WO2018033574A1 - Capteur numérique de détection de mouvement par radiofréquence - Google Patents

Capteur numérique de détection de mouvement par radiofréquence Download PDF

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Publication number
WO2018033574A1
WO2018033574A1 PCT/EP2017/070773 EP2017070773W WO2018033574A1 WO 2018033574 A1 WO2018033574 A1 WO 2018033574A1 EP 2017070773 W EP2017070773 W EP 2017070773W WO 2018033574 A1 WO2018033574 A1 WO 2018033574A1
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WIPO (PCT)
Prior art keywords
sensor
microcontroller
signal
transceiver
range
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PCT/EP2017/070773
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English (en)
Inventor
Stephen Mcmahon
Redmond Shouldice
Ronald MONTGOMERY
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Resmed Sensor Technologies Limited
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Publication of WO2018033574A1 publication Critical patent/WO2018033574A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/0205—Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/0245—Detecting, measuring or recording pulse rate or heart rate by using sensing means generating electric signals, i.e. ECG signals
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/0255—Recording instruments specially adapted therefor
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves 
    • A61B5/0507—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves  using microwaves or terahertz waves
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/08—Detecting, measuring or recording devices for evaluating the respiratory organs
    • A61B5/0816—Measuring devices for examining respiratory frequency
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7225—Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7228—Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7235—Details of waveform analysis
    • A61B5/725—Details of waveform analysis using specific filters therefor, e.g. Kalman or adaptive filters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/52—Discriminating between fixed and moving objects or between objects moving at different speeds
    • G01S13/522—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves
    • G01S13/524—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi
    • G01S13/534—Discriminating between fixed and moving objects or between objects moving at different speeds using transmissions of interrupted pulse modulated waves based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi based upon amplitude or phase shift resulting from movement of objects, with reference to the surrounding clutter echo signal, e.g. non coherent MTi, clutter referenced MTi, externally coherent MTi
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2503/00—Evaluating a particular growth phase or type of persons or animals
    • A61B2503/12—Healthy persons not otherwise provided for, e.g. subjects of a marketing survey
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2505/00—Evaluating, monitoring or diagnosing in the context of a particular type of medical care
    • A61B2505/07—Home care
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B2562/00—Details of sensors; Constructional details of sensor housings or probes; Accessories for sensors
    • A61B2562/02—Details of sensors specially adapted for in-vivo measurements
    • A61B2562/0228—Microwave sensors
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
    • A61B5/024—Detecting, measuring or recording pulse rate or heart rate
    • A61B5/02438—Detecting, measuring or recording pulse rate or heart rate with portable devices, e.g. worn by the patient
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
    • A61B5/1113—Local tracking of patients, e.g. in a hospital or private home
    • A61B5/1114—Tracking parts of the body
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
    • A61B5/1118—Determining activity level
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6887—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient mounted on external non-worn devices, e.g. non-medical devices
    • A61B5/6889—Rooms
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/68—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient
    • A61B5/6887—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient mounted on external non-worn devices, e.g. non-medical devices
    • A61B5/6891—Furniture

Definitions

  • the present invention relates to devices and methods for detecting characteristics of moving objects and living subjects. More particularly, it relates to sensors for generating radio frequency emissions, such as range gated pulses, motion sensing, with particular emphasis on improving sensor operation by utilizing digital technology.
  • radio frequency emissions such as range gated pulses, motion sensing
  • Doppler motion radio frequency sensors are commonly used to detect motion.
  • Continuous wave Doppler radar motion sensors transmit a continuous wave radio frequency carrier and mix the transmitted radio frequencies with the return echoes to produce a difference frequency equal to the Doppler shift produced by a moving target.
  • Continuous wave sensors typically do not have a definite range limit. For example, they usually receive signals for both near and far objects, wherein the received signal is a function of radar cross section. False triggers may result, either from motion artefact interference or due to undesirably high sensitivity of such sensor at close range.
  • Pulsed Doppler motion radio frequency sensors have been developed to reduce instances of false triggering.
  • An exemplary pulse Doppler motion sensor is described in U.S. Pat. No. 4,197,537 to Follen et al.
  • a short radio frequency pulse is transmitted and then self-mixed with its echo such that the pulse width defines a range-gated region.
  • the self-mixing ends such that target returns arriving after the end of the transmitted pulse are not mixed or "gated out.”
  • a differential pulse synchronous phase detection motion sensor is disclosed in U.S. Pat. No. 5,966,090, to McEwan. This sensor alternately transmits two pulse widths.
  • phase detection response is then subtracted from each width to produce a range gated phase detection sensing region having a fairly constant response versus range.
  • a two-pulse phase detection radar motion sensor as described in U.S. Pat. No. 5,682,164 to McEwan. This sensor transmits a first pulse and, after a delay, generates a second pulse that mixes with echoes from the first pulse to form a range gated sensing band with minimum and maximum ranges.
  • the detection range may also be limited to reduce instances of false triggering.
  • U.S. Pat. No. 5,361 ,070, to McEwan describes an ultra-wideband ("UWB") pulse radar with a very narrow sensing region that is related to the transmitted pulse width.
  • UWB ultra-wideband
  • U.S. Patent No. 6,426,716 to McEwan which describes a range gated microwave motion sensor having adjustable minimum and maximum detection ranges.
  • a radio frequency oscillator with associated pulse generating and delay elements is utilized to produce the transmitted and mixer pulses.
  • One or more antennas are used to transmit or receive said pulses.
  • a radio frequency receiver including a detector/mixer with associated filtering, amplifying and demodulating elements, is used to produce a range gated signal from said pulses.
  • Still other types of motion sensors may utilize range-gating to prevent false triggers.
  • U.S. Patent No. 7,952,515 to McEwan for example, a holographic radar is described with a range gate that limits response to a specific downrange region. McEwan states that cleaner, more clutter-free radar holograms of an imaged surface can be obtained, particularly when penetrating materials to image interior image planes, or slices.
  • the range-gating enables stacked hologram technology, wherein multiple imaged surfaces are stacked in the downrange direction.
  • Other technologies may alternatively be used to resolve some false triggers.
  • U.S. Patent Pub. No. 2010/0214158 to McEwan discloses a radio frequency magnitude sampler for holographic radar that can finely resolve interferometric patterns produced by narrowband holographic pulse radar.
  • U.S. Patent Application Publication No. 2014/0024917 to McMahon et al the entirety of which is hereby incorporated by reference, describes a physiological sensor that utilizes oscillating radio frequency pulses for range gated sensing.
  • the sensor may include a radio frequency transmitter configured to emit the pulses and a receiver configured to receive the echoed pulses.
  • the echoed pulses may be processed to detect physiology characteristics such as motion, sleep, respiration and/or heartbeat.
  • Analog circuits can have drawbacks including component and manufacturing cost, component reliability, physical size, current consumption, functional repeatability and flexibility.
  • One aspect of some embodiments of the present technology relates to a sensor for detecting physiology characteristics with radio frequency signals.
  • the senor may be implemented with digital circuit components.
  • Such implementations may be advantageous and enable additional functionality, such as for reducing false triggers or to provide further or more efficient processing of the various signals.
  • Another aspect of some versions of the technology relates to a sensor with an optimized architectural combination of analog and digital technologies.
  • the aspect further includes an optimized architectural separation between the analog and digital technologies.
  • Another aspect of some versions of the technology relates to a sensor with digital circuit(s) to generate and/or receive pulsed modulated radio frequency signals for range gated sensing.
  • the senor may comprise one or more microcontrollers adapted to improve functionality of the sensor and reduce circuit complexity.
  • a microcontroller may serve as a controller or programmable processor operable (i.e. by firmware included in the memory of the microcontroller) to control any number of functions of the sensing operations of the RF sensor.
  • the senor utilizes the microcontroller to detect the physiological signals with the functionalities of firmware.
  • the present technology include a radio frequency physiology motion sensor.
  • the sensor may include a transceiver configured to emit pulsed radio frequency signals toward a subject, in response to a first timing signal and, and to receive signals comprising emitted pulses reflected off the subject in response to a second timing signal.
  • the sensor may include a microcontroller coupled to the transceiver and configured to control the transceiver by controlling the first timing signal and the second timing signal.
  • the microcontroller may be further configured to digitally process data received from the transceiver in order to detect, based on the processed data, motion of the subject, such as physiological motion (e.g., cardiac motion, respiratory motion, etc).
  • the transceiver may include: an oscillator configured to generate a stable radio frequency signal; a switched amplifier that is coupled to the oscillator and configured to produce a switched output from the stable radio frequency signal in response to the first timing signal; and/or an antenna configured to receive the switched output and emit the pulsed radio frequency signals therefrom, the antenna being further configured to receive the reflected pulses.
  • the microcontroller may be configured to selectively control direct powering and de -powering of the oscillator.
  • the microcontroller may be configured to selectively control varying levels of supply voltage to the oscillator.
  • the senor may include a pulse generator configured to generate the first timing signal and the second timing signal.
  • the pulse generator may include a first set of digital gates responsive to the microcontroller.
  • the first set of digital gates may be configured to produce the first timing signal.
  • the pulse generator may include a second set of digital gates responsive to the microcontroller.
  • the second set of digital gates may be configured to produce the second timing signal.
  • the transceiver may include a set of magnitude detectors, wherein the second set of digital gates may produce one or more second timing signals to the set of magnitude detectors.
  • the microcontroller may be configured to sample output signals of the set of magnitude detectors.
  • the microcontroller may be configured to sample amplified output signals of the set of magnitude detectors.
  • the amplified output signals may include a signal output of a set of operational amplifiers.
  • the output signals may include in phase and quadrature phase motion signals.
  • the microcontroller may include a memory containing firmware programming instructions.
  • the firmware programming instructions may include a synchronous demodulator to generate a baseband signal derived from output signals from the transceiver.
  • the firmware programming instructions may include a baseband module to filter the baseband signal. The digital filtering of the baseband signal may produce one or both of a respiration signal and a motion signal.
  • the senor may include a display coupled to the microcontroller.
  • the microcontroller may be configured to output data to the display based on detected physiological motion of the subject.
  • the microcontroller, transceiver and an interface for the display may comprise or be formed on a single printed circuit board of the sensor.
  • the sensor may include a housing for the sensor. The housing may integrate the display and the single printed circuit board of the sensor.
  • the sensor may include a power supply regulation circuit configured to vary a voltage supply of a radio frequency oscillator of the transceiver to dither a frequency of the transceiver, wherein the microcontroller may be configured to vary the voltage supply controlled by the microcontroller by program instructions.
  • the microcontroller may include a timing module configured to dither timing of one or both of the first timing signal and the second timing signal.
  • the timing module may include a set of timer counter registers controlled by programming of the microcontroller.
  • the senor may include a plurality of interface circuits controlled by the microcontroller, wherein the interface circuits may include any one or more of universal serial bus interface, a wi-fi communications interface and a Bluetooth communications interface.
  • the microcontroller may be configured to transmit the processed data through an interface of the plurality of interface circuits.
  • the microcontroller may transmit the processed data to any one or both of a local processing device and a remote processing device.
  • the microcontroller may include a memory interface, wherein the microcontroller logs the processed data in a memory of the memory interface.
  • the microcontroller may be configured to control operation of a power supply that is configured to provide power to the transceiver.
  • the microcontroller may be configured to control operation of a power supply that is configured to provide power to an oscillator of the transceiver.
  • the microcontroller may be configured to control operation of a power supply that is configured to provide power to a switched amplifier of the transceiver.
  • the microcontroller may be configured to selectively control powering and de -powering the transceiver, whereby de -powering the transceiver reduces 1/f noise. De- powering the transceiver may completely turn off an RF circuit and/or an IF circuit of the transceiver.
  • the microcontroller may be configured to de -power the transceiver by controlling turning off of a power supply line that is configured to, when turned on, supply power to an oscillator of the transceiver.
  • the microcontroller may be configured to de -power the transceiver by controlling turning off of a power supply line that is configured to, when turned on, supply power to a switched amplifier of the transceiver.
  • the microcontroller may be configured to receive power from a power supply independently from power received by the transceiver from the power supply so that the microcontroller may continue to operate when the transceiver is de- powered.
  • the microcontroller may be configured to de -power any one or more of an RF switched amplifier, an RF demodulator, a pulse generator, and an IF amplifier and their respective power supply.
  • the microcontroller may be configured to synchronize repeated generation of a power supply control signal, an oscillator control signal and/or the first timing signal, wherein the generation of the power supply control signal, the oscillator control signal and the first timing signal control generation of the pulsed radio frequency signals.
  • the oscillator may be momentarily depowered by the microcontroller between pulses during the generation of the pulsed radio frequency signals.
  • the sensor may further include an oscillator control circuit coupled to the oscillator and the microcontroller.
