Systems and methods for monitoring physiological parameters during diathermy

Abstract

A system for monitoring physiological parameters during a medical intervention procedure involving high-intensity / energy radio frequency current / voltage applied through a subject's body is disclosed, the system comprising an electrode-based sensor configured to close a conductive path through the subject's body and one or more non-electrode-based sensors, a plurality of wires, a monitor, and a filter array, the filter array comprising an EMI filter mounted at a specific location and characterized by a frequency response curve having a greater attenuation within a first frequency range (a typical operating frequency of the high-intensity / energy radio frequency medical intervention device) than within a second frequency range (a typical sampling frequency of the electrode-based sensor and one or more non-electrode-based sensors), the system thereby being configured to suppress noise caused by the medical intervention device.

Description

Technical Field

[0001] The present disclosure generally relates to multi-parameter physiological signal acquisition during a medical procedure involving application of radio frequency alternating polarity current through a patient's body. Background Art

[0002] In a diathermy surgical procedure (also referred to herein as electrosurgery or electrocautery), an electric current is applied through electrodes, such as to close a conductive path through the patient's body. The current is applied at radio frequencies, such as to heat tissue at a target site on the patient's body, thereby cutting, drying and / or cauterizing the tissue, while coagulating the tissue and reducing blood loss. When a sufficiently high voltage is applied to generate an electric arc, the device applying the current may contact the patient's skin or may be in close proximity to the patient's skin.

[0003] The current / energy generated during a diathermy procedure may affect medical sensors that are in contact with the patient's body, thereby adding noise to the signals generated by the sensors, causing signal distortion or even signal saturation (i.e., complete disappearance of the signal). In particular, the noise caused by diathermy / electrocautery may affect electrode-based sensors (e.g., ECG, EMG, or galvanic skin response sensors). Due to the high energies (high currents and / or high voltages) involved, electrical interference effects (e.g., capacitive coupling, inductive coupling) may also distort / saturate the signals of medical / physiological sensors that are not in contact with the body but are positioned in close proximity (proximity) to the "affected" medical sensors (such as electrode-based sensors).

[0004] In particular, the noise caused by diathermy is detrimental to reliable monitoring of parameters (during diathermy / electrosurgery) and likewise detrimental to reliable assessment of, for example, the patient's physiological state and the patient's level of pain or nociception during diathermy. The lack of the ability to reliably monitor pain or nociception during diathermy surgical procedures may result in the patient receiving an over- or under-dose of anesthetic. An over-dose of anesthetic may contribute to hypotension and myocardial damage and / or acute kidney injury (which may occur even months after surgery) as well as hyperalgesia. On the other hand, an under-dose of anesthetic may result in a severe stress response, which may be dangerous for frail patients and may result in persistent and / or chronic pain (after surgery).

[0005] Therefore, there remains a need for reliable systems and methods for pain monitoring during diathermy procedures. Summary of the invention

[0006] According to some embodiments of the present disclosure, aspects of the present disclosure relate to monitoring of one or more physiological parameters during a procedure involving application of high intensity / energy radiofrequency current / voltage through a patient's body, such as, but not limited to, diathermy, RF ablation, etc. Specifically, some aspects of the present disclosure relate to reliably assessing a patient's autonomic nervous system activity during a diathermy or electrocautery procedure by monitoring one or more physiological parameters. More specifically, but not exclusively, according to some embodiments of the present disclosure, aspects of the present disclosure relate to suppressing diathermy-induced noise in physiological sensors, such as noise induced in non-electrode-based sensors due to proximity of the non-electrode-based sensors to electrode-based sensors.

[0007] The present disclosure advantageously provides reliable monitoring of pain, nociception, anesthesia, stress, anxiety, sleep and / or analgesia during a diathermy surgical procedure with the aid of an electromagnetic interference (EMI) filter placed at a specific location between a medical sensor for obtaining physiological data from a patient and a monitor for processing the sensor data to assess the level / extent of pain, nociception, anesthesia, stress, anxiety, sleep and / or analgesia in a patient. More generally, the present disclosure provides reliable monitoring of multiple physiological parameters and autonomic nervous system activity in a patient undergoing a diathermy surgical procedure.

[0008] Thus, according to one aspect of some embodiments, a system is provided, comprising a sensor assembly, a monitor, a plurality of wires, and a filter array. The sensor assembly comprises at least one electrode-based sensor configured to close a conductive path through a subject's body, and one or more non-electrode-based sensors configured to monitor one or more physiological parameters of a subject during a medical intervention procedure involving application of at least one selected from: (i) high-intensity radio frequency current, (ii) high-intensity radio frequency voltage, (iii) high-energy radio frequency current, and (iv) high-energy radio frequency voltage. The plurality of wires electrically associate the sensor assembly with the monitor. The plurality of wires comprises a first wire configured to transmit a plurality of first sensor signals from the electrode-based sensor to the monitor, and a second wire configured to transmit a plurality of second sensor signals from one or more non-electrode-based sensors to the monitor. The monitor is configured to assess the subject's physiological activity based at least on the plurality of second sensor signals. The filter array comprises a first proximal electromagnetic interference (EMI) filter mounted on the first wire, a second distal EMI filter mounted on the first wire, and a third EMI filter mounted on the second wire. The first proximal EMI filter is located between the electrode-based sensor and the second distal EMI filter. Each of the second distal EMI filter and the third EMI filter is characterized by a corresponding frequency response curve, and its attenuation in the first frequency range is at least 10 dB greater than the attenuation in the second frequency range. The combination of the sensor assembly, the plurality of wires, and the filter array is configured to suppress noise caused by a medical interventional device used in a medical interventional procedure.

[0009] According to some embodiments, a first proximal EMI filter is mounted on the first wire in or near the sensor assembly.

[0010] According to some embodiments, a second remote EMI filter is mounted on the first line in or near the monitor.

[0011] According to some embodiments, the first frequency range is a typical operating frequency of high intensity and / or high energy radio frequency medical interventional equipment.

[0012] According to some embodiments, the second frequency range is typical of one or more sampling frequencies of the electrode-based sensor and the one or more non-electrode-based sensors.

[0013] According to some embodiments, the second EMI filter and the third EMI filter have an attenuation of at least about 60 dB in the first frequency range.

[0014] According to some embodiments, the attenuation of the first EMI filter in the first frequency range is at least about 10 dB, and / or the attenuation of the first EMI filter in the first frequency range is at least about 10 dB greater than its attenuation in the second frequency range.

[0015] According to some embodiments, the first frequency range is between about 300 kHz and about 500 kHz.

[0016] According to some embodiments, the second frequency range is between 0 Hz and about 600 Hz.

[0017] According to some embodiments, the sensor assembly is a finger probe configured to be mounted on a finger of a subject.

[0018] According to some embodiments, the electrode-based sensor comprises a bioimpedance sensor and / or a biopotential sensor.

[0019] According to some embodiments, the electrode-based sensors include galvanic skin response (GSR) sensors, electrocardiographs (ECG), electromyographs (EMG), electrogastrographs (EGG), electroencephalograms (EEG), and / or electrooculograms (EOG).

[0020] According to some embodiments, the electrode based sensor is a GSR sensor.

[0021] According to some embodiments, the monitor includes an analog-to-digital converter (ADC). The remote filter is mounted at or near an input terminal of the ADC.

