodiment of a waveform generation generator 930. 60/117.097 is entitled “Universal/Upgrading pulse oximeter.” Masimo Corporation, Irvine (Calif.) was given this assignment and it is incorporated herein. The waveform generator 930 synthesizes a waveform that is not physiologically signal-like. However, one with ordinary skill will be able to recognize an alternative embodiment of the waveform generation 930.

“Further illustrated in FIG. 9 shows how the interface cable 95 functions in a similar way to the monitor interface (FIG. 7) as described above. Interface cable 950 can communicate the synthesized waveform 932 with the monitor 360 sensor port, and the sensor drive signal 934 with the waveform generator 930. Interface cable 950 may contain a ROM 960 which contains sensor characterization data. The waveform generator 930 reads the ROM 960 to adapt the synthesized waveform 932 to a specific monitor 360. The ROM 960 could contain data such as waveform amplitude, waveform shape information, and calibration data for red/IR versus oxygen saturation. U.S. Patent Application No. 60/117,092 describes an interface cable. 60/117,092 is referred to above. Monitor-specific SatShare? Masimo Corporation, Irvine (Calif.) offers brand interface cables. An alternative embodiment, such a direct-connect monitor module as illustrated at FIG. 5A: An interface cable 950 may not be used, and the ROM 960 can be incorporated into the monitor module 900.

“Plethysmograph Transmission”

“FIG. “FIG. 8, above. However, the encoder 1040 inputs a pulse rate measurement 832 and oxygen saturation signal 1014 to the plethysmograph. 8). According to this embodiment, the sensor module 1000 encodes and transmits a pulse rate signal 1014 to a corresponding module 1100 (FIG. 11) is in contrast to the derived physiological parameters such as oxygen saturation or pulse rate. FIG. 10 illustrates the plethysmograph signal 1004 FIG. 10 shows the plethysmograph signal 1014 as a direct output of the sensor interface 1010. Another embodiment of the sensor module 1000 includes a decimation process, not shown. This processor is used to produce a plethysmograph output 1014 with a lower sample rate.

“FIG. “FIG. 9, above. The monitor module embodiment 1100 has a waveform modator 1200 and not a generator 930 (FIG. 9), as described above. As shown in FIG. 9, the waveform modulator 1200 receives a plethysmograph signals from the decoder1120, rather than oxygen saturation or pulse rate measurements. 9, above. The waveform modulator 1200 also provides a modulated waveform 1132 to pulse oximeter monitor360, rather than a synthesized one, as shown in FIG. 9. Modulated waveform 1132 refers to a plethysmographic plethysmographic signal that has been modulated in accordance with the monitor drive signal input 1134. The waveform modulator 1200 doesn’t synthesize waveforms, but modifies the received signal from the plethysmograph 1124 to cause monitor 360 to calculate oxygen saturation (within clinical significance), and pulse rate generally equivalent to that calculated by compatible pulse oximeters directly from the sensor 1012 (FIG. 10). FIG. 12, below.”

“FIG. 12. shows a waveform moderator 1200 with a demodulator 1210 and an IR DAC (1230), a red amplifier (1240), an IR amplifier (1250), a modulator 1260 and a control 1270. A look-up table 1280 is also included. Waveform modulator 1200 can demodulate red and IR pletherysmographs (??pleths?) The decoder output 1124 is converted into a separate red pleth (1222) and IR pleth (1232). The waveform modulator 1200 adjusts the amplitudes in the pleths 1222 and 1232 using stored calibration curves. 10) and the monitor 360, (FIG. 11). The waveform modulator 1200 also re-modulates adjusted red pleth 1242, adjusted IR pleth 1202, and generates a modulated waveform 1132 for the monitor 360 (FIG. 11).”

“As shown at FIG. “As shown in FIG. 12, the demodulator 120 performs the above demodulation function, generating digital red pleth signals 1212 and 1214. The DACs 1220 and 1230 convert digital pleth signals 1212-14 to the corresponding analog pleth signal 1222, 1232. Amplifiers 1240, 1250 are equipped with variable gain control inputs 1262 and 1264. They perform the amplitude adjustment function, which generates adjusted red and IR signals 1242 and 1252. Modulator 1260 performs the above re-modulation function, by combining the adjusted red signal and the IR pleth signal 1242, 1252 in accordance with a control signal 1272. The control signal 1272 is generated by the modulator control 1270 synchronized with the LED drive signal(s), 1134 from monitor 360.

“Also seen in FIG. 12. The ratio calculator 1290 calculates a red/IR relationship from demodulator outputs 1212 and 1214. LUT 1280 contains empirical calibration data for sensor 310 (FIG. 10). The LUT1280 also downloads monitor-specific calibration information from the ROM 1160. (FIG. 11.) via the ROM out 1158. This calibration data allows the LUT 1280 to determine the desired red/IR ratio of the modulated waveform 1132. It then generates red and/or IR gain outputs 1262-1264 to the appropriate amplifiers 1240 and 1250. The monitor 360 can only determine a desired red/IR ratio if it is able to do so (FIG. 11) The monitor 360 can derive oxygen saturation measurements using the modulated waveform 1132. These are usually equivalent to those derived directly from the sensor signal (1012). (FIG. 10).”

