FR3093313A1 - Device for determining a physiological typology of a vehicle seat user - Google Patents

Abstract

Device (1000) for determining a physiological typology (T) of a user (U) of a vehicle seat (300), said device comprising: - said seat (300); - at least one sensor (312, 314) belonging to said seat, said at least one sensor being configured to acquire a first physiological signal (S1) from the user; and - a computer processing circuit (100) configured to implement said at least one sensor, to deduce from said first signal (S1) a value (F1) of a physiological characteristic of the first signal, to repeat a number K of times the implementation of said at least one sensor to deduce K values (F11, F12, ..., F1K) of physiological characteristics, K being a natural number at least equal to 2, and to determine, on the basis of said K values, said typology of the user. (Abstract figure: Figure 1)

Description

Device for determining a physiological typology of a vehicle seat user

This description relates to a device for determining a physiological typology of a vehicle seat user. The present description also relates to a device and a method for providing a bio-feedback signal to a user occupying a vehicle seat.

Technology background

Devices and methods are known for measuring and monitoring physiological attributes of a user occupying a vehicle seat, for example a driver seated in a car seat. These methods and these devices implement sensors located in the seat or in the passenger compartment of the vehicle and outside the seat, to measure the physiological attributes of the people present in the vehicle. Among known examples, the level of fatigue of the driver of a car can be monitored using a camera, the position of a passenger can be controlled using a motion sensor located in the underside of the seat or above the seat, etc.

A drawback of the known devices and methods is that they do not make it possible to accurately measure a heart rate or a respiratory rate of a user occupying a motor vehicle seat. In particular, it is not possible to accurately measure a cardiac or respiratory characteristic of a user while driving a motor vehicle. Indeed, the existing devices and methods use proximity sensors, by definition located at a distance from the user, for example in the passenger compartment of the vehicle. However, these sensors are not in direct contact with the user. As a result, the measured amplitude of the user's physiological attributes is greatly attenuated, which greatly reduces the accuracy of the acquired data. Reliable measurement of rhythmic signals from vehicle seat users is therefore difficult to achieve.

Another disadvantage is that the use of contact sensors is generally prescribed in motor vehicles for safety reasons. Indeed, contact sensors provided to be flush with the skin of a user whose physiological attributes are to be measured cannot be placed in the seat or in the back of a motor vehicle seat. These contact sensors pose various safety problems: they reduce the vehicle driver's attention behind the wheel during a measurement, they can generate short circuits or interference with other vehicle components, or even injure the occupant of the vehicle. seat in the event of a sudden or sudden movement of the vehicle.

Yet another drawback is that the known methods and devices do not make it possible to carry out measurements of physiological attributes of a user occupying a motor vehicle seat and to return these measurements to the user simultaneously, that is i.e. in real time. However, a significant time lag between the measurement of a physiological attribute and the communication of this measurement to the user can create discomfort for the user and prevent him from reacting in time.

There is therefore a need to provide a device that improves the situation and does not have at least one of the aforementioned drawbacks.

Objects

In order to respond to this or these drawbacks, the present description relates, according to a first aspect, to a device for determining a physiological typology of a user of a vehicle seat, said device comprising:
- said seat;
- at least one sensor belonging to said seat, said at least one sensor being configured to acquire a first physiological signal from the user; and
- a computer processing circuit configured to implement said at least one sensor, to deduce from said first signal a value of a physiological characteristic of the first signal, to repeat a number K of times the implementation of said at least one sensor to deduce K values of physiological characteristics, K being a natural number at least equal to 2, and to determine, on the basis of said K values, said user typology.

In the present, a computer processing circuit is any type of integrated circuit, for example an integrated circuit comprising a storage space such as a memory or a processor. The storage space is for example a non-volatile memory (ROM or Flash, for example) and can constitute a recording medium, this recording medium possibly also comprising a computer program. The processor is a data processor that implements the instructions of a computer program. These instructions can be stored in a memory of a computing device, for example a server, loaded and then executed by the processor. Herein, the computer processing circuit is connected to said seat and/or said at least one sensor.

Herein, a typology is defined as a set of physiological data, and in particular, a set of K values of physiological characteristics against which a given characteristic can be compared, for example according to whether it is included in this group or not. , or for example depending on whether its value is greater or less than the average of the values of this set. For a given group of physiological characteristics, it is possible to define an average and a variability defining an interval. When a given physiological characteristic of a user is in this interval, it is defined that said user belongs to this typology.

This makes it possible to provide a device capable of determining one or more typologies of a user of a vehicle seat according to physiological signals of this user, to collect corresponding data and/or to define different typologies of users.

In one embodiment, the seat comprises an armrest, said at least one sensor belonging to said armrest.

This makes it possible to provide an ergonomic device in which the acquisition of the first signal is facilitated by means of at least one contact sensor located near the user of the vehicle seat, and in particular near his arm, his hand, his his wrist and/or his fingers.

In one embodiment, at least one sensor is a contact sensor selected from a photoplethysmographic sensor, an electrodermal activity sensor or an electrocardiogram sensor.