  • the microcontroller may be further configured to generate an oscillator control signal, wherein the oscillator control signal controls activation and deactivation of the oscillator via the oscillator control circuit.
  • the oscillator control circuit may include a set of amplifiers with inputs coupled to an output port of the microcontroller. An output of the set of amplifiers may selectively couple a supply power of a voltage regulator of a power supply of the sensor to power the oscillator.
  • the microcontroller may be configured (a) to supply a power supply control signal to activate power to the oscillator indirectly through control of a power supply and/or (b) to supply another signal through an oscillator control circuit to directly control the oscillator.
  • the microcontroller of the sensor may include a range gating control application configured to control detection range of the sensor by varying a timing signal generated by the microcontroller.
  • the microcontroller may be configured to selectively control powering and de -powering the transceiver, whereby de -powering the transceiver reduces 1/f noise.
  • the microcontroller may be configured to control voltage rails of the transceiver by controlling a power supply coupled to the transceiver. Timing of the transceiver may be controlled by the microcontroller for implementing a variable range gating operation with a plurality of detection ranges to substantially contemporaneously monitor a plurality of users.
  • timing of the transceiver may be controlled by the microcontroller for implementing a variable range gating operation with a plurality of detection ranges by changing a range gating setting to change the sensor to monitor a user in a second range when the user moves to the second range from a first range previously monitored by the sensor.
  • timing of the transceiver may be controlled by the microcontroller for implementing a variable range gating operation with a plurality of detection ranges to substantially monitor a user upon a change in the user's location within the ranges of the sensor.
  • the microcontroller may implement a plurality of detection ranges by interleaving operation of magnitude detectors associated with establishing the detection ranges.
  • the microcontroller may be configured to control magnitude detectors to multiplex range gating with the sensor to digitally generate (1) paired in-phase and quadrature- phase motion signals in a first range and (2) paired in-phase and quadrature -phase motion signals in a second range, wherein the second range is at a greater detection distance from the first range.
  • the paired in-phase and quadrature -phase motion signals in a first range and the paired in-phase and quadrature -phase motion signals in a second range may be generated substantially contemporaneously.
  • the microcontroller is configured to control the magnitude detectors by alternating between modulating a first range gate signal, over a first number of RF pulses, and modulating a second range gate signal, over a second number of RF pulses.
  • the first number of RF pulses and the second number of RF pulses may be equal.
  • the microcontroller may be configured to detect subject specific physiological parameters over time for multiple subjects in a common sensing session, each subject may be associated with a different detection range.
  • the microcontroller may be configured to select a subset of ranges by controlling the sensor to automatically scan through a superset of potential ranges by adjusting a range setting of the sensor.
  • the selection of a range of the subset of ranges may be based on a detection of any one or more of bodily movement, respiration movement and/or cardiac movement in the range of the subset of ranges.
  • the microcontroller may be configured to control range gating to discretely implement a gesture -based user interface range and a physiological signal detection range.
  • the microcontroller may be configured to control range gating to initiate a scan through a plurality of available ranges upon determination of an absence of any one or more of previously detected bodily movement, respiration movement and/or cardiac movement in a detection range.
  • the microcontroller may be configured to control the range gating of the initiated scan through the plurality of available ranges of the range gating while detecting any one or more of bodily movement, respiration movement and/or cardiac movement in a different detection range of the range gating.
  • Some versions of the present technology may include a printed circuit board of a physiology motion sensor, such as any of the sensors described herein.
  • the printed circuit board may include a transceiver configured to emit pulsed radio frequency signals toward a subject in response to a first timing signal and in response to a second timing signal receive signals comprising emitted pulses reflected off the subject.
  • the printed circuit board may include a microcontroller coupled to the transceiver and configured to control the transceiver by controlling the first timing signal and the second timing signal.
  • the printed circuit board may include a display interface coupled to the microcontroller.
  • the microcontroller may be further configured to digitally process motion of the subject represented in the received signals and output data to a display coupled to the display interface based on detected physiological motion of the subject.
  • FIG. 1 illustrates an example detection device in use with a sensor, a user interface and a display in accordance with embodiments of the present technology
  • FIG. 2 illustrates a conceptual diagram of a system for radio frequency sensing in accordance with an embodiment of the present technology
  • FIG. 3A illustrates pulse generation for radio frequency sensing in accordance with some versions of the present technology
  • FIG. 3B further illustrates pulse generation with signal dithering for radio frequency sensing in some versions of the present technology
  • FIG. 4 illustrates transmitted and received (reflected) radio frequency signals after being combined in accordance with some versions of the present technology
  • FIG. 5A illustrates the amplitude of an exemplary signal generated by some embodiments of the technology
  • FIG. 5B shows the phase of the radio frequency signal illustrated in FIG. 5A
  • FIG. 6 is a block diagram illustrating an example sensor architecture for some versions of the present technology
  • FIG. 7 is another block diagram illustrating components of a sensor in some versions of the present technology.
  • FIG. 8 illustrates the generation of a sensing radio frequency signal with switched oscillation in accordance with an embodiment of the present technology
  • FIG. 9 illustrates the generation of timing signals in accordance with an embodiment of the present technology
  • FIG. 10 illustrates a first circuit portion of an example sensor of the present technology
  • FIG. 1 1 illustrates a second circuit portion of an example sensor of the present technology
  • FIG. 12 illustrates a third circuit of an example sensor of the present technology
  • FIG. 13 illustrates a fourth circuit portion of an example sensor of the present technology
  • FIG. 14 illustrates a fifth circuit portion of an example sensor of the present technology
  • FIG. 15 shows the combined circuit portions of the example sensor illustrated in
  • FIG. 16A is a signal graph illustrating magnitude detector operation during a sensor generated RF pulse.
  • FIG. 16B is a further signal graph illustrating magnitude detector operation during a sensor generated RF pulse.
  • FIG. 17 is a signal graph illustrating physiological signal tracking at different locations with dynamic range gating.
  • FIG. 18 is a signal graph illustrating example timing signals for operations controlled by the microcontroller in relation to RF pulse signal generation.
  • Examples of the present technology include a sensor 10 for physiology sensing, such as by radio frequency sensing.
  • the sensor 10 typically implements radio frequency signals for detecting physiological characteristics of a living subject 1.
  • analog and digital components may be employed or integrated in a common housing of the sensor 10. Such implementations may permit improved performance characteristics and decreased complexity.
  • Sensor 10 of FIG. 1 is part of a detection device 12 that can operate near a living subject 1.
  • Detection device 12 is preferably a stand-alone apparatus in a housing that utilizes sensor 10 integrated in the housing to detect the physiological characteristics of subject 1 from a signal with a high signal-to-noise ratio.
  • the detection device will also typically include a display 7 and/or user input interface 9 under control of a processor or microcontroller of the detection device.
  • the display may be, for example, an LCD display screen, which may be a touch screen.
  • the user interface may be integrated with the display and/or it may include user controls such as one or more buttons, for example.
  • the housing of the detection device may include an integrated display and/or user interface with the sensor.
  • the sensor 10 of the detection device 12 may be implemented to generate and receive reflected radio frequency signals from the subject for motion detection such as in accordance with the methodology illustrated in in FIG. 2. As shown, sensor 10 generates and transmits a signal 11 towards subject 1 (the "transmit” signal). A portion of transmit signal 1 1 is reflected away from a high permittivity target, such as subject 1 , and accepted by sensor 10 as a receive signal 13 (the "receive” signal). Once accepted, sensor 10 amplifies the receive signal 13 and, mixes it with a portion of transmit signal 11. The mixed signal is then filtered by filter 60 to form a combined signal 15 (FIG. 4), this intermediate signal being also referred to as a raw motion signal of the subject. Either sensor 10, via an integrated microcontroller, or an external application, may subsequently process and/or analyze the combined signal 15, to detect various physiological characteristics of subject 1.
  • transmit signal 11 is preferably a radio frequency signal that is modulated by a pulse repetition frequency (PRF) signal comprising a plurality of pulses 14 according to at least the following parameters: (1) a pulse repetition interval (or "PRI”); T and (2) a pulse width ⁇ (or “PW”).
  • the PW determines the time duration of each pulse 14, whereas the PRI determines the length of time between each pulse 14.
  • transmit signal 1 1 is modulated by pulses 14 at a pulse repetition frequency (or "PRF frequency”).
  • the PRF is the inverse of PRI, such that transmit signal 1 1 is shown to have a PRI 16 ("T”) and a PW 18 (" ⁇ ").
  • transmit signal 1 1 is a pulsed 10.525GHz radio frequency signal that has been modulated to have a PRI 16 of 4 ⁇ & and a PW 18 of 0.5 ⁇ 8. Once modulated, transmit signal 1 1 would thus be 0.5 ⁇ 8 long, produced every 4 ⁇ &.
  • sensor 10 includes a homodyne transceiver 40 configured to both emit pulses of transmit signal 1 1 at a desired frequency (e.g., 10.525GHz) (e.g., an RF pulse train) and accept received (reflected) pulses of signal 13 at the same frequency. Signals 1 1 and 13 are then mixed by transceiver 40 to produce an intermediate or combined signal 15. Arrows in FIG. 6 illustrate signal flow with respect to the digital, analog and control signal lines between components of the sensor.
  • transceiver 40 includes a magnitude detector 70 (FIG. 12) configured to produce a measure of the magnitude and phase of the received signal with respect to the transmitted signal.
  • FOG. 12 magnitude detector 70
  • magnitude detector 70 outputs a measure of motion based upon these changes.
  • dual magnitude detectors may be implemented in an orthogonal phase spacing fashion to produce quadrature intermediate signals (I and Q).
  • transmit and receive signals 1 1 , 13 may be presented to magnitude detector 70. For example, a portion of signal 13 may be received during a time interval in which signal 11 is emitted.
  • Magnitude detector 70 is preferably presented with at least a portion of receive signal 13 every time that transmit signal 11 is emitted.
  • magnitude detector 70 receives a 5ns portion of received signal 13 during the first 12ns of transmit signal 1 1.
  • signals 1 1 and 13 may be mathematically represented as follows:
  • Signals 1 1 and 13 are preferably from the same source and, thus, have the same frequency.
  • Combined signal 15 thereby has an amplitude that varies only with the phase and amplitude of receive signal 13. Accordingly, combined signal 15 may be represented with the following mathematical formula:
  • FIGs. 4 and 5A-B An exemplary combined signal 15 is illustrated in FIGs. 4 and 5A-B according to this formula. As shown, signal 15 has a periodic sinusoidal amplitude envelope 19 (FIGs. 4 and 5 A) and phase (FIG. 5B). Any movement of the subject 1 is associated with respective change in the phase ⁇ of the returning (reflected) signal. Therefore, the magnitude and phase of combined signal 15 generated by the magnitude detector 70 will also vary with the distance and movement of subject 1.
  • Sensor 10 utilizes these variations to detect the physiological characteristics of subject 1 based on movement.
  • bodily movement may be detected using a zero- crossing or energy envelope detection algorithm to form "motion on” or "motion off indicator, as described in U.S. Patent Application Publ. No. 2009/0203972, the entirety of which is hereby incorporated by reference.
  • Respiratory activity typically has a frequency range of 0.1 to 0.8 Hz
  • cardiac activity typically has a frequency range of 1 to 10Hz.
  • Sensor 10 may also be configured to diagnose certain conditions based upon these activities.
  • Sensor 10 may be configured to accept a DC power supply input and generate output concerning detected motion signals.
  • sensor 10 may be configured to output a motion signal having in phase and quadrature components corresponding to the respiration and movement of subject 1. Examples of sensor 10 are illustrated in FIGs. 6-7 and 10-15. As shown in FIG. 6, sensor 10 may include: (I) a pulse generator 20; (II) a homodyning transceiver 40; (III) a microcontroller 80 and (IV) a power supply circuit 110. A memory circuit 100 (see FIG. 7) may also be included.
  • the microcontroller 80 may include further components such as filter amplifier 82; a synchronous demodulator 88; a baseband module 89 and a plurality of interface circuits 93-99 (see FIG. 7).
  • the microcontroller has a plurality of integrated hardware peripheral circuits that greatly simplify interfacing to circuits 91 -99.
  • the microcontroller 80 may be configured with various input/output connections (pins and/or traces) and may include various digital modules (e.g., digital circuit components and/or firmware) to implement functionalities of some of these components.
  • the microcontroller may include digital signal processing algorithms 81 (FIG. 6) for processing detected motions signals.
  • the microcontroller components may be combined/formed on a common or single PCB.
  • the homodyning transceiver 40 (generally operates with analog signals (lines marked with reference characters "A- S” in FIG. 6) on wires or traces between its respective components whereas the microcontroller generally operates with digital signals (lines marked with reference characters “D-S” in FIG. 6) on wires or traces between its respective components.