“A person of ordinary skill in art will be able to recognize some of the signal processing operations described with regard to FIGS. 8-11 can be done either in a sensor module, or in a monitor module. The transmission bandwidth to a monitor modules may be reduced by signal processing functions within a sensor module. However, this can lead to increased module size and higher power consumption. Signal processing functions within a monitor modules may also reduce the size of sensor modules and power consumption, but at the expense of increasing transmission bandwidth.

“For example, a monitor module embodiment 900 (FIG. The 9) above measures pulse oximeter parameters such as oxygen saturation or pulse rate and produces a corresponding synthesized signal. The oxygen saturation and pulse rate calculations are done within the sensor module 800 (FIG. 8). FIG. 8 shows another embodiment of a monitor module 1100. 11), which is also described above, receives the plethysmograph signal and generates a modulated waveform. A sensor module 1000 (FIG.) performs minimal signal processing in this embodiment. 10). A sensor module can transmit a plethysmograph signal or a decimated, reduced-rate plethysmograph signal in another embodiment that is not shown. The signal processor of the corresponding monitor module is described in FIG. 8 and a waveform generator as described in FIG. 9. The signal processor calculates the pulse oximeter parameters, and the waveform generator generates the corresponding synthesized wavesform as described above. This embodiment uses minimal signal processing within the sensor module. The monitor module functions are performed using the monitored parameters.

“Wireless Multiple Parameter Measurements

“FIGS. 13-14 show a multi-parameter communications adapter. FIG. FIG. 13 shows a multi-parameter sensor module 1300 with sensor interfaces 1310 and one or more signal processing 1330. A multiplexer and encoder1340 is also included. A number of physiological sensors 1301 provide input signal signals 1312 to the sensor 1300. The controller 1390 may determine which sensors 1301 provide drive signals 1312 to the sensors 1300. The sensor interfaces 1310 receive the sensor signals 1312 from the controller 1390 and then output one or more condition signals 1314. The transmitter 1350 may then be connected to the conditioned signals 1314 or processed further by the signal processors1330. The sensor module configuration that utilizes signal processors 1330 can derive multiple parameter signals 1332 from the sensor signals 1312. These are then coupled with the transmitter 1350. The transmitter 1350 receives a baseband signal 1342 which is responsive to the sensor messages 1312. The transmitter 1350 modifies the baseband signal 1342 using a carrier to create a transmit signal 1354 that is coupled to the transmit antenna 1370 and communicated to the corresponding receive antenna 1470 (FIG. As described in FIG. 14, the transmitter 1350 modulates baseband signal 1342 with a carrier to generate a transmit signal 1354, which is coupled to the transmit antenna 1370 and communicated to corresponding receive antenna 1470 (FIG. 6, above. Alternately, multiple baseband signals 1342 may exist, and the transmitter 1350 could transmit on multiple frequency channels. Each channel receives data that is responsive to one or more sensor signals 1314.

“As shown at FIG. 13. The sensor interface 1310 conditions the sensor signals 1312 and digitizes them as described in FIG. 6, above. The sensor signals 1312 are then responsive to the resulting conditioned signal 1314. Signal processors 1330 process the conditioned signals 1314 and derive parameter signals1332. This is similar to what was described for a single condition signal in FIG. 6, above. Parameter signals 1332 can be physiological measures such as oxygen saturation and pulse rate, blood glucose, bloodpressure, blood pressure, EKG, respiration rates, body temperature, to name a few. They may also be intermediate results that may be used to calculate or derive the above-described measurements. Multiplexer and encoder 1340 combine multiple digital words or serial bit streams to create a single digital term or bit stream. As shown in FIG. 6, the multiplexer and encoder encodes the digital bit stream or word to create the baseband signal 1342. 6, above.”

“FIG. 14 shows a multiparameter monitor module 1400 with a receiver 1470, a demultiplexer 1420, decoder 1420 and one or more waveform processors 1405. The receiver 1410 receives the transmit signal 1354 from the transmitter and modifies it. 13) to create a baseband signal 1414, as described in FIG. 7, above. The demultiplexer/decoder 1420 separates symbol streams that correspond to multiple conditioned signals 1314 (FIG. 13) and/or the parameter signals 1332 (FIG. 13) and/or parameter signals 1332 (FIG. 7, above. Alternately, multiple frequency channels can be received to generate multiple baseband signal, which can then be decoded to produce multiple decoded signals 1422. Waveform processors 1430 receive the decoded signals and create multiple constructed signals 1432. This is similar to what we have described for a single signal in FIGS. 7-12, above. The monitor interface 1450 can communicate constructed signals 1432 to multiple parameter monitors 1401 and single parameter monitors in a similar way to the communication of one constructed signal as shown in FIGS. 7-12, above. The constructed signals 1432 have been adapted to the monitor 1401, so that the measurements derived from the built signals 1432 by the monitor 1401 are roughly equivalent to those derived directly from the sensor signal 1312 (FIG. 13).”

“A physiological measurement communication adapter” is described in this article with regard to wireless communications, and specifically radio frequency communications. However, a sensor module or monitor module can communicate with each other via wired communications such as telephone, Internet, and fiberoptic cable. Wireless communications can also use light frequencies such as IR and laser, to name a few.

“A physiological measurement communication adapter has been described in detail with respect to various embodiments. These embodiments are only examples. A person of ordinary skill in art will be able to appreciate many modifications and variations of a physiological communication adapter within the scope the claims.