In the present, a photoplethysmographic sensor is a contact sensor making it possible to measure in particular the heart rate of a user from a measurement taken at the level of the skin, for example at the level of the wrist of the user. The reflection of light by the skin of a user being influenced by the quantity of blood in the illuminated area, and therefore by any change in the blood supply of the user, it is possible to measure a modification of the heart rate of the user. 'user.

Herein, an electrocardiogram sensor makes it possible to measure in particular the electrical potential generated by the contraction of the heart and therefore to measure the heart rate.

Herein, an electrodermal activity sensor makes it possible to measure in particular the electrical activity at the surface of the skin in order to deduce therefrom a neurological state or a physiological rhythm from variations in the conductance of the skin.

This makes it possible to carry out direct measurements of the physiological characteristics of the user in a simple, fast way and without interference generated by the presence of a material separating the user from the sensor. In addition, the use of contact sensors makes it possible to provide a device that does not require amplifiers or signal preprocessing, in particular in amplitude.

In addition, the use of contact sensors belonging to an armrest of a seat makes it possible to carry out an acquisition directly at the level of the hand of the user, and preferably under the palm of the hand and/or under the end of the user's fingers, which provides more accurate measurements using these sensors.

In one embodiment, at least one physiological characteristic includes a physiological frequency.

In the present, a physiological frequency is defined as being a frequency of a rhythm resulting from one or more organs of the user. In particular, and preferably, this rhythm is a heartbeat or a breathing rhythm. When a physiological frequency is, for example, a heart rate, this is defined by the number of beats of the user's heart per unit of time (generally, a minute). This applies similarly to a breathing rate, which is obtained based on the number of inspirations and expirations of a user.

This also makes it possible to provide a device capable of detecting variations, in particular abnormal variations deviating from expected averages, of a physiological signal of a user of a vehicle seat, to identify whether a user corresponds to one or the other predetermined typology.

For example, a user's resting heart rate varies with age. From a predetermined database, it is thus possible to define a "newborn" typology when the user's heart rate has an average of between 90 and 190 beats per minute, an "adolescent-adult" typology when the average heart rate is between 60 and 80 beats per minute and an "elderly" typology when the average heart rate is between 60 and 70 beats per minute.

In one embodiment, said device further comprises a man-machine interface configured to transmit to the user a second signal, called stimulation signal, having a frequency having a second value dependent on said first value and/or on said typology .

In the present, a man-machine interface is an electronic device, and in particular, any type of electronic system configured to interact with a user by communicating data to him in various and varied forms, for example in a textual, mechanical, olfactory, haptic, sound and/or visual. Herein, the human-machine interface is connected to the computer processing circuit.

This makes it possible to provide a stimulation signal to the user and/or to communicate to him the results of measurements of certain of his physiological attributes, and in particular, of a temporal evolution of these attributes. A stimulation can be produced by a human-computer interface to help the user to understand the physiological attributes of his own body, with a view to modifying them by means of a voluntary reaction on his part.

In one embodiment, each of the K values and/or the determined typology of the user is/are supplied to the user, for example via a man-machine interface linked or connected to the circuit computer processing.

In one embodiment, during the implementation of said at least one sensor, each of the K values and/or the determined typology of the user is/are recorded by the computer processing circuit in a database , said database being included in the vehicle, in the seat or in a server external to the vehicle.

In one embodiment, the frequency of said second signal is synchronized in time with the frequency of the first measured signal.

This makes it possible to provide a method of stimulation by bio-feedback.

In the present, a stimulation by bio-feedback, also called feedback, action in return or biological feedback, is any stimulation of an individual based, on the one hand, on the measurement of physiological attributes of this individual by means of electrical sensors, and on the other hand, on the communication, to this same individual, of information depending on these physiological attributes, for example via a man-machine interface.

Stimulation by bio-feedback allows a user of a vehicle seat to reduce his level of anxiety, fatigue for example, by setting the frequency of his breathing rhythm to that corresponding to the second signal transmitted to him by the interface. It is thus possible, by bio-mimicry, to get the user to lower his breathing rate in order to relax gradually, when he is in a vehicle, and in particular, when he is driving this vehicle.

This also improves the effects of stimulation by means of the second signal, since a real-time feeling by the user of his own heart rate or his own breathing rate reinforces the effects of bio-feedback. There is therefore a better simultaneity between the first signal and the second signal, making the stimulation by bio-feedback more effective.

In one embodiment, the second transmitted signal includes sound, smell, image, video, and/or vibration or movement of a moving part of the seat.

This allows the user to synchronize his breathing rate, and indirectly his heart rate, with a frequency that the user perceives more easily from the second signal by means of his various physiological senses. Stimulation transmitted in the form of sensory or sensitive signals by the user optimizes the phenomenon of bio-feedback, in particular in the case of multimodal signals. Advantageously, a second signal combining several types of stimulation, for example a combination of a sound and an image to produce an audio-visual stimulation for the user, facilitates synchronization of the breathing rate of the user. with the second signal, which makes it easier for the user to regulate their heart rate.

In one embodiment, the device further includes a proximity sensor configured to acquire a third physiological signal from the user.

