Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
• • 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 for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/024—Measuring pulse rate or heart rate
• • 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 for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
  • A61B5/024—Measuring pulse rate or heart rate
  • A61B5/0245—Measuring 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
  • A61B5/103—Measuring 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 or mobility of a limb
• • 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
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/6802—Sensor mounted on worn items
  • A61B5/6803—Head-worn items, e.g. helmets, masks, headphones or goggles
• • 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
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/6813—Specially adapted to be attached to a specific body part
  • A61B5/6814—Head
  • A61B5/6819—Nose
• • 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
  • A61B5/6801—Arrangements of detecting, measuring or recording means, e.g. sensors, in relation to patient specially adapted to be attached to or worn on the body surface
  • A61B5/683—Means for maintaining contact with the body
  • A61B5/6838—Clamps or clips
• • 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
  • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
  • A61B5/7207—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts
  • A61B5/7214—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/74—Details of notification to user or communication with user or patient; User input means
  • A61B5/742—Details of notification to user or communication with user or patient; User input means using visual displays
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N1/00—Electrotherapy; Circuits therefor
  • A61N1/18—Applying electric currents by contact electrodes
  • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
  • A61N1/38—Applying electric currents by contact electrodes alternating or intermittent currents for producing shock effects
  • A61N1/39—Heart defibrillators
  • A61N1/3925—Monitoring; Protecting
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
• • 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
  • A61B2562/0219—Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches

Definitions

• the present invention generally relates to a heart rate monitor employing an accelerometer as a basis for detecting a pulse of a patient.
• the present invention specifically relates to a heart rate monitor employing multi-axis accelerometers in an angular orientation that facilitates a distinction of a pulse of a patient from motion artifacts derived from extraneous motion of the patient.
• Heart rate monitors as known in the art execute a measurement of a patient's heart rate in real time.
• heart rate monitors are designed to be simple to use, noninvasive and reliable for pulse detection purposes.
• current heart rate monitors are known to employ a multi-axis (XYZ) accelerometer 20 strapped to a chest of a person 10 over any of several easily accessible arteries of person 10 to thereby sense undulating physiological motion 12 of person 10 generated by a circulatory system 11 of person 10 as a basis for detecting the pulse of person 10.
• XYZ multi-axis
• XYZ axes 21 of accelerometer 20 experience acceleration derived from a totality of motion of person 10.
• pulses of person 10 produce measurable physiological motion 12
• motion sources extrinsic to person 10 may produce larger motion artifacts from larger undulating extraneous motion 13 that conceals
• CPR cardiopulmonary resuscitation
• the present invention as shown in FIG. 2 involves a placement of two (2) multi-axis (XYZ) accelerometers 20R and 20L on a body surface of person 10 at an angular orientation whereby respective XYZ axes 21R and 21L of accelerometers 20R and 20L individually sense physiological motions 12R and 12L generated by circulatory system 11 and equally sense motion artifacts generated from extraneous motion 13.
• respective vertical axes Z R and Z L are normal to the body surface of person 10 to individually experience acceleration primarily, if not entirely, derived from respective physiological motions 12R and 12L.
• respective longitudinal axes X R and X L and respective lateral axes Y R and Y L are parallel to the body surface of patient to commonly experience acceleration primarily, if not entirely, derived from extraneous motion 13.
• accelerometers 20R and 20L may be mounted to a nose 15 of person 10 as shown in FIG. 2 or strapped to a head 16 of person 10 as shown in FIG. 2 to individually sense respective physiological motion 12R and 12L and to commonly sense extraneous motion 13.
• Knowledge of the angular orientation of accelerometers 20R and 20L facilitates a mathematical rotation of XYZ axes 21R and 21L of accelerometers 20R and 20L to a baseline XYZ axes 2 IB that permits cancellation of extrinsic extraneous motion 13 and reinforcement of physiological motion 12 due to the difference in the orientation of the forces exerted by the totality of motion sensed by accelerometers 20R and 20L.
• One form of the present invention is a method for pulse detection of a person by a heart rate monitor including a plurality of multi-axis accelerometers.