[0022] According to some embodiments, a first line extends from the electrode-based sensor to the ADC. An input terminal of the proximal filter is coupled to the electrode-based sensor. An output terminal of the proximal filter is configured to transmit a filtered electrode-based sensor signal via the first line. A ground terminal of the proximal filter is connected to a floating ground. An input terminal of the distal filter is configured to receive a filtered electrode-based sensor signal via the first line. An output terminal of the distal filter is coupled to the ADC. A ground terminal of the distal filter is connected to a floating ground.

[0023] According to some embodiments, the system further includes an amplifier mounted on the first wire between the proximal filter and the distal filter and configured to amplify the filtered electrode-based sensor signal.

[0024] According to some embodiments, non-electrode based sensors include photoplethysmography (PPG) sensors, piezoelectric sensors, accelerometers, thermometers, blood pressure sensors, respiration sensors, near infrared spectroscopy (NIRS) sensors, dynamic light scattering (DLS) based sensors, laser Doppler flowmeters, diffuse correlation spectroscopy (DCS) based sensors, acoustic sensors and / or microphones.

[0025] According to some embodiments, the non-electrode based sensor is a PPG sensor.

[0026] According to some embodiments, the sensor assembly further comprises a third sensor that is non-electrode based. The plurality of wires further comprises at least one additional wire configured to transmit the sensor signal(s) from the third sensor to the monitor. The filter array further comprises at least one additional EMI filter mounted on the at least one additional wire.

[0027] According to some embodiments, the third sensor is an accelerometer. The at least one additional line includes at least three lines. The at least one additional EMI filter includes at least three EMI filters respectively mounted on the at least three lines.

[0028] According to some embodiments, where the non-electrode based sensor is a PPG sensor, the third filter is mounted at or near the second input terminal of the ADC, or at or near the input terminal of a second ADC in the monitor.

[0029] According to some embodiments, an input terminal of the third filter is configured to receive a second sensor signal from a non-electrode based sensor via a second line. An output terminal of the third filter is coupled to the ADC. A ground terminal of the third filter is connected to a floating ground.

[0030] According to some embodiments, the system further includes a second amplifier mounted on the second line before the third filter and configured to amplify the sensor signal received from the non-electrode based sensor.

[0031] According to some embodiments, the proximal EMI filter is housed within the sensor assembly and all other EMI filters in the filter array are housed within the monitor.

[0032] According to some embodiments, the system includes an amplifier and a second amplifier, the amplifier being housed within the monitor.

[0033] According to some embodiments, a plurality of wires are housed within a cable between the sensor assembly and the monitor.

[0034] According to some embodiments, the cable is about 2.8 m long.

[0035] According to some embodiments, a monitor includes a processor configured to allow assessment of a subject's physiological state during a medical intervention procedure based on sensor signals.

[0036] According to some embodiments, assessment of physiological status during a medical intervention procedure includes disregarding (ignoring, ignoring) data received from electrode-based sensors.

[0037] According to some embodiments, the physiological state is the subject's autonomic nervous system activity.

[0038] According to some embodiments, the autonomic nervous system activity comprises one or more of the subject's level of pain, nociception, anesthesia, analgesia, anxiety, and / or stress.

[0039] According to some embodiments, the autonomic nervous system activity is the subject's pain level.

[0040] According to some embodiments, each of the at least three EMI filters is a low ESL (equivalent series inductance) feed-through capacitor.

[0041] According to some embodiments, the capacitance of the first EMI filter is between approximately 0.05 μF and 0.2 μF.

[0042] According to some embodiments, the capacitance of the second EMI filter and the third EMI filter is between about 15 μF and about 40 μF.

[0043] According to some embodiments, the sensor assembly further includes a thermometer, and the plurality of wires includes a thermometer-dedicated wire configured to transmit sensor data obtained by the thermometer to the monitor.

[0044] According to some embodiments, the medical intervention procedure is diathermy.

[0045] According to some embodiments, the medical interventional procedure is RF ablation.

[0046] According to some embodiments, the proximal EMI filter is mounted near or adjacent to the first sensor.

[0047] According to some embodiments, assessment of a physiological state during a medical intervention procedure includes cleaning a signal obtained from at least one non-electrode-based sensor based on an estimate of noise introduced by at least one electrode-based sensor.

[0048] According to an aspect of some embodiments, there is provided a system comprising:

[0049] - At least one electrode-based sensor configured to close a conductive path through the body of the subject.

[0050] - At least one non-electrode based sensor configured to monitor one or more physiological parameters of a subject during a medical intervention procedure involving application of at least one selected from the group consisting of: high intensity radio frequency current, high intensity radio frequency voltage, high energy radio frequency current, and high energy radio frequency voltage.

[0051] -Analog to digital converter.

[0052] -Control circuit system.

[0053] -Electromagnetic Interference (EMI) Filters.

[0054] The EMI filter is configured to receive a plurality of first sensor signals from at least one electrode-based sensor, filter the first sensor signals, and transmit the filtered first sensor signals to an analog-to-digital converter. The non-electrode-based sensor is configured to transmit a plurality of second sensor signals to the analog-to-digital converter and / or the control circuit system. The analog-to-digital converter is configured to convert the filtered first sensor signals and the optional second sensor signals into digital signals and transmit the digital signals to the control circuit system. The EMI filter is configured to suppress noise in the signal of at least one electrode-based sensor caused by a medical intervention device used in a medical intervention procedure.

[0055] According to some embodiments, the system further comprises a first line and a second line. An EMI filter is mounted on the first line. A plurality of first sensor signals are relayed from at least one electrode-based sensor to an analog-to-digital converter via the first line (and filtered by the EMI filter en route). A plurality of second sensor signals are relayed from at least one non-electrode-based sensor to an analog-to-digital converter and / or a control circuit system via the second line.

[0056] According to some embodiments, the system further comprises a wireless communication unit.

[0057] According to some embodiments, the wireless communication unit is configured to receive a signal from the control circuitry and wirelessly transmit the signal to an external monitor that is configured to process the signal and assess the subject's physiological state based thereon.

[0058] According to some embodiments, the control circuitry includes processor circuitry configured to process the digital signal obtained from the analog-to-digital converter and assess the physiological state of the subject based thereon.

[0059] According to some embodiments, the processing of the signal includes cleaning a signal obtained from at least one non-electrode based sensor based on an estimate of noise introduced by at least one electrode based sensor.

[0060] According to some embodiments, assessment of physiological status during a medical intervention procedure includes disregarding data received from electrode-based sensors.

[0061] According to some embodiments, the EMI filter has an attenuation of at least about 10 dB in the first frequency range, and / or the EMI filter has an attenuation of at least about 10 dB greater in the first frequency range than in the second frequency range.

[0062] According to some embodiments, the first frequency range is a typical operating frequency of high intensity and / or high energy radio frequency medical interventional devices, and the second frequency range is a typical sampling frequency or frequencies of electrode-based sensors and at least one non-electrode-based sensor.

[0063] According to some embodiments, the first frequency range is between about 300 kHz and about 500 kHz, and the second frequency range is between 0 Hz and about 600 Hz.

[0064] According to some embodiments, the sensor assembly is a finger probe configured to be mounted on a finger of a subject.

[0065] According to some embodiments, the at least one electrode-based sensor comprises a bioimpedance sensor and / or a biopotential sensor.

[0066] According to some embodiments, at least one electrode-based sensor includes a galvanic skin response (GSR) sensor, an electrocardiograph (ECG), an electromyograph (EMG), an electrogastrograph (EGG), an electroencephalogram (EEG), and / or an electrooculogram (EOG).