In the present, the third physiological signal is preferably of the same type as the first physiological signal, in particular a heart rate or a respiratory rate, but perhaps of another type, for example a circadian rhythm.

In one embodiment, the computer processing circuit is further configured to modify said second value of the frequency of the second signal as a function of said third signal.

The first physiological signal being capable of changing over time, in particular after the first signal has been acquired and the user no longer makes contact with the contact sensors, this makes it possible to continuously generate the second signal with a frequency that remains as close as possible to the actual frequency of the user's physiological attribute, without requiring the continuous or permanent use of contact sensors.

In one embodiment, the first signal includes a heart rate, heart rate variability, and/or breathing rate of the user.

Herein, heart rate variability, known as HRV (“Heart Rate Variability”), corresponds to the variation in the duration of the interval between each beat of the heart. The HRV is higher or lower depending on the individual, and is often correlated to their level of heart health. A high HRV, often found in athletes, is a sign of good regulation of the heart rate according to needs. Rather, a low HRV is a sign of poor heart health, and increases the risk of heart failure. While heart rate is only concerned with the rate of contractions of a user's heart, HRV is determined from the heart itself through its various interactions with the autonomic nervous system. Knowledge of the heart rate and a given HRV of the user makes it possible to provide information on his tendency to practice a sport or his age from a combination of this information.

In addition to supplying a first signal reflecting the heartbeats and/or expiration/inspiration rhythms of a user of a vehicle seat, this makes it possible to supply a device capable of acquiring a first signal comprising several types of physiological rhythms of the user. This further provides a device capable of acquiring a first signal comprising both an average or instantaneous heart rate and an average or instantaneous respiratory rate of the user. When a second signal is transmitted, the value of the frequency of the second signal generated to stimulate the user depends in this case on a coupling of two different physiological attributes of the user, which makes it possible to take into account factors such as the variability of his heart rate, representative of states of anxiety, nervousness or fatigue, for example.

In one embodiment, the first signal is measured upon user request.

Herein, the acquisition of the first physiological signal of the user can be carried out via at least one sensor of the seat. In this case, the user can put his hand, or at least part of his arm, on this sensor to trigger the bio-feedback stimulation process.

This makes it possible to provide a device able to determine a typology of the user and/or to provide bio-feedback stimulation on the basis of a voluntary approach by the user, in particular at an instant deemed safe by the user. , which avoids diverting his attention, for example when driving the vehicle.

Advantageously, when the user occupying the seat is the driver of a motor vehicle, this driver can place his hand on the armrest in order to trigger the process when the vehicle is stationary. The user can subsequently receive the second signal via the human-machine interface when the vehicle is in motion, so that the bio-feedback stimulation is implemented in a safe manner when the hands of the user are placed on the steering wheel.

In one embodiment, the physiological frequency includes an average frequency.

This makes it possible to provide a device capable of improving the determination of a user typology on the basis of a large number of data taken over time.

In one embodiment, the physiological frequency includes an instantaneous frequency.

This makes it possible to provide a device capable of measuring the rate of variation of the heart rate and/or of the respiratory rate, for example to refine known models of physiological attributes of the user. An instantaneous heart rate is calculated by determining the time elapsed between each beat, then determining an average over a series of several beats.

According to another aspect, the present description relates to a computer program comprising instructions for the execution of a method according to the first aspect of the present description, when said program is executed by a computer processing circuit,

As used herein, such computer program may use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in partially compiled form, or in any other desirable form.

According to yet another aspect, the subject of the present description is an information storage means, removable or not, partially or totally readable by a computer or a microprocessor comprising code instructions of a computer program for the execution of each of the steps of the process according to any one of the preceding characteristics, taken individually or according to any technically possible combination.

In the present, the code instructions can be stored in a memory of a device, for example a server, loaded and then executed by a processor of this device.

According to yet another aspect, the subject of the present description is a method for determining a physiological typology of a user of a vehicle seat, said method being implemented by a computer processing circuit, said method comprising at least the following steps:
- implement at least one sensor belonging to said seat, to acquire at least a first physiological signal from the user;
- deducing from said first signal a first value of a physiological characteristic;
- repeating a number K of times the implementation of said at least one sensor to deduce K values of said physiological characteristic, K being a natural integer at least equal to 2;
- determining, on the basis of said K values, said user typology.

In one embodiment, the method further comprises further comprising the following step: - transmitting to the user, by means of a man-machine interface, a second signal, called stimulation signal, having a frequency having a second value dependent on said first value and/or on said typology.

In one embodiment, the second signal is transmitted so that the frequency of said second signal is synchronized in time with the frequency of the first measured signal.

This makes it possible to complete the second signal by means of additional information, for example information from proximity sensors located in the vehicle. Herein, at least one proximity sensor is a temperature sensor, a pressure sensor, a humidity sensor, a vibration sensor, a motion sensor, a microphone or a camera. This makes it possible to measure physiological attributes including, for example, the frequency of blinking of the driver's eyes, which is indicative of his level of fatigue, or even the body temperature of a user of the seat when the camera is an infrared camera, etc. This also makes it possible to provide a second signal more suited to the real state of the

Other characteristics, details and advantages of the aspects of this description will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

, FIG. 1, represents a schematic view of a device for a vehicle seat according to an exemplary implementation of the present description;

, FIG. 2, represents a schematic view of a device and of a method according to an exemplary implementation of the present description;

, FIG. 3, represents a schematic view of a device and of a method according to another example of implementation of the present description; and

, FIG. 4, represents a schematic block diagram of a computer processing circuit according to an example of implementation of the present description.

