Portable pupillometer, dynamic pupillometry measurement kit and associated method

Abstract

The present invention relates to a portable pupillometer (1) characterized in that it comprises: an opaque housing (2) having an opening at the front and a removable face opposite the opening. The housing has two internal grooves (3) in the longitudinal direction and a sliding plate (4) disposed in these internal grooves (3). an infrared camera (5) a panel (6) is fixed to the front of the plate (4) a mask body (7) fixed to the opening of the housing (2) at least a first visible light source (9) at least a first infrared light source (10) a user identification device (11) a power supply unit (12) a programmable processing unit (13) a second visible light source (14) a printed circuit board (15) Figure for the abstract: Figure 2

Description

Title of the invention: Portable pupillometer, dynamic pupillometry measurement system and associated method. Technical field

[0001] The invention relates for example to a portable pupillometer, a dynamic pupillometry measurement set, a method for measuring the characteristics of portable pupillometry and a method for determining the state of fatigue of an athlete.

[0002] Dynamic pupillometry, which consists of measuring and analyzing changes in pupil size in response to different stimuli, is an essential tool in various medical and scientific fields, including neurology, ophthalmology, and cognitive psychology. Pupillary responses can reveal information about the state of the autonomic nervous system, the integrity of visual pathways, and brain function.

[0003] Measuring autonomic nervous system activity has been used for many years as a tool for monitoring fatigue in athletes. This measurement is currently performed via heart rate variability analysis, which presents constraints for athletes in terms of testing conditions and measurement duration. In this context, exploring new methods for monitoring fatigue in athletes is therefore highly relevant.

[0004] Previous technique

[0005] Traditionally, pupillary reactivity is measured using stationary devices in clinical or hospital settings, requiring infrastructure and a controlled measurement environment. These devices are often expensive and bulky or require dedicated installation and environment, as in the case of US patent 2014063461A1.

[0006] To overcome this bulkiness problem, a pupillometer can be portable, as described in document WO9632879A1. The device is a handheld, user-operated pupillometer that allows for the characterization of the pupil of a subject's eye. This pupillometer is handheld but cannot be used without being interfaced with a computer, which makes mobile use impossible. Furthermore, the pupillometer of this patent does not allow for independent measurement by the user and requires the intervention of a third party to position the device and perform the measurement. Description of the invention

[0007] The present invention aims to overcome the limitations of current devices and methods, and for this purpose proposes a portable pupillometer, a dynamic pupillometry measurement set, a method for measuring the characteristics of portable pupillometry and a method for determining the state of fatigue of an athlete from the use of the portable pupillometer.

[0008] The portable pupillometer is composed of several elements: - an opaque housing having an opening at the front and a removable face opposite the opening. The housing has two internal grooves running lengthwise and a sliding plate disposed in these grooves. The internal grooves extend from the removable face for at least 50% of the housing's length, preferably for at least 80% of the housing's length. According to a preferred embodiment of the invention, the housing is obtained by additive manufacturing of a thermoplastic polymer material. - an opaque mask body fixed to the opening of the housing; the mask body comprises two concave portions and a foam on the face facing outwards from the portable pupillometer. According to a preferred embodiment of the invention, the mask body is obtained by additive manufacturing of a thermoplastic polymer material. - an infrared camera oriented towards the opening of the housing and fixed to the sliding plate. According to one embodiment of the invention, the camera is fixed directly to the housing. According to another embodiment, the camera is fixed to the sliding plate by a camera bracket opposite the center of the opening and at a distance of at least 8 cm from the concave portion of the mask body. According to one embodiment, the camera includes a wide-angle lens capable of capturing the entire width of the opening at the end of the mask body. The camera includes a high-pass filter that only allows wavelengths above 800 nm (preferably 850 nm) to pass through. According to one embodiment, the device includes two infrared cameras. According to one embodiment of the invention, the two cameras are arranged symmetrically with respect to the center of the housing opening. A panel is fixed to the front of the plate and extends across the width of the housing. The panel completely separates the front portion of the housing from the rear portion. The panel has an opening for the camera(s), sized to allow the camera(s) to film in the direction of the opening. In one embodiment of the invention, the panel is a printed circuit board. at least one first visible light source fixed to the panel on one face facing the opening. According to a preferred embodiment of the invention, this at least first visible light source emits white light. According to one embodiment of the invention, this at least first visible light source is an LED. at least one first infrared light source fixed to the panel on one face in the direction of the opening. According to one embodiment of the invention, the at least one first infrared light source is an LED, and emits light at a central wavelength of at least 800 nm, preferably 850 nm. a user identification device attached to the sliding plate; a power supply unit attached to the sliding plate. According to one embodiment of the invention, the power supply unit is a battery or cells. A programmable processing unit is connected to the infrared camera, the power supply, the user identification device, at least one first infrared light source, and at least one first visible light source. Preferably, the connection is made via connecting elements, which may consist of electrical cables and connectors. In one embodiment, the programmable processing unit is connected to the panel when the latter is a printed circuit board, the panel serving as an interface between the at least one first infrared light source and at least one visible light source and the programmable processing unit. In one embodiment of the invention, the programmable processing unit has a connection interface attached to it to ensure the connection with the connecting elements. A second visible light source is fixed to the panel at a distance of less than 2 cm, preferably less than 1 cm, from the camera opening, on the side facing the opening. This second visible light source is connected to the programmable processing unit. According to one embodiment of the invention, the second visible light source is connected to the panel when the panel is a printed circuit board, and the panel serves as an interface between the second visible light source and the programmable processing unit. A printed circuit board is fixed to the rear face of the sliding plate opposite the removable face of the housing. The printed circuit board includes at least one receiving means for making a connection with a source external power is supplied to the portable pupillometer and is connected to the programmable processing unit as well as to the portable pupillometer's power supply unit. The removable front of the housing has at least one opening opposite at least one connection means. According to one embodiment of the invention, the at least one receiving means is a pad.