[0067] According to some embodiments, the electrode based sensor is a GSR sensor.

[0068] According to an aspect of some embodiments, a system for monitoring physiological parameters during a medical intervention procedure involving high intensity / energy radio frequency current / voltage applied through a subject's body is provided. The system includes a sensor assembly, a plurality of wires, a monitor, and a filter array. The sensor assembly includes: an electrode-based sensor configured to close a conductive path through the subject's body; and one or more non-electrode-based sensors configured to monitor one or more physiological parameters of the subject. The plurality of wires associate the sensor assembly with the monitor and include a first wire and a second wire configured to transmit sensor signals from the electrode-based sensor and one or more non-electrode-based sensors to the monitor. The monitor is configured to assess the subject's physiological activity based on at least some of the sensor signals. The filter array includes at least three electromagnetic interference (EMI) filters:

[0069] - a first proximal filter mounted on the first line in or near the sensor assembly;

[0070] - a second remote filter mounted on the first line in or near the monitor; and

[0071] - A third filter mounted on the second line.

[0072] At least some of the EMI filters are characterized by a frequency response curve such that an amount of attenuation in a first frequency range is at least 10 dB higher than an amount of attenuation in a second frequency range, the first frequency range being a typical operating frequency of a high intensity / energy radio frequency medical interventional device and the second frequency range being a typical sampling frequency or frequencies of an electrode-based sensor and one or more non-electrode-based sensors. Thus, the system is configured to suppress noise caused by the medical interventional device.

[0073] Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more other technical advantages may be apparent to those skilled in the art from the drawings, descriptions, and claims included herein. Moreover, although specific advantages have been listed above, various embodiments may include all, some, or none of the listed advantages.

[0074] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. In the event of a conflict, the present patent specification, including definitions, will control. As used herein, the indefinite articles "a" and "an" mean "at least one" or "one or more" unless the context clearly indicates otherwise.

[0075] Unless specifically stated otherwise, as is apparent from this disclosure, it should be understood that, according to some embodiments, terms such as "process," "compute," "calculate," "determine," "estimate," "evaluate," "gauge," and the like refer to the actions and / or processes of a computer or computing system or similar electronic computing device that manipulates and / or transforms data represented as physical (such as electronic) quantities within registers and / or memories of the computing system into other data similarly represented as physical quantities within the computing system's memories, registers, or other such information storage, transmission, or display devices.

[0076] Embodiments of the present disclosure may include devices for performing the operations herein. The device may be specially constructed for the desired purpose, or may include one or more general-purpose computers selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer-readable storage medium, such as, but not limited to, any type of disk, including a floppy disk, an optical disk, a CD-ROM, a magneto-optical disk, a read-only memory (ROM), a random access memory (RAM), an electrically programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic card or an optical card, or any other type of medium suitable for storing electronic instructions and capable of being coupled to a computer system bus.

[0077] The processes and displays presented herein are not inherently related to any particular computer or other device. Various general purpose systems can be used together with the programs according to the teachings herein, or it may prove convenient to construct more specialized equipment to perform (multiple) desired methods. (Multiple) desired structures for various of these systems appear in the following description. In addition, embodiments of the present disclosure are described without reference to any special programming language. It should be understood that various programming languages ​​can be used to implement the teachings of the present disclosure as described herein.

[0078] Aspects of the present disclosure may be described in the general context of computer-executable instructions (such as program modules) executed by a computer. Typically, program modules include routines, programs, objects, components, data structures, etc., which perform particular tasks or implement particular abstract data types. The disclosed embodiments may also be practiced in a distributed computing environment in which tasks are performed by remote processing devices linked through a communication network. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Some embodiments of the present disclosure are described herein with reference to the accompanying drawings. Figure 1 The accompanying drawings are for illustrative purposes only and do not attempt to show the structural details of the embodiments in more detail than is necessary for a basic understanding of the present disclosure. For clarity, some objects depicted in the drawings are not drawn to scale.

[0080] In the attached picture:

[0081] Figure 1 is a block diagram of a system configured for monitoring physiological parameters during an interventional medical procedure, such as a diathermy surgical procedure, according to some embodiments; and

[0082] Figure 2 is a block diagram of a sensor assembly configured for monitoring one or more physiological parameters during an interventional medical procedure, such as a diathermy surgical procedure, according to some embodiments. DETAILED DESCRIPTION

[0083] The principles, uses and implementations of the teachings herein may be better understood with reference to the attached description and drawings. After carefully reading the description and drawings presented herein, those skilled in the art will be able to implement the teachings herein without undue effort or experimentation. In the accompanying drawings, the same reference numerals always represent the same parts.

[0084] In the description and claims of this application, the words "including" and "having" and forms thereof are not limited to the list of members that can be associated with the words.

[0085] As used herein, the term "about" may be used to specify a value of a quantity or parameter (e.g., the length of an element) as being within (and including) a continuous range of values ​​around a given (stated) value. According to some embodiments, "about" may specify a value of a parameter that is between 80% and 120% of the given value. For example, stating that "the length of the element is equal to about 1 m" is equivalent to stating that "the length of the element is between 0.8 m and 1.2 m". According to some embodiments, "about" may specify a value of a parameter that is between 90% and 110% of the given value. According to some embodiments, "about" may specify a value of a parameter that is between 95% and 105% of the given value.

[0086] Figure 1 is a block diagram of a monitoring system 100 including a plurality of physiological sensors according to some embodiments. According to some embodiments, the monitoring system 100 may be a multi-parameter physiological monitoring system configured to monitor a plurality (e.g., at least 2, at least 3, or at least 4) of physiological parameters of a subject. According to some embodiments, the monitoring system 100 may be a vital sign monitoring system configured to monitor at least 2, at least 3, or at least 4 vital signs of a subject, such as pulse rate, temperature, respiratory rate, blood pressure, and / or other parameters indicative of the state of the patient's basic bodily functions. According to some embodiments, the monitoring system 100 may be an autonomic nervous system monitoring system configured to monitor at least 2, at least 3, or at least 4 parameters indicative of autonomic nervous system activity / function.

[0087] The plurality of physiological sensors include electrode-based sensors and at least one non-electrode-based sensor, as described in detail below. The monitoring system 100 is configured to measure at least one physiological parameter of a subject undergoing a medical procedure in which a high intensity / energy radiofrequency current / voltage is applied through the subject's body, such as, but not limited to, diathermy and RF ablation procedures, thereby, for example, allowing for an assessment of the subject's autonomic nervous system activity (during the procedure). According to some embodiments, the monitoring system 100 may be configured to assess the level of pain experienced by the subject (during the procedure), as described in detail below. Additionally or alternatively, the monitoring system 100 may be configured to monitor the subject's analgesia, nociception, anesthesia, stress, and / or anxiety during the procedure.

[0088] Monitoring system 100 includes sensor assembly 102, monitor 104, wires 112, and a filter array (including multiple EMI filters as specified below). According to some embodiments, sensor assembly 102 may include an electrode-based sensor and at least one non-electrode-based sensor, which are positioned adjacent to each other, such as less than 10 cm, less than 5 cm, less than 2 cm, less than 1 cm, or less than 0.5 cm from each other. Each possibility is a separate embodiment. According to some embodiments, sensor assembly 102 is powered via monitor 104.

