EP4266995A1 - Device and method for measuring blood pressure and a state of stress - Google Patents
Device and method for measuring blood pressure and a state of stressInfo
- Publication number
- EP4266995A1 EP4266995A1 EP21845060.9A EP21845060A EP4266995A1 EP 4266995 A1 EP4266995 A1 EP 4266995A1 EP 21845060 A EP21845060 A EP 21845060A EP 4266995 A1 EP4266995 A1 EP 4266995A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- user
- module
- sensor
- stress
- state
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000036772 blood pressure Effects 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title claims description 28
- 238000005259 measurement Methods 0.000 claims description 35
- 230000000694 effects Effects 0.000 claims description 26
- 230000003287 optical effect Effects 0.000 claims description 14
- 230000004872 arterial blood pressure Effects 0.000 claims description 13
- 238000009530 blood pressure measurement Methods 0.000 claims description 10
- 230000037081 physical activity Effects 0.000 claims description 9
- 238000002847 impedance measurement Methods 0.000 claims description 8
- 230000033001 locomotion Effects 0.000 claims description 8
- 239000008280 blood Substances 0.000 claims description 7
- 210000004369 blood Anatomy 0.000 claims description 7
- 238000005286 illumination Methods 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 4
- 230000000644 propagated effect Effects 0.000 claims description 3
- 230000004913 activation Effects 0.000 claims description 2
- 230000001419 dependent effect Effects 0.000 abstract 1
- 210000001519 tissue Anatomy 0.000 description 18
- 230000006870 function Effects 0.000 description 11
- 230000000737 periodic effect Effects 0.000 description 9
- 230000000747 cardiac effect Effects 0.000 description 5
- 206010020772 Hypertension Diseases 0.000 description 4
- 230000000875 corresponding effect Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 230000005284 excitation Effects 0.000 description 4
- 238000012544 monitoring process Methods 0.000 description 4
- 238000013186 photoplethysmography Methods 0.000 description 4
- 230000000541 pulsatile effect Effects 0.000 description 4
- 230000005855 radiation Effects 0.000 description 4
- 230000004044 response Effects 0.000 description 4
- 210000000707 wrist Anatomy 0.000 description 4
- 210000001715 carotid artery Anatomy 0.000 description 3
- 230000001902 propagating effect Effects 0.000 description 3
- 230000000241 respiratory effect Effects 0.000 description 3
- 230000003595 spectral effect Effects 0.000 description 3
- 208000004301 Sinus Arrhythmia Diseases 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 230000017531 blood circulation Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229940079593 drug Drugs 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 230000008451 emotion Effects 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 238000002496 oximetry Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 210000001367 artery Anatomy 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 210000002302 brachial artery Anatomy 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000034994 death Effects 0.000 description 1
- 231100000517 death Toxicity 0.000 description 1
- 230000035487 diastolic blood pressure Effects 0.000 description 1
- 230000010339 dilation Effects 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 230000002996 emotional effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 210000001105 femoral artery Anatomy 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 210000000245 forearm Anatomy 0.000 description 1
- 210000003205 muscle Anatomy 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 230000004962 physiological condition Effects 0.000 description 1
- 210000002321 radial artery Anatomy 0.000 description 1
- 230000029058 respiratory gaseous exchange Effects 0.000 description 1
- 210000004243 sweat Anatomy 0.000 description 1
- 210000000106 sweat gland Anatomy 0.000 description 1
- 230000035488 systolic blood pressure Effects 0.000 description 1
- 210000003813 thumb Anatomy 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 238000002604 ultrasonography Methods 0.000 description 1
- 238000010200 validation analysis Methods 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- 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
- A61B5/021—Measuring pressure in heart or blood vessels
- A61B5/02108—Measuring pressure in heart or blood vessels from analysis of pulse wave characteristics
- A61B5/02125—Measuring pressure in heart or blood vessels from analysis of pulse wave characteristics of pulse wave propagation time
-
- 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
- A61B5/02405—Determining heart rate variability
-
- 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
- A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
- A61B5/053—Measuring electrical impedance or conductance of a portion of the body
- A61B5/0531—Measuring skin impedance
- A61B5/0533—Measuring galvanic skin response
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/16—Devices for psychotechnics; Testing reaction times ; Devices for evaluating the psychological state
- A61B5/165—Evaluating the state of mind, e.g. depression, anxiety
-
- 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
- A61B5/6824—Arm or wrist
Definitions
- the technical field of the invention is pulse wave velocity (PWV) and/or blood pressure measurement correlated to an estimate of a user's state of stress.