Unless otherwise indicated, the elements common or similar to several figures bear the same reference signs and have identical or similar characteristics, so that these common elements are generally not described again for the sake of simplicity.

More detailed description

Figure 1 shows an example of passenger compartment 1 of a motor vehicle, said passenger compartment comprising at least one seat 300 adapted to accommodate a user U. The seat 300 is, moreover, adapted to contribute to the implementation of a method according to embodiments of the present description.

In a non-limiting manner, these relate both to a driver's seat of a vehicle and to a passenger seat of a vehicle. More generally, these terms and conditions may apply to motor vehicle seats, aircraft seats, boat seats, etc.

In an example presented here, the seat 300 shown is the pilot's or driver's seat of the vehicle. The driver controls the movement of the vehicle by means of at least one pedal 400 and a steering wheel 500. The vehicle parameters are displayed to the driver via a dashboard 600.

The seat 300 includes a seat 340 on which a user U sits. The seat 300 further comprises a backrest 330 which optionally includes the seat 340 and on which the user U can support part of his back. The seat 300 further comprises a headrest 320 on which the user can rest part of his head. When the vehicle is moving, part of the user's body is always in contact with at least the seat 340 or the backrest 330 of the seat 300. The seat 340, the backrest 330 and the headrest 320 of the seat 300 allow the user U to lean on during the movement of the vehicle, and to absorb shocks.

In an example presented here, the seat 300 and in particular the headrest 320, the backrest 330 and/or the seat 340, comprises at least one mobile element 350. In examples, the seat 300 comprises a vibrating element and /or a heating element.

The mobile element 350 is for example a piezoelectric element making it possible to modify the position, the angle or more generally the relative position of the different parts of the seat 300.

In an example presented here, the seat 300 and in particular the headrest 320, the backrest 330 and/or the seat 340, the movable element 350 further comprises at least one vibrating element which can be controlled or programmed to vibrate with a predetermined frequency and intensity, for example to massage the back of the user U.

Preferably, an armrest 310 is fixed to the back of the seat at a height and at a suitable length so that the user U seated on the seat can put at least part of his arm or his hand. According to another variant, an armrest 310 is attached to one of the sides of the seat cushion. The armrest 310 comprises at least one surface having a horizontal face whose height and length are designed to accommodate at least part of the user's arm or of his hand, when the latter occupies the seat. The shape and dimensions of the seat 300, and in particular of an armrest 310, can be adapted to users of different sizes and builds.

In an example presented here, an armrest 310 that includes the seat 300 is located either to the right or to the left of the seat, to allow the user to support either part of his right arm if the armrest is located on the right, or part of his left arm if the armrest is on the left. As a variant, the seat 300 can comprise two armrests, one being located on the left and the other being located on the right.

In an example presented here, and in a non-limiting way, an armrest 310 of the seat 300 comprises at least one contact sensor, for example a single photoplethysmographic contact sensor, called PPG sensor, a single electrodermal activity contact sensor, called EDA sensor, or a single electrocardiogram sensor, said ECG sensor. In particular, an armrest 310 of the seat 300 comprises two sensors 312 and 314.

In another example presented here, an armrest 310 includes sensors 312 and 314 such as a PPG sensor and an EDA sensor, a PPG sensor and an ECG sensor, or even an ECG sensor and an EDA sensor. In another example, an armrest 310 includes three sensors 312, 314 and 316 (not shown) including a PPG sensor, an EDA sensor and an ECG sensor.

Each sensor comprises at least one receiver, preferably a plurality of receivers to increase the number of measurements. The use of several sensors, preferably located close to each other, makes it possible for example to carry out several measurements simultaneously, for example by contact with several fingers, with the palm and/or with the wrist of the user. . This also allows at least one contact sensor to be in contact with the wrist of the user and/or with at least one finger of the user, which facilitates the performance of a measurement with a PPG, ECG sensor. or EDA.

Advantageously, since the hand and wrist of a user are generally not covered with clothing, the configurations described in the present description allow at least one contact sensor of the armrest to be in direct contact with the skin. of user U.

In the example shown in Figure 1, an armrest 310 of the seat 300 comprises a first sensor 312 and a second contact sensor 314. In a non-limiting manner, an armrest 310 comprises two sensors, in particular the first sensor 312 which is a PPG sensor and the second sensor 314 which is an EDA sensor.

In the example presented here, the passenger compartment 1 of the vehicle further comprises at least one proximity sensor, for example a camera 700 located above the steering wheel 500 of the vehicle. Said at least one proximity sensor further comprises a motion sensor 360 located in the seat 300. This motion sensor 360 comprises for example eight strips of piezoelectric sensors, four of these eight strips being located in the seat 340 and four others of these eight tapes being located in folder 310.