[0089] The sensor assembly 102 includes a first sensor 122 and a second (additional) sensor 124. The first sensor 122 is an electrode-based sensor that includes electrodes (e.g., at least two electrodes) configured to close one or more conductive paths through the body of the subject. The first sensor 122 can be any bioimpedance sensor and / or biopotential sensor. Non-limiting examples of suitable bioimpedance and / or biopotential sensors include an electrocardiograph (ECG), an electromyograph (EMG), an electrogastrograph (EGG), an electroencephalograph (EEG), and / or an electrooculogram (EOG). Each possibility is a separate embodiment. According to some embodiments, the first sensor 122 can be or include a galvanic skin response (GSR) sensor.

[0090] The second sensor 124 can be configured to monitor another physiological parameter of the subject. According to some embodiments, the second sensor 124 is a non-electrode-based sensor, and the monitoring implemented by the second sensor 124 does not involve closing a conductive path through the subject's body. Non-limiting examples of suitable non-electrode-based sensors include piezoelectric sensors, accelerometers, thermometers, blood pressure sensors, respiratory sensors, near infrared spectroscopy (NIRS) sensors (e.g., to quantify oxygen saturation), sensors based on dynamic light scattering (DLS), laser Doppler flowmeters (e.g., to quantify blood flow), sensors based on diffusion correlation spectroscopy (DCS) (e.g., to monitor blood flow), acoustic sensors, and microphones. Each possibility is a separate embodiment. According to some embodiments, the second sensor 124 can include more than one sensor, for example, 2, 3, 4, 5 or more sensors. Each possibility is a separate embodiment. As a non-limiting example, the second sensor 122 can include two or more piezoelectric sensors, such as to allow extraction of pulse transit time (Ptt) readings. According to some embodiments, the second sensor 122 may include a piezoelectric sensor and a PPG sensor, such as to allow extraction of Ptt readings. According to some embodiments, the second sensor 122 may include two or more spaced-apart PPG sensors, such as to allow extraction of Ptt readings. According to some such embodiments, the second sensor 122 may be configured to allow extraction of a pulse velocity wave for determining Ptt and blood pressure related parameters. According to some embodiments, the second sensor 124 may be or may include a photoplethysmogram (PPG) sensor.

[0091] According to some embodiments, the first sensor 122 and the second sensor 124 may each be configured to sample at a rate between about 10 Hz and about 2 kHz or between about 50 Hz and about 1 kHz. According to some embodiments, the first sensor 122 and the second sensor 124 may each be configured to sample at a rate of about 500 Hz. According to some embodiments, the sensor assembly 102 may be configured to be mounted / placed on the patient's body, such as on the patient's forehead, back, chest, foot, arm, hand (e.g., on the back of the hand) and / or ear (e.g., in the earlobe). Each possibility is a separate embodiment. According to some embodiments, the sensor assembly 102 may be a finger probe configured to be mounted / worn on a subject's finger.

[0092] Wires 112 electrically connect sensor assembly 102 and monitor 104. Wires 112 are configured to transmit sensor data obtained by first sensor 122 and second sensor 124 (and optionally, when present, additional sensors) to monitor 104, as described in more detail below.

[0093] According to some embodiments, the sensor assembly 102 includes a control circuit system (including, for example, a microcontroller; not shown) that is functionally associated with the first sensor 122 and the second sensor 124 and is configured to control the operation of the first sensor 122 and the second sensor 124 (as well as additional operations in embodiments in which the sensor assembly 102 includes additional sensors).

[0094] Monitor 104 includes a processing circuit system that is configured to process sensor data received from sensor assembly 102 and to assess a physiological state of a subject, such as activity of the subject's autonomic nervous system during a high-intensity / energy radiofrequency interventional procedure (such as diathermy) based on the sensor data. According to some embodiments, the processing circuit system includes at least one processor 132, a memory (not shown), and an analog-to-digital converter (ADC) 134 that is configured to convert analog sensor data into one or more digital signals that are fed to processor 132. The processing circuit system may be mounted / located on a motherboard 136 (printed circuit board). Monitor 104 may additionally include a user interface (including a display) and a wireless communication unit and / or a port for wired communication (both not shown).

[0095] Processor 132 may include one or more microprocessors, application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), firmware, etc. (all not shown). In particular, processor 132 may include one or more customized processors for analyzing sensor data, such as to obtain physiological parameters of the subject therefrom, and based thereon assess the subject's autonomic nervous system activity (e.g., the level of pain experienced by the subject).

[0096] The memory may include transient memory components and / or non-transient memory components, which may be solid-state, magnetic, photonic, etc. According to some embodiments, some or all of the memory components may be integrated together or distributed. According to some embodiments, the memory may be fully or partially integrated with the processor 132. As described above, the memory stores therein software instructions executable by the processor 132 to analyze sensor data.

[0097] According to some embodiments, sensor assembly 102 and monitor 104 may be functionally associated such that controllable functions of sensor assembly 102 (eg, activating / deactivating a sensor) may be controlled using monitor 104 (eg, via its user interface).

[0098] The filter array includes a plurality of EMI filters 142. According to some embodiments, the EMI filters 142 may be characterized by a frequency response curve having a minimum value (when gain is plotted as a function of frequency) in a frequency range corresponding to an operating frequency of the medical device causing the noise. According to some embodiments, at least some of the EMI filters 142 may be characterized by a frequency response curve having an attenuation in a first frequency range that is at least 10 dB greater than an attenuation in a second frequency range (i.e., a gain in the first frequency range is at least 10 dB lower than a gain in the second frequency range). The first frequency range may be a typical operating frequency (applied current frequency) of diathermy, RF ablation, and similar surgical devices. The second frequency range may characterize a sampling frequency of a sensor. According to some embodiments, for example, when the medical device causing the noise is a diathermy electrosurgical device, at least some of the EMI filters 142 may be characterized by a frequency response curve having a minimum value between 100 kHz and 5 MHz. According to some embodiments, the minimum value is a global minimum value (maximum attenuation). According to some embodiments, at least some of EMI filters 142 may attenuate frequencies in the range of 300 kHz to 500 kHz by at least about 50 dB, at least about 55 dB, at least about 60 dB, or at least about 70 dB (i.e., a gain of at least about -50 dB, -55 dB, -60 dB, or -70 dB, respectively). Each possibility is a separate embodiment.

[0099] According to some embodiments, the attenuation in the range of 300kHz to 500kHz is at least about 10dB greater, at least about 15dB greater, at least about 20dB greater, or at least about 50dB greater than in the range of 0Hz to 600Hz. Each possibility is a separate embodiment. The EMI filter is thus configured to suppress the noise caused by diathermy / RF ablation and enables reliable measurement of physiological parameters (e.g., by the second sensor 124).

[0100] According to some embodiments, a first (near side) EMI filter 142a (from EMI filter 142) can be installed on the first line 112a (from wire 112) in or near the sensor assembly 102 and can be configured to filter the first sensor 122 measurement data. According to some embodiments, and as described in detail below, the first EMI filter 142a can be characterized by a capacitance of about 0.1 μF. According to some embodiments, the relatively low capacitance of the first EMI filter 142a can help preserve the signal obtained from the first sensor 122. According to some embodiments, the first EMI filter 142a can attenuate frequencies in the range of 300 kHz to 500 kHz by about 5 dB, about 10 dB, about 20 dB, or about 25 dB.

[0101] Additionally or alternatively, a second (remote) EMI filter 142b (from EMI filter 142) can be mounted on first line 112a in or near monitor 104. According to some embodiments, and as described in detail below, second EMI filter 142b can be characterized by a capacitance between about 20 μF and about 30 μF. According to some embodiments, second EMI filter 142b can attenuate frequencies in the range of 300 kHz to 500 kHz by about at least about 50 dB, at least about 55 dB, at least about 60 dB, or at least about 70 dB.