- PWV pulse wave velocity
- blood pressure measurement correlated to an estimate of a user's state of stress.
- High blood pressure disease is responsible for nine million deaths worldwide.
- Patient monitoring usually consists of spot measurements.
- Automated blood pressure monitors using the principle of oscillometric measurement are widely used by the medical profession and are also available to the general public.
- a cuff positioned on the arm, forearm or wrist is inflated until it blocks blood circulation, then deflated.
- oscillations in the cuff pressure are measured, these are at their maximum when the cuff pressure cancels out the mean arterial pressure. From the mean arterial pressure, the systolic pressure and the diastolic pressure are estimated according to rules of thumb.
- cuffless without inflatable cuff
- PPG PhotoPlethysmoGraphy
- acoustic methods or electric.
- This opens the way to blood pressure measurements performed continuously, by less constraining devices worn on a user.
- This type of device can be integrated into a patch, a headband or a watch.
- the measurement of a blood pressure can be influenced by the state of a person, in particular a state of stress. Indeed, when a person is in a state of stress, blood pressure increases.
- a known effect is emotional high blood pressure, of the "white coat effect” type, which can cause a sudden increase in blood pressure under the effect of an emotion, for example when measuring blood pressure in a doctor. It is a transient hypertension, which disappears when the effects of the emotion have disappeared.
- the white coat effect has been described in W02017/109064.
- the inventors propose a device and a method, allowing consideration of the stress factor in the event of measurements indicating high arterial pressure.
- a first object of the invention is a device for detecting arterial pressure, the device being intended to be worn on the skin of a user, the device comprising:
- the first module configured to estimate a pulse wave velocity and/or a blood pressure of the user, the first module comprising:
- At least one detector configured to measure a quantity representative of the pulse wave velocity and/or of the blood pressure of the user
- a first processing unit programmed to estimate a pulse wave velocity or an arterial pressure from the quantity measured by the detector; the device being characterized in that it also comprises:
- a second module configured to measure a physiological characteristic of the user, the value of the physiological characteristic being able to vary according to a stress level of the user, the second module comprising a second processing unit, programmed to estimate a stress level of the user as a function of the measured physiological characteristic;
- a central unit connected to the first module and to the second module, the central unit being programmed to generate an alert signal, for the attention of the user, when:
- the device may include a control module, the control module being configured to be activated, by the central unit following the generation of the alert signal, the control module being such that:
- control module is intended to follow a relaxation activity, carried out by the user, following the transmission of the alert signal
- control module comprises a sensor, intended to measure a physiological characteristic of the user, the value of the physiological characteristic being capable of varying according to the level of stress of the user; - the control module is configured to send the user an accompanying signal, representative of a change in the state of stress of the user during the relaxation activity.
- control module is configured to measure heart rate variability.
- the control module can include:
- a light source configured to emit light towards the body of the user
- a photodetector configured to detect light backscattered or transmitted by a part of the user's body, following illumination by the light source;
- a processing unit configured to process a signal generated by the photodetector, representative of the light detected by the latter, so as to extract a quantitative value relating to a variability of the heart rate.
- the control module can be configured to activate the second module, the accompanying signal then being determined according to the physiological characteristic measured by the second module.
- the first module comprises at least one transmitter, configured to emit an optical, or electrical, or acoustic signal so that the signal propagates through a part of the user's body;
- the detector of the first module being configured to detect the signal emitted by the transmitter, and having propagated through a part of the user's body.
- the device comprises an actimetry module, the actimetry module comprising a motion sensor configured to detect a movement of the user, the actimetry module being configured to detect a physical activity exerted by the user, the central unit being connected to the actimetry module and configured to invalidate the blood pressure measurement when a physical activity considered significant has been detected.
- the first module comprises a first sensor and a second sensor, the first sensor and the second sensor being remote from each other, each sensor being configured to generate a signal representative of a variation in blood volume in a part of the body of the user in front of which he is disposed;
- the first processing unit is configured to estimate a pulse wave velocity, between the first sensor and the second sensor, from the signals respectively generated by each sensor.
