WO1998032058A1

WO1998032058A1 - Portable device for acquiring and transmitting physiological signals, and wristwatch integrating such a device

Info

Publication number: WO1998032058A1
Application number: PCT/FR1997/000092
Authority: WO
Inventors: Jean-Louis Caballe
Original assignee: Caballe Jean Louis
Priority date: 1997-01-17
Filing date: 1997-01-17
Publication date: 1998-07-23

Abstract

The invention concerns a portable device (1) for acquiring and transmitting physiological signals, comprising: wristband means (2-4) to be worn around a person's wrist; means (25, 35) for picking up physiological signals at the surface of the wrist; means for conditioning the picked up signals in a main housing (10); and means for transmitting the picked up signals to an acquiring and processing device. The sensors are arranged to be in permanent contact with the skin of the wrist, for picking up signals representing neuromuscular tension. This device (1), preferably in the form of a wristwatch, is useful in, particular, in a system for evaluating the impact of messages (films, adverts,...) on the public, for carrying out measurements of audience, for medical monitoring and financial analysis.

Description

"Portable device for the acquisition and transmission of physiological signals, and wristwatch incorporating this device"

DESCRIPTION

The present invention relates to a portable device for acquiring and transmitting physiological signals. It also relates to a wrist watch or wrist watch incorporating this device.

Portable devices for acquiring and transmitting physiological signals are already known. For example, US Pat. No. 4,063,410 describes a wristwatch capable of detecting the frequency of the pulse; US Pat. No. 4,819,860 describes an apparatus for controlling parameters such as the pulse rate or the temperature of a subject. They find their applications in particular in medical remote monitoring. Patents US-4,625,733 and US-4,681,118 describe telemetric measurement devices for parameters such as heartbeats, which are processed to be viewed in the form of EKGs. Their applications are mainly sports: swimming, hurdling, skiing, ...

However, despite the diversity of embodiments of the prior art in the field of the acquisition of physiological signals, current portable devices are not designed to provide signals representative of the neuro-muscular tension of the wearer. These signals are of considerable interest for the evaluation of the emotional shock felt by an individual in response to a communication message. The object of the invention is to propose an acquisition device which can supply these neuro-muscular tension signals under acceptable conditions of portability and reliability. This portable acquisition and transmission device, in particular in the form of a wristwatch, comprises: bracelet means supporting a main case and arranged around a wrist of a person, means for picking up physiological signals , means for conditioning said picked up signals, and means for transmitting said picked up signals to a collection and processing device.

According to the invention, the sensor means are arranged in permanent contact with the skin of the wrist, to pick up signals representative of a neuro-muscular tension.

The present invention finds a remarkable application in the methods of biometric measurement of the emotional shock implemented to evaluate the effectiveness of communication messages.

Any communication message created simultaneously by the individual receiving it:

- on the psychological level, an emotional shock, on the physiological level, a set of modifications of the cardiac system, skin temperature and neuro-muscular tension. This last modification is the most reactive modification.

These modifications, which precisely quantify the force of the emotional shock, can be measured on any individual by means of biometric technologies, called "bio-feedback". The experience acquired after several thousand experimental measurements has taught that, in order to assess the emotional shock created by commercial communication messages, for example advertising messages, measures of the differences in neuro-muscular tension before, during and after reception of a communication message, are sufficient. These measures, up to present performed by means of suitable devices of the "myoscan" type, can now be performed by means of a wristwatch according to the invention.

Neuro-muscular tension signals are captured in the form of voltage signals of the order of a few micro-volts (μV). These signals are then conditioned, amplified, processed and calibrated to achieve an emotional shock value measured on a scale of 1 to 10. An emotional shock less than 5 on this scale is considered to be insufficient to ensure the impact of a message of communication on its target. A new conception of the message then becomes, on this level, essential to optimize its effectiveness. A major difficulty encountered in the acquisition of physiological signals on the surface of the skin of a wearer essentially lies in the fact that it is difficult to ensure sufficient contact with the sensors and that the reliability of the measurements is affected. In a preferred embodiment of the invention, the sensor means comprise a reference electrode disposed under the main housing and two first and second measuring electrodes, and the portable device comprises first and second means for mechanically connecting the bracelet means to the main housing, these first and second mechanical connection means being arranged (i) to receive in a limited area at the end of their respective lower faces said first and second measuring electrodes and (ii) to be subjected to forces substantially directed towards the inside of the wearer's wrist when the bracelet means are tight.

