EP4236786A2

EP4236786A2 - Wireless system for medical device triggering

Info

Publication number: EP4236786A2
Application number: EP21805863.4A
Authority: EP
Inventors: Georgios Kokovidis
Original assignee: Draegerwerk AG and Co KGaA
Current assignee: Draegerwerk AG and Co KGaA
Priority date: 2020-10-29
Filing date: 2021-10-28
Publication date: 2023-09-06
Also published as: WO2022090369A3; WO2022090369A2; CN116437858A

Abstract

A ventilator communication system includes an electromyography ("EMG") device including EMG electrodes configured to generate electrical signals based on muscular respiratory activity of the patient, and a ventilator. The EMG device is configured to generate a patient respiratory effort waveform based on the electrical signals and analyze the patient respiratory effort waveform. The EMG device includes a first near-field magnetic induction ("NFMI") transceiver configured to generate at least one transmission signal derived from the analysis of the patient respiratory effort waveform and transmit the at least one transmission signal on at least one NFMI communication channel. The ventilator is configured to provide breathing assistance to the patient, wherein the ventilator includes a second NFMI transceiver configured to receive the at least one transmission signal from the EMG device and a controller configured to adjust the breathing assistance provided to the patient based on the at least one transmission signal.

Description

WIRELESS SYSTEM FOR MEDICAL DEVICE TRIGGERING

RELATED APPLICATIONS

[0001] This document claims the priority of U.S. Application Serial No. 63/106,932, filed October 29, 2020, filed in the name of Georgios Kokovidis and titled “Wireless Medical Device Trigger”, the content of which is hereby incorporated by reference for all purposes, including the right for priority, as if set forth verbatim herein.

TECHNICAL FIELD

[0002] The present disclosure generally pertains to medical device utilization for patient care and, more particularly, to a wireless system for medical device triggering.

BACKGROUND

[0003] In a clinical environment, various physiological sensors are typically coupled to a patient. Some of these sensors provide time-critical data to lifesustaining medical devices. Sensors may be coupled to life-sustaining devices via low-latency physical connection (e.g. , wires). However, improved connections that retain the low-latency of physical connections and present less clutter, less restrictions on patient movement, and are more robust to disruption are desirable.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Illustrative embodiments of the subject matter claimed below will now be disclosed. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort, even if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0005] FIG. 1 illustrates a system for triggering a medical device via a physiological sensor device according to one or more embodiments.

[0006] FIG. 2 illustrates a system for triggering a medical device by a surface electromyography (“sEMG”) module via a near-field magnetic induction (“NFMI”) communications link according to one or more embodiments.

[0007] FIG. 3 illustrates the magnetic field coupling associated with the NFMI communications technology utilized in one or more embodiments.

[0008] FIG. 4 illustrates performance of various placements of a receiver coil relative to a transmitter coil according to one or more embodiments.

[0009] While the invention is susceptible to various modifications and alternative forms, the drawings illustrate specific examples herein described in detail by way of example. It should be understood, however, that the description herein of specific examples is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

[0010] Embodiments provide a low-latency wireless communication link used to trigger a medical device based on physiological sensor data.

[0011] Embodiments are discussed below in the context of near-field magnetic induction (“NFMI”) communications used to activate or otherwise trigger a ventilator to operate in order to provide enhanced life-sustaining treatment or medical assistance to a patient. Other implementations and uses are also possible. That is, while the present systems are described with respect to a ventilator, other medical devices (e.g., patient monitors or anesthesia machines) could also be implemented in addition to, or in place of, place of the ventilator.

[0012] Some advantages of the use of NFMI wireless communications are its high interference rejection capability, privacy of the NFMI communications at short distances, and the ability of the transmissions to pass through a patient’s body with little degradation in signal integrity. NFMI is a short-range radio technology that is well-suited for low latency data streaming applications NFMI has excellent human-body compatibility, which is a function of the radio frequency at which it operates. Typically, NFMI operates at about 10.6 MHz, at which frequency the human body appears almost transparent. This is in contrast to other higher frequency RF signals, which are absorbed or impeded by the body.

[0013] One or more embodiments provide a communication system for communication between medical devices. The communication system includes an electromyography (“EMG”) device including electrodes configured to be attached to a patient and generate electrical signals based on respiratory activity of the patient; wherein the EMG device is configured to generate a respiratory effort waveform based on the electrical signals and analyze the respiratory effort waveform; wherein the EMG device includes a first near-field magnetic induction (“NFMI”) transceiver configured to generate at least one transmission signal derived from the analysis of the patient respiratory effort waveform and transmit the at least one transmission signal on at least one NFMI communication channel; and a ventilator configured to provide breathing assistance to the patient, wherein the ventilator includes a second NFMI transceiver configured to receive the at least one transmission signal from the EMG device and a controller configured to adjust the breathing assistance provided to the patient based on the at least one transmission signal.

[0014] One or more embodiments provide a method of wirelessly communicating with a ventilator to provide breathing assistance to a patient. The method includes receiving, by an electromyography (“EMG”) device, electrical signals based on muscular respiratory activity of the patient; generating, by the EMG device, a patient respiratory effort waveform based on the electrical signals; analyzing, by the EMG device, the patient respiratory effort waveform; generating, by the EMG device, at least one near-field magnetic induction (“NFMI”) transmission signal derived from the analysis of the patient respiratory effort waveform; transmitting, by the EMG device, the at least one NFMI transmission signal on at least one NFMI communication channel to the ventilator.