[0009] The user identification device is a fingerprint sensor comprising internal memory and is attached to the sliding plate via a user identification device holder. The upper face of the housing has an opening opposite the user identification device to allow the user to place a finger on it. The user identification device holder includes pressure means for bringing the identification device to the level of the opening in the housing, while also allowing, by pressure from the user on the identification device, for bringing it into a so-called disassembly position in which the identification device is under the upper face of the housing. According to a preferred embodiment of the invention, the pressure means are springs.The top of the casing has a dome above the opening to isolate the user identification device from external light. The opening is located on a lateral portion of the top surface, in an area between the edge and one-third of the top surface's width. Extending from the opening towards the adjacent side surface, the top of the casing has at least one external groove to guide the user in positioning their finger on the user identification device. The external grooves continue onto the side surface adjacent to the opening.

[0010] The housing has an opening in the center of its upper face. A control device is positioned in this opening. The control device consists of: - a circular control body disposed on the outer face of the control device, divided into 4 deformable fins connected to each other at the center of the control body. According to a preferred embodiment of the invention, the control body is obtained by additive manufacturing of a thermoplastic polymer material. - a threaded rod extending under the control body through the opening in the housing and towards the inside of the housing. According to a preferred embodiment of the invention, the threaded rod is obtained by additive manufacturing of a thermoplastic polymer material. According to one embodiment of the invention, the threaded rod is part of the control body. - a nut located on the inner part of the upper face of the housing. According to a preferred embodiment of the invention, the nut is obtained by additive manufacturing of a thermoplastic polymer material. - at least one push button positioned under at least one deformable fin

[0011] The control device is connected to the programmable processing unit. According to one embodiment of the invention, the control device comprises a printed circuit board on which at least one push button is fixed. The printed circuit board serves as an interface for the connection between the programmable processing unit.

[0012] The control device comprises 4 pushbuttons, each arranged under a different fin, each button corresponding to one of the following functions: - Turning the portable pupillometer on / off: Preferably, the portable pupillometer can be turned on with a single press of the push button associated with this function. Preferably, the portable pupillometer can be turned off by pressing the push button associated with this function for at least 2 seconds, preferably for at least 5 seconds. - Entering and exiting standby mode: Standby mode is a mode in which the portable pupillometer limits its energy consumption by switching off the second visible light source, thus providing more power to the user identification device. However, the programmable processing unit remains active. - Entering "connection" mode, this mode allows the device to attempt to connect to a new device or network. Connection to a new network can be made via a QR code read by the camera or via a connection procedure performed by the user. - Initiate a measurement without identification or a calibration sequence

[0013] The portable pupillometer has a light ring on the top of the housing, around the control device. The light ring emits in the visible spectrum and emits a different colored light depending on the device's state or mode. When the portable pupillometer is switched on but not in a particular mode or during measurement, the light ring indicates the power supply unit's charge level. The light ring is connected to the programmable processing unit.

[0014] The light ring is composed of a plurality of individually controllable LEDs.

[0015] The light ring has several light modes:

[0016] - a mode emitting a blue light when the device is not plugged in, not in standby or connected mode, nor during measurement. The number of LEDs lit The brightness of the light ring is proportional to the battery charge level, so the user can quickly know the status of the battery and the device.

[0017] - a green LED indicator mode when the device is charging on the base. The number of LEDs lit on the light ring is proportional to the battery charge level so the user can quickly know the status of the battery and the device.