This gives permanent and quality contact of the measurement and reference electrodes with the skin of the wrist, thus contributing to a reliable acquisition of physiological signals.

In an advantageous embodiment of the invention, the packaging means and the means transmission are included in a housing to which the bracelet means are connected.

According to another aspect of the invention, there is proposed a wristwatch combining the conventional functions of a watch and possibly a stopwatch and the functions devolved to the device for acquiring and transmitting physiological signals according to the invention.

The wristwatch according to the invention is a real watch which gives the time and which can therefore be worn by panelists on a daily basis. It captures, amplifies, digitizes, records and transmits so-called bio-feedback signals, which will be described below, and the movements of the panelists to a central electronic unit responsible for locally controlling the entire system. The data is transmitted regularly in packets, each packet containing the signals acquired during a period of five or ten seconds. The wristwatch according to the invention also has the function of capturing the answers to the so-called coherence test questions posed to the panelists at determined times. The responses are transmitted in the same way as the signals from the sensors. Furthermore, several watches according to the invention must be able to operate near a television set without interfering with each other.

Other features and advantages of the invention will appear in the description below. In the appended drawings given by way of nonlimiting examples:

- Figure 1 shows a wristwatch according to the invention;

- Figure 2 is an exploded view of a wristwatch according to the invention; - Figure 3 is a sectional view of a wristwatch according to the invention, in which two positions I, II of the bracelet are shown; - Figure 4 is a bottom view of the case of a wristwatch according to the invention; Figure 5 is a block diagram of the internal electronic circuit of a wristwatch according to the invention; FIG. 6 illustrates a first embodiment of the front face of a liquid crystal wristwatch according to the invention;

- Figures 7A and 7B illustrate a second embodiment of the front face of a liquid crystal wristwatch according to the invention; and FIG. 8 comprises two chronograms representing the respective temporal evolutions of a bio-feedback signal and of a movement signal obtained with a wristwatch according to the invention.

We will now describe an embodiment of a wristwatch according to the invention, with reference to FIGS. 1 to 4.

A wristwatch 1 according to the invention comprises a main unit 10 integrating chronometric functions and functions for signal acquisition and transmission, and a bracelet system comprising for example two flexible parts 2, 4 having respective first ends permanently connected to the main housing 10 and second ends connectable by a closing and tightening device 3. The bracelet is connected to the main housing 10 by means of two mechanical connection parts 20, 30 which also provide a support function measuring electrodes 25, 35 and an electrical connection function with the main housing 10. Each mechanical connection piece 20, 30, made of a metallic material, comprises at the end of its lower face a reduced delimited area having a boss at the end acting as a measuring electrode 25, 35 and sinking into the skin of the wearer's wrist 6, and on the central part of the lower face, an insulating plate 21, 31 (Fig. 2) and / or two insulating strips 210, 211; 310, 311 ensuring electrical isolation of the lower face with respect to the skin of the wrist 6. The insulating plates 21, 31 and / or the insulating strips 210, 211; 310, 311 can be added glued to the undersides of the mechanical connection parts, or even clipped.

Each mechanical connection part 20, 30 further comprises a strap attachment zone 26, 36 arranged to receive one end of the strap parts 2, 3, a first articulation ensuring the mechanical connection between the mechanical connection piece 20, 30 and the main housing 10 and a second articulation ensuring the mechanical connection between the mechanical connection part 20, 30 and the bracelet part 2,3. These first and second articulations conventionally use pump axes 22, 32; 24, 34.

The main housing 10 is constituted by the assembly of a decorative ring or cover 12, a mineral glass 13 serigraphed on its internal face, and a main body 11 containing an electronic circuit. The main body 11, which can for example be made of injected polyurethane, has on its lower part an O-ring 14 molded in shape, a housing bottom 15, made for example of machined stainless steel with screw head housings and a reference electrode in relief, and an insulating plate 16 comprising a recessed area 160 to allow the contact of the reference electrode 18 with the skin of the wrist 6. This insulating plate 160 thus has the function of reducing the contact surface of the central reference electrode. A piezoelectric buzzer 54 is glued to the internal face of the bottom of the housing 15. The main housing also includes, with reference to FIG. 2, a validation and backlight button 17. The capture of physiological or "bio-feedback" signals is ensured by means of three metal contacts 25, 18, 35 ensuring the function of measurement electrodes, for example stainless steel, gold or any other highly conductive material, l one of the electrodes constituting a reference or ground electrode 18 and being disposed on the underside of the main case 10 of the wristwatch 1 and the two other measurement electrodes 25, 35 being disposed at the ends of the undersides of the pieces of mechanical link 20, 30 of the watch strap according to the invention.