Summary for “Body-worn mobile medical patient monitor”

“Patient vital signs monitoring may include measurements such as blood oxygen, blood pressure and respiratory gas. These physiological parameters require a sensor that is in direct contact with the patient and a cable to connect it to a monitor device. FIGS. FIGS. 1-2 show a conventional pulse-oximetry system 100 that is used to measure blood oxygen. FIG. FIG. 1 shows a pulse oximetry device that includes a sensor 110 and a patient cable 140 as well as a monitor 160. As shown, the sensor 110 is usually attached to a finger 10. The plug 118 of the sensor 110 can be inserted into a socket 142 for patient cables. The socket 162 on the monitor 160 accepts a patient-cable plug 144. The patient cable 140 transmits a LED drive signal 252 to the monitor 160 (FIG. 2) From the monitor 160 to sensor 110, a resulting detector sign 254 (FIG. 2) From the sensor 110 to monitor 160. Monitor 160 processes the detected signal 254 (FIG. 2) to provide, usually, a numerical reading of patient’s oxygen saturation and pulse rate as well as an audible indicator (or?beep?). This is done in response to each arterial pulse.

“As shown at FIG. 2 The sensor 110 includes both infrared and red LED emitters (212) and a photodiode detection (214). Monitor 160 includes a sensor interface 271, an output driver 276, a controller 273, and a signal processor 273. As is well-known, the monitor 160 calculates oxygen saturation by computing differential absorption by arterial blood for the two wavelengths emitted from the sensor emitters. The sensor interface 271 supplies LED drive current 252, which alternately activates IR and red LED emitters 212. The photodiode detector 214, generates a signal 254 that corresponds to the infrared and red light energy, attenuated by transmission through patient finger 10 (FIG. 1). The input circuitry of the sensor interface 271 allows for the amplification, filtering, and digitization 254 of the detected signal. Based on the ratio of red and infrared intensities detected, the signal processor 273 computes an arterial oxygen saturation value. The controller 275 is a hardware and software interface that manages the audible indicator 278, keypad 278, and display. The controller 275 provides hardware and software interfaces for managing the display and audible indicators 278 and keypad 279. The keypad 279 allows you to set alarm thresholds, enable alarms, and select display options.

The patient cable connection between the monitor and sensor limits conventional physiological measurement systems. The monitor must be in close proximity to the patient. Relocating a patient requires disconnection of the monitoring equipment, resulting in a loss of measurements and/or awkward simultaneous movements of cables and equipment. Many devices have been developed or implemented to allow wireless communication between monitors and sensors, which frees patients from the patient’s cable tether. However, these devices are not compatible with existing sensors and monitors, so caregivers and institutions will need to upgrade their wireless networks. It is therefore desirable to offer a communications adapter, which is compatible with existing sensors and monitors, and that replaces the patient’s cable wirelessly.

“A physiological measurement communications adapter is a device that allows for the reception of sensor signals. The transmitter modulates the first baseband signal that is responsive to the sensor signal to create a transmit signal. A receiver demodulates the receive signal that corresponds to the transmit signal in order to generate a second baseband sign. A monitor interface can also be configured to transmit a waveform to a sensor port on a monitor that is responsive to the second-baseband signal. The waveform is adaptable to the monitor so that measurements taken by the monitor using the waveform are equivalent to those derived from the sensor signal. A signal processor may be included in the communications adapter. This processor can operate to determine a parameter from the sensor signal. The first baseband signal will also be responsive to this parameter. The parameter could correspond to at most one of measured oxygen saturation or a pulse rate.

One embodiment could also include a waveform generator, which synthesizes waveforms from predetermined shapes. The waveform generator synthesizes a waveform at a frequency that is generally equal to the pulse rate. The waveform can have a first and second amplitude. The generator may adjust the amplitudes to ensure that the monitor’s measurements are equivalent to measured oxygen saturation.

“Another embodiment of the sensor interface can be used to generate a plethysmograph output signal from the sensor signal. The first baseband signal is responsive the the plethysmograph signals. The waveform modulator in this embodiment modifies the decoded signal that is responsive to the second-baseband signal to produce the waveform. A waveform modulator could include a demodulator, which separates a first and a secondary signal from the decoded signals, an amplifier that adjusts the amplitudes to generate a first adjusted and second signal, and a modator that combines both the first- and second adjusted signals into a waveform. The monitor and sensor may have predetermined calibration data that will affect the amplitudes and frequency of the first and second signals.

A physiological measurement communications adapter process includes the following steps: Input a sensor signal at patient location, transmit patient data between patient location and monitor location, construct a waveform at monitor location responsive to sensor signal and provide the waveform via a sensor port to a monitor. The waveform is designed so that the monitor can calculate a parameter which is generally equivalent to the measurement derivable by the sensor signal.

“In one embodiment, communication may include the substeps deriving a condition signal from the sensor signals, computing a parameter signal using the conditioned signal, then transmitting that parameter signal to the monitor location. The substep of synthesizing a waveform from the parameter signals may be included in the constructing step. Alternately, the communicating step could include the substeps that derivate a condition signal from said sensor signals and transmit the condition signal from the patient to the monitor location. The substeps of demodulating and remodulating the condition signal to create the waveform may be included in the constructing step. Substeps may include input of a monitor signal from the LED drive output of a sensor port, modulation of the waveform in response, and output of the waveform to a detector input of a sensor port.