  • Control signals (lines marked with reference characters "C-S"), such as from the microcontroller peripheral control bus 801 , which may be digital, on wires or traces, may be generated from the microcontroller 80 to any one of more of the power supply 1 10, pulse generator 20 and homodyning transceiver 40 for control of these respective components.
  • a homodyne receiver also known as direct-conversion, synchrodyne, or zero-IF receiver, is a radio receiver design that demodulates the incoming radio signal whose frequency is identical to the carrier frequency of the intended signal.
  • the simplification of performing only a single frequency conversion reduces circuit complexity. This is in contrast to the standard superheterodyne receiver where this is accomplished only after an initial conversion to an intermediate frequency.
  • the homodyning transceiver combines an RF transmitter and homodyning RF receiver circuit and has a number of advantages and disadvantages associated with homodyning. It can have advantages of lower circuit complexity, lower cost, and smaller physical size.
  • the microcontroller 80 such as via its modulation demodulation timing module
  • FIG. 6 shows an enhanced system where the generator 20 communicates directly to the oscillator 42 to provide frequency dithering and timing synchronisation, on/off control etc.
  • FIG. 8 is a simplified version where the generator 20 communicates with the oscillator 42 via a switched circuit.
  • the architecture of the FIG. 7 is similar to that of FIG. 6.
  • oscillator 42 is shown as a combination of an RF oscillator and switched amplifier.
  • analog output of the magnitude detectors may be amplified in IF amplifier 82 before being received and digitally sampled in the microcontroller 80. Further details of these sensor architectures may be considered in relation to the operation of the various elements which are described herein in further detail.
  • Pulse generator 20 is configured to generate the aforementioned pulses in conjunction with timing signals from timing module 22 of the microcontroller 80.
  • the pulse generator generates pulses for switching the RF signal from oscillator 42 of FIG. 8 and FIG. 1 1 on and off.
  • the oscillator 42 is external to microcontroller 80 and part of the transceiver 40. It also generates pulses that control the on/off timing of the magnitude detectors 70 of the transceiver 40 as shown in relation to signal associated with reference character "T-P" along a signal line or trace between these components in FIG. 6.
  • pulse generator 20 receives signal(s) from a timing module 22.
  • the pulse generator circuit includes six high speed gate pulse circuits (gates 28A to 28F).
  • the pulse generator circuit accepts the PRF and IF timing signals from the microcontroller and generates the RF modulation and demodulation signals as well as the synchronous phase detector signals.
  • the PRF and IF timing signals received from the microcontroller include the PRF, the modulated PRF and the IF timing signals which control the RF transmit oscillator switching, as well as the RF receive magnitude detector diodes switching and the synchronous demodulator switching.
  • the timing module 22 of the microcontroller includes a clock oscillator (e.g., 16 MHz) and a plurality of timer counter registers 24 (see FIG. 9) integrated into the microcontroller 80 which are operated by the microcontroller.
  • the counter registers 24 are set to divide down the clock and produce the timing signals.
  • Each counter of the registers 24 may be for example, a 16 stage binary counter.
  • the clock oscillator may be a 16MHz Pierce oscillator realized by a buffer amplifier inside of microcontroller 80. Such timing may optionally also employ an external clock oscillator.
  • timing module of the microcontroller 80 may be configured to generate: (i) a PRF timing signal; (ii) an IF timing signal; and (iii) a dither timing signal (not shown).
  • output of the (e.g., 16MHz) clock oscillator is presented to the input of binary counter registers 24, which then divide down the input clock frequency to generate the respective PRF, IF, and dither timing signals. Generation of these timing signals is illustrated in FIG. 9, showing a portion of the counter. It will be understood that further elements of the counter (flip flops) are utilized.
  • a lMHz PRF timing signal is made available on an output 24A of a stage of the counter registers 24; a 500 kHz PRF timing signal on an output 24B; a 250 kHz PRF timing signal on an output 24C; a 7.812 kHz IF timing signal on an output 24D; and a 976Hz dither feedback signal on an output 24E (not shown).
  • the precise frequency of each of the PRF, IF and dither timing signals can be generated by microcontroller 80 and flexibly controlled by its firmware.
  • Synchronous dithering may be implemented by resetting binary counter registers
  • the frequency of the PRF timing signal may be varied in a synchronous and linear manner. For example, said frequency may be varied about every 1ms approximately.
  • Timing dithering may be implemented because it removes synchronous radio frequency demodulation noise artefacts.
  • Ramp dithering may be implemented because it is easy to realize; however, it can produce tone artefact. Synchronous ramp dithering is preferably utilized to prevent these unwanted tones being generated by the phase synchronous IF demodulator described below.
  • the pulse generator 20 operates with ultra-fast signal timing used for radio frequency pulse generation and radio frequency diode switching demodulation. To ensure that sensor 10 is not compromised by the slow rising and falling edges of the PRF and IF timing signals from the microcontroller, these signals may be buffered and delayed by the pulse generator.
  • pulse generator 20, which is illustrated in FIG. 10, includes a plurality of high speed NAND gates and associated passive components. In this version the top three gates (gate 28A, gate 28C and gate 28D) of the transmission timing portion 32 are generally for producing the PRF timing signal whereas bottom three gates (gate 28B, gate 28E and gate 28F) for the reception timing portion 36 are generally for producing the IF timing signal.
  • the top three gates (gate 28A, gate 28C and gate 28D) produce a signal for turning on and off the switched amplifier 52 circuit associated with the RF oscillator 42 to produce transmission pulses (see FIG. 3B).
  • the bottom three gates (gate 28B, gate 28E and gate 28F) produce a signal for operation of the magnitude detector 70, thus serving for synchronous IF demodulation.
  • the pulse generator 20 allows the PRF timing signal to determine the switching times, i.e., the turn on and off times, for the switched amplifier 52.
  • the pulse generator 20 allows the IF timing signal to determine the synchronous demodulation times for the magnitude detector 70.
  • the PRF timing signal is output from a port
  • microcontroller 80A of microcontroller 80 and then buffered and delayed by a first gate 28 A (U14), while the IF timing signal is output from a port 80D and then buffered and delayed by a second gate 28B (U7).
  • the PRF timing signal is presented to transmission timing portion 32 from port 80A, after an initial delay by first gate 28A (U14), on the falling edge of said PRF timing signal. This initial delay provides a fast edge on each pulse contained therein.
  • the PRF timing signal is then buffered and further delayed by gates 28C (U2), 28D (U4).
  • the so delayed PRF timing signal determines the switching times for amplifier 52 so as to thereby produce the RF pulses.
  • Each of gates 28C (U2), 28D (U4) may be a single input inverter with associated propagation delays.
  • the purpose of the double buffer delay realized by gates 28C (U2), 28D (U4) is to near match the additional modulation delay described below.
  • the output of gate 28D drives the switching of the switched amplifier 52 for the RF pulsing.
  • Lower gates (28B, 28E and 28F) of the pulse generator 20 participate in the control of demodulation effected by the magnitude detector 70, which is synchronized with the pulse generation of the switched amplifier 52.
  • the pulse generator also controls timing of operation of magnitude detector 70 as illustrated by the coupling between the pulse generator and the magnitude detectors in Figs. 6 and 7.
  • the demodulation timing components e.g. gate 28B, gate 28E and gate 28F
  • the pulse generation gates gate 28A, gate 28C and gate 28D
  • these gates may be single input inverters with associated propagation delays.
  • the PRF timing signal is presented from port 80A, after a delay by first gate 28A (U14), on the falling edge of said PRF timing signal to gate 28E. As before, this initial delay provides a fast edge on each pulse contained therein.
  • the lower gates also provide an additional modulation delay that is responsive to the IF timing signal output by microcontroller at port 80D to gate 28B.
  • the modulation level of the IF timing signal is set by microcontroller 80 to low, then the buffered PRF timing signal on gate 28A (U14) is subjected to a short delay provided by an integrator comprising of a resistor 35A (R2) and a capacitor 35B (C35).
  • the buffered PRF frequency signal is routed through gate 28B and subjected to a long IF modulation delay provided by a resistor 36A (R5) and a capacitor 36B (C35).
  • the PRF timing signal is then subsequently buffered by gate 28E (U9) to reinstate the digital signal.
  • the now buffered and delayed PRF timing signal output from gate 28E (U9) is fed to a pulse circuit comprising of, for example, a resistor 37A (R7), a capacitor 37B (C9), and gate 28F (U10).
  • the output from gate 28F is normally low.
  • the output of gate 28F (U10) goes high.
  • the output of gate 28F (U10) goes low.
  • a positive pulse is output from gate 28F after a defined delay on the falling edge of the PRF timing signal output from gate 28E (U9).
  • the defined delay is modulated by the IF timing signal.
  • each positive pulse is used to switch on the radio frequency receive diodes of magnitude detector 70.
  • the pulse generator 20 may also include a range gating control circuit 38, as illustrated in FIG. 10. It may include a first resistor 38A (R17) and a second resistor 38B (R20). Each resistor is correspondingly under the control of microcontroller 80 via port 80B (RG1) and port 80C (RG2). Either port may be set by microcontroller 80 to low, high or high impedance. Detection range gating is realized by operation of the programming of the microcontroller (e.g., firmware) to change the impedance values of ports 80B (RG1) and 80C (RG2). For example, the setting of the signal at each port 80B, 80C by microcontroller 80 can vary the IF timing signal with respect to the operation of gate 28E, and, thus, control the detection range of sensor 10.
  • a range gating control circuit 38 as illustrated in FIG. 10. It may include a first resistor 38A (R17) and a second resistor 38B (R20). Each resistor is correspondingly under the control of microcontroller 80
  • the transmitted RF signal is continuous, there is no range gating because the receiver receives most, or all, of the room reflections.
  • the continuous RF signal may produce many reflections which may be received by the sensor.
  • Some of the received RF signals will have a static RF signal phase difference with regard to that of the transmitted RF signal, while other received RF signals, such as those which are reflected off moving targets, will contain a changing RF signal phase difference with regard to the transmitted RF signal.
  • "movement information" corresponding to the targets movements may be determined based on the phase difference between the transmitted RF signal and the received RF signal.
  • the sensor may transmit a pulsed RF signal into a room.
  • the OFF time i.e., the time when the pulsed RF signal is not being transmitted, the RF signals resulting from reflections of the transmitted pulsed RF signal will diminish, and eventually fade away.
  • the time to for RF signals resulting from the reflections after a transmitted pulsed RF signal has been switched OFF to fade away is about 200ns (nano seconds).
  • the only signals a receiver can receive are reflections from targets within a range of c * (t) / 2 where c is the speed of light.
  • c is the speed of light.
  • the only reflections received at the RF receiver can come from targets within the time of flight of the transmitted RF signal, namely 0.5ns out and 0.5ns back.
  • the detectable target range of a 0.5ns RF pulse may be around 0.15m.
  • the microcontroller may control the timing of transmission and reception of RF pulses.
  • the microcontroller may send a timing pulse to a pulse generator, such as pulse generator 20.
  • the pulse generator may send a pulsed repetition frequency (408-PRF) at a rate such as lMHz to a switched RF oscillator, such as switched RF oscillator (RF oscillator 42 and/or modulated amplifier 52).
  • the switched RF oscillator may then transmit, for example, 10.525 GHz.
  • RF pulses modulated at a 1 MHz rate to an antenna feed such as antenna feed for transmission/reception by an antenna.
  • the detector 70 may be a switched magnitude detector or any other such mixer that is switched by the timing control of the microcontroller.
  • the magnitude detector may then receive both the transmitted signal and the received signals as a combined signal according to this timing control.
  • This combined signal from the antenna feed may be demodulated by the mixer to determine a baseband signal, which includes the "movement information.”
  • This baseband signal may represent the change in phase due to static and moving target reflections of the receive signal wrt (with respect to) the transmit signal.
  • the RF receiver such as magnitude detector 70, may receive a combined signal of 1 ) ASin( ⁇ ot) + BSin( ⁇ ot + phi), where ASin( ⁇ ot) is the transmitted RF pulse and BSin( ⁇ t +phi) is the received signal, ⁇ ot is the angular frequency at time (t), and phi is the phase of oscillation.
  • the magnitude detector may mix the two signals as follows: 2) [ASin( ⁇ ot) + BSin( ⁇ ot + phi)] * [ASin( ⁇ ot) + BSin( ⁇ ot + phi)].
  • the resulting output is a demodulated signal that may be considered a baseband signal.
  • an additional magnitude detector(s) may be added to implement two or more receivers for a common sensor.
  • the two receivers may be positioned at a known distance apart (e.g., lambda/8), such that in-phase and quadrature (I/Q) components of a signal may be generated in two signals.
  • one magnitude detector may produce a single baseband signal for the in-phase component.