[0015] One or more embodiments provide a system for triggering a medical device. The system includes a physiological sensor device configured to sense and transmit a first physiological signal; a medical device configured to receive and process the first physiological signal to determine the presence of a trigger; and a near-field magnetic induction (“NFMI”) communications link coupling the physiological signal from the physiological sensor device to the medical device with a latency of less than 10 milliseconds, wherein upon determination that the first physiological signal contains a first trigger, the medical device performs a first action.

[0016] One or more embodiments provide a method for triggering a medical device. The method includes sensing a first physiological signal from a physiological sensor device; wirelessly coupling the physiological signal to a medical device; receiving the physiological signal at the medical device; determining that the first physiological signal contains a first trigger; and performing a first action upon the determining.

[0017] One or more embodiments provide an apparatus for coupling a physiological sensor device to a medical device. The apparatus includes a first coil with a first primary winding axis oriented in a first direction; a second coil with a second primary winding axis oriented in a second direction, substantially parallel with the first direction; a driver connected to the first coil, the driver configured to receive a first physiological sensor output signal, amplify the sensor output signal, and energize the first coil with the amplified sensor output signal to create a magnetic field; and a receiver connected to the second coil, the receiver configured to receive a loop current from the second coil when the second coil is proximate the first coil and amplify the current to recover an original sensor output signal.

[0018] One or more embodiments provide an electromyography (“EMG”) device, including: one or more electrodes configured to be attached to a patient and generate electrical signals based on muscular respiratory activity of a patient; one or more processors configured to generate a patient respiratory effort waveform based on the electrical signals and analyze the patient respiratory effort waveform; and a first near-field magnetic induction (“NFMI”) transceiver configured to generate at least one transmission signal derived from the analysis of the patient respiratory effort waveform and transmit the at least one transmission signal on at least one NFMI communication channel to a second NFMI transceiver included in a ventilator.

[0019] One or more embodiments provide a method for wirelessly triggering a therapy device. The method includes receiving, by a physiological parametermonitoring device, electrical signals based on physiological activity of the patient; generating, by the physiological parameter-monitoring device, a waveform representing the physiological activity of the patient based on the electrical signals; generating, by the physiological parameter-monitoring device, at least one near-field magnetic induction (“NFMI”) transmission signal derived from the waveform; and wirelessly transmitting, by the physiological parameter-monitoring device, the at least one NFMI transmission signal on at least one NFMI communication channel to a therapy device, wherein the at least one NFMI transmission signal is configured to trigger an action performed by the therapy device corresponding to the physiological activity represented in the waveform.

[0020] Illustrative examples of the subject matter claimed below will now be disclosed. In the interest of clarity, not all features of an actual implementation are described for every example in this specification. It will be appreciated that in the development of any such actual implementation, numerous implementationspecific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort, even if complex and time-consuming, would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

[0021] Further, equivalent or like elements or elements with equivalent or like functionality are denoted in the following description with equivalent or like reference numerals. As the same or functionally equivalent elements are given the same reference numbers in the figures, a repeated description for elements provided with the same reference numbers may be omitted. Hence, descriptions provided for elements having the same or like reference numbers are mutually exchangeable.

[0022] It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).

[0023] In embodiments described herein or shown in the drawings, any direct electrical connection or coupling without additional intervening elements may also be implemented by an indirect connection or coupling or vice versa, as long as the general purpose of the connection or coupling, for example, to transmit a certain kind of signal or to transmit a certain kind of information, is essentially maintained. Features from different embodiments may be combined to form further embodiments. For example, variations or modifications described with respect to one of the embodiments may also be applicable to other embodiments unless noted to the contrary.

[0024] Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0025] In the present disclosure, expressions including ordinal numbers, such as “first”, “second”, and/or the like, may modify various elements. However, such elements are not limited by the above expressions. For example, the above expressions do not limit the sequence and/or importance of the elements. The above expressions are used merely for the purpose of distinguishing an element from the other elements. For example, a first box and a second box indicate different boxes, although both are boxes. For further example, a first element could be termed a second element, and similarly, a second element could also be termed a first element without departing from the scope of the present disclosure.

[0026] One or more aspects of the present disclosure may be implemented as a non-transitory computer-readable recording medium having stored thereon a program embodying methods/algorithms for instructing the processor to perform the methods/algorithms. Thus, a non-transitory computer-readable recording medium may have electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective methods/algorithms are performed. The non-transitory computer-readable recording medium can be, for example, a compact disc, readonly memory (“CD-ROM”), digital video disc (“DVD”), BLU-RAY® disc, a random- access memory (“RAM”), a read-only memory (“ROM”), a programmable read-only memory (“PROM”), an electrically programmable read-only memory (“EPROM”), an electrically erasable, programable read-only memory (“EEPROM”), a FLASH memory, or an electronic memory device.

[0027] Each of the elements of the present disclosure may be configured by implementing dedicated hardware or a software program on a memory controlling a processor to perform the functions of any of the components or combinations thereof. Any of the components may be implemented as a central processing unit (“CPU”) or other processor reading and executing a software program from a recording medium such as a hard disk or a semiconductor memory device. For example, instructions may be executed by one or more processors, such as one or more CPUs, microcontrollers, digital signal processors (“DSPs”), general- purpose microprocessors, application-specific integrated circuits (“ASICs”), field programmable logic arrays (“FPGAs”), programmable logic controller (“PLC”), or other equivalent integrated or discrete logic circuitry.