A physiological measurement communications adapter also includes a sensor interface for inputting a signal and outputting it as a condition signal, a transmitter for transmitting data and a receiver for receiving that data. A waveform processor is used to construct a waveform using the data. This allows for measurements to be derived from the waveform by a monitor to be roughly equivalent to those derived from the sensor signal. A signal processor may be included in the communications adapter to deduce a parameter signal using the conditioned signal. The data must include the parameter signal. The waveform processor may include a method for synthesizing waveforms from the parameter signal. The data could include the conditioned signals, and the waveform processing means may be used to modulate the conditioned signals in response to the monitor.

“Overview”

“FIG. “FIG. FIGS. FIGS. 4-5 show physical configurations of a communications adapter. Particularly, FIGS. FIGS. 5A-C show configurations of monitor modules. FIGS. FIGS. 6-14 show communications adapter functions. Particularly, FIGS. FIGS. 6-7 show the general functions of a sensor module or a monitor module. FIGS. FIGS. 8-9 illustrate functionally a communications adapter in which derived pulse oxygen parameters such as saturation or pulse rate, are transmitted between a monitor module and a sensor module. Also, FIGS. FIGS. 10-12 show a communication adapter that transmits a plethysmograph between a sensor module, and a monitor module. FIGS. FIGS. 13-14 show a multi-parameter communication adapter functionally.

“FIG. 3. An illustration of a communications adapter 300 with a sensor module 400, and a monitor module 500. The communications adapter 300 transmits patient data from a sensor module 400 to the monitor module 500. This sensor module is located close to a patient 20. The wireless link 340 connects the sensor module 400 to the monitor module 500. It replaces the traditional patient cable 140, which is a pulse oximetry patient cabling 140 (FIG. 1). The sensor module 400 can be used in conjunction with the 310. The sensor connector 318 connects to sensor module 400 in the same way as a patient cable. The sensor module 400 outputs the drive signal to the sensor 318 and receives the sensor signal from the sensor 311. This is in a similar manner to a traditional monitor 360. The 400-watt sensor module can be either battery powered or externally charged. External power can be used to recharge internal batteries, power the module during operation, or both.

“As illustrated in FIG. 3. The monitor module 500 can be used with a standard monitor 360. The monitor module 500’s sensor port 362 is connected to the monitor module 500 in the same way as a patient cable (FIG. 1). The monitor module 500 also inputs a drive signals from the monitor 360, and outputs the corresponding sensor signal to that monitor 360 in the same manner as a traditional sensor 310. The combination sensor module 400 with monitor module 500 provides a plug-compatible wireless replacement to a patient cable. It adapts an existing wired physiological measuring system into a wireless one. The monitor module 500 can be powered by a battery, from the monitor, using current from the monitor’s LED drive or from an external AC or DC power source.

“A communications adapter 300 is described in this document with respect to a pulse-oximetry sensor. However, an ordinary skilled person will know that a communications connector may be used to provide a plug compatible wireless replacement for a patient cable. This adapter can connect any physiological sensor or monitor. A communications adapter 300 could be used to connect a biopotential sensor to non-invasive blood pressure sensors (NIBP), a respiratory rate sensor to measure glucose and the corresponding monitors.

“Sensor Module Physical Configurations”

“FIGS. 4A-B show physical embodiments for a sensor module 400. FIG. FIG. 4A shows a wrist-mounted module (410), which includes a strap 411, a case 412, and an auxiliary cable 442 The case 412 houses the electronic components of the sensor module electronics. These are described in detail with reference to FIG. 6, below. The case 412 attaches to the wrist strap 411 which connects the wrist-mounted module (410) to patient 20. A 420 auxiliary cable connects to a connector 318 and a connector 414. This provides a wired connection between a wrist-mounted module (410) and a conventional sensor. Alternativly, the auxiliary cables 420 can be directly connected to the sensor module 400. A display 415 may be included on the wrist-mounted module. This displays sensor status, sensor measurements, and other visual indicators such as monitor status. Keys (not shown), or other input mechanisms may be used to control the module’s operational mode and characteristics. Alternately, the sensor 310 could have a tail (not illustrated) that connects directly with the wrist-mounted module. This eliminates the need for the auxiliary cable.

“FIG. “FIG. Clip 461 attaches clip-on module460 to patient clothing and objects, such as a bed frame. The auxiliary connector 470 is a mate to the sensor connector 318, and performs the same functions as the auxiliary cables 420 (FIG. 4A) of wrist-mounted module (FIG. 4A, as described above. The clip-on module460 could have a display 463 or keys 464, as in the wrist-mounted module module 410 (FIG. 4A). 4A.

“Monitor Module Physical Configurations”

“FIGS. 5A-C show physical embodiments for a 500-watt monitor module. FIG. FIG. 5A shows a direct-connect module510 with a case 512, and integrated monitor connector 514. The monitor module electronics are contained in the case 512. These electronic components will be described functionally with reference to FIG. 7, below. The monitor connector 514 is similar to the monitor end of a patient cables, such as a pulse-oximetry patient cable 140 (FIG. 1) and connects the monitor module 514 to the monitor 360 via its sensor port 362 (electrically and mechanically).