  • the other magnitude detector may then produce a single baseband signal for the quadrature phase component.
  • Further modulation, such as IF modulation can be further implemented based on these two orthogonal components.
  • Post processing of the baseband and IF signals such as by the IF amplifier 82 and microcontroller 80 may be performed on each of the signals produced by the magnitude detector(s).
  • each magnitude detector may include a non-linear diode.
  • the magnitude detector may demodulate the combined signal during the time period it is switched ON by the microcontroller to determine a phase difference between the transmitted RF pulse signals and the received RF signals (i.e., the movement information), at a certain range.
  • the microcontroller 80 may provide range gating control by sending a pulse timing signal to the pulse generator 20, which in turn sends a pulse to cause the magnitude detector to turn on.
  • the magnitude detector may turn on at time (tl) for a detection time of T seconds.
  • the range gating may be determined by the time period tl + T, and may produce a range of c * (tl + T) / 2. Any reflections after the time period tl + T are not detected, and hence range gating is realised.
  • the microcontroller may enable the magnitude detector to switch ON for a second period tO to provide an intermediate frequency amplification stage.
  • the baseband signal output by the magnitude detector 70 carries the movement signal information.
  • the baseband signal may contain natural noise at the low target moving frequencies (e.g., breathing frequencies of 0.2Hz), commonly referred to as 1/f noise or flicker noise. As such, there may be an undesirable amount of noise added to the baseband signal when it is amplified to a signal level for processing.
  • the magnitude detector may modulate the baseband signal with an IF signal to bring the low target moving frequencies up to a higher frequency which can be amplified with less noise.
  • the magnitude detector 70 may demodulate the combined signal during a second time period further controlled by additional timing pulses generated by the microcontroller to determine a difference between the transmitted RF pulse signals and the received RF signals to determine a reference signal.
  • the microcontroller may provide additional timing signals to the pulse generator 20, which in turn sends a pulse to cause the magnitude detector to turn on for a second time, prior to, or after, the first time period tl .
  • the magnitude detector may turn ON at time (tO) for a detection time of T seconds.
  • the previously introduced time period (starting at tl) may intentionally target an area of the room where the user's movements were expected to occur, in order to generate a movement signal.
  • the targeted range of the newly introduced period (starting at tO) may target a location where not too much movement is anticipated, so as to generate a reference signal.
  • the range gating may be determined by the time period tO + T, and may produce a second range of c * (tO + T ) / 2. Any reflections after the time period tO + T are not detected during this first ON period.
  • the detection time of T seconds is shown as the same for the first and second detections, the detection times may be different.
  • the number of pulses N, which are detected at tO and tl may be non- successive pulses, such as every other pulse and the number of pulses detected at tO and tl may be different.
  • tl and tO may be measured in the same or different pulses.
  • the combined signal received by the magnitude detectors from the first and the second time periods may be processed by the microcontroller to determine a baseband reference signal, which is based on the difference between the movement signal and the reference signal.
  • the magnitude detector 70 may:
  • the IF signal frequency may be PRF/2N.
  • N may be 64 and PRF may be lMHz.
  • the resulting IF frequency may be 8kHz.
  • the IF signal may be amplified by an IF amplifier 82 for amplification prior to signal processing.
  • the magnitude detector 70 may pass the IF signals to the IF pre-amplifier which may switch on at 8kHz, thereby amplifying the 8kHz IF signal.
  • 1/f noise may be mitigated by a factor of 40000, or more or less.
  • the amplified IF signal may then be forwarded to the microcontroller, which may demodulate the IF signal back to an amplified baseband signal.
  • the baseband signal may then be processed by the microcontroller, as described herein.
  • the sensor may provide range gating, but not IF amplification.
  • double demodulation timing, such as tO and tl the sensor may be capable of providing both range gating and IF stage amplification.
  • a first detection range can be implemented with different reception pulse timing (tO and tl) (e.g., tO integrated N times and then tl integrated N times for an IF frequency of 1/(2 *N*T)).
  • reception pulse timing tO and tl
  • a second detection range may be implemented with t2 and t3 timing (e.g., t2 integrated N times and then t3 integrated N times for an IF frequency of 1/(2*N*T)).
  • the system may have an intermediate frequency (IF) of 1/(2 *N*T) where N is the number of transmit pulses and T is the period of the repetition as illustrated in FIGs. 16A and 16B.
  • the senor may be implemented with dynamic range gating control.
  • the detection range may be periodically changed for detection of separate subjects in different ranges (multiple ranges during a common detection time frame), such as with using a single transceiver having different detection ranges.
  • the periodic range change may be sufficiently close in time so that sensing of multiple subjects may be performed substantially contemporaneously, such as for detection of motion related physiological metrics during a common time period with the same sensor (e.g., motion data over the course of a night sleep session for each person with the same sensor).
  • the sensor may determine a raw motion signal from a near range and a raw motion signal from a far range, where the near and far ranges are implemented by dynamically changing the range of the sensor such as by interleaving different detection ranges. This may be accomplished with time domain range multiplexing.
  • the resulting processed baseband biomotion signals can be considered to be essentially simultaneously detecting both a near range and one or more far ranges. This may also be considered effectively a type of in parallel range gating by a single sensor.
  • the senor may be implemented with dynamic / multi range gating.
  • a sensor that may be implemented to detect physiological motion characteristics (such as movement, activity level, periodic leg movement, breathing morphology such as breathing rate, depth and modulation, apnea, hypopnea, heart rate etc.) from two people in bed at the same time.
  • the sensor may be implemented, such as from one side of a bed, to detect/sense motion of the nearest person one side of the bed, and could also detect/sense motion of the person on the farther side of the bed.
  • the interleaving or multiplexing may be implemented by the microcontroller adding a further pulse(s) (e.g., addition of a pulses t2/t3 (see FIG.
  • Further pulses such as for further range interleaving (e.g., near, middle, far, etc.) could be added (using the same IF pulse).
  • the system such as with first and second receivers in a quadrature relationship, for a near and far gate, can yield two pairs of I/Q signals - I/Q (near) and VQ (far) which are digitally extracted by time multiplexing processing from the in-phase receiver and the quadrature phase receiver.
  • time tO - can be considered a reference pulse (in order to implement an IF stage)
  • time tl can be considered as near range
  • time t2/t3 as far range (relatively).
  • the times can be dynamically changed by the microcontroller to enable parallel range gating.
  • the automatic adjustment can be sequential - the sensor switching from one range to another.
  • the described process goes further in that it allows the management of two or more sets of parameters in parallel, thus providing substantially contemporaneously sensing data for two or more different users, each located at a different distance from the sensor (for example, lm distance for a subject close to the sensor, or 2.5m for a subject further away from the sensor).
  • microprocessor controlled system can be implemented to:
  • This identification is enabled by the microcontroller choosing tl and t2, etc., by checking for breathing and/or heart beat signals in two or more different ranges.
  • the sensor is now automatically configured to detect both subjects simultaneously - i.e., the tl and t2 times are switched after each 62.5ms (set by the IF) to the appropriate distance range (i.e., an integrated sample of data from subject 1 , then subject 2, then subject 1 and so on.
  • the appropriate distance range i.e., an integrated sample of data from subject 1 , then subject 2, then subject 1 and so on.
  • Each range band spans the typical movement of the person in the bed, and is dynamically updated as a person rolls over, or leaves the bed.
  • a single sensor that can "see” multiple subjects during a common detection session, can simultaneously extract the biomotion from the multiple subjects, and recover the baseband to produce multiple processed outputs for each subject in each range (e.g., breathing signal, cardiac signal, movement, activity, presence and absence, etc.)
  • the system can check range in a way that does not impact the baseband signal.
  • the system might not have a near-in range gate per se (it does not detect extremely close to the sensor due to switch-on time).
  • the ranges could be configured as near-in to 1.5m, and near-in to 3.2m.
  • the first range is designed to capture the first person, and the second range captures both persons.
  • the system may optimise the signal for the second person. In some versions this can be achieved by subtracting the near and far signals (i.e., manipulate these to get the difference). In theory, this would provide ideal separation.
  • the sensor may receive a stronger signal for the far person, and weaker for the near person.
  • blocks of RF pulses for a specified range can be used, whereby a sequence (block) of RF pulses are used for the first range, then the next range(s), then back to the first range.
  • the blocks can have the same or different number of RF pulses.
  • the number or pulses of each block can also vary in time, for example if averaging over a larger number or pulses is required for one of the signals.
  • a guard band such as a quiet time, or selectively ignored the first and last pulses in a block may be implemented in case of any interference between blocks.
  • the pulses are processed digitally, such as using high speed digital signal processing, instead of averaging across a sequence of interleaved or block of pulses, alternative approaches such as taking the median (50th percentile) or robust mean (i.e., by sorting the sequence, and excluding a percentage of the smallest and largest such as the top and bottom 5% or 10%, then taking the average of the remainder) may be performed. This may effectively permit replacing the diodes/low pass filtering component operations with DSP operations.
  • median 50th percentile
  • robust mean i.e., by sorting the sequence, and excluding a percentage of the smallest and largest such as the top and bottom 5% or 10%, then taking the average of the remainder
  • these can be pre-set at the factory to a standard two-in bed king size bed with the sensor placed on a bedside locker or night stand.
  • These settings may be configurable by the user through a controller, such as through a software application (app) on a smartphone.
  • these ranges can be automatically optimised by the system, using movement, activity, respiration, and heart (i.e. from ballistocardiogram) features. For example, a subset of ranges may be automatically determined/selected, such as in a setup or initial operation procedure, by controlling the sensor to automatically scan or iterate through a larger superset of potential ranges by changing the range settings (e.g., magnitude detector receive timing pulse(s)).
  • the selection of the detection range subset (e.g., one or more) can be dependent on detection of any one or more of the body movement or other human activity, respiration (respiration movement) and/or heart beat (cardiac movement) features in a particular range(s).
  • the selected subset of ranges may then be used during a detection session (e.g., a night of sleep).
  • a close-in range can be optimised for detecting gesture in the vicinity of the device, e.g., to activate or deactivate a process or feature. This can provide a gesture -based user interface in a certain close range or predetermined range. By detecting near in signals only for this range bin, inadvertent control of the process or feature by further away motion is prevented.
  • a device may have a closer user interface detection range in addition to one or more further detection ranges for other motion detection such as physiological signal detection (e.g., heart motion and/or respiratory motion monitoring.) In this way, sensed motions may be processed differently by the microcontroller depending on whether the motion is detected in a near/close gesture -based user interface range or a physiological signal detection range.
  • the microcontroller 80 may analyse the detected motion signal to detect a control gesture whereas in a further range, the microcontroller may disregard such gestures and instead analyse such motions for physiological sensing (e.g., heart rate or respiration detection, gross motion for sleep detection, etc.). In this way, the microcontroller may control range gating to implement a gesture -based user interface as well as physiological signal detection.
  • the microcontroller may be configured to control range gating to discretely implement a gesture- based user interface range and a physiological signal detection range.
  • the senor may include a microcontroller that is configured to select a subset of ranges by controlling the sensor to automatically scan through a superset of potential ranges by adjusting a range setting of the sensor.
  • the selection of a range of the subset of ranges is based on a detection of any one or more of bodily movement, respiration movement and/or cardiac movement in the range of the subset of ranges.
  • the microcontroller may be configured to control range gating to discretely implement a gesture- based user interface range and a physiological signal detection range.
  • the microcontroller may also be configured to control range gating to initiate a scan through a plurality of available ranges upon determination of an absence of any one or more of previously detected bodily movement, respiration movement and/or cardiac movement in a detection range.
  • the microcontroller may be configured to control the range gating of the initiated scan through the plurality of available ranges of the range gating while detecting any one or more of bodily movement, respiration movement and/or cardiac movement in a different detection range of the range gating.
  • dynamic range gating under control of the microcontroller, may be implemented to follow user(s)' movement within a sensing space. For example, a user may roll over in a bed and potentially leave a sensing area defined by a current range of the range gating of the sensor.
  • the sensor may adjust or scan through different available ranges by adjusting the range gating to locate a range where such motion (body motion or physiological motion) is present/detected.
  • the microcontroller may control a power supply to depower the sensor circuits (e.g., sensor transceiver circuits) to reduce power consumption.
  • the sensor may periodically repower the transceiver circuits and rescan through the ranges to select a detection range for sensing if such motion is detected in an available range.
  • Such dynamic range gating may involve multiple users.
  • the sensor under control of the microcontroller, may scan through available ranges when motion is no longer detected from a first user in one range, while continuing to sense user motion of a second user in a different range.
  • the sensor may change the range gating (e.g., scan through available ranges other than the range of the second user) to detect motion of the first user in another available range and continue sensing of the first user upon detection of motion in such an available range, while maintaining sensing in the gated range being used for the second user.