[0028] Accordingly, the term “processor,” as used herein refers to any of the foregoing structures or any other structure suitable for implementation of the techniques described herein. A controller including hardware may also perform one or more of the techniques of this disclosure. A controller, including one or more processors, may use electrical signals and digital algorithms to perform its receptive, analytic, and control functions, which may further include corrective functions. Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various techniques described in this disclosure.

[0029] A signal processing circuit and/or a signal conditioning circuit may receive one or more signals from one or more components and perform signal conditioning or processing thereon. Signal conditioning, as used herein, refers to manipulating a signal in such a way that the signal meets the requirements of a next stage for further processing. Signal conditioning may include converting from analog to digital (e.g., via an analog-to-digital converter), amplification, filtering, converting, biasing, range matching, isolation and any other processes required to make a signal suitable for processing after conditioning.

[0030] Thus, a signal processing circuit may include an analog-to-digital converter (“ADC”) that converts the analog signal from the one or more sensor elements to a digital signal. The signal processing circuit may also include a digital signal processor (“DSP”) that performs some processing on the digital signal.

[0031] FIG. 1 illustrates a system 100 for triggering a medical device via a physiological sensor device according to one or more embodiments. It includes a medical device 102, a physiological sensor device 104 comprising one or more sensors 105, and a low-latency wireless communications link 106 communicatively coupling the physiological sensor device 104 to the medical device 102 via wireless communications transceivers 108 and 110 (e.g., via a communication channel). The latency is preferably less than 10 milliseconds (ms) and, more preferably, 5 milliseconds (ms) or less, thereby transmitting time-critical data from the physiological sensor device or data from the medical device across the wireless communications link 106.

[0032] In operation, one or more signals generated by the sensor 105 are transmitted via the wireless communications transceiver 108 over wireless communications link 106 to the medical device 102 via wireless communications transceiver 110. In some embodiments, the sensor 105 may be a physiological sensor. As further detailed below, the wireless communication link 106 between the medical device 102 and the physiological sensor device 104 is a bi-directional communications link. The medical device 102 processes the signal to determine if there is any actionable information in the signal that could be used to trigger the medical device 102 to perform an action, such as generate an alert, initiate a medical assistance function, or to modify one of its operating parameters of a currently administered medical treatment while in progress. [0033] By way of example, the sensors 105 may be placed proximate to, on, or inside a patient’s body. For example, the sensors 105 may be electrodes that attach to the patient for reading electrical signals generated by or passed through the patient. The sensors 105 may be configured to measure vital signs, measure electrical stimulation, measure brain electrical activity such as in the case of a electroencephalogram (“EEG”), measure blood oxygen saturation fraction from absorption of light at different wavelengths as it passes through a finger, measure a CO2 level and/or other gas levels in an exhalation stream using infrared spectroscopy, measure oxygen saturation on the surface of the brain or other regions, measure cardiac output from invasive blood pressure and temperature measurements, measure induced electrical potentials over the cortex of the brain, measure blood oxygen saturation from an optical sensor coupled by fiber to the tip of a catheter, and/or measure blood characteristics using absorption of light.

[0034] Thus, the sensors 105 measure a physiological characteristic of a patient and transmit electrical measurement signals over a wired or wireless link to the physiological sensor device 104. The physiological sensor device 104 is configured to analyze the sensor data received in the measurement signals in order to monitor or otherwise evaluate a condition of the patient. For example, the physiological sensor device 104 may detect a monitored condition of the patient based on the sensor data (e.g., via comparing one or more types of sensor data to one or more thresholds). A monitored condition is a condition that requires medical treatment, assistance, or intervention in order to sustain the life of the patient or otherwise assist in sustaining or improving the health of the patient.

[0035] Multiple threshold tiers may also be used for detecting tiered monitored conditions. For example, a first tier monitored condition may correspond to a first treatment level administered by the medical device 102 and a second tier monitored condition may correspond to a second treatment level administered by the medical device 102 that is enhanced with respect to the first treatment level. Thus, different operation parameters may be set at the medical device 102 based on the treatment level indicated by the physiological sensor device 104. What constitutes first tier and second tier conditions may be implementation specific, and may depend on factors such as, without limitation, the condition(s) being monitored and the health of the patient.

[0036] In response to detecting a monitored condition, the physiological sensor device 104 is configured to generate a one or more communication signals (e.g., a raw sensor data signal, a control signal, an event signal, a flag signal, and/or a trigger signal), and transmit the one or more communication signals via the wireless communications transceiver 108 across the wireless communications link 106 to the wireless communications transceiver 110 of the medical device 102. The wireless communications transceivers 108 and 110 are induction coils that are capable of transmitting and receiving NFMI communication signals. This allows for bi-directional communication between the physiological sensor device 104 and the medical device 102. In particular, the wireless communications transceivers 108 and 110 communicate by coupling a magnetic field between the two devices. The magnetic field may be referred to as a non-propagating magnetic field or an evanescent field and the coupling between the two coils may be referred to as an evanescent coupling or a near-field coupling.