[0102] The first EMI filter 142a and the second EMI filter 142b may be installed in series on the first line 112a so that the measurement data of the first sensor 122 is filtered twice. Specifically, the second EMI filter 142b may be configured to filter the measurement data received from the first EMI filter 142a (which has been filtered once).

[0103] A third EMI filter 142c (from EMI filter 142) can be mounted on second line 112b (from wire 112). According to some embodiments, including some embodiments where second sensor 124 is a non-electrode-based sensor (e.g., a PPG sensor), third EMI filter 142c can be mounted on second line 112b in or near monitor 104. According to some embodiments, and as described in detail below, third EMI filter 142c can be characterized by a capacitance between about 20μF and about 30μF. According to some embodiments, third EMI filter 142c can attenuate frequencies in the range of 300kHz to 500kHz by about at least about 50dB, at least about 55dB, at least about 60dB, or at least about 70dB.

[0104] The positioning of the EMI filters 142a-142c can result in reliable diathermy-induced noise suppression. In particular, positioning the first EMI filter 142a at the start (proximal end) of the first wire 112a helps reduce EMI interference between the first wire 112a and the second wire 112b (e.g., due to capacitive coupling between the two wires along their lengths).

[0105] According to some embodiments, an input terminal of the first EMI filter 142a may be electrically coupled to the first sensor 122 and may be configured to receive therefrom measurement data of the first sensor 122. According to some embodiments, the first EMI filter 142a may be positioned such that its input terminal is adjacent to the first sensor 122. An output terminal of the first EMI filter 142a may be configured to relay the filtered measurement data of the first sensor 122 to the monitor 104 via the first line 112a. A ground terminal of the first EMI filter 142a may be connected to a first floating ground (e.g., a signal ground).

[0106] According to some embodiments, the input terminal of the second EMI filter 142b can be configured to receive the filtered first sensor 122 measurement data via the first line 112a. The output terminal of the first EMI filter 142a can be electrically coupled to the ADC 134 and can be configured to relay the first sensor 122 measurement data that has been filtered twice to the ADC 134. The ground terminal of the second EMI filter 142b can be connected to the floating ground. According to some embodiments, the input terminal of the third EMI filter 142c can be configured to receive the second sensor 124 measurement data via the second line 112b. The output terminal of the third EMI filter 142c can be electrically coupled to the ADC 134 and can be configured to relay the filtered second sensor 124 measurement data to the ADC 134. The ground terminal of the third EMI filter 142c can be connected to the floating ground.

[0107] According to some embodiments, sensor assembly 102 may be powered independently of monitor 104 (eg, sensor assembly 102 is powered by a battery rather than via monitor 104). In such embodiments, ground terminals of second EMI filter 142b and third EMI filter 142c may be connected to a second floating ground.

[0108] According to some embodiments, the second EMI filter 142b and the third EMI filter 142c may be positioned close to the ADC 134, for example on the main board 136 of the monitor 104 (near or adjacent to the ADC 134). According to some embodiments, the second EMI filter 142b and the third EMI filter 142c may be positioned at respective entrances of the ADC 134. According to some embodiments, the second EMI filter 142b and the third EMI filter 142c may be positioned so that their output terminals are adjacent to the ADC 134. According to some embodiments, the first EMI filter 142a may be positioned at a distance less than about 5 cm, less than about 2 cm, or less than about 1 cm from the first sensor 122 (indicated by the dashed double arrow D1). Each possibility is a separate embodiment.

[0109] According to some embodiments, second EMI filter 142b may be positioned at a distance less than about 10 cm, less than about 5 cm, less than about 2 cm, or less than about 1 cm from ADC 134 (indicated by dashed double arrow D2). Each possibility is a separate embodiment.

[0110] According to some embodiments, third EMI filter 142c may be positioned at a distance less than about 10 cm, less than about 5 cm, less than about 2 cm, or less than about 1 cm from ADC 134 (indicated by dashed double arrow D3). Each possibility is a separate embodiment.

[0111] According to some embodiments, ADC 134 may refer to a plurality of ADCs, each ADC being communicatively associated with a different sensor. Thus, for example, according to some embodiments, EMI filter 142b may be associated with a first ADC, and second EMI filter 142c may be associated with a second ADC.

[0112] According to some embodiments, including embodiments in which the sensor assembly 102 is a finger probe, the sensor assembly 102 may include a substrate (e.g., a printed circuit board) on which the first sensor 122, the second sensor 124, and the first EMI filter 142a may be mounted / positioned (as well as control circuitry and additional non-electrode-based sensors, such as but not limited to accelerometers and thermistors, substantially as described herein). According to some embodiments, the first sensor 122 may not be positioned on the substrate, but rather on a separate disposable (replaceable) element (not shown) that is configured for use with the sensor assembly 102. According to some embodiments, the first EMI filter 142a may not be positioned on the substrate, but rather on the disposable element. According to some embodiments, the disposable element is configured to be attached to the sensor assembly 102 or mounted within the sensor assembly 102 so that contact is established between the electrodes of the first sensor 122 and the skin of the subject. According to some embodiments, the disposable element is flexible, and the electrodes of the first sensor 122 form an electrode array on the disposable element. According to some embodiments, the disposable element includes an electrical connector on an end thereof that is configured to connect to a mating electrical connector in the sensor assembly 102, such as to electrically couple the first sensor 122 to a printed circuit board of the sensor assembly 102. In some embodiments, the first EMI filter 142a can be positioned between the first sensor 122 and the electrical connector.

[0113] As a non-limiting example, each of the EMI filters 142 may be a low ESL (equivalent series inductance) feed-through capacitor having three terminals (input, output, and ground), as is known in the art.

[0114] According to some embodiments, the first EMI filter 142a is different from the remaining EMI filters (particularly, the second EMI filter 142b and the third EMI filter 142c), and the capacitance of the first EMI filter 142a is between about 0.01 μF and about 1 μF. According to some embodiments, the capacitance of the first EMI filter 142a is about 0.1 μF. According to some embodiments, the first EMI filter 142a can be a (non-polar) chip multilayer ceramic capacitor, such as, for example, the NFM21 series from Murata.

[0115] According to some embodiments, the capacitance of each of the second EMI filter 142b and the third EMI filter 142c (and EMI filters 142d-142g in the following embodiments including additional filters associated with the third sensor 162) is between about 1 μF and about 100 μF, between about 20 μF and about 30 μF, or about 27 μF. Each possibility is a separate embodiment. According to some embodiments, each EMI filter 142b-142g can be a (non-polar) chip multilayer ceramic capacitor, such as, for example, Murata's NFM31PC276B0J3 EMI filter.

[0116] According to some embodiments, one or more EMI filters in filter 142 include at least two EMI filters connected in series, for example, a low pass filter and a high pass filter connected in series.

[0117] As used herein, according to some embodiments, the wire 112 may include any electrical wire / wiring, conductive trace (e.g., copper trace when the second EMI filter 142b, the third EMI filter 142c, and the ADC 134 are mounted on the mainboard 136), etc., which define a conductive path that electrically connects the first sensor 122 and the second sensor 124 to the ADC 134, or to the processor 132 without passing through the ADC 134 when the transmitted signal is digital. For example, in an embodiment in which the first sensor 122 is mounted on a disposable element, the first wire 112a may extend from within the disposable element, via the finger probe (control circuitry), via the cable, and extend into the monitor 104 (e.g., to the ADC 134). According to some embodiments, the wire 112 extends along a common cable between the sensor assembly 102 and the monitor 104. According to some embodiments, the cable may be a 2.8m cable.