  • these dynamic range gating adjustments may be made by interleaving or multiplexing detection ranges by making programmatic adjustments to the pulse timing implemented with the microcontroller controlled range gating of the transceiver.
  • This may be considered in reference to the graph of Fig. 17, which shows sensor movement signals in relation to different settings for range gating.
  • a first pulse timing is used to with no significant detection of a physiological signal.
  • the sensor may scan through different ranges, such as by varying the gate timing, and evaluate sequentially the motion signals at 1704, 1706, 1708, 1710 and 1712.
  • these signals may be multiplexed in time so that the signals are generated substantially in parallel.
  • Detection of significant physiological motion in any of the particular ranges may then serve as a basis for monitoring the physiological characteristics in the particular range. As illustrated in the right half of the Fig. 17, a user moved closer to the sensor and the detection of the significant physiological motion (e.g., cardiac frequency respiratory frequency) at the closer range may initiate or continue the focus of monitoring at the closer range setting.
  • the significant physiological motion e.g., cardiac frequency respiratory frequency
  • timing of the transceiver may be controlled by the microcontroller for implementing a variable range gating operation with a plurality of detection ranges by changing a range gating setting to change the sensor to monitor a user in a second range when the user moves to the second range from a first range previously monitored by the sensor.
  • timing of the transceiver may be controlled by the microcontroller for implementing a variable range gating operation with a plurality of detection ranges to substantially monitor a user upon a change in the user's location within the ranges of the sensor.
  • the senor may be configured, such as with the timing settings of the dynamic range gating, to monitor the physiological characteristics of any of, for example: (a) one or more stationary users; (b) one or more users, where at least one of them is changing their location; (c) one or more users who have just entered the range of the sensor; (d) one or more users where one is stationary or otherwise, and another user who has just entered the range of the sensor and is stationary or otherwise, etc.
  • Transceiver 40 emits transmit signal 1 1 and accepts receive signal 13, which it modulates and demodulates under the control of pulse generator 20 as previous discussed.
  • An example transceiver 40 is illustrated schematically in FIGs. 6, 11 and 15.
  • Oscillator 42 is preferably high-frequency radio frequency oscillator realized as a transistor 43 (Q8), depicted in FIG. 1 1 as a pseudomorphic high-electron-mobility radio frequency field effect transistor (or "pHEMT radio frequency FET”) with an associated dielectric resonator puck 44.
  • pHEMT radio frequency FET pseudomorphic high-electron-mobility radio frequency field effect transistor
  • Feedback from oscillator 42 is realized by locating puck 44 between a pair of coupled micro strip lines 45 A and 45B in the respective gate and drain circuits. Fine tuning is achieved by adjusting a grounded mechanical screw 46 in close proximity to oscillator 42. Power is supplied to oscillator 42 via a resistor 47 (R59). Power supply decoupling is provided by a first capacitor 48A (C59) and a second capacitor 48B (C61). A third capacitor 48C (C62) provides radio frequency output decoupling. An attenuator pad comprising of a pair of resistors 49A (R72) and 49B (R74) provides isolation and level control.
  • the DC voltage supplied to oscillator 42 by power source circuit 110 may be varied by microcontroller 80 for frequency dithering.
  • An example dithering control circuit 50 is illustrated in FIG. 14 and may also be considered in relation to FIG. 15.
  • RF frequency dithering is an enhanced feature that can be used to improve noise immunity and also increase signal to noise (it dithers the frequency, and as a homodyning receiver/transceiver 40 is used, dithering, oversampling and averaging all together can reduce noise and improve resolution).
  • a dither timing signal is generated by microcontroller at port 80E, using the integrated timing module 22, to have a linear or pseudo random timing.
  • the dither timing signal is output, via the dithering control circuit 50, to control the power supply 1 10 voltage (VDD) that operates the oscillator 42.
  • Port 80E may set to one of two states by the firmware: high or low. When port 80E is in the high state, it pulls the filtered supply voltage (e.g., 3.3 volts) high to produce a higher output voltage from the second linear regulator 1 13B (U*) described below. A capacitor 51 (C*) is coupled to port 80E to integrate this, thereby producing a positive going ramp control voltage and a positive going ramped regulator output voltage. When port 80E is in the low state, capacitor 51 (*C) pulls from second regulator 1 13B to generate a negative going ramp. Varying the DRO power supply voltage varies the RF frequency and hence RF frequency dithering is realised.
  • the oscillator 42 may optionally include a further oscillator control circuit 11 11 to permit the microcontroller 80 to more directly control switching "on" and “off of the operation of the oscillator (DRO) component whereby the microcontroller may generate an oscillator control signal from a port of the microcontroller.
  • a control signal may activate and deactivate the oscillator for fast switching of the oscillator.
  • This control may be in addition to the indirect switching control of the power to the oscillator as discussed in more detail herein in relation to the microcontroller controlling the power to the oscillator by activating and deactivating a voltage regulator of the power supply.
  • the oscillator control circuit 1 1 11 (not shown in FIG.
  • the oscillator control circuit may be formed with high speed gate(s).
  • the control circuit 1 11 1 may include a set of amplifiers that, when activated by the oscillator control signal from the microcontroller, permit the power from a controlled voltage regulator of the power supply to power the oscillator.
  • the oscillator control circuit may have a set of amplifiers with inputs coupled to an output port of the microcontroller. The output of the set of amplifiers then selectively couples a supply power of a voltage regulator of a power supply of the sensor to selectively power the oscillator by control of the microcontroller.
  • the microcontroller may be programmed (a) to supply a power supply control signal to activate power to the oscillator indirectly through control of the power supply and (b) to supply another signal through the oscillator control circuit 11 11 to more directly control the oscillator.
  • control can also permit isolation of the sensor(s), such as when multiple sensors are operating in a common sensing area. As discussed in more detail herein in reference to FIG. 18, such control can also permit reduction of 1/f noise.
  • the senor may include a microcontroller configured to generate an oscillator control signal so that the oscillator control signal controls activation and deactivation of the oscillator via an oscillator control circuit coupled to the microcontroller and the oscillator.
  • the stable RF frequency signal output from oscillator 42 is injected into a switched amplifier 52 (see Figs. 6 and 11) to produce a switched radio frequency output (pulsed).
  • amplifier 52 may be an injection locked wideband amplifier including a transistor 53 (Q7) such as a pHEMT radio frequency FET and associated passive components.
  • the PRF timing signal output from gate 28D (U4) is applied to a drain 54 of the switched amplifier 52 (Q7).
  • Gate 28D (U4) thereby serves to drive amplifier 52 (Q7).
  • the PRF timing signal may be applied to amplifier 52 to produce a 10.525GHz radio frequency pulse at the stable reference frequency each time a positive pulse is applied to drain 54.
  • Amplifier 52 (Q7) is associated with a series resistor 55 (R77), a series inductor
  • a second attenuator 58 is illustrated in FIG. 1 1 having three resistors 58A (R75), 58B (R42), and 58C (R76).
  • the pulsed (e.g., 10.525GHz) radio frequency output from the amplifier 52 (Q7) may be fed via second attenuator 58, through the magnitude detector 70, and then through a bandpass filter 65 (FLT1) to an antenna 63.
  • attenuator 59 can optimize the drive level to magnitude detector 70 and improve system impedance match.
  • An antenna feed circuit 62 routes the transmit and receive signals 1 1, 13 (see FIG. 5A) to and from an antenna 63.
  • the pulsed radio frequency output signal from amplifier 52 is fed via a series resistor 58 A (R42) through a microstrip bandpass filter 65 (FLT1) to antenna 63, which may be a monopole or like structure.
  • Series resistor 58 A isolates switched amplifier 52 from signal reflections and improves system impedance match.
  • Capacitor 57B (C53) provides radio frequency decoupling.
  • Bandpass filter 65 may be a high performance sub-miniature energy- trapping low insertion loss coupled H resonator bandpass filter.
  • filter 65 (FLT1) is a microstrip bandpass filter that rejects out of band interfering signals and low harmonic emissions. Together with a horn antenna feed, which has an excellent low cut-off frequency, filter 65 (FLT1) may provide high rejection of frequencies that are commonly encountered in domestic and clinical environments, such as those associated with radio/TV broadcast, Wi-Fi, DECT, ISM and mobile phones. Filter 65 (FLT1) may also provide sufficiently high rejection at the second harmonic frequency of 21.05GHz so as to ensure product regulatory compliance.
  • Magnitude detector 70 is configured to measure the magnitude and phase of transmit and receive signals 1 1, 13. As illustrated in FIG. 1 1 , magnitude detector 70 is coupled to the antenna feed.
  • the magnitude detector 70 may include a first magnitude detector 70A (D2) and a second magnitude detector 70B (D3).
  • Each magnitude detector 70A (D2) and 70B (D3) has a pair of diodes located on the transmission line between amplifier 52 and antenna 63 serving as homodyning receivers. The diodes operate when biased by one of positive pulses output from gate 28F pulse generator 20. For example, each diode of first and second detectors 70A (D2) and 70B (D3) may operate in response to a 5ns pulse output from gate 28F (U10) (see Fig 10).
  • each magnitude detector 70A (D2) and 70B (D3) is presented to each magnitude detector 70A (D2) and 70B (D3) during a time interval.
  • the spacing between first magnitude detector 70A and second magnitude detector 70B permits generation of quadrature output (I or Q) signals from each.
  • magnitude detector 70 A produces I signal (in phase) and magnitude detector 70B produces Q signal (quadrature phase).
  • the magnitude detectors as homodyning receiver magnitude detectors provide a measure of the magnitude and phase of the combined receive signal 13 (See FIG. 5 A) and transmit signal 1 1.
  • the phase and/or magnitude of receive signal 13 will be different from that of transmit signal 1 1 when the target moves.
  • the combined signal 15 output from each of the magnitude detectors 70A, 70B provides a measure of said movement.
  • the second magnitude detector 70B is used to overcome nulls in movement sensitivity, which may occur every ⁇ /2, wherein " ⁇ " is the wavelength of combined signal 15.
  • the second detector 70B serves as a quadrature phase magnitude detector that is spaced apart from first detector 70A by a physical distance equal to the sum of ⁇ /8 plus n* ⁇ /2, wherein "n” is an integer.
  • magnitude detectors 70A (D2) and 70B (D3) are switched in by the positive pulses output from gate 28F of pulse generator 20 (Because each pulse is staggered by the IF timing signal, detectors 70A (D2) and 70B (D3) may be activated at different points during transmit signal 1 1 , depending upon the modulation level of the IF timing signal. For example, during a first portion of a timing cycle, magnitude detector 70B may be switched in at the start of a pulse to provide an initial reference receive level (or "RLo"). This operation may be repeated a number of times (N) to obtain an average RLo for the combined signal 15 output from magnitude detector 70B over the duration of the timing cycle.
  • RLo initial reference receive level
  • detector 70B may be switched in at a time ti after the start of said pulse to provide one or more subsequent receive levels (or "RLi") for signal 15. As before, this operation may be repeated a number of times (N) to obtain an average RLi output from magnitude detector 70B.
  • the difference between the Receive Level 0 (RLo) and the Receive Level 1 (RLi) provides a measure of the movement that has occurred in the time period tl from the start of the RF pulse and hence the movement that has occurred within the range (c*tl)/2, where c is the speed of the light.
  • transceiver there are multiple aspects in the transceiver that may be considered synchronous. For example:
  • the receive RF signal may be considered “identical” to the demodulating RF Local oscillator; This is not normally referred to as synchronous but instead “homodyne, or direction conversion".
  • the range gating can be achieved using a switched magnitude detector that is synchronised in time to the start of the receiver pulse; This is not normally referred to as synchronous but can be so considered.
  • the IF modulation, and amplification can use a technique known as "synchronous phase detection". This is the item normally referred to as synchronised.
  • the modulation timing is synchronous with the timing of the demodulation.
  • Synchronous may be understood to be control such that you know at what point in time it is possible to switch off so that you do not switch off in the middle of a modulation / demodulation sequence and produce unwanted transients or spurious signals in the baseband. It also can also permit resuming without transients. Such control can also permit operations to be performed quickly,
  • the 70A, 70B may be amplified by an IF filter amplifier 82 for digital processing.
  • An example IF filter amplifier 82 is illustrated in FIGs. 6-7 and 12.
  • the amplifier 82 configured as a preamplifier, may be a dual channel preamplifier comprising a first operational amplifier (“OpAmp") circuit 82B (U13B), a second OpAmp circuit 82A (U13A), and associated passive components.
  • Each circuit may be used to amplify either the I or Q version of combined signal 15. Both circuits have similar or identical topology.
  • first OpAmp circuit 82B (U13B), which is shown in FIG. 12 as a non-inverting filter amplifier.