• the method involves the accelerometers generating differential mode signals indicative of a sensing by the accelerometer of physiological motion of the person relative to acceleration sensing axes, and the accelerometers generating common mode signals indicative of a sensing by the accelerometers of extraneous motion by the person relative to the acceleration sensing axes.
• the method further involves the heart rate monitor generating a pulse signal as a function of a vertical alignment of the acceleration sensing axes combining the differential mode signals and cancelling the common mode signals.
• physiological motion is broadly defined herein as any motion of a body or a portion thereof generated by a circulatory system of the body to any degree, whether natural (e.g., a pulse from a self- regulated heartbeat) or induced (e.g., a pulse induced by a CPR chest compression), and the term “extraneous motion” is broadly defined herein as any motion of a body or a portion thereof resulting from an application of a force from a source external to the body.
• a second form of the present invention is heart rate monitor for detecting a pulse of a person that employs a platform, a plurality of multi-axis accelerometers and a pulse detector.
• the multi-axis accelerometers are adjoined to the platform to generate differential mode signals indicative of a sensing by the accelerometers of physiological motion of the person relative to acceleration sensing axes and to generate common mode signals indicative of a sensing by the accelerometers of extraneous motion by the person relative to the acceleration sensing axes
• the pulse detector generates a pulse signal as a function of a vertical alignment of the acceleration sensing axes combining the differential mode signals and cancelling the common mode signals.
• a third form of the invention is a cardiac therapy system (e.g., an automated external defibrillator or an advanced life support defibrillator/monitor) employing the aforementioned heart rate monitor and a pulse monitor responsive to the pulse signal to monitor the pulse of the patient.
• a cardiac therapy system e.g., an automated external defibrillator or an advanced life support defibrillator/monitor
• FIG. 1 illustrates an exemplary placement of a multi-axis accelerometer on a body surface of a patient as known in the art.
• FIG. 2 illustrates exemplary placements of two (2) multi-axis accelerometers on a body surface of a patient in accordance with the present invention.
• FIG. 3 illustrates an exemplary embodiment of a heart rate monitor in accordance with the present invention.
• FIG. 4 illustrates a flowchart representative of an exemplary embodiment of pulse detection method in accordance with the present invention.
• FIG. 5 illustrates an exemplary embodiment of a nose clip in accordance with the present invention.
• FIG. 6 illustrates an exemplary embodiment of a heart rate monitor
• FIG. 7 illustrates an exemplary embodiment of a headband/head strap in accordance with the present invention.
• FIG. 8 illustrates an exemplary embodiment of a heart rate monitor
• FIG. 9 illustrates an exemplary embodiment of a cardiac therapy device incorporating a heat rate monitor in accordance with the present invention.
• exemplary embodiments of a heartbeat monitor of the present invention will be provided herein directed to a stand-alone monitor and an incorporation of the heartbeat monitor of the present invention into a cardiac therapy device (e.g., an automated external defibrillator or an advanced life support).
• a cardiac therapy device e.g., an automated external defibrillator or an advanced life support.
• a heartbeat monitor 40 of the present invention employs a pair of multi-axis (XYZ) accelerometers 41R and 41L, a platform 43, a pulse detector 44 and a display 45.
• XYZ multi-axis
• Accel erometer 41R structurally configured as known in the art for generating a longitudinal acceleration sensing signal Ax R , a lateral acceleration sensing signal A YR , and a vertical acceleration sensing signal A ZR responsive to a sensing of motion force(s) acting upon an XYZ axes 42R.
• Accelerometer 41L structurally configured as known in the art for generating a longitudinal acceleration sensing signal A XL , a lateral acceleration sensing signal A YL , and a vertical acceleration sensing signal A ZL responsive to a sensing of motion force(s) acting upon an XYZ axes 42L.
• heartbeat monitor 40 may employ additional accelerometers 41. Also in practice, heartbeat monitor 40 may alternatively or concurrently employ two (2) or more multi-axis (XY) accelerometers, and may alternatively or concurrently employ two (2) or more groupings of single-axis (X) accelerometers serving as multi- axis accelerometers.
• XY multi-axis
• X single-axis
• Platform 43 is structurally configured in accordance with the present invention for positioning respective vertical axes Z R and Z L of accelerometers 41R and 41L normal to body surface of a person, and for positioning respective longitudinal axes X R and X L and respective lateral axes Y R and Y L of accelerometers 41R and 41L parallel to the body surface of the person. As exemplary shown in FIG.