[0037] The communications concept involves a transmitter coil in one device modulating a magnetic field that is measured by means of a receiver coil in another device. A current passed through the transmitter coil produces a corresponding magnetic field. The magnetic field induces a corresponding voltage across the terminals of the receiver coil via inductive or magnetic coupling that can be detected by the receiver. Thus, a modulated current produces a modulated magnetic field. The transceiver that performs a transmission may be referred to as a transmitter comprising the transmitter coil and corresponding transmitter circuitry configured to energize the transmitter coil and modulate the magnetic field that is the communication signal). Conversely, the transceiver performs the receiving may be referred to as a receiver comprising the receiver coil and corresponding receiver circuitry configured to detect the modulated magnetic field via the receiver coil and demodulate or otherwise decode the communication signal.

[0038] The medical device 102 is a medical treatment device that is configured to administer medical treatment to a patient. The one or more communication signals from the physiological sensor device 104 is intended to, for example, provide raw sensor data, a control signal, an event signal, a flag signal, and/or a trigger signal to trigger an action, such as a medical assistance function, or a response, including modifying one or more operating parameters corresponding to the medical assistance function, to list a few examples. A communication signal may also indicate a treatment level based on the detected condition of the patient.

[0039] A transmitter of the physiological sensor device 104 may be configured to modulate the magnetic field and thereby modulate the communication signals transmitted by the wireless communications transceiver 108 based on the information to be transmitted via the corresponding communication signal. For example, the transmitted signal may be modulated by amplitude and/or frequency modulation that is to be decoded by the receiver circuitry at the medical device 102. A communication signal may be a trigger signal that triggers a specific function of the medical device 102. In response to detecting the trigger signal, the medical device is configured to perform the triggered function or action. Another communication signal may include control information that may include control data, instructions, or data indicating an instruction set corresponding to which functions the medical device 102 is to perform and/or which operating parameters are to be set or adjusted by the medical device 102 for administering treatment to a patient. In response to receiving a communication signal, the medical device 102 may transmit, via its wireless communications transceiver 110, an acknowledgement signal to the physiological sensor device 104 indicating that the communication signal was successfully received. For example, the acknowledgement signal may indicate that the trigger signal was successfully received and/or that the operating parameters have been set or adjusted according to the received instructions.

[0040] In one or more embodiments, the medical device 102 comprises a ventilator and physiological sensor device 104 comprises a surface electromyography (“sEMG”) sensor module or pod. sEMG is a non-invasive procedure involving the detection, recording, and interpretation of the electric activity of groups of muscles at rest and during activity. Electrical measurements for muscles at rest may referred to as “static” and for muscles during activity may be referred to as “dynamic”. The procedure is performed using a single or an array of electrodes placed on the skin surface at different sites and specifically over the muscles to be tested. Electrical activity is assessed by computer analysis of the frequency spectrum, amplitude, or root mean square of the electrical action potential. An sEMG pod, via the sensors 105 that are attached in proximity to the chest or abdomen of the patient, may act as a trigger or as a controller for a ventilator, attached to that same patient. The communication signals will be communicated wirelessly, and meet an over-the-air latency requirement of less than 10 milliseconds.

[0041] In the case where the physiological sensor device 104 comprises an sEMG device and the medical device 102 is a ventilator, the sEMG device within the physiological sensor device 104 may send communication signals to the ventilator to trigger a function or to adjust one of its breathing assistance parameters in response to electrical activity detected around the musculature of the respiratory system of a patient by the sEMG device. Such adjustments may be made to one or more of the ventilator operating or control settings including but not limited to assist control (“AC”), tidal volume (“TV”), positive end-expiratory pressure (“PEEP”), synchronized intermittent mandatory ventilation (“SIMV”), airway pressure release ventilation (“APRV”), pressure support (“PS”), bi-level positive airway pressure (“BIPAP”), continuous positive airway pressure (“CPAP”), high frequency oscillatory ventilation (“HFOV”), and fraction of inspired oxygen (“F1O2”). The adjustments to these settings may be made in proportion to a patient’s respiratory effort waveform and may be signaled to the ventilator by the sEMG device.

[0042] In particular, the sEMG device and the ventilator are configured to perform proportional breathing assistance such as proportional assist ventilation (“PAV”), and, more specifically, neurally adjusted ventilatory assist (“NAVA”) in order to improve patient-ventilator synchrony. NAVA is specifically controlled by changes in the EMG activity of the diaphragm measured by the sEMG device. Accordingly, the breathing rhythm of the patient who is actively breathing can be assisted by the ventilator such that the breathing rhythm is synchronized with the muscle activity detected by the sEMG device.

[0043] The ventilator is configured to respond to changes in a patient's ventilatory demand and to decrease patient breathing effort while the patient is actively breathing by actively regulating gas pressure, volume, and flow. Thus, the gas delivery changes as the patient demand changes. The ventilator does this based on the communication signals received from the sEMG device. The sEMG device generates the communication signals based on an analysis it performs on the sensor data it receives from the sensors 105. Thus, the sEMG device triggers and controls the PAV or NAVA functions and operation settings of the ventilator. For example, ventilator pressure, ventilator flow, ventilator volume, inhalation timing, exhalation timing may all be controlled by the sEMG device via communication signals transmitted to the medical device 102 (e.g., the ventilator). The sEMG device controls these parameters based on generating a patient’s respiratory effort waveform and analyzing the waveform to determine the occurrence of one or more events or to determine one or more proportional settings corresponding to ventilator pressure, ventilator flow, ventilator volume.