- the first sensor comprises a first light source and a first photodetector, the first photodetector being arranged to detect light backscattered or transmitted by the part of the user's body facing which it is positioned, following illumination by the first light source ;
- a second sensor comprises a second light source and a first photodetector, the second photodetector being arranged to detect light backscattered or transmitted by the part of the user's body facing which it is positioned, following illumination by the second light source.
- the second module comprises:
- a second processing unit configured to estimate a state of stress as a function of the impedance measured by the impedance measurement circuit.
- a second object of the invention is a method for measuring a user's blood pressure, the user wearing a device according to the first object of the invention, the method comprising
- the alert signal comprises an invitation addressed to the user, to carry out a relaxation activity
- the device comprises the control module described in connection with the first object of the invention
- the method comprises, following the generation of the alert signal, an activation of the control module, so as to send the user an accompanying signal, representative of a change in the state of the user.
- the method may comprise, following the generation of the alert signal:
- the control module can be configured to repeat step b) and to emit the accompanying signal according to the state of stress determined during each repeated step b), until the state of the user is considered a state of rest.
- FIG. 1A represents an example of a device comprising a first module, placed at the level of a user's arm, and a second module, placed at the level of the user's wrist.
- Figure IB schematizes the main components of the first module.
- FIGS. 1C and 1D illustrate the operation of the first module respectively according to a backscatter configuration and according to a transmission configuration.
- FIG. 1E shows the time shift of two signals resulting respectively from two sensors, distant from each other, of the first module.
- FIG. 1F is an example of a first one-piece module.
- FIG. 2A shows an example of measurement of the time shift of two signals resulting respectively from two sensors of the first module.
- FIG. 2B schematizes a method for determining a characteristic instant of each signal resulting from the sensors of the first module.
- Figure 3A schematizes the main components of the second module.
- FIG. 3B shows an evolution of a conductance of a user's skin as a function of time from measurements taken by the second module.
- FIG. 4A schematizes the main steps of a method of using a device according to the invention.
- FIG. 4B schematizes four modules of a device according to the invention, connected to a central unit.
- Figure 5A shows a control module
- FIG. 5B represents a signal resulting from the control module when the user is in a state of stress (top curve) or when he is in a state considered to be at rest (bottom curve).
- the device 1 combines a first module 10, allowing a measurement of the arterial pressure as well as a second module 20, allowing a measurement of a physiological characteristic varying in the case of the occurrence of a state of stress.
- FIG. IA represents an example of the first module 10, dedicated to the measurement of arterial pressure. It is preferably a cuffless module (without inflation).
- the first module 10 comprises a first sensor 11 and a second sensor 12 remote from each other.
- the first module 10 is placed against a person's skin, at arm level.
- Each sensor can be attached to the arm by a band 15. Other arrangements are possible, as described below.
- the headband can be replaced by another type of tie, making it possible to hold the sensor on the skin, in contact with the tissues of the user. It can be a biocompatible adhesive, a bracelet.
- the first sensor 11 comprises a first light source IIi as well as a first photodetector II2.
- the first light source is for example a light emitting diode (LED: Light Emitting Diode).
- the light source 111 emits an incident light beam 13 propagating towards the user's tissues, along a propagation axis Z, for example perpendicular to the surface 2s of the user's body.
- the light beam is preferably emitted in a narrow spectral band, preferably ⁇ 50 nm, in a spectral range between 400 nm and 1100 nm.
- the photons of the incident light beam 13 are emitted along a propagation axis Z. They penetrate the tissues 2 and part of them is backscattered, for example along a direction parallel to the axis of propagation Z, in a direction opposite to the latter.
- the backscattered photons constitute backscattered radiation 14.
- the backscattered radiation 14 can be detected by photodetector II2, placed facing a surface 2s of the user's body.
- the photodetector II2 can be configured in such a way as to detect backscattered radiation emanating from the sample at a distance d, called the backscattering distance, generally non-zero and less than a few millimeters, or a few tens of millimeters.
- the photodetector 11 2 thus makes it possible to measure the intensity of the backscattered radiation.
- the photodetector 11 2 is for example a photodiode, or a set of photodiodes.
- the dotted curved arrow represents an optical path of photons emitted by the light source IIi, then diffused in the body of the user.