The use of at least one optional proximity sensor makes it possible to measure physiological attributes of the user U when the user U is not necessarily in contact with one of the sensors 312 and 314. In one example presented here, a sensor can be a vibration sensor included in the seat 300, for example an acoustic or piezoelectric sensor, or even an accelerometer.

Without limitation, the passenger compartment 1 or the seat 300 includes other sensors used separately or in combination with the contact sensors 312, 314, for example sensors configured to measure physiological attributes of the user such as the temperature of his skin, the frequency of his brain waves, etc.

In an example presented here, at least one contact sensor 312, 314 is connected to a computer processing circuit 100 in the vehicle, this connection being able to be made wired or wirelessly. At least one contact sensor 312, 314 is configured to acquire a first physiological signal S1 coming from the user U. A value F1 of a characteristic of S1 can thus be measured once or any number K of times during the time, K being an integer greater than 2, to obtain K physiological characteristics F11, F12, …, F1K. The corresponding values are then processed and possibly recorded via the computer processing circuit 100.

In an example presented here, the passenger compartment 1 comprises at least one proximity sensor connected to the computer processing circuit 100, which makes it possible to complete the signal S1 with information additional to that coming from the contact sensors of an armrest 310. In general, at least one contact sensor, at least one proximity sensor, the dashboard 600, at least one moving element 350 of the seat 300 are connected to the computer processing circuit 100.

In an example presented here, the computer processing circuit 100 is connected to a man-machine interface 200. In a non-limiting manner, a man-machine interface 200 is located in the dashboard 600. Alternatively, a man-machine interface 200 is located in the passenger compartment 1 of the vehicle, for example behind the dashboard 600 or above it. As a variant, the man-machine interface 200 can be located anywhere in the passenger compartment 1, for example in the seat 300 or on an armrest 310 of said seat.

In an example presented here, the mobile element 350 can be controlled by a man-machine interface 200 or by the user U. The mobile element 350 is configured to generate a vibration or a displacement of the seat 300 or even of an element particular of the seat 300. Advantageously, a movement produced by the movable element 350 is rhythmic, that is to say has a determined frequency.

According to variants, the computer processing circuit 100 or a man-machine interface 200 is located in the seat 300 or close to it. In an example presented here, the computer processing circuit 100 is located behind the dashboard 600. In a non-limiting manner, and according to other variants, the computer processing circuit 100 is located in the passenger compartment 1 of the vehicle, in the seat 300 or on/in an armrest 310 of said seat.

In an example presented here, the man-machine interface 200 comprises a display and input device configured in such a way as to allow the user U to navigate among different options or among different graphic representations on a screen integrated into a device, for example the dashboard 600, a telephone screen or a touch pad screen.

In an example presented here, the man-machine interface 200 is configured to emit a second signal S2 to the user U. As a variant, the man-machine interface can also comprise various electronic elements configured to emit the second signal S2. The second signal S2 has various and varied forms. At least one of these electronic elements is a holographic projector, a scent emitter, a vibrating element and/or a loudspeaker configured to emit the second signal S2. At least one of these electronic elements is located in the passenger compartment 1, and possibly in the seat 300.

The connections described in the present description and linking different elements together can be of various natures. For the sake of clarity, a single connection 2 is illustrated in FIG. 1. In the case of several sensors and elements configured to emit a signal, these sensors are connected by at least one direct connection to the computer processing circuit 100. These connections can comprise a wired connection, for example of the Ethernet or PLC type, a wireless connection, for example of the WiFi or Bluetooth type, or any other type of connection which may vary according to the preferred hardware for implementing the method.

In an example presented here, the dashboard 600 is connected to the man-machine interface 200 and/or to the computer processing circuit 100, and comprises a luminous screen configured to transmit the second signal S2 in the form of an image dynamic or video. This dynamic image or this video is generated by the computer processing circuit 100, and is for example a graph representing physiological attributes of the user measured by sensors in the passenger compartment 1, as a function of time, or of a video intended for viewing by the user U.

In a situation, for example when he is driving a vehicle, a user U may want to increase his level of concentration or reduce his level of stress by means of an appropriate modification of his breathing rhythm. If the user U can hardly directly modify his heart rate, it is however possible for him to increase or reduce it indirectly by accelerating or slowing down voluntarily the rhythm of his breathing.

In an example presented here, the user U can know his breathing rate and/or his heart rate in real time by placing his hand or his arm on at least one of the contact sensors 312, 314 of an armrest 310. A value F1 of the frequency of the measured rhythm can then be determined from the analysis of the signal S1 by the computer processing circuit 100, and possibly supplied to the user U via the man-machine interface 200 as a reference. Similarly, the acquisition of the K physiological characteristics F11, F12, …, F1K can lead to the analysis of a number K of first signals S11, S12, …, S1K which can be provided to the user or recorded in a database.

In an example presented here, the computer processing circuit 100 generates a dynamic animation having a regular frequency whose value F2 is equal to that of the first signal S1. Similarly, a number K of dynamic animations based on K first signals S11, S12, …, S1K can be generated. In general, the second value F2 is dependent on the first value F1, and at least is chosen to be greater, less than or equal to this value.