“FIG. 5B shows a cable-connect Module 540 with a case 542, and an auxiliary Cable 550. The case 542 functions the same as the direct-connect module (FIG. 5A, described above. The cable-connect module540 is not wired directly to the monitor 360. Instead, it uses the auxiliary cable550. This mimics the monitor end a patient cable such as the pulse oximetry patient cables 140 (FIG. 1.) and connects the cable connector module 540 to monitor sensor port 362 by using an electrical connection.

“FIG. “FIG. The plug-in casing 572 is mechanically compatible to the multiparameter monitor’s plug-in chassis 370. It may or not be electrically connected to the chassis backplane. The auxiliary cable 580 is a replica of a patient cable. It electrically connects to the sensor port 372 on another plug-in device. Direct-connect module (FIG. 5A or a cable connector module 540 (FIG. 5B) can also be used in conjunction with a multiparameter display 370.

“In a multiparameter configuration, such as the one described in FIGS. 13-14, below, a single monitor module 500 can be connected to multiple plug-in devices on a multiparameter display 370. For example, a cable-connect module 540 (FIG. 5B may include multiple auxiliary cables (FIG.550). 5B) connects to multiple plug-in device installed within a multiparameter chassis. A plug-in module 570 could also have one or more auxiliary cable 580 with multiple connectors to attach to the sensor ports 372 and multiple plug-in devices.

“Communications Adapter Functions.”

“FIGS. FIGS. 6-7 show functional embodiments for a communications adapter. FIG. FIG. 6 shows a sensor module 400 with a sensor interface610, a signal processor630, an encoder640, a transmitter650, and a transmitting radio 670. An input sensor signal 612 is provided by a physiological sensor 310 at the sensor connector 313. The sensor module 400 can provide one or more drives signals 618 depending on the sensor. The sensor interface610 inputs the sensor signal 612 to generate a conditioned 614. The transmitter 650 may receive the conditioned signal 614, or it can be further processed by a signal processing 630. A signal processor 630 is used to generate a parameter signal 632 that responds to the sensor signal 612. This is then coupled with the transmitter 650. The transmitter 650 receives a baseband signal 642 which is responsive to the sensor signals 612. To generate a transmit signal 654, the transmitter 650 modifies the baseband signal 642 using a carrier. As is well-known in the art, there are many ways to generate the transmit signal 654: it can be generated using different amplitudes, frequencies, or phase modulation schemes. The transmit signal 654 is connected to the transmit antenna 670 which transmits wirelessly to a corresponding receiver antenna 770 (FIG. 7), as described below.”

“As shown at FIG. 6. The sensor interface 610 digitizes and conditions the sensor signal 612 in order to create the conditioned signal 614. The sensor signal conditioning can be done in either the analog or digital domains, or both. It may include filtering, buffering, and data rate modification in digital domain. The resulting conditioned signals 614 are responsive to the sensor signal 602 and can be used to calculate, or derive, a parameter signal 632.

“Further illustrated in FIG. 6. The signal processor 630 processes the conditioned signal 614 and generates the parameter signal 632. Signal processing can include smoothing, buffering, digital filtering or smoothing. The parameter signal 632 can be used to calculate or derive measurements from the conditioned signal. This includes oxygen saturation, pulse rate and blood glucose. The parameter signal 632 could also be an intermediate result that can be used to calculate or derive the previously mentioned measurements.

“The sensor interface 610, as described above, performs mixed analog-digit pre-processing on an analog sensor signal and then provides a digital out signal to the signal processing unit 630. The front-end processor output is then processed digitally by the signal processor 630. Alternate embodiments allow for the input sensor signal 612 or the output conditioned sign 614 to be analog or digital. The front-end processing can be purely or purely digital and the back-end may be purely or mixed digital or analog.

“In addition, FIG. FIG. 6 also shows an encoder 642, which converts a serial bit stream or digital word into baseband signal 642. This is well-known to the art. The baseband signal 642 is the symbol stream that drives transmit signal 654 modulation. It may be one signal or multiple related signal elements, such as quadrature and in-phase signals. Data compression and redundancy are also possible in encoder 640, which is well-known in this art.

“FIG. 7 shows a monitor module 500 with a receive antenna 710, a receiver 710 and a decoder 730. A monitor interface 750 is also included. The receive signal 712 is connected to the antenna 770. This provides wireless communications with a 670 corresponding transmit antenna (FIG. 6), as described above. The receiver 710 receives the 712-bit transmit signal, which corresponds with the FIG. 6). Receiver 710 demodulates the received signal to create a baseband signal 714. The decoder 710 converts the symbols from the demodulated baseband signals 714 to a decoded 724. This can be a digital word stream, bit stream, or digital word stream. The waveform processor 730 receives the decoded 724 signal and creates a constructed 732. Monitor interface 750 can transmit the constructed signal 732 from a monitor 360 to a sensor port 362. Monitor 360 may output a sensor driver signal 754, which is input by the monitor interface 754 to the waveform processor 730. This signal can be used as a monitor drive sign 734. The monitor drive signal 734 may be used by the waveform processor 730 to generate the constructed sign 732. The monitor interface 758 may also provide 758 characterization information to the waveform process 730. This information could relate to the monitor 360, sensor 310, or both.