- part of the user's body extends between the light source IIi and the photodetector II2.
- the photodetector II2 measures an intensity of the light having passed through a part of the user's body.
- the photodetector is arranged to measure an intensity of light formed by photons having propagated through a part of the user's body: this is either backscattered photons, or photons having passed through biological tissues.
- this is either backscattered photons, or photons having passed through biological tissues.
- the second sensor 12 comprises a second light source 12i as well as a second photodetector 122.
- the second light source and the second photodetector are preferably identical to those described in connection with the first sensor 11.
- the first sensor 11 and the second sensor 12 are preferably identical to each other.
- the first module 10 comprises a processing unit 18 configured to control the first sensor 11 and the second sensor 12.
- the processing unit 18 is configured to collect the signals acquired by the first photodetector 11 2 and the second photodetector 12 2 .
- the processing unit 18 is linked to a memory, in which are stored instructions for implementing the method described below.
- the processing unit may include a microprocessor.
- the first sensor 11 and the second sensor 12 are spaced apart by a distance D.
- the distance D can be between 1 cm and 10 cm.
- the center of each sensor corresponds to a point equidistant from the light source and the photodetector of said sensor. The distance between two sensors is center to center.
- each sensor The principle of operation of each sensor is based on the fact that at each heartbeat, the blood flow in front of each sensor leads to a modulation of the light propagating through the biological tissues forming the body 2 of the user. This results in a modulation of the light detected by the photodetector associated with the light source (photodetector II2 or photodetector 122).
- the intensity detected by each photodetector forms a periodic signal, the fundamental frequency of which corresponds to the heart rate.
- the spacing D between the two sensors 11, 12 makes it possible to determine a time shift At between the periodic signals resulting respectively from the first sensor and from the second sensor. Estimating the time lag, called the pulse wave transit time, allows an estimation of a velocity, known as the "pulse wave velocity" (PWV).
- PWV pulse wave velocity
- FIG. 1E represents a first signal Si resulting from the first sensor 11 (solid line) and a second signal S2 resulting from the second sensor 12 (dotted line).
- the offset ⁇ t makes it possible to determine the pulse wave velocity, the latter allowing an estimation of the arterial pressure.
- a signal corresponding to the opposite of the detected signal, representative of tissue absorption, has been represented.
- the frequency of acquisition of the signals resulting from each sensor can be between 100 Hz and 100 kHz, which allows an estimation of the pulse wave velocity with sufficient precision.
- the first module 10 is placed at the wrist of a person.
- the first sensor 11 and the second sensor 12 are spaced apart by a distance D of between 5 mm and 5 cm.
- Each sensor is preferably placed facing the radial artery.
- the first module 10 is placed at the level of a person's neck, facing the carotid artery.
- the first sensor 11 and the second sensor 12 are spaced apart by a distance D of between 5 mm and 5 cm. Each sensor can be maintained by a patch.
- each sensor 11, 12 of the first module 10 can be configured to perform other optical measurements relating to other physiological characteristics. It may for example be a measurement of the heart rate, or of the arterial oxygen saturation (oximetry), or of a variability of the heart rate.
- Each sensor can include several light sources, of different wavelengths, to perform this type of measurement.
- Each sensor can comprise for example five light-emitting diodes, respectively emitting in spectral bands centered, typically, on the wavelengths 525 nm, 660 nm, 740 nm, 805 nm, 850 nm.
- the heart rate can for example be taken using the diode emitting at the 525 nm wavelength.
- the 660 nm, 805 nm and 850 nm wavelengths can be used for oximetry measurements.
- the 740 nm wavelength can be used to measure pulse wave velocity VOP.
- the 525 nm wavelength can be used to measure heart rate.
- each sensor may comprise several photodetectors, for example several photodiodes, respectively arranged at different backscatter distances from a light source.
- the backscatter distances can be for example 6 mm, 12 mm, 18 mm. It also allows different tissue depths to be addressed, with the depth examined increasing with backscatter distance.
- FIG. 1F shows a first one-piece module, the first sensor 11 and the second sensor 12 being arranged on the same support.
- the support can for example be a support fixed to the body of the user by a headband. It can also be an adhesive support, of the patch type.
- FIG. 2A represents two curves Si, S2, respectively shifted by a time shift At.