  • the input signal is initially high pass filtered by a decoupling capacitor 83B and a resistor 84B.
  • the output voltage is biased by connecting the non-inverting input (+) of first OpAmp circuit 82B to the 1.25V reference rail VR described below via a resistor 189B (R39).
  • the gain and first order filter characteristics of the I component of signal 15 are determined by the gain bandwidth product (the "GBH") of OpAmp circuit 82B (U13B) and its passive components as follows:
  • first preamplifier at OpAmp circuit 82B (U13B) is configured to provide a first order low pass filter and second order high pass filter characteristic used to pre-amplify and filter the I component of the combined signal 15 output from first detector 70A.
  • the Q component of said signal 15 is likewise pre-amplified and filtered by second preamplifier at OpAmp circuit 82 A (U13A).
  • the Q version of the combined signal 15 output from magnitude detector 70B is presented to second OpAmp circuit 82 A (U13A), which is shown in FIG. 12 as a non-inverting filter amplifier.
  • the input signal is initially high pass filtered by a decoupling capacitor 83A and a resistor 84A.
  • the output voltage is biased by connecting the non-inverting input (+) of first OpAmp circuit 82A to the 1.25V reference rail VR described below via a resistor 189A.
  • the gain and first order filter characteristics of the Q component of signal 15 are determined by the gain bandwidth product (the "GBH") of OpAmp circuit 82A (U13A) and its passive components as follows:
  • second preamplifier at OpAmp circuit 82 A (U13A) is configured to provide a first order low pass filter and second order high pass filter characteristic used to pre-amplify and filter the Q version of the combined signal 15 output from magnitude detector 70B.
  • Synchronous demodulator 88 is configured to determine the difference between the RLo and RLi levels previously described which are both present on both channels (I and Q) of the intermediate signal.
  • each of the I and Q channels of the combined signal 15 output from first and second amplifiers (opAmp circuit 82A (U13A) and opAmp circuit 82B (U13B)) is digitised by microcontroller 80 via a set of analog-to-digital converters ("ADC") at inputs 80F and 80G of microcontroller 80.
  • ADC analog-to-digital converters
  • ksps analog-to-digital converters
  • the digitised samples of each channel (I and q) are then averaged (or summed) in a digital processor of the microcontroller to provide a digitised combined signal 15 that is both low pass filtered and amplified by the averaging process.
  • the difference between RLo and RLi provides a measure of the movement that has occurred between to (at the start of a pulse) and ti (at some point thereafter) within a predetermined range.
  • a synchronous demodulator 88 of FIG. 6-7 that is programmed by firmware of the microcontroller 80 detects the difference between the levels for each channel.
  • This processing is realized with a dual channel register operated by an IF amplifier and demodulator algorithm included in the firmware. The algorithm operates as follows:
  • the I component of combined signal 15 is output from first preamplifier at opAmp circuit 82B (U13B) and presented to an analog input 80F of microcontroller 80 such that,
  • results are stored, e.g., in any of the storage mediums described below.
  • the stored results represent the amplified and filtered difference between the average signal levels and, hence, the difference between RLo and RLi. (i.e., delta RL 1 )
  • the microcontroller algorithm serves as an IF amplifier and demodulator to thereby amplify, filter, and synchronously demodulate combined signal 15 so as to produce a wideband baseband signal.
  • the wideband baseband signal requires narrowband filtering to complete the process.
  • the algorithm may be used to perform a similar process for the Q component of combined signal 15 (e.g., determining delta RL Q ).
  • Baseband module 89 of the microcontroller 80 provides for narrowband filtering and amplification of the digital wideband baseband signal from the synchronous demodulator.
  • the baseband module 89 is illustrated in FIG. 6 and is realized digitally by a baseband program/algorithm (e.g., firmware).
  • the algorithm accepts the low level I and Q (delta RL 1 and delta RL Q ) demodulated components from the synchronous detector 88.
  • Baseband module 89 then amplifies and filters the I and Q components separately to provide at least one output for movement.
  • baseband module 89 outputs four digital baseband signals at a suitable level for subsequent processing; including outputs for: (1) 1 movement; (2) I respiration; (3) Q movement; and (4) Q respiration. Separation of respiration from movement in either the I or Q baseband signals is effected by digital filtering in the microcontroller since respiration movement and other movements in the signals are at different frequencies.
  • each of I channel and Q channel baseband signals may be digitally filtered according to a pre-determined set of filtering parameters in the firmware depending on desired movement to be targeted (e.g., respiration movement).
  • desired movement to be targeted e.g., respiration movement
  • This configuration allows the functionality of respiration and movement algorithm components to be kept as separate blocks so that the filtering parameters may be changed, or removed entirely, to deliver a targeted functionality.
  • the main advantages of digital baseband filtering and amplification are high dynamic range, low signal distortion, and low unit- to-unit variation of the filtering transfer function.
  • the sensor may include analog I/Q output interface.
  • the microcontroller may convert the digital I and Q baseband signals into analog motion signals.
  • any of the four digital baseband signals generated by baseband module 89 may be presented to an analog interface circuit 90 shown in FIG. 13.
  • This analog interface is optional, and can for example be used to be backward compatible with analog RF sensors or if other processing of analog motion signals is desired.
  • the microcontroller 80 utilizes an integrated pulse width modulator 91 (a "PWM") functionality integrated in the microcontroller 80.
  • the PWM 91 module produces an analog signal representation of the baseband channel signals in conjunction with external low pass filtering circuits.
  • the digital signal level from the baseband filter amplifier 89 (which is digital) is loaded into a PWM counter, which can be a standard register associated with a PWM peripheral inside the microcontroller) that generates a pulse width PW signal proportional to the digital signal level.
  • This digital pulse width PW signal is then presented to PWM output/input ports 91A and 91B of microcontroller 80.
  • each of these digital signals is low pass filtered by a second order filter, it regenerates the analog representation of the digital signal.
  • the two filters are realized as two individual low pass second order filter circuits 92A and 92B, each having a 16Hz cut-off frequency.
  • Each filter 92A and 92B is comprised, respectively, of a plurality of resistors 92A-1 (R36), 92A-2 (R37), 92B-1 (R38), and 92B-2 (R3); as well as a plurality of capacitors 92A-3 (C32), 92A-4 (C4), 92B-3 (C34), and 92B-4 (C6) associated therewith.
  • Filter circuits 92A, 92B prevent interference from any high frequency radio frequency signals that might be injected via the output wiring into sensor 10.
  • Resistors 92A-1 (R36), 92A-2 (R37), 92B-1 (R38), and 92B-2 (R3) provide output overage and over current protection by limiting the current.
  • Sensor 10 may be implemented with further interface circuits for communication with other devices.
  • microcontroller 80 has a plurality of interface circuits, each being adapted for data communication.
  • analog interface circuit 90 a number of example communication interface circuits are described below. These interface circuits may be peripherals integrated within the microcontroller for easy realisation and interfacing to external interfaces.
  • a universal serial bus (USB) interface 93 may be provided for communications to other devices, such as computers, mobile phones, and like, when acting as a peripheral device or with other peripheral devices, such as an external memory device, when serving as a host. Such an example interface is illustrated in FIGs. 7 and 13. As shown, the physical USB interface 93 ports may be integrated with microcontroller 80 with the communications protocol being included in firmware for the microcontroller. Any USB technology may be employed, including USB OTG or its equivalent.
  • a serial interface 94 such as that illustrated in FIGs. 7 and 13 may also be provided.
  • the microcontroller may include an integrated serial wired digital interface that is realized by a universal asynchronous receiver/transmitter circuit (a "UART circuit") that sends and receives asynchronous or asynchronous serial data over separate transmit and receive lines 94A and 94B.
  • the circuit may be configured to operate from a 3.3V supply, and adapted to utilize complementary metal-oxide-semiconductor (or "CMOS”) threshold levels.
  • CMOS complementary metal-oxide-semiconductor
  • a set of series resistors 94C (R8), 94D (R6), and 94E (R4), together with a corresponding set of clamping diodes may be integrated with the ports in microcontroller 80 (not shown). These may serve to limit the current, facilitate electrostatic discharge (or “ESD”), and provide overvoltage protection.
  • ESD electrostatic discharge
  • a debug interface 95 is provided to facilitate emulation and programming of the functionality of the microcontroller (e.g. firmware).
  • Interface 95 is conceptually shown in FIGs. 7 and 13 as being integral with microcontroller 80.
  • the debug interface 95 is internal to the microcontroller.
  • debug interface 95 provides for reset, serial communications, and programming control of microcontroller 80.
  • Interface 95 may be designed to facilitate Joint Test Action Group (JTAG) interfacing.
  • JTAG Joint Test Action Group
  • a user input/output interface 96 for enabling a user to interface with the sensor, allows subject 1 , or other user, to operate the microcontroller 80.
  • the interface 96 is illustrated in FIGs. 7 and 15 as including a graphic display, such as and LCD screen coupled to an input surface that provides for push button or touch screen inputs.
  • Each element of interface 96 may be controlled by firmware of the microcontroller.
  • the graphic display may be a touch screen with an input surface that is directly connected to one or more control ports on microcontroller 80.
  • the touch screen graphic display may be controlled by a three wire I2C and/or SPI digital control port, for example.
  • Sensor 10 may be configured to communicate wirelessly, such as by using
  • Bluetooth® technology A conceptual Bluetooth interface 97 is illustrated in FIGs. 7 and 15.
  • the interface 97 can be realized by a single-chip Bluetooth 4.0 Connectivity integrated chip (IC).
  • the circuit function of interface 97 may be realized by an nRF IC made by Nordic Semiconductor that integrates a fully compliant Bluetooth Smart v4.0 radio, link layer, and host stack and features a simple serial interface.
  • the components of an IC, such as the nRF8001 may be integrated into microcontroller 80.
  • Bluetooth interface 97 preferably operates in the peripheral or slave role.
  • the on-chip link layer and host stack may also include support for the peripheral GAP role, client, server, and security functions.
  • Microcontroller 80 can include a low tolerance 32kHz RC oscillator that can eliminate the need for an external 32kHz crystal, as well as a 16MHz crystal oscillator that may eliminate the need for an additional 16MHz crystals. Thus, in some cases, one or more oscillator components may be included within or integrated with the microcontroller.
  • NFC interface 98 of FIG. 7 enables a close proximity data transmission to other devices, such as computers, smartphones, or the like, using the near field communications protocol (or "NFC").
  • Interface 98 of FIGs. 7 and 13 may be integrated into microcontroller 80.
  • the external antenna for the integrated NFC communications protocol physical layer may be provided by a loop antenna 98 A.
  • antenna 98A illustrated in FIG. 13 may be a copper tracking on a perimeter of sensor 10 that provides a square profile magnetic loop antenna such as with 4 turns, wherein two turns are placed on each of the top and bottom sides of sensor 10.
  • a pair of capacitors 98B (C37) and 98C (C37) provide low pass and bandpass filtering for loop antenna 98 A.
  • Wi-Fi wireless interface 99 allows microcontroller 80 to communicate wirelessly with another device using the 802.1 lb/g radio communications protocol or its equivalent.
  • An example interface 99 is illustrated in FIG. 7.
  • interface 98 is Wi-Fi module that provides a radio frequency 802.11 physical layer front end and a complete Wi-Fi protocol stack.
  • Interface 98 is coupled to controller (microcontroller 80) by serial peripheral interface (or "SPI") communications .
  • SPI serial peripheral interface
  • a memory circuit 100 is provided to store digital signal or processed data.
  • Memory circuit 100 is illustrated in FIG. 7 as a storage medium integral with microcontroller 80
  • Memory 100 can be internal or external to the controller (microcontroller 80).
  • circuit 100 may, alternatively or in addition thereto, be an external storage medium that is placed in communication with microcontroller 80 via one of the interfaces described above.
  • Any embodiment of circuit 100 may be comprised of flash memory, EEProm memory, or like storage medium.
  • the sensor may implement an internal storage medium, external storage medium, or a combination thereof, of any particular memory circuit type (e.g., EEProm, Flash etc.).
  • internal flash memory allows for a more-fully integrated circuit with greater storage capacity, whereas EEProm has reliability advantages when small amounts of data are read or stored repeatedly.
  • a plurality of memory circuits 100 may be provided.
  • microcontroller 80 of FIG. 7 may have an internal memory circuit 100A configured to store program and data memory. This memory circuit may be flash memory.
  • Microcontroller 80 may have a second memory circuit for serial data. Additional memory circuit may be implemented by with a socket adapted to receive a removable storage medium, such as an SD card or the like.
  • a further memory circuit may utilize EEProm memory,
  • sensor 10 operates with a DC power supply from power source circuit 1 10 that generates multiple voltage levels (e.g., 3.3V, 2.5V internal DC power supply rails and the 1.25V reference rail). Input from an external source may be a DC input voltage from 4.5V to 6V, for example.