We will now describe an exemplary embodiment of an electrical connection between each measurement electrode 25, 35 and the electronic circuit of the central box 10, with particular reference to FIGS. 3 and 4.

In this exemplary embodiment, for each mechanical connection piece 20, 30, a conductive elastomer pin 23, 33 is inserted between a rounded end 220, 330 of the mechanical connection piece 20, 30 electrically conductive since it is metallic and an electrical contact ( not shown) located on the side face of the housing 10 opposite the mechanical connection part 20, 30. When the mechanical connection part is in rotational movement around its first articulation, the head of the conductive elastomer pin 23, 33 remains in electrical contact with the rounded end 220, 320 and thus ensures a permanent electrical connection between the measurement electrode 25, 35 and the electronic circuit 100 of the central housing 10. It should be noted that this exemplary embodiment is not not limiting and that other modes of electrical connection can be envisaged for a wristwatch according to the invention. It is thus possible to make an electrical connection between each mechanical connection piece and the electronic circuit of the main housing using a flexible welded film. When the wristwatch 1 according to the invention, initially in an unclamped free position (I), is placed in the clamped position (II) around the wrist 6 of a person, with reference to FIG. 3, the two electrodes of measure 25, 35 penetrate the skin of the wrist due to the forces exerted on the two mechanical connecting pieces 20, 30 by the tension of the strap parts 2, 4. At the same time, the reference electrode 18, which has for example a longitudinal shape projecting from the bottom of the housing 15, also penetrates the skin of the wrist. This contributes to achieving satisfactory electrical contact between the electrodes 25, 35, 18 and the skin, thus making it possible to achieve, under good conditions, the acquisition of physiological skin signals, in particular neuromuscular signals. In this way, the measurements are no longer dependent on the position and tightening conditions of the bracelet and have a significantly higher level of reliability than that found with the capture devices of the prior art.

We will now describe a nonlimiting example of an electronic circuit 100 fitted to a wristwatch according to the invention, more particularly with reference to FIG. 5.

The conditioning of the signals picked up at the terminals of the measurement electrodes 25, 35 and of reference 18 is ensured by a differential amplifier with variable gain 56. The wristwatch 1 according to the invention further comprises a motion detector 51, including for example a miniature accelerometer, to provide data relating to the movement of the watch wearer.

Four input keys 55 are provided, for example on the periphery of the wristwatch case according to the invention, for inputting responses to consistency tests, as well as a cancellation key 66 and a validation key 65 . The wristwatch 1 according to the invention further comprises a buzzer 54, preferably of the sub-miniature type, to prevent or call to order the panelist during a consistency test, and to draw his attention in the event of an anomaly. , in particular in the event of a weak battery, leaving the field for a long period of time, sensor faults or even a systematic erroneous radio frequency link.

The radio communication implemented in a wristwatch 1 according to the invention can, by way of non-limiting practical example, be of the half-duplex, single-channel type. This communication is provided by a transmitter-receiver assembly 52 comprising a transmitter 521, a receiver 522 and an antenna 520. The transmitter 521 can be a simple modulated oscillator. The receiver 522 is necessary to separate the watches and avoid transmitting if they are not in the field. A radiated power of -30 dBm represents sufficient power for this application. The HF 520 antenna is integrated in the housing 10 of the wristwatch 1 according to the invention. The range is approximately 5 to 10 meters and no particular directivity is provided, the wristwatch 1 having to operate in all positions. The frequency band used can be for example the IETS 300-220 / 433 Mhz band and a speed of 9600 baud can be provided.

This radio communication allows the transmission, to a collection and processing device, of the physiological signals picked up and conditioned and of a signal indicative of the movements of the wearer of the wristwatch according to the invention. The received signals are then correlated and processed to provide information representative of the emotional shocks felt by the wearer.