- the time shift can be estimated by detecting, on each curve, a characteristic instant. This is for example a time at which the measured signal reaches a minimum level.
- the curves in FIG. 2A correspond to an attenuation signal (axis of ordinates—arbitrary unit), as a function of time (axis of abscissas—unit: second).
- Each minimum corresponds to a minimum attenuation, that is to say an instant at which the volume of blood is minimum. At this instant, the backscattered signal detected by the sensor is maximum.
- Each of these instants can be determined as described in the publication Chiù Y, “Determination of pulse wave velocities with computerized algorithms”, Am.
- FIG. 2B shows an example of attenuation curve S as described in connection with FIG. 2A.
- the identification of the characteristic instant can be carried out by determining an intersection between: a horizontal tangent Ti to the attenuation curve. a straight line T 2 considered as representative of the increasing part of the attenuation curve, the increasing part being designated “systolic rise”.
- the systolic rise corresponds to a rapid dilation of the artery, resulting in a rapid increase in blood volume, which causes an increase in attenuation.
- the first module 10 can allow measurement of the pulse wave velocity by a method different from the optical method, as described later.
- the first module 10 can also be configured to determine a blood pressure (AP), without prior estimation of the pulse wave velocity.
- the blood pressure PA can for example be determined by optical means, as described in the publication Lubin M. et al “Blood pressure measurement by coupling an external pressure and photo-plethysmographic signals”, EMBC, July 2020.
- the device comprises a second module 20, intended to evaluate a state of stress of the user wearing the device.
- the second module 20 is configured to measure a physiological signal, at different measurement instants, from which a value of a physiological characteristic of the user is estimated.
- the value of the physiological characteristic considered can vary according to a level of stress of the user.
- the physiological characteristic can be: a characteristic of cardiac activity, measured for example by an electrocardiogram (ECG) or a simple determination of a heart rate or an inter-beat interval and its variations obtained for example with one of the optical sensors of the first VOP or PA determination module; a characteristic of muscle activity, measured by an electromyogram (EMG); a characteristic of the user's electrodermal activity, representative of electrical conduction or electrical impedance properties of the skin (eg electrodermal conductance or impedance); a characteristic of skin temperature; a characteristic of a respiratory signal.
- ECG electrocardiogram
- EMG electromyogram
- the characteristic is an electrical impedance of the skin.
- the second module comprises two electrodes 21, 22.
- An impedance measurement circuit 23 makes it possible to apply a potential difference between the electrodes, and to measure the electric current flowing in the circuit 23. alternatively, an electric current is injected into the circuit 23 and the potential difference between the electrodes is measured.
- the applied potential difference is sinusoidal, with zero mean value.
- the induced current has an effective intensity of less than 10 pA.
- the frequency of the potential difference is for example 1 kHz, the amplitude being IV.
- a processing unit 28 allows a calculation of a complex impedance of the skin. It can also determine the occurrence of a state of stress.
- the link between the value of the measured characteristic and the occurrence of a state of stress can be established by a membership function, as described in the publication: Charbonnier, Sylvie et al "A Multi-feature Fuzzy Index to Assess Stress Level from Bio-signals. Conference proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society". IEEE Engineering in Medicine and Biology Society. Conference. 2018. 1086-1089, or in patent application US20200015729A1.
- the processing unit 28 can generate a membership function, quantifying the state of stress, ranging between 0 (state of rest) and 1.
- the membership function quantifies a probability that the user is in a state of stress. Beyond a certain threshold, for example 0.6, the user is considered to be in a state of stress.
- FIG. 3B represents a real part of the impedance during the occurrence of a stress. This figure represents an increase in conductance (axis of ordinates - unit nanoSiemens nS), as a function of time (axis of abscissas - unit of seconds), under the effect of stress.
- the device 1 makes it possible to simultaneously perform a measurement of the arterial pressure or at least of the pulse wave velocity as well as an estimation of a state of stress.
- FIG. 4A shows the main steps in the implementation of device 1. These steps are now described.
- Step 100 blood pressure measurement.
- the blood pressure and/or the VOP of the user is measured, for example using a first module 10 as described in connection with FIGS. 1A to 1F and 2A and 2B.
- This step is implemented at a measurement instant t.
- the measurement times can be distributed throughout a day, on a regular basis.