[0044] In other words, the sEMG device utilizes the measurement of the patient respiratory effort waveform (e.g., the diaphragmatic EMG signal) to control the gas delivery of the ventilator. As EMG activity increases, pressure is applied during the inspiratory phase, and as the diaphragm relaxes, airway pressure decreases.

Inspiration ends at a specific percentage of the peak EMG activity.

[0045] The sEMG device may trigger on and cycle off the ventilatory assist. It may also control the inhalation phase duration by triggering an activity starting time of the inhalation phase via an inspiratory ventilation trigger and by triggering an activity stop time of the inhalation phase via an expiratory ventilation trigger. The expiratory ventilation trigger also coincides with a starting time of the exhalation phase of the ventilator. Likewise, the activity starting time of the inhalation phase coincides with an activity stop time of the exhalation phase of the ventilator. Thus, by starting one phase the opposite breathing phase is inherently stopped.

[0046] In order to transmit start and stop times, the sEMG device may transmit an event signal to the ventilator on a first transmission channel via the NFMI. The event signal includes a plurality of event flags or event indicators, each of which triggers a specific activity or function of the ventilator and/or may trigger an alarm. For example, an inspiratory ventilation trigger is an event flag or an event indicator that triggers the ventilator to pump air into the lungs of the patient. An expiratory ventilation trigger is an event flag or an event indicator that triggers the ventilator to stop the inspiratory phase and allow the patient to exhale to start the expiratory phase. The event flags may be referred to as discrete event flags as they only occur at discrete time instances when a corresponding event is detected by the sEMG.

[0047] The sEMG may also transmit a proportional control signal to the ventilator on a second transmission channel via the NFMI. The sEMG device generates the proportional control signal based on the patient’s respiratory effort waveform. In particular, the proportional control signal is transmitted continuously during ventilator assist to the ventilator (e.g., as a continuous-time signal or analog signal) to provide dynamic, real-time proportional parameter settings, including a proportional ventilator pressure setting, proportional ventilator flow setting, a proportional ventilator volume setting, or any of the other settings noted above that are derived based on the patient’s respiratory effort waveform. The sEMG device constantly adjusts the proportional parameter settings in proportion to the patient’s respiratory effort waveform throughout an entire duration of the ventilator assist or only during the inspiratory phase of the ventilator assist. In the case of the latter, the proportional control signal may be triggered and transmitted by the sEMG in response to initializing the inspiratory phase of the ventilator assist, and stopped by the sEMG when the inspiratory phase concludes for a given cycle.

[0048] In response to receiving one or more of the proportional parameter settings, the ventilator applies a corresponding gas pressure, gas flow, or gas volume to the patient throughout inspiration and exhalation. Such proportional parameter settings may be dynamically adjusted during the inspiratory phase or expiratory phase in real-time as the settings are received from the sEMG device.

[0049] In addition, the sEMG device may transmit raw sensor data signal or the patient’s respiratory effort waveform on another transmission channel via the NFMI. The raw sensor data may be raw analog data received from the sensors 105 or raw digital data derived therefrom via, for example, an ADC. The ventilator may be configured to display the sensor data or the patient’s respiratory effort waveform on a display or perform further analysis for regulating the PAV functions, particularly, for regulating and adjusting the activity starting times, activity stopping times, and the proportional parameter settings.

[0050] In view of the above, the sEMG device is configured to analyze the measurement signals received from the sensors 105 corresponding to the muscular electrical activity and use one or more communication signals to trigger the ventilator to perform an action based on the analysis and/or adjust ventilator parameter settings. Conversely, the sEMG may be configured to transmit sensor data received from the measurement signals via the communication signal, and the ventilator may be configured to analyze the sensor data to determine a corresponding action. The signal transmissions are wireless, secure, and fast with low latency.

[0051] FIG. 2 illustrates a system 200 for triggering a ventilator 210 by an sEMG module via a near-field magnetic induction (“NFMI”) communications link using a signal from the sEMG module according to one or more embodiments. The system 200 includes an sEMG module 208 and an NFMI ventilator 210.

[0052] The sEMG module 208 includes an sEMG sensor device 218, an NFMI wireless transceiver 214 coupled to an NFMI wireless transceiver coil 202, control electronics 212 (e.g., a “CPU”), and sensors (e.g., physiological sensors such as sensors 105 from FIG. 1 , not illustrated in FIG. 2) that may be placed strategically on a patient for monitoring electrical signals associated with muscular activity. A power management unit (“PMU”, not separately shown) manages the power of the sEMG module 208. The sEMG sensor device 218 is configured to assess the sensed electrical activity by computer analysis of the frequency spectrum, amplitude, or root mean square of the electrical action potential.

[0053] The NFMI ventilator 210 includes an NFMI wireless transceiver 216 that is coupled to an NFMI wireless transceiver coil 204, control electronics 220 (e.g., a “CPU”), and various tubes, pumps, oxygen tanks, and control electronics related to providing breathing assistance to a patient (not illustrated). A power management unit (“PMU”, not separately shown) manages the power of the NFMI ventilator 210.