• platform 43 is further structurally configured to angularly orientate XYZ axes 42R and XYZ axes 42L whereby respective vertical axes Z R and Z L are normal to the body surface of the person to individually experience acceleration primarily, if not entirely, derived from respective physiological motion 12R and 12L, and whereby respective longitudinal axes X R and X L and respective lateral axes Y R and Y L are parallel to the body surface of patient to commonly experience acceleration primarily, if not entirely, derived from extraneous motion 13.
• vertical acceleration sensing signal A ZR and vertical acceleration sensing signal A ZL are deemed differential mode signals while longitudinal acceleration sensing signal Ax R , lateral acceleration sensing signal A YR , longitudinal acceleration sensing signal A XL , and lateral acceleration sensing signal A YL are deemed common mode signals.
• platform 43 is a hinged or jointed nose clip 43n as shown in FIG. 5, which is structurally configured to flexibly affix accelerometers 41R and 41L to opposite right and left sides of a bridge of a nose of the person whereby the underlying nasal bone will rigidly maintain the angular orientation of accelerometers 41R and 41L with respect to one another and the nose of the person. More particularly, dorsal nasal arteries of the person are intimately connected via the opthalmic artery to the internal carotid, and thus to the blood supply of the brain. A pulse at the bridge of the nose is preserved, if it is preserved anywhere in physiological distress, and in particular it is not subject to peripheral shutdown common in patients needing emergency care.
• respective vertical axes Z R and Z L (FIG. 3) of accelerometers 41R and 41L will experience physiological motion from pulsation of the dorsal nasal arteries primarily normal to the plane of the temporal bone, and respective longitudinal axes X R and X L and respective lateral axes Y R and Y L will experience motion artifacts of the nose of the person primarily along the plane of the nasal bone.
• platform 43 is a headband/head strap 43h as shown in FIG. 7, which is structurally configured with hardened surfaces 49R and 49L to respectively affix accelerometers 41R and 41L to opposite right and left temples of the person whereby surfaces 49R and 49L will rigidly maintain the angular orientation of accelerometers 41R and 41L with respect to one another and the temples of the person.
• the temporal arteries is substantially preserved and not subject to peripheral shutdown common in patients needing emergency care.
• respective vertical axes Z R and Z L (FIG. 3) of accelerometers 41R and 41L will experience physiological motion from pulsation of the temporal arteries primarily normal to the plane of the nasal bone, and respective longitudinal axes X R and X L and respective lateral axes Y R and Y L will experience motion artifacts of the temples of the person primarily along the plane of the temples.
• pulse detector 44 is structurally configured with hardware, software, firmware and/or circuitry for executing a pulse detection method of the present invention as represented by a flowchart 50 shown in FIG. 4.
• a stage S51 of flowchart 50 encompasses pulse detector 44 implementing technique(s) for conditioning acceleration sensing signals X R , Y R , Z R , X L , Y L and Z L as needed for accelerometers 41R and 41L.
• Examples of the known signal conditioning include, but are not limited to, signal amplification and analog-to-digital conversion.
• a stage S52 of flowchart 50 encompasses pulse detector 44 implementing technique(s) for spatially analyzing an angular orientation of XYZ axes 42R and 42L relative to a baseline axes (e.g., one of XYZ axes 42R or XYZ axes 42L, or a distinct baseline XYZ axes such as 2 IB shown in FIG. 2).
• gravity acceleration vectors of XYZ axes 42R and 42L are used as excitation field to determine a tile angle between accelerometers 41R and 41L or to a distinct baselines axes (e.g., baseline XYZX axes 2 IB shown in FIG. 2) to facilitate a mathematical rotation of XYZ axes 42R and 42L in all three dimensions to align vertical axes Z R and Z L whereby individual physiological motion vectors, common motion artifact vector and the gravity acceleration vectors are identifiable by pulse detector 44.
• a stage S53 of flowchart 50 encompasses pulse detector 44 implementing technique(s) for extracting the physiological motion vectors to communicate a pulse signal PS (FIG. 3) to display 45.