- Several measurements can be implemented at close times, so as to be averaged: the arterial pressure then corresponds to an average or a combination of the arterial pressures measured.
- Step 110 estimation of a state of stress
- step 100 an estimation of a stress state of the user is carried out, using a second module 20, for example as described in connection with FIGS. 3A and 3B.
- Step 120 estimation of a movement
- Device 1 comprises an actimetry circuit 30, allowing detection of a movement.
- the actimetry circuit may include one or more motion sensors, of the accelerometer, gyrometer or magnetometer type.
- the actimetry circuit can detect that the user is carrying out a significant physical activity at the time of measurement, for example a sports activity, liable to impact the measurement of the blood pressure or the estimation of the state of stress.
- Step 130 centralization The measurements resulting from steps 100 (blood pressure), 110 (state of stress) and 120 (movement) are centralized in a central processing unit 50, connected to the various modules 10 (blood pressure), 20 (stress), 30 (actimetry ) of device 1.
- the central unit 50 analyzes the level of stress resulting from the module 20.
- the module 20 can carry out an estimation of the state of stress simultaneously with the measurement of the blood pressure, or being triggered when a blood pressure is higher than the pressure threshold.
- an alert signal is sent, by the central unit 50, to the user.
- the alert message corresponds to a concomitance between a high AP (or a PWV) and a stress state of the user.
- Step 140 is activated, so as to invite the user to relax.
- step 150 is activated.
- step 160 is activated.
- the central processing unit can perform an interface function with the user: addressing the alert signal and addressing the accompanying signal described below.
- This step is activated when a pressure greater than the threshold has been measured, and when a state of stress has been detected. It may for example be: an increase in blood pressure greater than 20 mmHg on average during the last 30 minutes; of a value greater than 0.6 of the membership function resulting from the module 20, and this for more than one hour, the membership function varying between 0 (state of rest) and 1 (state of stress). the absence of physical activity possibly detected by the actimetry module.
- This step constitutes an important aspect of the invention: it is a question of accompanying the user in a process of stress management, on the basis of a control module 40.
- the control module 40 is intended to provide measurements quantifying an evolution of the stress state of the user when the latter follows a relaxation activity.
- the relaxation activity is for example a cardiac coherence activity.
- the objective of the control module 40 is to interact with the user, so that the latter becomes aware of the evolution of his state of stress.
- the control module interacts with the user by establishing an accompanying signal, perceptible by the user: audible signal and/or visible signal.
- the accompanying signal is representative of the evolution of the stress state of the user during the relaxation activity.
- the control module can use the stress state determination module 20.
- the module 20 is activated during the relaxation of the user, so that the latter can be informed of the evolution of his state. of stress.
- the control module 40 can be separated from the module 20.
- An example of control module 40 has been represented in FIG. 4B.
- the control module 40 is in this example an optical module, similar to the sensors 11 and 12 described in connection with figures IA to IC.
- the control module can use all or part of the components of sensors 11 and 12
- the control module 40 comprises a light source 41, for example of the LED type, and a photodetector 42, for example of the photodiode type. It is carried by a support 44, so as to be applied against the body of the user. It includes a processing unit 48 allowing processing of the light information detected by the photodetector 42, so as to estimate the heart rate of the user.
- the heart rate is estimated on the basis of variations in the light transmitted or backscattered by the tissues using the photodetector 42.
- the signal detected by the photodetector 42 comprises a continuous component, to which is added a pulsatile component, the latter varying with heart rate. Heart rate information is contained in the pulsatile component. It can be extracted by high pass filtering of the signal detected by the photodetector.
- amplitude thresholding makes it possible to identify characteristic instants, typically extremums (maxima or minima).
- the time interval separating the characteristic instants allows an estimation of a heart rate.
- FIG. 5B represents pulsatile components of detected optical signals, representative of heartbeats, corresponding respectively to a stress situation (top) and to a normal situation (bottom), ie at rest.
- the curve corresponding to the rest situation presents relatively regular undulations.
- the heart rate is modulated by respiratory sinus arrhythmia (RSA), causing a slight increase in heart rate during inspiration (reduction of the inter-beat interval) and a slight decrease in heart rate during expiration (lengthening of the inter-beat interval).