[0054] In operation, electrical activities of a patient’s muscles are detected and analyzed by sEMG sensor device 218. The sEMG sensor device 218 determines data to be transmitted and relays the data to a NFMI wireless transceiver 214. The NFMI wireless transceiver 214 determines a transmission channel based on the data type and creates a modulated magnetic field via the NFMI wireless transceiver coil 202 to transmit the data on the assigned transmission channel. The NFMI wireless transceiver coil 202 is placed within an NFMI communication range of the NFMI wireless transceiver coil 204. For example, the sEMG module 208, along with its NFMI wireless transceiver coil 202, may be placed on one lateral side of a patient’s body and the NFMI ventilator 210, along with its NFMI wireless transceiver coil 204, may be placed on an opposite lateral side of a patient’s body. This set up allows both the sEMG module 208 and the NFMI ventilator 210 to be attached to the patient without their cables, cords, tubes, and the like becoming entangled with one another. The magnetic field generated by one of the transceiver coils is emitted across the patient’s body to the receiving transceiver coil. Thus, the communication signal can be transmitted through the patient’s body. However, due to the nature of the modulated magnetic field, for example, having a carrier frequency around 10.6 MHz, the patient’s body has little degradation impact on the signal. Thus, the communication signal can be transmitted through the patient’s body with low latency and can fulfill an over-the- air latency requirement of less than 10 milliseconds, and, more preferably, 5 milliseconds (ms) or less.

[0055] In the case that the sEMG module 208 is transmitting signals (e.g., communication data) to the NFMI ventilator 210, the modulated magnetic field generated by the NFMI wireless transceiver coil 202 is coupled to the NFMI wireless transceiver coil 204, and sensed and processed by the NFMI wireless transceiver 216 to extract the communication data. The extracted communication data is further processed by control electronics 220 and is used to trigger an operation and/or an adjustment of the operating parameters of the NFMI ventilator 210. In other words, breathing assistance may be triggered or initialized by the communication data, breathing assistance functions may be triggered according to a triggered timing by the communication data, and/or one or more of the ventilator operating settings or control settings may be adjusted based on the communication data.

[0056] FIG. 3 illustrates the magnetic field coupling associated with the NFMI communications technology utilized in one or more embodiments. It includes a modulated input signal 302 being driven to NFMI wireless transceiver coil 202 (e.g., transmitter coil), a modulated magnetic field 306 associated with the modulated input signal, a coupling 308 (e.g., a wireless link) of the modulated magnetic field 306 into the NFMI wireless transceiver coil 204 (e.g., receiver coil), and the subsequent recovery and output of the received signal 304 that corresponds to the modulated input signal 302.

[0057] FIG. 4 illustrates performance of various placements of receiving coils relative to a transmitting coil according to one or more embodiments. It includes a transmitting (“TX”) coil 402, a receiving coil A (“RX A”) 404, a receiving coil B (“RX B”) 406, and a receiving coil C (“RX C”) 408. The RX A 404 exhibits the best coupling because the area of the TX 402 and the RX A 404 are co-axial. The RX B 406 exhibits good coupling since the area of the TX 402 and the RX B 406 are co-planer. The RX C 408 exhibits poor coupling due to the area of the RX C 408 being orthogonal to the area of the TX 402.

[0058] In other words, communication signals are stronger at greater distances for a co-axial arrangement between coils when compared to a co-planar arrangement, and communication signals are stronger at greater distances for the co-planar arrangement between coils when compared to an orthogonal arrangement. With that said, the co-axial arrangement is the most sensitive to alignments (or misalignments) between coils given that is has the smallest overlapping area among the three arrangements. In contrast, the co-planar arrangement is the least sensitive to alignments (or misalignments) between coils given that is has the largest overlapping area among the three arrangements. A misalignment can have a negative effect on the signal strength of the communication signals. It will be appreciated that any of the coil arrangements may be implemented in the embodiments shown FIGS. 2 and 3 as a matter of design choice.

[0059] The foregoing outlines the features of several embodiments so that those of ordinary skill in the art may better understand various aspects of the present disclosure. Those of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of various embodiments introduced herein. Those of ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

[0060] Although the subject matter has been described in language specific to structural features or methodological acts, it is to be understood that the subject matter of the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing at least some of the claims.

[0061] Various operations of embodiments are provided herein. The order in which some or all of the operations are described should not be construed to imply that these operations are necessarily order dependent. Alternative ordering will be appreciated having the benefit of this description. Further, it will be understood that not all operations are necessarily present in each embodiment provided herein. Also, it will be understood that not all operations are necessary in some embodiments.

[0062] It will be appreciated that layers, features, elements, etc., depicted herein are illustrated with particular dimensions relative to one another, such as structural dimensions or orientations, for example, for purposes of simplicity and ease of understanding and that actual dimensions of the same differ substantially from that illustrated herein, in some embodiments. Moreover, "exemplary" is used herein to mean serving as an example, instance, illustration, etc., and not necessarily as advantageous. As used in this application, "or" is intended to mean an inclusive "or" rather than an exclusive "or". In addition, "a" and "an" as used in this application and the appended claims are generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Also, at least one of A and B and/or the like generally means A or B or both A and B. Furthermore, to the extent that "includes", "having", "has", "with", or variants thereof are used, such terms are intended to be inclusive in a manner similar to the term "comprising”. Also, unless specified otherwise, “first,” “second,” or the like are not intended to imply a temporal aspect, a spatial aspect, an ordering, etc. Rather, such terms are merely used as identifiers, names, etc. for features, elements, items, etc. For example, a first element and a second element generally correspond to element A and element B or two different or two identical elements or the same element.