The electronic circuit 100 of the wristwatch 1 according to the invention is constructed around a central unit comprising for example a microcontroller 50 incorporating most of the control and processing functions achievable by this watch, and an analog / digital converter processing the captured and amplified signals. It is possible to provide for a sampling of the signals received every 0.2 to 1 second, a memorization of the last packet of signals transmitted, and a transition to "low energy" mode (low-po er) in the following cases: low battery, output extended interface box, watch not worn, operating anomalies detected.

The wristwatches according to the invention can be produced using different techniques. In a prototype version, they can be made with encapsulated components available in CMS technology (surface-mounted circuits). It is advantageous to use C.O.B technology (Chip On Board) and for mass production, ASIC technology

(Application Specifies Integrated Circuit). The manufacturing method envisaged must also allow use taking into account shocks and vibrations.

The chronometry part of the wristwatch according to the invention can be supplied by a rechargeable Lithium 53 battery of 3 volts.

The display 6, 7 can advantageously be produced by the conventional technique of liquid crystal display.

In a first display embodiment for a wristwatch according to the invention, with reference to FIG. 6 which represents a front face 60, the liquid crystal display comprises a central part 633 grouping information of a watchmaking nature ( hour, minute, date, ...), a visualization 640 of the test keys actually selected by the panelist wearing the wristwatch, and pictograms 630, 631, 632 (which will be described below) indicative of the working condition of the wristwatch. The display area is surrounded by a control crown comprising for example four command keys 61, 62, 63, 64 provided in particular for entering responses to consistency tests, a validation key 65 and a cancellation key 66.

In a second embodiment of a display mode for a wristwatch according to the invention illustrated by FIGS. 7A and 7B, the display is produced by white and black serigraphy on the internal face of the mineral glass 13. This serigraphy comprises for example a black outer ring 700 having graduations in minutes, a white inner ring 710 in which moves an element 79 indicating the minutes and an element 78 indicating the hours and a central part 70 comprising on its periphery graduations in hours 71 and grouping together a set of information and pictograms for status and control.

The display of a wristwatch according to the invention can advantageously be designed to provide the following information, for example in the form of pictograms, with reference to FIGS. 6, 7A and 7B: information relating to the function of communication with the case interface:

- proximity to the 632 interface box,

- rechargeable battery 631 (in the case of an external energy supply),

- transmission link,

- chronometric and horological information 780, 633

- hours, minutes, seconds, date 780,

- test information: - consistency tests Gl, G2, G3, G4; 74-77;

61-64;

- malfunction information:

- fault bracelet 73, 630, low battery (in the case of an external energy supply).

Setting the wristwatch 1 according to the invention and entering the consistency test results can be carried out for example by use of validation keys 65 and cancellation keys 66, and for example be of the selection type, then incrementation followed by validation. These validation and cancellation keys can be located either on the main case of the wristwatch, or on a removable module.

The “proximity” pictogram 632 lights up in the presence of a collection device in the radiofrequency field of the wristwatch according to the invention. The "battery" pictogram 631 lights up permanently when the battery is charging, flashes when the battery is low and goes out when the battery charge is satisfactory.

The pictogram "bracelet fault" 630 lights up if the sensors are not in correct contact with the panelist's skin.

The keys usable by the panelist are the Cancellation and Validation keys, and the four keys 1, 2, 3, 4 for choosing a consistency grid. It is also possible to provide an active backlight only during the input phases of the consistency test grids.

We will now describe the main operating characteristics of a wristwatch according to the invention, in the particular application of audience measurement. For this application, panelists are each equipped with a wristwatch according to the invention. Collection and transmission devices, designed to receive physiological signals picked up on these panelists from each wristwatch worn by panelists, are installed in their homes.