- RSA respiratory sinus arrhythmia
- the occurrence of a stressful situation can lead to a reduction in heart rate variability, as represented in FIG. 5B (top curve), and a disappearance of the respiratory sinus arrhythmia.
- the control module 40 is programmed to quantify a score representative of the variability of the heart rate, for example the RMSSD (Root Mean Square of Successive Differences of the interbeat interval - quadratic mean of successive differences of the interbeat interval).
- RMSSD Root Mean Square of Successive Differences of the interbeat interval - quadratic mean of successive differences of the interbeat interval.
- the device can generate an accompanying signal, prompting the user to adopt regular breathing, typically between 5 and 7 breaths per minute.
- the accompanying signal visual and/or auditory, can be modulated by the RMSSD score.
- the control module quantifies a relaxation score representative of the variation in the heart rate.
- the relaxation score, quantified is an indication transmitted to the user during the relaxation phase. When the relaxation score enters an acceptable value range, the user can again trigger step 100 for a new blood pressure measurement.
- the device makes it possible to operate in a closed loop. This allows the user to take action during the relaxation phase by monitoring the relaxation score. It can then start a blood pressure measurement when the physiological conditions are more favorable.
- Step 150 Validation of the measurement
- step 150 the blood pressure measurement is validated, because the user is considered to be in a state of rest, i.e. not in a stressful situation.
- Step 160 Invalidation of the measurement
- the pressure measurement is invalidated by the detection of significant physical activity by the actimetry circuit 30.
- the invention can be applied to other measurement methods sensitive to a periodic variation.
- blood volume in the tissues under the effect of cardiac activity include methods for establishing a response of biological tissues to an excitation signal.
- an optical response of the tissues to an optical excitation is measured.
- the optical response, corresponding to the backscattered beam (or the beam transmitted in the case of a transmission configuration) is modulated by the quantity of blood present in the illuminated tissues.
- the determination of the VOP can be carried out by a passive measurement, for example by using a mechanical sensor of the tonometer type: with this type of sensor, a deformation of the tissue is measured under the effect of the pulse wave , without excitation signal.
- the module 10 can include two sensors 11, 12, remote from each other. Each sensor makes it possible to obtain a periodic variation of the electrical impedance. The offset between the periodic variations respectively determined by each sensor makes it possible to estimate the pulse wave velocity. This type of modality is described in the publication Bassem I. et al “Multi-source multi-frequency bio-impedance measurement method for localized pulse wave monitoring”, 2020.
- the measurement of a pulse wave velocity can also be obtained by an acoustic method, by determining a periodic variation in the acoustic impedance of tissues induced by cardiac activity. The principle is then based on an emission of an acoustic wave propagating towards the tissues, and on a detection of an acoustic wave reflected by the tissues.
- the module 10 can include two sensors 11, 12, remote from each other. Each sensor makes it possible to obtain a periodic variation of the acoustic impedance. The offset between the periodic variations respectively determined by each sensor makes it possible to estimate the pulse wave velocity. This type of modality is described in the publication Hermeling E et al. “The dicrotic notch as alternative time-reference point to measure local pulse wave velocity in the carotid artery by means of ultrasonography”, Journal of hypertension, 2009, 2028-2035.