A generation of the animation can be performed simultaneously with the acquisition of the first signal S1, or after this acquisition. This animation is transmitted in real time or delayed to the man-machine interface 200 and displayed to the user U, for example via a display means of the dashboard 600.

A dynamic animation constitutes an example of a second signal S2 supplied by a man-machine interface 200. For example, this dynamic animation is a sphere whose volume increases and decreases simultaneously with the actions of inspiration and expiration of the user.

FIG. 2 represents, in the form of a flowchart, an example of a device and steps of a method for determining a physiological typology T of a user U.

As represented, the method is implemented by a device 1000 and comprises a step E10 of acquisition of at least one first physiological signal S1 of the user, this first signal S1 preferably comprising a heartbeat and/or a rhythm breathing of the user U. This first signal S1 is acquired via at least one contact sensor located in an armrest 310 of the seat 300, in this case, the PPG sensor 312 and the EDA sensor 314 located on an upper surface of the armrest 310, and which are able to implement step E10. The acquisition is performed at the request of the user U, for example when the user U places one of his hands on these two sensors.

In other examples, a request from the user U to trigger the acquisition of the signal S1, and more generally the stimulation method of the present description, comprises other means such as a voice command transmitted to a human interface -machine 200 or the press of a button on an armrest 310, on a steering wheel 500 or on a dashboard 600.

In an example presented here, the computer processing circuit 100 of the device 1000 implements a step E20 comprising the determination of a value F1 of a physiological characteristic resulting from the first signal S1. From the heart rate and/or the respiratory rate acquired during step E10, the computer processing circuit 100 deduces a value F1 of the corresponding characteristic, for example by deducing an average frequency by calculating the number of cycles per unit of corresponding time. In particular, the computer processing circuit 100 is configured to process the signal S1 and determine, from the latter, at least a heart rate, a respiratory rate, a variability of the heart rate, even an arterial pressure or a level. user stress U.

In an example presented here, a frequency can be calculated by the computer processing circuit 100 using a process of detecting the number of cycles present in the signal S1 coming from a PPG, EDA or ECG sensor. A peak analysis can also be used, for example to remove erroneous data, the mean square of the signal S1 to determine the strongest signals. A signal-to-noise ratio analysis can also be used to identify more reliable signals.

As a variant, the computer processing circuit 100 calculates other quantities resulting from the first signal S1, in particular an instantaneous frequency resulting from the heart rate and/or the respiratory rate of the user U, for example via the application of a Fourier transform or any other suitable signal processing means.

In an example presented here, following step E20, the computer processing circuit 100 then implements a step E30 comprising a repetition of step E10 a number K of times to acquire a number K of first signals S11, S12 , …, S1K from which physiological characteristics can be extracted, K preferably being a predetermined value greater than or equal to two. According to a variant, step E30 comprises a repetition of steps E10 and E20 to deduce from the first signal S1 or from K first signals S11, S12, …, S1K a number K of values F11, F12, …, F1K of a characteristic physiological outcome of these signals.

In an example presented here, once K values have been deduced, the computer processing circuit then implements a step E40 aimed at determining, on the basis of the K values, a typology T of the user. In another example, step E40 can be implemented at any time, preferably when at least two values have been acquired by at least one sensor.

By way of illustration, two contact sensors 312 and 314, respectively PPG and EDA sensors, are implemented during step E10 to acquire two first signals S11 and S12, S11 being a heart rate of the user and S12 being a respiratory rhythm of this user. During step E20, a first value F11 of an instantaneous heart rate is deduced from the signal S11 and another first value F12 of a respiratory rate is deduced from the other first signal S12. During step E30, steps E10 and E20 are repeated three times, K here being equal to three, to constitute two sets of three measurements (F111, F112, F113) of instantaneous heart rate and of three measurements (F121, F122 , F123) of respiratory rate. During step E40, the computer processing circuit 100 then determines, from the three measurements (F111, F112, F113), a typology T1 of the user, for example a "stressed" typology if the average of these three measurements is greater than 80 beats per minute. The computer processing circuit 100 also determines, from the three measurements (F121, F122, F123), a typology T2 of the user, for example an "asleep" typology if the average of these three measurements is less than 12 cycles inspiration-expiration per minute.

In an example presented here, the determination of several typologies of the user makes it possible to deduce his state. This determination can be obtained more precisely by combining the acquisitions obtained from the contact sensors 312 and 314 using other sensors, for example proximity sensors.

FIG. 3 represents, in the form of a flowchart, a device and an example of steps of a method of stimulation, and in particular of a method of stimulation by bio-feedback, according to a particular embodiment of the present description.

In an example presented here, and in addition to steps E10 to E40, the method comprises a step E50 implemented by the computer processing circuit 100 aimed at transmitting a second signal S2 having a frequency having a second value F2 dependent on the value F1 and/or the T typology.

In an example presented here, the second signal S2 is generated so as to present, preferably, a rhythm whose frequency value F2 is equal to the value F1, within a few cycles per minute, for example 5 cycles per minute. On command from user U or in a pre-programmed manner, value F2 can also be set to be lower or higher than value F1, when user U wishes to require a specific stimulation.