“The constructed signal 732 has been adapted to monitor 360 to ensure that measurements derived from the built signal 732 by the monitor 360 are roughly equivalent to those derived from sensor signal 612 (FIG. 6). The sensor 310 (FIG. The monitor 360 may not be compatible with the sensor 310 (FIG. The sensor 310 (FIG. If the sensor 310 (FIG. 6). The sensor 310 (FIG. If the sensor 310 (FIG. 6) with a compatible monitor.

“Wireless Pulse Oximetry.”

“FIGS. 8-11 show embodiments of a communications connector that pulse oximeters. FIGS. FIGS. 8-9 show a sensor module as well as a monitor module that are configured to transmit measured pulse oximeter parameters. FIG. FIG. 10-11 shows a sensor module (or monitor module) that can communicate a plethysmograph signals.

“Parameter Transmission”

“FIG. 8 shows a pulse-oximetry sensor module 800 with a signal processor 830 and encoder 840. It also has a sensor interface 810 and a transmitter 850, transmitting an 870, and controller 890. As shown in FIG. 2, the sensor interface 810 and signal processor 830, as well as controller 890, work according to the following description. 2, above. The sensor interface 810 communicates to a standard pulseoximetry sensor 310. It provides an LED drive signal 818 for the LED emitters 312, and receives a sensor signal 812 back from the detector 314 as a response. The sensor interface 810 performs front-end processing for the sensor signal 812. It also provides a plethysmograph signals 814 to signal processor 830. The signal processor 830 then generates a parameter signal 832, which includes a real-time measurement of oxygen saturation as well as pulse rate. Other parameters may be included in the parameter signal 832, including measurements of signal quality and perfusion index. One embodiment of the signal processor uses an MS-5 or MS-7 board, which can be purchased from Masimo Corporation, Irvine (Calif.).

“As shown at FIG. “As shown in FIG. 8. The encoder 840 and transmitter 850 function as described in FIG. 6, above. The parameter signal 832 could be, for example, a digital word stream serialized into a bitstream and encoded into the baseband signal 842. For example, the baseband signal 842 could be two bit symbols that drive a quadrature Phase Shif Keyed (QPSK), modulator in transmitter 850. As mentioned above, there are many other encodings or modulations that can be used. The transmitter 850 receives the baseband signal 842, and generates a transmit message 854 which is a modulated carrier with a frequency that can be used for short-range transmissions, such as in a hospital, doctor’s office or emergency vehicle. The transmit signal 854 is connected to the transmit antenna 870 which allows wireless communication to a corresponding receiver antenna 970 (FIG. 9), as described below.”

“FIG. 9. illustrates a monitor 900 with a receiver 970, a receiver 920, and a waveform generator 930. An interface cable 950 is also included. As shown in FIG. 9, the receive antenna 970 and receiver 910, as well as decoder 9920, function according to the following: 7, above. The receive signal 912 is mainly coupled to the receive antenna 970. This provides wireless communications to the corresponding transmit antenna 870 (FIG. 8). The receiver 910 receives the 912 signal, which corresponds with the 854 transmit signal (FIG. 8). The receiver 810 modifies the receive signal 912 to produce a baseband signal 914. The baseband signal 914, which does not account for transmission errors (FIG. 8), which is a symbol stream with two bits each. The baseband signal 914 is converted by the decoder 920 into a parameter signal 924. This may include a sequence digital words that correspond to oxygen saturation or pulse rate. The monitor module parameter signals 924 and 832 correspond to each other, but this time transmission errors are not taken into account. 8), which is derived from the signal processor 830. (FIG. 8).”

“Also seen in FIG. “Also shown in FIG. 9 is the waveform generator 930, which is an embodiment of the waveform processor 730 (FIG. 7) as described above. The waveform generator 930 creates a synthesized 932 waveform that the pulse monitor 360 can process in order to calculate SpO2 or pulse rate values, or exception messages. The waveform generator output is not a physiological waveform in the present embodiment. The synthesized waveform, which is not physiological data from sensor module 800, is instead a waveform that is synthesized using predetermined waveform data. This allows the monitor 360 calculate oxygen saturation and pulse rate equal to, or generally equivalent (within the clinical significance) to the one calculated by signal processor 830 (FIG. 8). FIG. 314 shows the actual intensity signal received from the patient by the detector 314 (FIG. In the present embodiment, the monitor 360 is not provided with the intensity signal from the patient (FIG. The waveform that is provided to the monitor 360 does not usually resemble a plethysmographic or other physiological data of the patient for whom the sensor module 800 was attached (FIG. Attached is a number 8.

“The drive signal input 934 modulates the synthesized waveform 932. The pulse oximeter monitor360 expects to be able to detect a red or IR modulated intensity signal from a detector. 1-2, above. Waveform generator 930 creates the synthesized waves 932 according to a predetermined form, such as a triangular and sawtooth waveform that is stored in waveform memory or generated by a waveform generation algorithm. The drive input 934 modulates the waveform synchronously. The first and second amplitudes are used in the monitor 360 to process the red and IR portions. The frequency and second amplitudes of the pulse oximeter monitor360 are adjusted to make sure that the oxygen saturation and pulse rates are equivalent to those derived from the signal processor 830 (FIG. 8), as described above. U.S. Patent Application No. 930 describes one embodiment of a waveform generation generator 930. 60/117.097 is entitled “Universal/Upgrading pulse oximeter.” Masimo Corporation, Irvine (Calif.) was given this assignment and it is incorporated herein. The waveform generator 930 synthesizes a waveform that is not physiologically signal-like. However, one with ordinary skill will be able to recognize an alternative embodiment of the waveform generation 930.