The wristwatch 1 according to the invention is worn on the wrist like an ordinary watch. The two metal contacts 25, 35 acting as measurement electrodes and inserted into the bracelet and the reference electrode 18 placed under the housing 10 make it possible to measure the surface currents of the skin in mode differential and high impedance. The signals are amplified, filtered and converted into digital signals by the central unit 50 integrated in the wristwatch 1 according to the invention. The "bio-feedback" signal is a complex signal linked to nervous and neuro-muscular activity. The miniature accelerometric sensor 51 acting as a motion detector or any other equivalent device provides motion information making it possible to correct, if necessary, signals for which an excessively high correlation with the movements of the panelist would be detected. A corresponding correction law can for example be stored in the collection device and possibly downloadable. This involves performing a correlation between the bio-feedback signals from the sensors arranged under the central case and the watch strap, and the movement signals obtained by means of the motion detector 51. The bio- feedback takes the form of voltage signals proportional to the stress of the watch wearer. The movement signals are in the form of pulses whose frequency is proportional to the physical agitation of the wearer. We observe, with reference to FIG. 8, several characteristic states:

- an El state, corresponding to strong physical and mental activity; an E2 state, corresponding to physical activity;

- states E3, E4 corresponding to psychic activity, respectively normal and strong; an E5 state, corresponding to no activity, as in the case of a sleeping person. We can note that a strong physical activity necessarily corresponds to a psychic activity (state

El). This is explained by the fact that the movement of muscles generates an electric current which is detected by bio-feedback signal sensors.

The correction then consists in attenuating or amplifying the bio-feedback signals according to the movements of the wearer.

In the El state of high physical and mental activity, the bio-feedback signals are strongly attenuated, for example by an attenuation coefficient of between 20 and 100. In the E2 state corresponding to physical activity, the bio signals -feedback are attenuated, for example by a coefficient between 1 and 20.

In states E3 and E4 corresponding to a psychic activity without significant physical activity, the bio-feedback signals are amplified, for example by a coefficient between 1 and 50.

These corrections thus make it possible to obtain a relatively homogeneous signal indicating as faithfully as possible the psychic state of the wearer by disregarding the movements thereof.

The bio-feedback signals transmitted by the wristwatch 1 according to the invention and possibly corrected make it possible to determine for each period of time, programmable for example from 1 to 10 seconds, a so-called emotional shock coefficient.

This emotional shock coefficient is then combined with the results of consistency tests to which each panelist is subjected. In particular, these are panelists' responses to symbol grids. This emotional shock and consistency test data feeds into an assessment database and is used directly for analysis.

During the day or each time the wristwatch 1 according to the invention leaves the field of the collection device beyond a predetermined period of time, the wristwatch 1 goes into low consumption mode or standby mode. It is put back into operation when activated by a radio signal issued by the collection system and coded in a specific way.

When the wristwatch 1 according to the invention enters the radio field of the collection device, the central unit 50 receives a coded radio signal and controls the lighting of the pictogram 632 or indicator light indicating the presence of the radio field. The two "bio-feedback" signals and the accelerometer signal are then acquired and regularly sampled at a period of 0.1 to 1 second then are transmitted in packets to the collection device.

The management of collisions between emissions from several wristwatches according to the invention is managed by the collection device by synchronizing each wristwatch according to a predetermined code which can for example be generated from the serial number of the watch- bracelet.

When a panelist watches a determined channel known to the collection device at a given time, appropriate consistency grids programmed for a given time can be triggered. They must correspond to the channel actually watched by the panelist. By way of nonlimiting example, it can be considered that a chain is valid for a consistency grid when this chain has been watched continuously during the quarter of an hour preceding the triggering.

When a consistency grid is presented to a panelist, he is expected to enter answers to the proposed tests by selecting one of the four selection keys 61-64 (Fig. 6) accessible on the box 10 of the wristwatch 1 according to the invention. When a response is selected, the corresponding display box 640 is inverted to allow the panelist to verify that the response key he has just pressed is indeed the one he wants to select. The response to a consistency test is validated either automatically by the collection device after a predetermined period of time, or by pressing the validation key 65 accessible on the case 10 of the wristwatch 1. Pressing the cancel key 66 allows the panelist to start again the selection of the answers corresponding to the complete grid if he believes he has made a mistake. The responses are then transmitted to the collection device by a particular packet.

Contact sensor fault detections are continuously processed and transmitted to the collection device. It is also possible to provide at the level of the collection device an additional fault key which can be actuated by the panelist to indicate the existence of a radio fault, this type of fault cannot be detected automatically.

It is advantageous to provide a self-test function within the wristwatch which can be activated for example by a determined combination of keys.

Of course, the invention is not limited to the examples which have just been described and numerous modifications can be made to these examples without departing from the scope of the invention. The wristwatch according to the invention can integrate many other functions than those which have just been described. For the detection of the movements of a panelist wearing a wristwatch according to the invention, it is possible to envisage the use of more rustic and / or more economical motion detectors than a miniature accelerometer.