[0063] This concludes the detailed description. The particular examples disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular examples disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A communication system for communication between medical devices, the communication system comprising: an electromyography (“EMG”) device including: electrodes configured to be attached to a patient and generate electrical signals based on respiratory activity of the patient, the EMG device configured to generate a respiratory effort waveform based on the electrical signals and analyze the respiratory effort waveform, and a first near-field magnetic induction (“NFMI”) transceiver configured to generate a transmission signal derived from the analysis of the respiratory effort waveform and transmit the transmission signal on a NFMI communication channel; and a ventilator configured to provide breathing assistance to the patient, the ventilator including: a second NFMI transceiver configured to receive the transmission signal from the EMG device, and a controller configured to adjust the breathing assistance provided to the patient based on the transmission signal.

2. The communication system of claim 1 , wherein the ventilator is configured to synchronize the breathing to the respiratory effort waveform based on the transmission signal.

3. The communication system of claim 1 , wherein: the breathing assistance is a proportional breathing assistance, the transmission signal includes a proportional control signal that includes a proportional ventilator parameter setting, and the EMG device is further configured to:

22 dynamically adjust the proportional ventilator parameter setting in real time in proportion to the respiratory effort waveform, and transmit the adjusted proportional ventilator parameter setting to the ventilator via the proportional control signal.

4. The communication system of claim 3, wherein the ventilator is further configured to: receive the proportional control signal; and adjust the proportional breathing assistance according to the proportional ventilator parameter setting.

5. The communication system of claim 3, wherein: the proportional control signal is a continuous-time signal; and the first NFMI is configured to continuously transmit the proportional control signal during at least an entire duration of an inspiratory phase of the proportional breathing assistance.

6. The communication system of claim 3, wherein the proportional ventilator parameter setting includes at least one of gas pressure, gas volume, or gas flow.

7. The communication system of claim 3, wherein: the transmission signal includes an event signal that further includes a plurality of discrete event flags; and the EMG device is further configured to monitor for a plurality of discrete events corresponding to the respiratory effort waveform and signal each of the plurality of discrete events by a corresponding discrete event flag in the event signal.

8. The communication system of claim 7, wherein: the plurality of discrete events includes an inspiratory start event corresponding to a start of an inspiratory phase of the proportional breathing assistance, and includes an expiratory start event corresponding to a start of an expiratory phase of the proportional breathing assistance, and the plurality of discrete event flags includes inspiratory ventilation trigger indicating the start of the inspiratory phase and an expiratory ventilation trigger indicating the start of the expiratory phase.

9. The communication system of claim 8, wherein the ventilator is further configured to: receive the event signal, initiate the inspiratory phase in response to receiving the inspiratory ventilation trigger, and initiate the expiratory phase in response to receiving the expiratory ventilation trigger.

10. The communication system of claim 9, wherein the EMG device is further configured to trigger the proportional control signal in response to detecting the inspiratory start event.

11 . The communication system of claim 1 , wherein: the transmission signal includes an event signal that further includes a plurality of discrete event flags, and the EMG device is further configured to monitor for a plurality of discrete events corresponding to the respiratory effort waveform and signal each of the plurality of discrete events by a corresponding discrete event flag in the event signal.

12. The communication system of claim 11 , wherein: the plurality of discrete events includes: an inspiratory start event corresponding to a start of an inspiratory phase of the breathing assistance, and includes an expiratory start event corresponding to a start of an expiratory phase of the breathing assistance, and the plurality of discrete event flags includes: inspiratory ventilation trigger indicating the start of the inspiratory phase, and an expiratory ventilation trigger indicating the start of the expiratory phase.

13. The communication system of claim 1 , wherein the electrical signals represent diaphragm electrical activity and the respiratory effort waveform is a diaphragmatic EMG signal.

14. The communication system of claim 1 , wherein the transmission signal is transmitted from the EMG device to the ventilator through the patient body.

15. The communication system of claim 1 , wherein the transmission signal has an over-the-air latency of less than 10 milliseconds.

16. The communication system of claim 1 , wherein the transmission signal has an over-the-air latency of less than 5 milliseconds.

17. A method of wirelessly communicating with a ventilator to provide breathing assistance to a patient, the method comprising: receiving, by an electromyography (“EMG”) device, electrical signals based on muscular respiratory activity of the patient; generating, by the EMG device, a patient respiratory effort waveform based on the electrical signals; analyzing, by the EMG device, the patient respiratory effort waveform; generating, by the EMG device, at least one near-field magnetic induction (“NFMI”) transmission signal derived from the analysis of the patient respiratory effort waveform;

25 transmitting, by the EMG device, the at least one NFMI transmission signal on at least one NFMI communication channel to the ventilator.

18. The method of claim 17, further comprising: receiving, by the ventilator, the at least one NFMI transmission signal; providing, by the ventilator, the breathing assistance to the patient, including adjusting the breathing assistance provided to the patient based on the at least one transmission signal.

19. A system for triggering a medical device, comprising: a physiological sensor device configured to sense and transmit a first physiological signal; a medical device configured to receive and process the first physiological signal to determine the presence of a first trigger; and a near-field magnetic induction (“NFMI”) communications link coupling the physiological signal from the physiological sensor device to the medical device with a latency of less than 10 milliseconds, wherein, upon determination that the first physiological signal contains the first trigger, the medical device performs a first action.