[0118] According to some embodiments, the monitoring system 100 includes one or more amplifiers 152 for amplifying analog sensor data. In particular, the data relayed to the second EMI filter 142b and the third EMI filter 142c may be first amplified to improve its noise immunity. For example, and as Figure 1 As depicted, according to some embodiments, the monitor 104 includes a first amplifier 152a and a second amplifier 152b (of the amplifier 152) configured to amplify data of the first sensor 122 and the second sensor 124. The first amplifier 152a can be installed on the first line 112a before the second EMI filter 142b. The second amplifier 152b can be installed on the second line 112b before the third EMI filter 142c.

[0119] According to some embodiments, amplifier 152 is housed within a single unit.

[0120] According to some embodiments, and as Figure 1 As depicted, sensor assembly 102 may also include a third (non-electrode-based) sensor 162, such as, but not limited to, an accelerometer (e.g., a digital accelerometer). The accelerometer may be used to measure / detect, for example, movement / trembling / seizures of the subject. According to some embodiments, third sensor 162 may be electrically associated with at least one additional EMI filter positioned in monitor 104. As a non-limiting example, according to some embodiments, including embodiments in which third sensor 162 is a digital accelerometer, third sensor 162 may be electrically associated with, for example, three EMI filters, or as Figure 1 As depicted, four EMI filters: a fourth EMI filter 142d, a fifth EMI filter 142e, a sixth EMI filter 142f, and a seventh EMI filter 142g. The EMI filters 142d, 142e, 142f, and 142g are electrically associated with the third sensor 162 via the third line 112c, the fourth line 112d, the fifth line 112e, and the sixth line 112f (from the electrical line 112), respectively. When the output of the third sensor 162 is digital, the filtered third sensor 162 measurement data can be directly transmitted from the EMI filters 142d-142g to the processor 132. According to some embodiments, for example, in embodiments in which the third sensor 162 is a digital accelerometer, the EMI filters 142d-142g are not grounded because the high capacitance (e.g., greater than 10 μF) of the EMI filters 142d-142g can cause communication failures between the accelerometer and the processor 132. According to some embodiments, the EMI filters 142b - 142g may be the same or substantially the same and / or have substantially the same properties.

[0121] According to some embodiments, and as Figure 1As depicted, the sensor assembly 102 may also include a fourth (non-electrode-based) sensor 172, such as but not limited to a thermometer configured to measure the temperature of the subject. According to some embodiments, the fourth sensor 172 is a thermistor. The fourth sensor 172 dedicated line 112g may be configured to relay the fourth sensor 172 measurement data to the processor 132. According to some embodiments, the monitor 104 may include a third amplifier 152c (before the processor 132) for amplifying the relayed measurement data of the fourth sensor 172.

[0122] According to some embodiments, when the third sensor or the fourth sensor is non-electrode based and sufficiently electrically isolated, installation of an EMI filter on the associated electrical wires may be avoided.

[0123] Processor 132 may be configured to determine a physiological state (e.g., autonomic nervous system activity or pain level) of a subject based on measurement data received from sensor assembly 102 (e.g., measurement data received from first sensor 122 and second sensor 124 and optionally from additional sensors (when present)). According to some embodiments, processor 132 may be configured to allow any electrical signal received via first wire 112a (or any of the wires 112 connected to the electrode-based sensor) to be disregarded (i.e., not considered) when evaluating (calculating) the physiological state of a patient during a diathermy procedure, an RF ablation procedure, etc. Specifically, processor 132 may be configured to allow any electrical signal picked up by the electrodes of first sensor 122 to be disregarded.

[0124] According to some embodiments, processor 132 may be configured to detect when a diathermy (or RF ablation) current / voltage is applied to the patient. According to some embodiments, processor 132 may be configured to detect based on measurement data received from sensor assembly 102, such as based on noise levels in the measurement data. According to some embodiments, upon detecting application of a diathermy (or RF ablation) current, processor 132 may disregard measurement data of any of wires 112 (e.g., first wire 112a) connected to the electrode-based sensor when assessing the patient's physiological state.

[0125] According to some embodiments, processor 132 may be configured to estimate noise introduced by first sensor 122 and take the noise estimate into account when assessing the patient's physiological state (during a diathermy procedure, an RF ablation procedure, etc.).

[0126] According to some embodiments, sensor assembly 102 and monitor 104 may include an electrical switch and an electrical bypass element (not shown) that allow switching between two configurations: a first configuration in which EMI filter 142 may be decoupled and thus measurement data may not be relayed therethrough, but rather is relayed via the electrical bypass element; and a second configuration in which EMI filter 142 may be coupled and measurement data may be relayed through EMI filter 142, as described above. According to some embodiments, processor 132 may be configured to switch from the first configuration to the second configuration when application of a diathermy (or RF ablation) current is detected.

[0127] According to some embodiments, the sensor assembly 102 is configured to allow an operator to select which sensor is active (e.g., the operator can select whether to activate the first sensor 122, the second sensor 124, or both). According to some embodiments, any electrode-based sensor, such as the first sensor 122, can be controllably disabled during a diathermy procedure.

[0128] refer to Figure 2 According to an aspect of some embodiments, a sensor assembly 202 is provided. Sensor assembly 202 is similar to sensor assembly 102, but differs therefrom at least in that sensor assembly 202 is wireless. That is, sensor assembly 202 is configured for wireless communication with an associated (external) monitor (not shown), which can be configured to process sensor measurement data received from sensor assembly 102, such as to assess a patient's physiological state (e.g., level of pain or nociception) during a diathermy surgical procedure or an RF ablation procedure.

[0129] Additionally or alternatively, according to some embodiments, processing of sensor measurement data may be performed by the wireless sensor assembly, and in particular by the control circuitry, as described in further detail below.

[0130] According to some embodiments, sensor assembly 202 may be configured to be mounted / placed on the forehead, back, chest, foot, arm, hand, and / or ear (e.g., in the earlobe). Each possibility is a separate embodiment. According to some embodiments, sensor assembly 102 may be a finger probe.

[0131] More specifically, the sensor assembly 202 includes a first (electrode-based) sensor 222 and a second (non-electrode-based) sensor 224, which are similar to the first sensor 122 and the second sensor 124, respectively. The sensor assembly 202 also includes an EMI filter 242, an ADC 274, a control circuit system 276 (including, for example, a microcontroller), and a wireless communication unit 278. The control circuit system 276 is functionally associated with the sensors 222 and 224 and the wireless communication unit 278, and is configured to control the operation thereof.

[0132] EMI filter 242 is similar to first EMI filter 142a. EMI filter 242 is electrically coupled to first sensor 222, such as to filter first sensor 222 measurement data. The filtered first sensor 222 measurement data is transmitted from EMI filter 242 to ADC 274, and from ADC 274 to wireless communication unit 278.

[0133] According to some embodiments, the input terminal of the EMI filter 242 can be electrically coupled to the first sensor 222 and can be configured to receive therefrom the measurement data of the first sensor 222. The output terminal of the EMI filter 242 can be configured to relay the filtered measurement data of the first sensor 222 to the ADC 274. The ground terminal of the EMI filter 242 can be grounded. According to some embodiments, the ground is a floating ground.