In an example presented here, the transmission to the user U of the second signal S2 is implemented by a man-machine interface 200, said man-machine interface controlling for example an electronic element located in the passenger compartment 1. According to different variants , this transmission can be done by a loudspeaker configured to emit sounds or music, by light-emitting diodes configured to emit light with a given frequency, or even an emitter of odorous molecules to generate a stimulating perfume, etc. . Preferably, these signals comprise at least one rhythmic component whose frequency is of value F2.

In an example presented here, the stimulation method may include the implementation of additional steps following step E10, and not shown in the figures. These additional steps include, for example, a step of measuring a third physiological signal of the user U via sensors other than the contact sensors 312, 314. These sensors include proximity sensors, which are less precise than the contact sensors to measure the first signal S1, but nevertheless making it possible to complete the information obtained from S1 by the computer processing circuit 100. This measurement step can be initiated at any time, for example when no contact is made between the sensors 312, 314 and the user U.

In an example presented here, these additional steps include, for example, a calibration of the frequency of the second signal S2 via the computer processing circuit 100, that is to say an adaptation of its value F2, as a function of the third signal, preferably as a function of a frequency which characterizes this third signal.

For example, the user U is a driver who, before setting his vehicle in motion, requested the triggering of the stimulation process by placing his left hand in contact with an armrest 310 of his seat 300. The sensors 312, 314 acquire , over a time interval of a few seconds, for example 10 seconds, the heart rate of the user U whose frequency value F1 will be used subsequently. When the vehicle is moving, the user U preferably keeps both hands on the steering wheel 500, which no longer allows the method to determine a possible change in the user's heart rate. These changes can however be determined with the aid of the proximity sensors placed in the vehicle, for example an ECG sensor placed in the base 340 of the seat 300 which, although less precise in providing a precise value of a frequency of the rhythm the user's heart rate, allows the F2 value to be updated and adapted using signal processing techniques.

In an example presented here, the man-machine interface 200 or the user U chooses a value F2 of a target frequency lower than the value F1 of the frequency measured by the sensors 312, 314 to allow the user U to adjust his breathing rate to the rate of increase and decrease of the sphere displayed to him. To allow optimal stimulation by bio-feedback, the value F2 of the frequency of increase-decrease of the volume of the sphere is ideally equal to the value of the frequency of the respiratory rate and/or the heart rate measured by at least one sensor of contact.

In another example presented here, the second signal S2 is determined by the man-machine interface 200 so as to present a target frequency whose value F2 is lower than the value F1 of the frequency of the first signal S1. In a situation of intense stress, for example after narrowly avoiding a wild boar on a road bordering a forest, the user U wishes to reduce his level of anxiety. To do this, the user U asks the man-machine interface 200 to send him a signal S2 which allows him to relax. In this case, the user U places one of his hands on one or more contact sensors 312, 314 of an armrest 310 of the seat 300, triggering the acquisition of a first signal S1 comprising the heart rate and/or the breathing rate of the user U. Once the first signal S1 has been acquired, the computer processing circuit 100 determines a frequency value F1 thereof and the man-machine interface 200 then produces the emission of a second signal S2 whose the frequency F2 is lower than the value F1, for example lower by 2, 5, 10 or 20 cycles per minute. The choice of the value F2 can be preprogrammed or selected directly by the user U and used by the man-machine interface 200 to adapt the frequency of a sound emitted by a speaker in the passenger compartment 1. The user U can then rely on the sound from the loudspeaker to gradually reduce the rate of his breathing by adjusting his breathing to the sound.

As a variant, the user U can himself provide the man-machine interface 200 with a target frequency whose value F2 will be used to generate the second signal S2 in a manner personalized by the user U.

In another example presented here, the second signal S2 can be determined by the man-machine interface 200 so as to present a target frequency whose value F2 is greater than the value F1 of the first signal S1 acquired. In a situation requiring a high level of stimulation, for example during a night trip on a poorly lit road or in the context of a car race, the user U wishes to increase his rate of cerebral oxygenation in order to maximize his level. of concentration, for example by voluntarily accelerating his breathing rate. To do this, the user U places for example one of his fingers on a receiver of a PPG sensor of an armrest 310 and another of his fingers on an EDA sensor of an armrest 310, to trigger the process of stimulation by bio-feedback, and thus controlling the emission of a second signal S2 whose frequency F2 is higher than the value F1, for example higher by 2, 5, 10 or 20 cycles per minute. For example, the man-machine interface 200 can control a mobile element 350 located in the seat 300 so that it emits vibrations having a frequency of value F2, to help the user U to increase the rate of his breathing by setting the frequency of its inspirations and its expirations on the rhythm corresponding to the vibrations. By oxygenating more quickly, the user U can then concentrate on the road more efficiently.

In an example presented here, the computer processing circuit 100 is programmed to provide the user, via the man-machine interface 200, with pre-recorded relaxation or stimulation sequences, these sequences presenting at least one signal S2 whose frequency value F2 varies according to the breathing rate and/or the heart rate of the user U.