• pulse detector 44 extracts corresponding physiological motion vectors, motion artifact vectors and the gravity vectors from vertically aligned XYZ axes 42R and 42L by combining the differential mode signals A ZR and A ZL and cancelling common mode signals A XR , A XL , A yr and A YL .
• PCA Principal Component Analysis
• ICA Independent Component Analysis
• PCA may sort the signal components from the biggest to the smallest.
• the gravity acceleration vectors and common motion artifact vectors are bigger signals than the physiological motion vectors, and the gravity acceleration vectors and the common motion artifact vectors identified by PCA and removed.
• ICA may extract the independent components if they are linearly combined. Since the
• physiological motion vectors the gravity acceleration vectors and the common motion artifact vectors are independent to each other and the recordings by accelerometers 41R and 41L are a linear sum, the physiological motion vectors may be identified from the ICA results. Furthermore, since the pulses from both sides of the bridge of nose are correlated and synchronized, the extracted physiological motion vectors by ICA should by default be the sum of the blood pulses recorded by the two accelerometers 41R and 41L.
• pulse detector 44 may employ one or more modules with each module being affixed to platform 43, within a stand-alone housing or incorporated within display 45.
• pulse detector 44 employs modules in the form of signal conditioners 46R and 46L, a spatial analyzer 47 and a pulse extractor 48 affixed to nose clip 45n and headband/head strap 45h.
• display 45 is structurally configured as known in the art for visually displaying pulse signal PS or visual indications thereof and optionally providing audio information related to pulse signal PS.
• display 45 may provide a heartbeat readout of pulse signal PS and provide a pulsating heart as an indication of pulse signal PS.
• display 45 may be affixed to platform 43, within a stand-alone housing or incorporated within a cardiac therapy device.
• display 45 is provided in stand-alone housing.
• a cardiac therapy device 60 of the present invention employs a pair of electrode pads/paddles 61, optional ECG leads 62, a compression pad 63, a pulse monitor 64, a compression controller 66, an ECG monitor 66 (internal or external), a defibrillation controller 67, and a shock source 67 as known in the art.
• defibrillation controller 67 controls shock source 68 in delivering a defibrillation shock via electrode pads/paddles 61 to a heart 17 of patient 10 in accordance with one or more shock therapies (e., synchronized cardioversion). Additionally, responsive to a pulse signal from pulse monitor 65, compression controller 66 provides audio instructions to a user of compression pad 63 in accordance with one or more compression therapies.
• shock therapies e.g., synchronized cardioversion
• cardiac therapy device 60 further employs a heartbeat monitor of the present invention, such as, for example, a nose clip based heartbeat monitor 69n mounted on a nose of patient 10 as shown in FIG. 9 or a headband/head strap based heartbeat monitor 69h wrapped/strapped around a head of patient 10 as shown in FIG. 9.
• a heartbeat monitor of the present invention such as, for example, a nose clip based heartbeat monitor 69n mounted on a nose of patient 10 as shown in FIG. 9 or a headband/head strap based heartbeat monitor 69h wrapped/strapped around a head of patient 10 as shown in FIG. 9.
• the displays for heartbeat monitors 69n and 69h e.g., display 45 shown in FIG. 3
• the pulse detectors for heartbeat monitors 69n and 69h e.g., pulse detector 44 shown in FIG. 3 may also be incorporated within pulse monitor 64.
• the pulse detectors e.g., pulse detector 44 shown in FIG. 3
• the pulse detectors for heartbeat monitors 69n and 69h may concurrently or alternatively provide the pulse signal to defibrillation controller 65 and/or compression controller 66.
• monitors 64 and 66 may be combined and/or controllers 65 and 67 may be combined.

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• 2014
  • 2014-12-10 JP JP2016539038A patent/JP6470755B2/ja active Active
  • 2014-12-10 CN CN201480069479.2A patent/CN105828707B/zh active Active
  • 2014-12-10 WO PCT/IB2014/066745 patent/WO2015092618A1/en not_active Ceased
  • 2014-12-10 EP EP14830881.0A patent/EP3082577B1/en active Active
  • 2014-12-10 CA CA2934022A patent/CA2934022A1/en not_active Abandoned
  • 2014-12-10 RU RU2016129487A patent/RU2683847C1/ru active
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