[0134] According to some embodiments, EMI filter 242 may be positioned at a distance less than about 5 cm, less than about 2 cm, or less than about 1 cm from first sensor 222 (indicated by dashed double arrow L). Each possibility is a separate embodiment.

[0135] As a non-limiting example, as known in the art, the EMI filter 242 can be a low ESL feed-through capacitor with three terminals (input, output and ground). According to some embodiments, the capacitance of the capacitor is between about 0.01 μF and about 1 μF. According to some embodiments, the capacitance of the capacitor is about 0.1 μF. According to some embodiments, the capacitor can be a (non-polar) chip multilayer ceramic capacitor, such as, for example, the NFM21 series from Murata.

[0136] According to some embodiments, the EMI filter 242 may be mounted adjacent to / close to the first sensor 222, and the ADC 274 may optionally be mounted adjacent to / close to the EMI filter 242, such as to minimize the length of wires (not numbered) connecting / coupling the EMI filter 242 to the first sensor 222 and the ADC 274. As used herein, according to some embodiments, "wires" may include any type of conductive path (e.g., conductive traces on a PCB) or electrical connection that electrically couples the first sensor 222 and the second sensor 224 to the ADC 274, directly or indirectly (e.g., when the EMI filter is mounted on the wire), or to the control circuit system 272 when the transmitted signal is digital, without passing through the ADC 274.

[0137] According to some embodiments, where the second sensor 224 output is analog, the second sensor 224 is configured to relay its measurement data to the ADC 274, from which the measurement data is relayed to the control circuit system 276, which further relays the measurement data to the wireless communication unit 278. According to some embodiments, where the second sensor 224 output is digital, the second sensor 224 measurement data is relayed to the wireless communication unit 278 (via the control circuit system 276) without passing through the ADC 274.

[0138] According to some embodiments, one or more of the non-electrode based sensors may be optically coupled to the control circuitry, such as via optical fibers.

[0139] According to some embodiments, sensor assembly 202 also includes one or more additional (non-electrode-based) sensors: third sensor 262 and / or fourth sensor 272, which are similar to third sensor 162 (e.g., accelerometer) and fourth sensor 172 (e.g., thermometer). According to some embodiments, where the output of third sensor 272 is digital, such as embodiments where third sensor 272 is a digital accelerometer, third sensor 272 can be connected via multiple wires (not numbered) (e.g., three wires (e.g., Figure 2 depicted) or four lines) are communicatively associated with the control circuit system 276.

[0140] Wireless communication unit 278 is configured to transmit measurement data obtained by the sensors to an associated monitor.

[0141] According to some embodiments, the sensor assembly 202 may include an amplifier (not shown) mounted between the sensor and the ADC 274, such as to amplify the corresponding sensor signal. More specifically, the amplifier associated with the first sensor 222 may be mounted between the EMI filter 242 and the ADC 274, such as to amplify the filtered first sensor 222 signal.

[0142] According to one aspect of some embodiments not depicted in the accompanying drawings, a monitoring system including a plurality of physiological sensors is provided. The monitoring system is similar to the sensor assembly 202, but differs in that the monitoring system constitutes a single unit, wherein both the plurality of sensors and the monitor are required parts (unlike the case of a sensor assembly associated with an external monitor). More specifically, the components of the monitoring system may be housed in a single unit (housing), wherein the processing of the sensor readings is performed within the unit. In particular, the unit includes a processing circuit system (which may be similar to the processing circuit system in the monitor 104), which is configured to assess the patient's physiological state based on the sensor readings. The unit may also include a user interface, which may include a display. Note that the sensors, EMI filters, and ADCs of the monitoring system may be arranged similarly to sensors 222 and 224 (and sensors 262 and 272 in embodiments including a third sensor and a fourth sensor), EMI filter 242, and ADC 274.

[0143] The skilled artisan will appreciate that while some of the discussion regarding the monitoring system 100 / sensor assembly 202 has focused on embodiments configured to assess the level of pain experienced by a patient during a diathermy surgical procedure, the scope of the present application also encompasses embodiments in which the monitoring system 100 / sensor assembly 202 is additionally or alternatively configured to assess the degree / level of anesthesia, nociception, sleep, stress, anxiety, and / or analgesia of a subject during a diathermy surgical procedure. More generally, the scope of the present application also encompasses embodiments in which the monitoring system 100 / sensor assembly 202 is configured to determine the activity of the subject's autonomic nervous system during a diathermy surgical procedure. Even more generally, the scope of the present application also encompasses embodiments in which the monitoring system 100 / sensor assembly 202 is configured to reliably monitor at least one physiological parameter using a non-electrode-based sensor of a subject during a diathermy surgical procedure in the event that the electrode-based sensor is mounted on the subject's body and electromagnetically interferes with the reading / signal of the non-electrode-based sensor (e.g., due to the non-electrode-based sensor, the electrode-based sensor being positioned in close proximity to each other).

[0144] The skilled person will also understand that, although some of the discussion regarding the monitoring system 100 / sensor assembly 202 focuses on an embodiment in which the sensor assembly 102 / sensor assembly 202 is a finger probe, the scope of the present application encompasses any multi-sensor assembly / probe, including or associated with an electrode-based sensor (e.g., the first sensor 122 or the like) configured to close a conductive path within the subject's body and at least one non-electrode-based sensor (e.g., the second sensor 124 or the like). In particular, the sensor assembly 102 / sensor assembly 202 may be configured to be mounted / placed on the forehead, back, chest, foot, hand (additionally or alternatively on a location other than a finger), and / or ear.

[0145] Finally, the skilled artisan will appreciate that while some of the discussion regarding the monitoring system 100 / sensor assembly 202 has focused on diathermy, the monitoring system 100 may also be used to reliably assess a patient's physiological state (e.g., autonomic nervous system activity) during an RF ablation procedure, and more generally, to reliably monitor physiological parameters during an RF ablation procedure. Indeed, RF ablation procedures are typically characterized by operating frequencies (i.e., the frequency of the applied AC current / voltage) in the range of 350 kHz to 500 kHz that overlap with the operating frequencies of diathermy surgical devices, thereby making the disclosed EMI filters (e.g., EMI filter 142) also suitable for suppressing noise caused by RF ablation. More generally, the skilled artisan will appreciate that the monitoring system 100 / sensor assembly 202 may be used to reliably assess a patient's physiological state during any procedure involving the application of high intensity / energy radio frequency current / voltage through the patient's body.

[0146] As used herein, the terms "sensor data" (and corresponding derivatives such as "sensed data") and "measurement data" are interchangeable according to some embodiments. According to some embodiments, the terms "sampling" and "measurement" (and corresponding derivatives such as "to sample" and "to measure") are interchangeable.

[0147] As used herein, according to some embodiments, the terms "subject" and "patient" are interchangeable.

[0148] As used herein, according to some embodiments, the terms "first EMI filter" and "near-side EMI filter" may be interchanged. According to some embodiments, the terms "second EMI filter" and "far-side EMI filter" may be interchanged.

[0149] As used herein, according to some embodiments, the term "sensor data" may be interchangeable with "sensor signal(s)" with respect to measurement data of a sensor transmitted / relayed / sent via electrical wires.

[0150] As used herein, according to some embodiments, with respect to two electrically associated elements / components, the term "coupling" (and its derivatives such as "coupled") may refer to "direct" coupling, in which the two elements are directly connected by wires, as well as indirect coupling, in which a third element (such as an amplifier) ​​is present on the wires between the two elements.