FIG. 4 represents a schematic block diagram of a computer processing circuit according to an example implementation.

In a non-limiting manner, a computer processing circuit 100 configured to implement a stimulation method comprises a communication bus connected, for example, to a central processing unit 101, such as a microprocessor, denoted CPU. The circuit 100 also comprises a random access memory 102, denoted RAM, for memorizing the executable code of the production method as well as the registers suitable for recording variables and parameters necessary for the implementation of the method according to embodiments, the memory capacity of the latter can be supplemented by an optional RAM memory connected to an expansion port, for example.

Furthermore, the computer processing circuit 100 comprises a read only memory 103, denoted ROM, for storing computer programs for the implementation of the embodiments, as well as a network interface 104 which is normally connected to a communication network on which digital data to be processed is transmitted or received. The network interface 104 can be a single network interface, or composed of a set of different network interfaces (e.g. wired and wireless interfaces or different types of wired or wireless interfaces). Data packets are sent over the network interface for transmission or are read from the network interface for reception under the control of the software application running in processor 101.

Furthermore, the computer processing circuit 100 comprises a user interface 105 for receiving inputs from a user or for displaying information to a user, an optional storage medium 106 denoted HD, and an input-output module 107, noted IO, for receiving, sending data from or to external devices such as hard disk, removable storage medium or others.

In an example presented here, the executable code can be stored in a read only memory 103, on the storage medium 106 or on a digital removable medium such as for example a disc. According to a variant, the executable code of the programs can be received by means of a communication network, via the network interface 104, in order to be stored in the storage medium 106, before being executed.

The central processing unit 101 is suitable for controlling and directing the execution of the instructions or software code portions of the program or programs according to one of the embodiments, instructions which are stored in one of the storage means aforementioned. After power-up, the CPU 101 is able to execute instructions stored in the main RAM memory 102, relating to a software application, after these instructions have been loaded from the ROM for example.

In the example shown here, the device is a programmable device that uses software. However, in the alternative, this description may be implemented in hardware (eg, as a specific integrated circuit or ASIC).

Claims (15)

Device (1000) for determining a physiological typology (T) of a user (U) of a vehicle seat (300), said device comprising:
- said seat (300);
- at least one sensor (312, 314) belonging to said seat, said at least one sensor being configured to acquire a first physiological signal (S1) from the user; and
- a computer processing circuit (100) configured to implement said at least one sensor, to deduce from said first signal (S1) a value (F1) of a physiological characteristic of the first signal, to repeat a number K of times the implementation of said at least one sensor to deduce K values (F11, F12,…, F1K) of physiological characteristics, K being a natural integer at least equal to 2, and to determine, on the basis of said K values, said typology of the user.
Device according to claim 1, in which the seat comprises an armrest (310), said at least one sensor belonging to said armrest.
Device according to any one of claims 1 to 2, wherein said at least one sensor is a contact sensor chosen from among a photoplethysmographic sensor, an electrodermal activity sensor or an electrocardiogram sensor.
A device according to any one of the preceding claims, wherein at least one physiological characteristic comprises a physiological frequency.
Device according to any one of the preceding claims, further comprising a man-machine interface (200) configured to transmit to the user a second signal (S2), said stimulation signal, having a frequency having a second value (F2) dependent on said first value and / or on said typology.
Apparatus according to claim 5, wherein the second signal is transmitted such that the frequency of said second signal is time synchronized with the frequency of the first measured signal.
Device according to claim 6, wherein the second transmitted signal comprises sound, smell, image, video and / or vibration or movement of a movable member of the seat.
A device according to any one of claims 5 to 7, further comprising a proximity sensor configured to acquire a third physiological signal (S3) from the user, the computer processing circuit being further configured to modify said second value of the frequency of the second signal as a function of said third signal.
A device according to any one of the preceding claims, wherein the first signal comprises a heart rate, a heart rate variability and / or a respiratory rate of the user.
Apparatus according to any preceding claim, wherein the first signal is measured at the request of the user.
Device according to any one of the preceding claims, in which at least one physiological characteristic comprises an average frequency.
Device according to any one of the preceding claims, in which at least one physiological characteristic comprises an instantaneous frequency.
Method for determining a physiological typology (T) of a user (U) of a vehicle seat (300), said method being implemented by a computer processing circuit (100), said method comprising at least the following steps:
- implementing (E10) at least one sensor (312, 314) belonging to said seat, to acquire at least a first physiological signal (S1) from the user;
- deducing (E20) from said first signal (S1) a first value (F1) of a physiological characteristic;
- repeating (E30) a number K of times the implementation of said at least one sensor to deduce K values (F11, F12,…, F1K) of said physiological characteristic, K being a natural number at least equal to 2;
- determining (E40), on the basis of said K values, said typology of the user.
The method of claim 13 further comprising the step of:
- transmitting (E50) to the user, by means of a man-machine interface (200), a second signal (S2), called a stimulation signal, having a frequency having a second value (F2) dependent on said first value and / or said typology.
A method according to claim 14, wherein the second signal is transmitted such that the frequency of said second signal is time synchronized with the frequency of the first measured signal.