“Further illustrated in FIG. 9 shows how the interface cable 95 functions in a similar way to the monitor interface (FIG. 7) as described above. Interface cable 950 can communicate the synthesized waveform 932 with the monitor 360 sensor port, and the sensor drive signal 934 with the waveform generator 930. Interface cable 950 may contain a ROM 960 which contains sensor characterization data. The waveform generator 930 reads the ROM 960 to adapt the synthesized waveform 932 to a specific monitor 360. The ROM 960 could contain data such as waveform amplitude, waveform shape information, and calibration data for red/IR versus oxygen saturation. U.S. Patent Application No. 60/117,092 describes an interface cable. 60/117,092 is referred to above. Monitor-specific SatShare? Masimo Corporation, Irvine (Calif.) offers brand interface cables. An alternative embodiment, such a direct-connect monitor module as illustrated at FIG. 5A: An interface cable 950 may not be used, and the ROM 960 can be incorporated into the monitor module 900.

“Plethysmograph Transmission”

“FIG. “FIG. 8, above. However, the encoder 1040 inputs a pulse rate measurement 832 and oxygen saturation signal 1014 to the plethysmograph. 8). According to this embodiment, the sensor module 1000 encodes and transmits a pulse rate signal 1014 to a corresponding module 1100 (FIG. 11) is in contrast to the derived physiological parameters such as oxygen saturation or pulse rate. FIG. 10 illustrates the plethysmograph signal 1004 FIG. 10 shows the plethysmograph signal 1014 as a direct output of the sensor interface 1010. Another embodiment of the sensor module 1000 includes a decimation process, not shown. This processor is used to produce a plethysmograph output 1014 with a lower sample rate.

“FIG. “FIG. 9, above. The monitor module embodiment 1100 has a waveform modator 1200 and not a generator 930 (FIG. 9), as described above. As shown in FIG. 9, the waveform modulator 1200 receives a plethysmograph signals from the decoder1120, rather than oxygen saturation or pulse rate measurements. 9, above. The waveform modulator 1200 also provides a modulated waveform 1132 to pulse oximeter monitor360, rather than a synthesized one, as shown in FIG. 9. Modulated waveform 1132 refers to a plethysmographic plethysmographic signal that has been modulated in accordance with the monitor drive signal input 1134. The waveform modulator 1200 doesn’t synthesize waveforms, but modifies the received signal from the plethysmograph 1124 to cause monitor 360 to calculate oxygen saturation (within clinical significance), and pulse rate generally equivalent to that calculated by compatible pulse oximeters directly from the sensor 1012 (FIG. 10). FIG. 12, below.”

“FIG. 12. shows a waveform moderator 1200 with a demodulator 1210 and an IR DAC (1230), a red amplifier (1240), an IR amplifier (1250), a modulator 1260 and a control 1270. A look-up table 1280 is also included. Waveform modulator 1200 can demodulate red and IR pletherysmographs (??pleths?) The decoder output 1124 is converted into a separate red pleth (1222) and IR pleth (1232). The waveform modulator 1200 adjusts the amplitudes in the pleths 1222 and 1232 using stored calibration curves. 10) and the monitor 360, (FIG. 11). The waveform modulator 1200 also re-modulates adjusted red pleth 1242, adjusted IR pleth 1202, and generates a modulated waveform 1132 for the monitor 360 (FIG. 11).”

“As shown at FIG. “As shown in FIG. 12, the demodulator 120 performs the above demodulation function, generating digital red pleth signals 1212 and 1214. The DACs 1220 and 1230 convert digital pleth signals 1212-14 to the corresponding analog pleth signal 1222, 1232. Amplifiers 1240, 1250 are equipped with variable gain control inputs 1262 and 1264. They perform the amplitude adjustment function, which generates adjusted red and IR signals 1242 and 1252. Modulator 1260 performs the above re-modulation function, by combining the adjusted red signal and the IR pleth signal 1242, 1252 in accordance with a control signal 1272. The control signal 1272 is generated by the modulator control 1270 synchronized with the LED drive signal(s), 1134 from monitor 360.

“Also seen in FIG. 12. The ratio calculator 1290 calculates a red/IR relationship from demodulator outputs 1212 and 1214. LUT 1280 contains empirical calibration data for sensor 310 (FIG. 10). The LUT1280 also downloads monitor-specific calibration information from the ROM 1160. (FIG. 11.) via the ROM out 1158. This calibration data allows the LUT 1280 to determine the desired red/IR ratio of the modulated waveform 1132. It then generates red and/or IR gain outputs 1262-1264 to the appropriate amplifiers 1240 and 1250. The monitor 360 can only determine a desired red/IR ratio if it is able to do so (FIG. 11) The monitor 360 can derive oxygen saturation measurements using the modulated waveform 1132. These are usually equivalent to those derived directly from the sensor signal (1012). (FIG. 10).”