In addition, it is possible to provide applications other than audience measurement. Thus, a wristwatch according to the invention can be used for the purposes of medical telemonitoring or for measuring the physiological reactions of a wearer to external events. Such a watch can for example be worn by finance professionals to carry out analyzes financial from physiological data thus collected.

More generally, the wristwatches according to the invention can be advantageously used for measuring the reaction of participants in all kinds of events or demonstrations, in particular conferences, political meetings or of any kind, artistic representations , for example cinematographic performances, or events of a commercial or promotional nature.

Claims

1. Portable device (1) for acquiring and transmitting physiological signals, comprising: - bracelet means (2, 3, 4) supporting a main housing (10) and arranged around a wrist (6) of one person,

- means (25, 35, 18) for picking up physiological signals, - means (56) for conditioning said captured signals, and

- means (52) for transmitting said captured signals to a collection and processing device, characterized in that the sensor means are arranged in permanent contact with the skin of the wrist (6), for picking up signals representative of a voltage neuro-muscular.

2. Device (1) according to claim 1, characterized in that the sensor means comprise a reference electrode (18) disposed under the main housing (10) and two first and second measuring electrodes (25, 35), and in that the portable device (1) comprises first and second means (20, 30) for mechanically connecting the bracelet means (2, 4) to the main housing (10), these first and second mechanical connection means (20, 30 ) being arranged: (i) to receive in a zone delimited at the end of their respective lower faces (210, 310) said first and second measuring electrodes (25, 35) and (ii) to be subjected to forces substantially directed towards the inside of the wearer's wrist (6) when the bracelet means (2, 3, 4) are tight.

3. Device (1) according to claim 2, characterized in that the first and second mechanical connection means (20, 30) each comprise a first articulation (22, 32) relative to the housing main (10) and a second articulation (24, 34) relative to one end (240, 340) of the bracelet means (2, 3), these second articulations (24, 34) being arranged so that the two ends ( 240, 340) bracelet means (2, 3) bear against the respective upper faces (26, 36) of said first and second mechanical connection means (20, 30).

4. Device (1) according to claim 3, characterized in that it further comprises first and second means (23, 33) for making an electrical connection between said first and second measuring electrodes (25, 35) and the conditioning means (56) within the main housing (10).

5. Device (1) according to claim 4, characterized in that the first and second mechanical connection means (20, 30) are electrically conductive and in that the first and second electrical connection means comprise means (23, 33 ) to bring said first and second mechanical connection means (20, 30) into contact with first and second input contacts at the periphery of the main housing (10).

6. Device (1) according to any one of claims 2 to 5, characterized in that the first and second mechanical connection means (20, 30) further comprise, on their respective lower faces, means (21, 31 ; 210, 310) for electrically isolating said lower faces from the skin of the wrist (6), with the exception of the end zones receiving said first and second measuring electrodes (25, 35).

7. Device (1) according to any one of claims 2 to 6, characterized in that the housing main (10) further comprises on its internal face means for electrically insulating the bottom (15) of said main housing (10) with the exception of the reference electrode (18), relative to the skin of the wearer's wrist .

8. Device (1) according to any one of the preceding claims, characterized in that it further comprises means (51) for generating signals representative of movements of the wearer of said device.

9. Device (1) according to claim 8, characterized in that the sensed and conditioned physiological signal is correlated with the movement signal and is corrected to provide a signal representative of emotional shocks felt by the wearer.

10. Device (1) according to claim 9, characterized in that the collection and processing device comprises means for correlating the physiological signal and the movement signal received from said device (1) and for generating a signal representative of emotional shocks received by the wearer.

11. Wrist watch (1) incorporating the portable acquisition and transmission device according to any one of the preceding claims.

12. Application of a wristwatch according to claim 11, to the measurement of television audience.

13. Application of a wristwatch according to claim 11, to financial analysis.

14. Application of a wristwatch according to claim 11, to medical analysis of the reactions of human subjects to a message.

15. Application of a wristwatch according to claim 11, to the medical remote monitoring of patients.

16. Application of wristwatches according to claim 11 to measure the emotional shock felt by a group of individuals in response to the reception of a communication message.