  • a more detailed schematic of an example power source circuit 110 is presented in FIG. 14. As shown, circuit 1 10 has a set of power supply inputs on interface pins 111 (GND) and 112 (J3-2). Although not required, double regulation is used to achieve a high noise rejection performance.
  • a first linear regulator 1 13A (Ul l) and a second linear regular 113B (U8) are cascaded to generate an internal 2.5V regulated DC supply.
  • First linear regulator 113A (Ul 1) accepts the input supply voltage on a pin 113A-
  • a sensor power down capability is provided on a connector pin 1 16 (J3-3) that controls output terminal 1 13A-5 of regulator 113A (Ul l).
  • a resistor 117 (R68) provides a current limiting. As illustrated, radio frequency immunity is provided by a ferrite bead 1 18 (FBI) and a capacitor 1 19 (C48) on pin 112 (J3-2), and a resistor 120 (R80) and a capacitor 121 (C49) on pin l l6 (J3-3).
  • the intermediate 3.3V DC supply output from terminal 1 13 A-5 is low pass filtered by a resistor 122 (R69) and a capacitor 123 (CI).
  • second linear regulator 1 13B (U8) accepts the filtered 3.3V supply voltage on a pin 1 13B-5 with respect to its ground terminal pin 1 13B-2 and generates a 2.5V DC internal supply on an output terminal pin 113B-4.
  • Capacitor 114 (C52) improves the thermal noise performance of the regulator.
  • a resistor 125 (R44) enables second linear regulator 1 13B (U8) by connecting a SHUTDOWN pin 1 13B-1 to the filtered 3.3V supply output from a pin at output terminal 113 A-5 of first regulator 1 13 A.
  • Local power supply decoupling is provided by three capacitors 126 (C28), 127 (C55), and 128 (C29).
  • Two resistor dividers 129 (Rl) and 130 (R30) generate a 1.25V referencevoltage (VR).
  • a capacitor 131 (C23) provides decoupling.
  • the 1.25V reference supply is used to bias preamplifier circuit (amplifier 82), as described previously.
  • the power supply may include multiple voltage regulators for different power supply control schemes.
  • the power supply may include one or more voltage regulator(s) to supply a more continuous power to the microcontroller so that the microcontroller may be powered for various operations when other components of the sensor are not powered.
  • a portion of the power supply may provide continuous supply of power.
  • the power supply may optionally include additional voltage regulator(s) that may be selectively operated (e.g., activated) by the microcontroller.
  • the microcontroller may be programmed to turn “on” and “off such a voltage regulator (for example, by operation of a control switch or transistor of the power supply) so that the power supply via the controlled voltage regulator may selectively provide power to additional components of the sensor.
  • the power supply may include a voltage regulator controlled by the microcontroller that provides power to the transceiver circuits (e.g., the DRO oscillator, the pulse generator, the IF preamplifier, and/or the magnitude detectors), (see, e.g., Fig. 6.)
  • the microcontroller may be programmed to send control signals to the power supply (e.g., one or more voltage regulators) to selectively control, at programmed times, activation of any one or more (e.g., all) of these components.
  • detection device 12 including circuit elements for sensor 10 described can provide various benefits.
  • the designs can improve functionality such as through control of a microcontroller 80 and its firmware.
  • the circuit can provide lower cost embodiments relative to analog components.
  • Sensor functionality may also be expanded with one or more peripheral devices in communication with sensor 10 via interfaces 93-99. Numerous methods are enabled by this configuration.
  • Integrated circuits can provide these benefits.
  • a microcontroller can permit integrated circuit functionality, which may be reused by a multiplicity of customers in a multiplicity of products and versions of products and can produce a cost reduction advantage associated with this large volume.
  • Pulse generator 20 utilizes the oscillator and counter registers 24 of microcontroller 80 to generate the respective PRF, IF, and dither timing signals. These circuits, together with digitally implemented transmission timing portion 32 and reception timing portion 36, using digital circuit components, realize an integrated pulse generator 20 that is controlled by microcontroller 80 and its firmware. Numerous methods are enabled by this configuration. For example, a method of mitigating noise may include dynamically changing, with microcontroller 80, the respective frequencies of the PRF and IF timing signals so as to realize modulation timing dithering. Desirably, this method may be used to mitigate radio frequency coexistence noise without additional hardware circuitry. This method may further include implementing, with microcontroller 80, a dither timing signal with a pseudorandom sequence that further mitigates radio frequency coexistence noise.
  • a dynamic range gating may be implemented by controlling, with microcontroller
  • the method may include adjusting, with the microcontroller 80 and based on a position of the subject 1, which position is either determined with the microcontroller 80 or predicted otherwise, the range of sensor 10. This may improve the strength of receive signal 13 by changing the timing of the IF timing signal. This method allows sensor 10 to provide enhanced physiological signal strength and improve signal to noise performance.
  • Another implementation may include optimising, with the microcontroller 80, the position of subject 1 in order to reject any portion of receive signal 13 that is echoed back from a second person sleeping in the same bed.
  • the graphic display of user interface 96 may be controlled by the microcontroller to output instructions to provide the subject 1 with the feedback necessary to either change positions or move sensor 10. This may be done during setup or when the device detects signals indicative of multiple subjects.
  • Yet another method may include determining, with microcontroller 80, whether the receive signal 13 is reflected off of subject 1 or another subject in range of sensor 10.
  • sensor 10 may be configured to distinguish between a signal 13 reflected from a non-moving subject 1 from a signal 13 reflected from a moving subject.
  • Oscillator 42 may be controlled by microcontroller 80 using, for example, PWM output/input ports 91 A and 9 IB to realize radio frequency control. Accordingly, the sensor may implement a method of mitigating noise by dynamically changing, with microcontroller 80, the supply voltage to the oscillator 42 to realize frequency dithering or frequency synchronisation. This method may be performed under programmed logic control (e.g. firmware), without additional hardware circuitry.
  • Microcontroller 80 may, for example, utilize the power supply regulator voltage control reference input to produce ramp frequency dithering or frequency synchronisation.
  • Amplifier 52 may be controlled by microcontroller 80 to produce variable pulse width modulation under firmware control.
  • This configuration enables correcting, with microcontroller 80, the occupied bandwidth ("OBW") of the pulse modulated radio frequency signals spectrum so as to meet a pre -determined approval requirement.
  • the microcontroller 80 may control the PW and PRF frequency so as to change the pulsed modulation parameters.
  • the microcontroller may further include controlling/changing the PW and PRF frequency to provide a dynamic pulsed modulation control.
  • the programming of the microcontroller 80 may be implemented to improve signal quality by switching antenna 63 to provide diversity and directional control.
  • an element of antenna feed circuit 62 may alternatively be switched to realize this advantage.
  • IF filter amplifier 82 (FIG. 12) is implemented to amplify the combined signal 15 output from magnitude detector 70. It may be implemented digitally in/with the microcontroller 80 by oversampling combined signal 15 at a multiple of the PRF frequency and averaging the result. This configuration can provide a complete IF filter amplifier with automated gain control (“AGC”) and without additional hardware.
  • AGC automated gain control
  • 1/f noise is a naturally occurring noise that is innate in all systems having a memory.
  • the 1/f noise level is inversely proportional to frequency.
  • Digital oversampling and averaging of combined signal 15 at its frequency overcomes this issue because the baseband signal is modulated at the intermediate frequency, whereas the 1/f noise is at the baseband frequency.
  • a method of improving 1/f noise may comprise oversampling and averaging, with microcontroller 80, the combined signal 15 at its frequency.
  • the microcontroller 80 may be configured to adaptively filter the combined signal 15 as its frequency is modulated or changed.
  • amplifier 52 may be configured to perform such filtering on a sample-by-sample basis, with or without the use of microcontroller 80.
  • Synchronous demodulator 88 and baseband module 89 are utilized to synchronously demodulate combined signal 15 and generate a baseband signal frequency therefrom.
  • Demodulator 88 and module 89 may be fully realized by microcontroller 80 without additional hardware. Accordingly, the microcontroller 80 may be configured to change the processing characteristics of the demodulator 88 so as to obtain a pre-determined degree of flexibility in the demodulation of combined signal 15. The multiplier architectures may also be switched on and off and adjusted. Additionally, the microcontroller may be configured to adjust the sensitivity of sensor via quadrature phase correction.
  • Baseband module 89 provides for narrowband filtering and amplification of the wideband baseband signal at the required baseband frequency.
  • Module 89 may be fully realized by the programmed digital processing of microcontroller 80.
  • module 89 may perform baseband filtering amplification to amplify the baseband signal at the required baseband frequency.
  • a processor of the microcontroller employing programmed instructions e.g., firmware
  • firmware may improve 1/f noise by oversampling and averaging, with microcontroller 80, the combined signal 15 and reducing, with microcontroller 80, amplification of the baseband signal.
  • Other programming may include adaptively filtering, with microcontroller 80, the baseband signal so as to provide a plurality of outputs with variable functionality.
  • separate outputs may be provided for respiration and movements.
  • This method may be utilized to filter these outputs even further according to varying types of motion (e.g., gesturing, gross motion) and respiration (e.g., breathing, coughing).
  • the methods may provide for automated gain control, improved distortion, and improved dynamic range as the amplifier voltage rails, which can be large, are replaced by use of microcontroller voltage rail control that sets voltage level with numeric values in the microcontroller 80.
  • a plurality of interface circuits are described above, including analog interface circuit 90 as well as interface circuits 93-99.
  • Each interface is configured to present aspects of the baseband signal to other devices and systems, such as the I and Q components contained therein or other data derived with processing of the baseband signal in a digital processor of the microcontroller.
  • Another method may include presenting, with microcontroller 80, the I and Q components of the baseband signal to another device.
  • the sensor I and Q baseband signal analog outputs may be presented to PWM 91 and filter 92.
  • the I and Q components of the baseband signal may be presented to a wired digital interface utilizing the integral wired communications protocols, such as USB, USB OTG, RS232.
  • the baseband signal may be presented wirelessly using communications protocols such as Wi-Fi, Bluetooth, NFC, etc.
  • Power supply circuit 1 10 provides a low noise and high frequency rejection voltage rail for each circuit controlled by microcontroller 80.
  • the microcontroller may be configured to vary the control voltage, such as with voltage regulator 103B, for example, to provide a variable power supply voltage rail (i.e., the electronic circuit DC power supply line(s)) for frequency dithering of the DRO. Standby control of the power supply rail may also be provided.
  • the microcontroller may be configured to control the power supply to selectively de -power (i.e., turn off) power supplying the oscillator 42 or transceiver 40 or vice versa power (i.e., turn on) the oscillator.
  • the microcontroller controls voltage rails of the transceiver or oscillator by controlling the power supply coupled to the transceiver or oscillator.
  • the microcontroller 80 may digitally process the motion signals to produce output based on signal, such as by detection respiratory conditions, sleep conditions, etc.
  • Other methods may comprise accepting, with the microcontroller 80, one or more inputs from user interface 96, or other input device; processing said inputs with microcontroller 80, and providing an output to one or more output devices.
  • sensor 10 may have a self-contained power source that is monitored by a signal input to microcontroller 80 and operated by a signal output to microcontroller 80 in response to said input signal.
  • the algorithm e.g., DSP algorithm 81 "takes in” aspects of the IF stage (i.e., the processing of the intermediate frequency signal or the combined signal 15), using oversampling and filtering to produce a 64Hz baseband from the oversampled 8kHz IF.
  • the IF stage as described herein, is a modulation and demodulation stage, that might otherwise be completely incorporated in the homodyning RF transceiver, that overcomes the issue of 1/f noise associated with homodyning "direct conversion" receiver and also provides range gating.
  • IF modulation is generated on the RF demodulated receive signal by detecting RF reflected signals that occur near the sensor for a period of half the IF and comparing these with RF reflected signals that occur further away from the sensor for the remaining period of the IF. Because this IF signal is at a higher frequency than the baseband signal it can be amplified and subsequently demodulated to baseband without introducing low frequency 1/f noise during the high frequency amplification stage (i.e., IF Filter amplifier 82). Because the sensor only detects signals within two defined ranges it is range gated. Demodulation is synchronous demodulation of the IF.
  • Apnea may be processed on the basis of a four state model, namely: breathing normally, user absence, apnea, and user movement.
  • the system operation proceeds to an absence (or undefined) state. It must go from absence (e.g., a long time with no signal - a signal below empirically selected temporal and frequency parameters such as low signal level) and must end up in a breathing state.
  • absence e.g., a long time with no signal - a signal below empirically selected temporal and frequency parameters such as low signal level
  • a breathing state there must be a certain number of breaths per minute for certain number of cycles before the system can confirm valid breathing (e.g., 12 br/min +/- a certain threshold - such as 6-45 breaths per minute).