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Cardiology (AREA)
- Engineering & Computer Science (AREA)
- Heart & Thoracic Surgery (AREA)
- Physiology (AREA)
- Biophysics (AREA)
- Pathology (AREA)
- Veterinary Medicine (AREA)
- Biomedical Technology (AREA)
- Physics & Mathematics (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Vascular Medicine (AREA)
- Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR2014198A FR3118409B1 (en) | 2020-12-28 | 2020-12-28 | Device and method for measuring blood pressure and a state of stress |
PCT/EP2021/087681 WO2022144336A1 (en) | 2020-12-28 | 2021-12-27 | Device and method for measuring blood pressure and a state of stress |
Publications (1)
Publication Number | Publication Date |
---|---|
EP4266995A1 true EP4266995A1 (en) | 2023-11-01 |
Family
ID=75108526
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP21845060.9A Pending EP4266995A1 (en) | 2020-12-28 | 2021-12-27 | Device and method for measuring blood pressure and a state of stress |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP4266995A1 (en) |
FR (1) | FR3118409B1 (en) |
WO (1) | WO2022144336A1 (en) |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB0320297D0 (en) * | 2003-08-29 | 2003-10-01 | Univ Warwick | Blood pressure monitor |
JP2005237531A (en) * | 2004-02-25 | 2005-09-08 | Daikin Ind Ltd | Pulse wave velocity evaluation device |
EP3393339B1 (en) * | 2015-12-23 | 2022-11-23 | Koninklijke Philips N.V. | A computer program product for assessing the reliability of a blood pressure measurement and an apparatus for implementing the same |
FR3048173B1 (en) | 2016-02-29 | 2018-03-16 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | METHOD FOR ESTIMATING CARDIAC FREQUENCY AND DEVICE THEREOF |
US20170293727A1 (en) * | 2016-04-08 | 2017-10-12 | Apple Inc. | Intelligent blood pressure monitoring |
FR3083690B1 (en) | 2018-07-13 | 2022-10-07 | Commissariat Energie Atomique | METHOD FOR DETERMINING THE STATE OF STRESS OF AN INDIVIDUAL |
-
2020
- 2020-12-28 FR FR2014198A patent/FR3118409B1/en active Active
-
2021
- 2021-12-27 EP EP21845060.9A patent/EP4266995A1/en active Pending
- 2021-12-27 WO PCT/EP2021/087681 patent/WO2022144336A1/en active Application Filing
Also Published As
Publication number | Publication date |
---|---|
FR3118409A1 (en) | 2022-07-01 |
FR3118409B1 (en) | 2024-04-12 |
WO2022144336A1 (en) | 2022-07-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP3940150B2 (en) | Caffres electronic blood pressure monitor | |
Ray et al. | A review of wearable multi-wavelength photoplethysmography | |
KR102299361B1 (en) | Apparatus and method for monitoring blood pressure, wearable device having function of blood pressure monitoring | |
US20220175258A1 (en) | Non-invasive blood pressure estimation and blood vessel monitoring based on photoacoustic plethysmography | |
JP6662459B2 (en) | Blood pressure measurement device | |
BR112020021760A2 (en) | methods to estimate blood pressure and arterial stiffness based on photoplethysmographic signals (ppg) | |
EP3355775B1 (en) | Vital signs sensor and method of measuring vital signs of a user | |
US20070185393A1 (en) | System for measuring vital signs using an optical module featuring a green light source | |
Liu et al. | PCA-based multi-wavelength photoplethysmography algorithm for cuffless blood pressure measurement on elderly subjects | |
US20140142434A1 (en) | System and method of measurement of systolic blood pressure | |
US20070070800A1 (en) | Externally worn vasovagal syncope detection device | |
US20030032887A1 (en) | Heartbeat synchronous information acquiring apparatus and pulse wave propagation velocity related information acquiring apparatus, blood pressure monitoring apparatus and preejection period measuring apparatus utilizing heartbeat synchronous information | |
CN112426141B (en) | Blood pressure detection device and electronic device | |
Kao et al. | Towards maximizing the sensing accuracy of an cuffless, optical blood pressure sensor using a high-order front-end filter | |
KR20190105421A (en) | apparatus and method for measuring blood presure based on PPG | |
Priyadarshini et al. | Review of PPG signal using machine learning algorithms for blood pressure and glucose estimation | |
Mouradian et al. | Continuous wearable health monitoring using novel PPG optical sensor and device | |
CN110226924B (en) | Wearable blood pressure monitoring device and method | |
EP4356822A2 (en) | Sleep staging using an in-ear photoplethysmography (ppg) | |
KR20190081527A (en) | Earphone for monitoring blood pressure and method for monitoring blood pressure using the same | |
EP4266995A1 (en) | Device and method for measuring blood pressure and a state of stress | |
KR20200129811A (en) | Blood Pressure Meter And Method For Measuring Blood Pressure Using The Same | |
JP2017213123A (en) | Blood flow rate measurement device and blood flow rate measurement method | |
US20160360978A1 (en) | Interferometric focusing beam optical cardiovascular sensor | |
KR20200043900A (en) | Blood Pressure Meter And Method For Measuring Blood Pressure Using The Same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: UNKNOWN |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20230621 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
DAV | Request for validation of the european patent (deleted) | ||
DAX | Request for extension of the european patent (deleted) | ||
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
17Q | First examination report despatched |
Effective date: 20240628 |