[0151] As used herein, according to some embodiments, the term "proximal" with respect to the positioning of an element / component may refer to an element / component that is located on or near the subject's body (e.g., in a finger probe worn by the subject). According to some embodiments, the term "distal" with respect to the positioning of an element / component may refer to an element / component that is not located near the subject's body (e.g., on a monitor).

[0152] It should be understood that, for the sake of clarity, certain features of the present disclosure described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, for the sake of brevity, various features of the present disclosure described in the context of a single embodiment may also be provided individually or in any suitable subcombination or as appropriate in any other described embodiment of the present disclosure. Unless explicitly stated, features described in the context of an embodiment should not be considered essential features of that embodiment.

[0153] Although the steps of the method according to some embodiments can be described in a specific order, the method of the present disclosure may include some or all of the described steps performed in a different order. The method of the present disclosure may include several of the described steps or all of the described steps. Unless explicitly stated, no particular step in the disclosed method is considered to be an essential step of the method.

[0154] Although the present disclosure is described in conjunction with specific embodiments of the present disclosure, it is apparent that there may be many substitutions, modifications and variations that are apparent to those skilled in the art. Therefore, the present disclosure encompasses all such substitutions, modifications and variations that fall within the scope of the appended claims. It should be understood that the application of the present disclosure is not necessarily limited to the details of the construction and arrangement of the components and / or methods set forth herein. Other embodiments may be practiced, and the embodiments may be performed in various ways.

[0155] The words and terms used herein are for descriptive purposes and should not be considered limiting. The citation or identification of any reference in this application should not be construed as an admission that such reference can be used as prior art for the present disclosure. Section headings are used herein to simplify the understanding of the specification and should not be construed as necessary limitations.

Claims

1. A system for monitoring physiological parameters during diathermy therapy, comprising: A sensor assembly configured to monitor a physiological state of a subject, the sensor assembly comprising: an electrode-based sensor configured to close a conductive path through the subject's body, and At least one non-electrode-based sensor configured to monitor one or more physiological parameters of a subject during a medical intervention procedure involving application of at least one selected from: 1) High-intensity radio frequency current, 2) High-intensity radio frequency voltage, 3) High-energy radio frequency current, and 4) high energy radio frequency voltage; and a first electromagnetic interference (EMI) filter coupled to the electrode-based sensor and configured to suppress noise in a signal of the electrode-based sensor caused by a medical interventional device through the electrode-based sensor during the medical interventional procedure; and a plurality of wires, a second EMI filter, a third EMI filter, and a monitor, wherein the monitor includes an analog-to-digital converter ADC and a processor, Wherein, the plurality of wires electrically associate the sensor assembly with the monitor, and the plurality of wires include: a first wire configured to transmit a signal from the electrode-based sensor to the monitor; and a second wire configured to transmit a signal from the non-electrode based sensor to the monitor; wherein the first EMI filter and the second EMI filter are mounted on the first line, the first EMI filter is positioned between the electrode-based sensor and the second EMI filter, and wherein the third EMI filter is mounted on the second line; wherein noise suppression in the signal of the non-electrode based sensor is achieved by attenuating frequencies within a first frequency range by 10 dB or more compared to frequencies within a second frequency range, the first frequency range including the radio frequency of the applied current or voltage, and the second frequency range including the sampling frequency of the sensor assembly; wherein each of the second EMI filter and the third EMI filter is characterized by a corresponding frequency response curve, and the attenuation of the frequency response curve in the first frequency range is at least 10 dB greater than the attenuation in the second frequency range; and Wherein the processor is configured to assess the physiological state of the subject based at least on the signal of the non-electrode based sensor.

2. The system according to claim 1, wherein: The first frequency range is between 300 kHz and 500 kHz, and wherein the second frequency range is between 0 Hz and 600 Hz, and wherein the attenuation of the first EMI filter in the first frequency range is at least 10 dB.

3. The system according to claim 1, wherein: The medical interventional procedure is diathermy or RF ablation.

4. The system according to claim 1, wherein: The non-electrode based sensor is or comprises a photoplethysmogram (PPG) sensor.

5. The system according to claim 1, wherein: The electrode-based sensor is or comprises a galvanic skin response (GSR) sensor.

6. The system according to claim 1, wherein: The physiological state is the subject's autonomic nervous system activity, which includes one or more of the subject's level of pain, nociception, anesthesia, analgesia, anxiety, and stress.

7. The system according to claim 1, wherein: The attenuation of the second EMI filter and / or the third EMI filter in the first frequency range is at least 60 dB.

8. The system according to claim 1, wherein: The first wire extends from the electrode-based sensor to the ADC, and the second wire extends from the non-electrode-based sensor to the ADC; wherein an input terminal of the first EMI filter is coupled to the electrode-based sensor, wherein an output terminal of the first EMI filter is configured to transmit a signal via the first line, the signal being induced in the electrode-based sensor during the medical intervention procedure and filtered by the first EMI filter, and wherein a ground terminal of the first EMI filter is connected to a floating terminal; wherein an input terminal of the second EMI filter is configured to receive a signal from the first EMI filter via the first line, wherein an output terminal of the second EMI filter is coupled to the ADC, and wherein a ground terminal of the second EMI filter is connected to the floating terminal; and An input terminal of the third EMI filter is configured to receive a signal of the non-electrode based sensor via the second line, an output terminal of the third EMI filter is coupled to the ADC, and a ground terminal of the third EMI filter is connected to the floating ground.

9. The system of claim 1 , further comprising a first amplifier and a second amplifier, wherein the first amplifier is installed on the first line between the first EMI filter and the second EMI filter, the first amplifier being configured to amplify a signal transmitted by the first EMI filter; and in, The second amplifier is mounted on the second line proximate the third EMI filter, the second amplifier being configured to amplify a signal received from the non-electrode based sensor.

10. The system according to claim 9, wherein: The first EMI filter is housed near or adjacent to the electrode-based sensor within the sensor assembly, wherein the ADC, the second EMI filter, the third EMI filter, the first amplifier, and the second amplifier are housed in the monitor, and wherein each of the second EMI filter and the third EMI filter is positioned near or adjacent to the ADC.

11. The system according to claim 1, wherein: Each of the EMI filters is a low ESL (equivalent series inductance) feed-through capacitor, wherein the capacitance of the first EMI filter is between 0.05 μF and 0.2 μF, and wherein the capacitance of the second EMI filter and the third EMI filter is between 15 μF and 40 μF.

12. The system of claim 1, wherein: The assessment of the physiological state includes disregarding data received from the electrode-based sensor and / or cleaning signals obtained from the non-electrode-based sensor based on an estimate of noise introduced by the electrode-based sensor, the medical intervention device.

13. The system of claim 1, wherein: The sensor assembly also includes a digital accelerometer, wherein the system also includes at least three additional lines and at least three additional EMI filters, each of the at least three additional EMI filters being mounted on a corresponding line of the at least three additional lines, and wherein the additional lines are configured to relay signals of the accelerometer to the processor via the EMI filters.

14. The system according to claim 9, wherein: The sensor assembly further includes a thermometer, wherein the system further includes a thermometer dedicated line and a third amplifier mounted on the thermometer dedicated line, and wherein the thermometer dedicated line is configured to relay a signal of the thermometer to the ADC via the third amplifier.

15. The system of claim 1, wherein: The plurality of wires are housed within a cable between the sensor assembly and the monitor.

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