  • Basic apnea this is a state of valid breathing transitioning to a state of 'not valid' breathing (absence) for more than 10 seconds.
  • Central and obstructive states may be combined or considered separately based on the signal
  • Movement this state is where there is signal(s) above a specific threshold and has a power content that falls within a specific frequency band.
  • this uses the absolute value of differences between samples - i.e., looking at the slope (differential / rate of change for curve for defined step). For small differences, the breathing state is favoured.
  • Hysteresis i.e., a dependence on past and present inputs
  • modulation of the time domain baseband signal can be implemented to detect hypopnea.
  • the above described system(s) constitute an optimised form of a hybrid sensor which has transferred portions of what can be an entire analogue RF sensor into a partially digitised form. It brings physical size reduction, component and manufacturing cost reduction, increased reliability, accuracy, reduces sensor to sensor variability, allows reconfiguration, and introduces enhanced features not easily implemented in analogue system such as dynamic range gating, and can run algorithms on-board (i.e., within the sensor circuits).
  • the microcontroller is configured to selectively turn off (and on) the complete RF and IF circuit (transceiver 40) (i.e., all associated circuits), by turning off (or on) the power supply to the oscillator (and all associated circuits). Turning off the complete RF and IF circuit reduces 1/f noise. This may be done while still permitting other operations with the microcontroller.
  • the microcontroller may power or turn on (and de -power or turn off) the RF sensing when desired, such as according to a programmed schedule or detection of a stand by condition (e.g., turn off upon detection of absence of movement or absence of movement for a predetermined period of time etc.)
  • Signal to Noise improvement is a beneficial goal for RF sensor design.
  • sources of circuit noise including thermal, shot, flicker, burst, etc.
  • 1/f noise is particularly problematic as it increases tenfold for every factor of ten reduction in frequency and hence is very high at the signal frequencies of the example sensors described herein.
  • example sensors may include a microcontroller configured to control operation of a power supply that is configured to provide power to the transceiver.
  • the microcontroller may be configured to control operation of a power supply that is configured to provide power to an oscillator of the transceiver.
  • the microcontroller may be configured to control operation of a power supply that is configured to provide power to a switched amplifier of the transceiver.
  • the de -powering the transceiver may completely turn off an RF circuit and IF circuit of the transceiver.
  • the microcontroller may be configured to de -power the transceiver by controlling turning off of a power supply line that is configured to, when turned on, supply power to an oscillator of the transceiver.
  • the microcontroller may be configured to de -power the transceiver by controlling turning off of a power supply line that is configured to, when turned on, supply power to a switched amplifier of the transceiver.
  • the microcontroller may be configured to receive power from a power supply independently from power received by the transceiver from the power supply so that the microcontroller may continue to operate when the transceiver is de -powered.
  • the microcontroller may be configured to de -power any one or more of an RF switched amplifier (e.g., amplifier 52), an RF demodulator (e.g., magnitude detector 70 switched by the pulse generator to demodulate the RF received signal), a pulse generator (e.g., pulse generator 20), and an IF amplifier (e.g., IF filter amplifier 82) and their respective power supply(s).
  • the IF stage or IF circuit may be formed by an IF modulator (RF receiver diodes switched at an IF frequency, such as magnitude detector 70), IF amplifier (e.g., amplifier 82) and an IF demodulator, unless implemented by software, such as in the optional case of a software IF demodulator.
  • the IF filter amplifier and IF demodulator produce an amplified baseband signal.
  • the microcontroller 80 may turn off (de -power) the RF sections (e.g., circuit components involved in RF transmission/reception/modulation/demodulation) of the circuit as well as the power supply for the transceiver such as a linear or voltage regulator that powers the RF sections or transceiver, or other related components.
  • Noise such as 1/f noise (and only 1/f noise), can be a result of energy storage (memory) within a system, which has a low pass filter characteristic.
  • One of the ways to remove the memory / storage effect is to remove power from the system, preferably in a way that does not introduce an unwanted transient or step response to the system.
  • Thermal noise is another form of noise that is not affected or reduced by this turning off.
  • the main component is the RF DRO oscillator.
  • Other 1/f sources of the system include: power supply, RF switch or RF switched amplifier, RF demodulator (e.g., the diode/RF magnitude detector), pulse generator, and the IF amplifier.
  • the microcontroller may then be configured to selectively switch off (depower) one or more of these components without introducing an unwanted transient based on the system architecture. This is an advantage of a pulsed (i.e., intermittent in time) RF architecture.
  • the oscillator may be momentarily depowered between pulses during the generation of the pulsed radio frequency signals or it may be turned off at other times when it is not needed for sensing operations.
  • control of the sensor's circuits by the microcontroller 80 in a synchronized manner for RF pulse generation that can help to reduce 1/F noise may be considered in reference to the timing signal graph in the illustration of FIG. 18.
  • the microcontroller 80 may control the power supply to activate and de-activate power to the transceiver circuits (including the DRO oscillator.)
  • the microcontroller switches this power to the pulse generator, the DRO, and the IF stage indirectly via a switched voltage regulator of the power supply. This power switching is performed at a much lower duty cycle to overcome transients.
  • the microcontroller may generate a power supply control signal (signal 1802) to time operations of the power supply an order of, for example, approximately 1000 cycles per second.
  • a control signal may activate and deactivate a voltage regulator for the powering/depowering the transceiver components as previously discussed.
  • the microcontroller 80 may also generate an oscillator (DRO) control signal (signal 1804) on the order of, for example, one million cycles per second.
  • DRO oscillator
  • Such a control signal may activate and deactivate the oscillator via oscillator control circuit 1 1 11 as previously discussed.
  • the microcontroller may also generate the PRF signal (signal 1806) previously described for control of the pulse generator (and its control of the switched amplifier 52) on the order of approximately, for example, the frequency of the oscillator control signal, e.g., one million cycles per second.
  • the PRF signal may typically have a different period ("on” or rising edge timing) when compared to the "on" edge timing of the oscillator control signal as illustrated in FIG. 18 to permit the DRO time to power up to a stable "on” operation before PRF signal generation.
  • the PRF signal may have approximately an earlier half “off time and a later half “on” time (e.g., 500 nanoseconds "on” time and 500 nanoseconds “off time.)
  • 1/f noise is reduced with the generation of such controlled timing signals by the microcontroller 80 so that the "on" times of the DRO can be minimized or reduced when compared to a sensor with a continuously operating DRO during RF pulse generation.
  • the oscillator "on” time may be limited to being briefly longer than the needed "on” period of the pulse generator timing signal (PRF).
  • a DRO can take approximately 50 nanoseconds to switch off and about 100 nanoseconds to switch back on so that it is able to achieve a stable oscillation.
  • the PRF signal "on” times are synchronized with the DRO “on” times so that the PRF is “on” during stable oscillation of the DRO.
  • the DRO "on” times implemented with its fast or high speed switching, are appropriately switched “on” to ensure stable DRO operation for the PRF "on” times.
  • the DRO is actively switched during the PRF quiet time. This provides both 1/f noise reduction and RF isolation during the quiet period.
  • frequency and time values are referenced herein, it will be understood that these frequency and time values are merely examples. Other frequencies and times may be implemented in relation to the desired operations and/or configuration of the sensor components.
  • the microcontroller may be configured to synchronize repeated generation of a power supply control signal, an oscillator control signal and a PRF timing signal, wherein the generation of the power supply control signal, the oscillator control signal and the PFR timing signal control generation of the pulsed radio frequency signals.
  • the oscillator may be momentarily depowered by the microcontroller such as between pulses during the repeated generation of the pulsed radio frequency signals, whereby 1/F noise in the system may be reduced.
  • the sensor may include an oscillator control circuit coupled to the oscillator and the microcontroller so that the oscillator control signal controls activation and deactivation of the oscillator.
  • switching of components can serve to create transients that could produce noise.
  • the architecture of the present sensor technology can achieve quiet switching.
  • its switched "digital" architecture provides a timing that permits signal demodulation during a settled period.
  • demodulation is utilized outside of the turning "off and turning "on” transient times associated with switching.
  • the RF stages can be switched fast.
  • the DRO can be switched fast with is carefully designed driver and timing.
  • the relatively slower speed gate circuit (pulse generator) and very slow speed IF stage e.g., If amplifier
  • demodulation may be timed so as to permit producing of a baseband signal only during an "on" and settled period of the system.
  • timing control over the oscillator/transceiver is that it can provide excellent RF attenuation between the RF pulses and enhance range gating. Moreover, it can also provide RF isolation when two or more sensor units are time-synchronised such as in a common sensing area. Such fast time switching allows for good time synchronisation and enables coexistence. In addition, this microcontroller control of the circuit switching can be done synchronously to ensure the resultant baseband signal transients do not introduce noise. Such control of transmitter and receiver is not easily possible to realize in an analogue system.
  • 1/F noise can be reduced by implementation of sensor reception at an intermediate (IF) frequency (e.g., by using IF preamplifier) as previously described.
  • IF intermediate
  • a further potential enhancement concerns the ability to take digitised signals and process them through a number of different routes (e.g., transferred back over a number of interfaces such as via wired or wireless communications).
  • the sensor also has the configuration to log data (e.g., on the sensor) and send data (raw data or processed data) for external processing and/or storage.
  • analogue circuits may be implemented to accomplish all of the above aspects.
  • such a device would be substantial in dimensions, be expensive and have very high unit-to unit variability.
  • the sensor device may be implemented in various system configurations.
  • the sensor device with its operational processing functionalities described herein may be implemented as a stand-alone unit such as one placed on a bedside table illustrated in FIG. 1.
  • Such a device may require no additional components for data processing.
  • such a device may be powered by a battery, such that it may be a portable device.
  • such a sensor device may be integrated with a mobile phone, smart phone or tablet processing device.
  • some aspects of the circuit/processing components of the devices may be shared.
  • the processing of motion data or other data from the sensor device may be transferred to a further local processing device, such as a tablet PC, smart phone or computer, that directly or indirectly communicates or otherwise couples with the sensor, such as via one of its wired or wireless interfaces (e.g., Bluetooth or Wi-Fi).
  • a further local processing device such as a tablet PC, smart phone or computer
  • processing of sensor data or motion data may be shared with, or transferred to, the local processing device.
  • the processing of motion data or other data from the sensor may be transferred to a further remote processing device, such as a server over a communications network (e.g., an internet), that communicates or otherwise couples with the sensor device, such as via one of its wired or wireless interfaces (e.g., Bluetooth or Wi-Fi).
  • a communications network e.g., an internet
  • processing of sensor data or motion data may be shared with, or transferred to, the remote processing device.
  • processing activities may be distributed or shared amongst or between the sensor, a local processing and a remote processing device.
  • the processing of motion data or other data from the sensor may be transferred to a further local processing device, such as a tablet PC, smart phone or computer, which communicates or otherwise couples with the sensor, such as via one of its wired or wireless interfaces (e.g., Bluetooth or Wi-Fi).
  • the sensor data or motion data may be transferred to the remote processing device from the local processing device, i.e. via a communication network such as an internet.
  • the local processing device may transfer any of sensor data, raw motion data or partially processed data (e.g., processed by one or both of the sensor and the local processing device) to the remote processing device (e.g., server) such as for further processing.
  • Data access such as for display on a user interface for viewing by a user, may then occur on any of the sensor device, local processing device and/or remote processing device.
  • processed data may be returned/received from the remote processing device or local processing device, to any one of the sensor device or local processing device such as for display on a user interface of such.
  • the sensor device may be configured to receive such data via any one of its interfaces.

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Abstract

L'invention concerne un capteur 10 de mouvement physiologique utilisant des composants de circuit numérique et analogique pour améliorer des opérations de détection. Le capteur utilise une combinaison de composants numériques et analogiques qui peuvent être configurés pour mettre en œuvre une détection de mouvement par radiofréquence. Les composants de circuit peuvent être configurés pour améliorer les performances et diminuer la complexité du capteur. Des exemples de capteurs peuvent émettre et recevoir des signaux de radiofréquence réfléchis pour détecter des caractéristiques physiologiques d'un sujet vivant en présence d'une ou plusieurs sources de bruit avec un microcontrôleur intégré et sortir des données concernant le mouvement détecté vers une interface utilisateur intégrée (par exemple un afficheur à écran tactile). Le capteur peut présenter une fonction de repérage à plage dynamique pour détecter quasiment simultanément des caractéristiques physiologiques provenant de plusieurs sujets à différentes distances au cours d'une session de détection commune.
PCT/EP2017/070773 2016-08-16 2017-08-16 Capteur numérique de détection de mouvement par radiofréquence WO2018033574A1 (fr)

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