“A person of ordinary skill in art will be able to recognize some of the signal processing operations described with regard to FIGS. 8-11 can be done either in a sensor module, or in a monitor module. The transmission bandwidth to a monitor modules may be reduced by signal processing functions within a sensor module. However, this can lead to increased module size and higher power consumption. Signal processing functions within a monitor modules may also reduce the size of sensor modules and power consumption, but at the expense of increasing transmission bandwidth.

“For example, a monitor module embodiment 900 (FIG. The 9) above measures pulse oximeter parameters such as oxygen saturation or pulse rate and produces a corresponding synthesized signal. The oxygen saturation and pulse rate calculations are done within the sensor module 800 (FIG. 8). FIG. 8 shows another embodiment of a monitor module 1100. 11), which is also described above, receives the plethysmograph signal and generates a modulated waveform. A sensor module 1000 (FIG.) performs minimal signal processing in this embodiment. 10). A sensor module can transmit a plethysmograph signal or a decimated, reduced-rate plethysmograph signal in another embodiment that is not shown. The signal processor of the corresponding monitor module is described in FIG. 8 and a waveform generator as described in FIG. 9. The signal processor calculates the pulse oximeter parameters, and the waveform generator generates the corresponding synthesized wavesform as described above. This embodiment uses minimal signal processing within the sensor module. The monitor module functions are performed using the monitored parameters.

“Wireless Multiple Parameter Measurements

“FIGS. 13-14 show a multi-parameter communications adapter. FIG. FIG. 13 shows a multi-parameter sensor module 1300 with sensor interfaces 1310 and one or more signal processing 1330. A multiplexer and encoder1340 is also included. A number of physiological sensors 1301 provide input signal signals 1312 to the sensor 1300. The controller 1390 may determine which sensors 1301 provide drive signals 1312 to the sensors 1300. The sensor interfaces 1310 receive the sensor signals 1312 from the controller 1390 and then output one or more condition signals 1314. The transmitter 1350 may then be connected to the conditioned signals 1314 or processed further by the signal processors1330. The sensor module configuration that utilizes signal processors 1330 can derive multiple parameter signals 1332 from the sensor signals 1312. These are then coupled with the transmitter 1350. The transmitter 1350 receives a baseband signal 1342 which is responsive to the sensor messages 1312. The transmitter 1350 modifies the baseband signal 1342 using a carrier to create a transmit signal 1354 that is coupled to the transmit antenna 1370 and communicated to the corresponding receive antenna 1470 (FIG. As described in FIG. 14, the transmitter 1350 modulates baseband signal 1342 with a carrier to generate a transmit signal 1354, which is coupled to the transmit antenna 1370 and communicated to corresponding receive antenna 1470 (FIG. 6, above. Alternately, multiple baseband signals 1342 may exist, and the transmitter 1350 could transmit on multiple frequency channels. Each channel receives data that is responsive to one or more sensor signals 1314.

“As shown at FIG. 13. The sensor interface 1310 conditions the sensor signals 1312 and digitizes them as described in FIG. 6, above. The sensor signals 1312 are then responsive to the resulting conditioned signal 1314. Signal processors 1330 process the conditioned signals 1314 and derive parameter signals1332. This is similar to what was described for a single condition signal in FIG. 6, above. Parameter signals 1332 can be physiological measures such as oxygen saturation and pulse rate, blood glucose, bloodpressure, blood pressure, EKG, respiration rates, body temperature, to name a few. They may also be intermediate results that may be used to calculate or derive the above-described measurements. Multiplexer and encoder 1340 combine multiple digital words or serial bit streams to create a single digital term or bit stream. As shown in FIG. 6, the multiplexer and encoder encodes the digital bit stream or word to create the baseband signal 1342. 6, above.”

“FIG. 14 shows a multiparameter monitor module 1400 with a receiver 1470, a demultiplexer 1420, decoder 1420 and one or more waveform processors 1405. The receiver 1410 receives the transmit signal 1354 from the transmitter and modifies it. 13) to create a baseband signal 1414, as described in FIG. 7, above. The demultiplexer/decoder 1420 separates symbol streams that correspond to multiple conditioned signals 1314 (FIG. 13) and/or the parameter signals 1332 (FIG. 13) and/or parameter signals 1332 (FIG. 7, above. Alternately, multiple frequency channels can be received to generate multiple baseband signal, which can then be decoded to produce multiple decoded signals 1422. Waveform processors 1430 receive the decoded signals and create multiple constructed signals 1432. This is similar to what we have described for a single signal in FIGS. 7-12, above. The monitor interface 1450 can communicate constructed signals 1432 to multiple parameter monitors 1401 and single parameter monitors in a similar way to the communication of one constructed signal as shown in FIGS. 7-12, above. The constructed signals 1432 have been adapted to the monitor 1401, so that the measurements derived from the built signals 1432 by the monitor 1401 are roughly equivalent to those derived directly from the sensor signal 1312 (FIG. 13).”

“A physiological measurement communication adapter” is described in this article with regard to wireless communications, and specifically radio frequency communications. However, a sensor module or monitor module can communicate with each other via wired communications such as telephone, Internet, and fiberoptic cable. Wireless communications can also use light frequencies such as IR and laser, to name a few.

“A physiological measurement communication adapter has been described in detail with respect to various embodiments. These embodiments are only examples. A person of ordinary skill in art will be able to appreciate many modifications and variations of a physiological communication adapter within the scope the claims.

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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.