20. The system of claim 19, wherein the physiological sensor device includes a transmitter coil and the medical device includes a receiver coil and the near-field magnetic induction (“NFMI”) communications link comprises a physical layer that communicates by coupling non-propagating magnetic fields between the transmitter coil and the receiver coil.

21. The system of claim 19, wherein the physiological sensor device comprises a surface electromyography (“sEMG”) module that senses the first physiological signal.

22. The system of claim 21 , wherein the medical device is a ventilator and the first action is one of an adjustment of one of the following parameters of the ventilator

26 including: assist control (“AC”), tidal volume (“TV”), positive end-expiratory pressure (“PEEP”), synchronized intermittent mandatory ventilation (“SIMV”), airway pressure release ventilation (“APRV”), pressure support (“PS”), bilevel positive airway pressure (“Bl PAP”), continuous positive airway pressure (“CPAP”), high frequency oscillatory ventilation (“HFOV”), and fraction of inspired oxygen (“FiC ”).

23. The system of claim 22, wherein the first signal comprises a representation of electrical activity of a group of muscles related to the respiratory system of a patient.

24. The system of claim 19, wherein the physiological sensor device is configured to sense and transmit a second physiological signal, wherein, upon determination that the second physiological signal contains a second trigger, the medical device performs a second action different from the first action.

25. The system of claim 19, wherein the first trigger comprises a patient-initiated request for a breath.

26. The system of claim 19, wherein the physiological sensor device comprises a first coupling coil and the medical device comprise a second coupling coil, each coupling coil having a primary winding axis, wherein the primary winding axis of the first coupling coil is oriented substantially parallel to the primary winding axis of the second coupling coil.

27. A method for triggering a medical device, comprising: sensing a first physiological signal from a physiological sensor device; wirelessly coupling the physiological signal to a medical device; receiving the first physiological signal at the medical device; determining that the first physiological signal contains a first trigger; and performing a first action upon the determining.

28. The method of claim 27, wherein the wireless coupling comprises magnetically coupling, via non-propagating magnetic fields, the first physiological signal, between a

27 transmitter coil within the physiological sensor device and a receiver coil within the medical device.

29. The method of claim 27, wherein the sensing comprises using a surface electromyography (“sEMG”) sensor module to sense the first physiological signal.

30. The method of claim 27, wherein the medical device is a ventilator and performing the first action comprises adjusting of one of the following parameters of the ventilator including: assist control (“AC”), tidal volume (“TV”), positive end-expiratory pressure (“PEEP”), synchronized intermittent mandatory ventilation (“SIMV”), airway pressure release ventilation (“APRV”), pressure support (“PS”), bilevel positive airway pressure (“Bl PAP”), continuous positive airway pressure (“CPAP”), high frequency oscillatory ventilation (“HFOV”), and fraction of inspired oxygen (“FiC ”).

31. The method of claim 30, wherein the first physiological signal comprises a representation of electrical activity of a group of muscles related to the respiratory system of a patient.

32. The method of claim 27, the method comprising: transmitting a second physiological signal from the physiological sensor device; determining that the second physiological signal contains a second trigger, and performing a second action upon the determining, the second action different from the first action.

33. The method of claim 27, wherein the first trigger comprises a patient-initiated request for a breath.

34. The method of claim 27, wherein the physiological sensor device comprises a first coupling coil and the medical device comprise a second coupling coil, each coupling coil having a primary winding axis, the method further comprising orienting the primary axis

28 of the first coupling coil substantially parallel to the primary winding axis of the second coupling coil.

35. An apparatus for coupling a physiological sensor device to a medical device, the apparatus comprising: a first coil with a first primary winding axis oriented in a first direction; a second coil with a second primary winding axis oriented in a second direction, substantially parallel with the first direction; a driver connected to the first coil, the driver configured to receive a first physiological sensor output signal, amplify the physiological sensor output signal, and energize the first coil with the amplified physiological sensor output signal to create a magnetic field; and a receiver connected to the second coil, the receiver configured to receive a loop current from the second coil when the second coil is proximate the first coil and amplify the current to recover an original sensor output signal.

36. An electromyography (“EMG”) device, comprising: one or more electrodes configured to be attached to a patient and generate electrical signals based on muscular respiratory activity of a patient; one or more processors configured to: generate a patient respiratory effort waveform based on the electrical signals; and analyze the patient respiratory effort waveform; and a first near-field magnetic induction (“NFMI”) transceiver configured to: generate at least one transmission signal derived from the analysis of the patient respiratory effort waveform; and transmit the at least one transmission signal on at least one NFMI communication channel to a second NFMI transceiver included in a ventilator.

37. A method for wirelessly triggering a therapy device, comprising:

29 receiving, by a physiological parameter-monitoring device, electrical signals based on physiological activity of the patient; generating, by the physiological parameter-monitoring device, a waveform representing the physiological activity of a patient based on the electrical signals; generating, by the physiological parameter-monitoring device, at least one nearfield magnetic induction (“NFMI”) transmission signal derived from the waveform; and wirelessly transmitting, by the physiological parameter-monitoring device, the at least one NFMI transmission signal on at least one NFMI communication channel to a therapy device, wherein the at least one NFMI transmission signal is configured to trigger an action performed by the therapy device corresponding to the physiological activity represented in the waveform.

30