[0018] - a flashing red mode when the battery charge level is below 5% to alert the user.

[0019] - a measurement mode, the LEDs light up one after the other during the measurement, When the light ring is fully illuminated, the measurement is complete.

[0020] At least one mounting bracket is fixed to the panel on the side facing the opening. The mounting bracket extends in the direction of the opening into the area of ​​the mask body. The mounting bracket has at its end a support on which at least one second infrared light source is fixed. This at least second infrared light source is connected to the programmable processing unit.

[0021] The portable pupillometer comprises at least three first visible light sources arranged uniformly in an upper portion of the panel. A light diffuser is fixed over the at least three first visible light sources to allow homogeneous illumination of the aperture when the at least three light sources are switched on.

[0022] Dynamic pupillometer measuring assembly characterized in that it comprises: - a portable pupillometer according to an embodiment described above, including a battery charge level indicator. According to an embodiment of the invention. The charge level indicator is the luminous ring. - a charging station The charging station includes: - a first means of connection to an electrical power supply network - a base - an energy storage device - a support for the energy storage device located in a lower part of the base - an upper part of the base has a cavity suitable for receiving the portable pupillometer oriented with its removable face towards the bottom of the cavity. - at least one second means of connection to at least one receiving means of the portable pupillometer, the at least one second means of connection are placed at the bottom of the cavity facing outwards from the base and are located opposite at least one means of receiving the portable pupillometer when it is placed on the base.

[0023] The light ring can indicate the following states of the portable pupillometer: - a state when switched on and connected to the charging station, in which the light ring emits a green light on an area of ​​the ring proportional to the charge level of the portable pupillometer - a state when the device is on, with a charge level above 10% and disconnected from the charging station, in which the light ring emits a blue light on an area proportional to the charge level of the portable pupillometer - a state where the device is switched on with a charge level below 10% and disconnected from the charging station, in which the light ring emits a flashing red light - When switched on and measuring, the light ring emits a blue light over an area that increases proportionally to the progress of the measurement. - a standby state in which the light device is switched off to save energy on the portable pupillometer

[0024] A method for measuring the dynamic pupillometry characteristics of a user using a dynamic pupillometry measurement set according to an embodiment described above, characterized in that it comprises the following steps: - a step in which the user places the portable pupillometer on their face, resting it against the side of the mask, after removing it from the charging station - a user identification step, carried out by the user identification device, and the launch of a measurement - a measurement sequence step which unfolds as follows, during which a video is recorded using the infrared camera: - a phase where the second visible light source is switched on at minimum intensity and at least one first infrared light source and at least one second infrared light source are switched on. The beginning of this phase corresponds to the start of video recording. - a phase where at least one first source of visible light is switched on at a high intensity and at least one first source of infrared light and at least one second source of infrared light are switched on - a phase where only the second visible light source is switched on at minimum intensity, and at least one first infrared light source and at least one second infrared light source are switched on. The end of this phase marks the end of the video recording. - a pre-treatment phase - an information phase on the measurement process for the user via the second visible light source Preferably, the measurement phase unfolds as follows: - at t=Os, the intensity of the second light source is reduced to a minimum state to signal the start of the measurement to the user; at least one first infrared light source and at least one second infrared light source are switched on; the infrared camera is switched on and video recording begins. - at t=4s, at least one first source of visible light turns on - at t=5s, at least one of the first visible light sources goes out - at t=9s, end of video recording by the infrared camera, the video is stored on the programmable processing unit and video pre-processing begins. The second visible light source increases in intensity and turns purple throughout the pre-processing stage. - at the end of the pre-processing step, the second visible light source turns green if the pre-processing step does not return any errors or turns red if the pre-processing step returns an error. - a step of transferring the video to a server. According to one embodiment of the invention, the transfer is made via a wireless connection, which can be WLFI or Bluetooth. According to another embodiment, the transfer is made via a wired connection to a PC. - a video analysis step, determining and recording the parameters of a pupillary response in a database. This step is broken down as follows: - An algorithm for detecting the position of both eyes is applied to the entire video. Preferably, the algorithm is applied only to the first 50 frames of the video, or even only to the first 30 frames of the video. - A reflection detection algorithm linked to the illumination of at least one first infrared light source and at least one second infrared light source on each eye of the user is used. The difference between at least two reflections is then determined in pixels and a function A conversion function is applied to determine a value in millimeters for each pixel. This conversion function is obtained by performing a calibration procedure on the portable pupillometer. According to one embodiment of the invention, the value in millimeters for each pixel is obtained by detecting the diameter of the individual's iris. Since the size of the iris is constant for a given individual, it can serve as a reference for comparing measurements. The contours of the iris are detected using several image processing steps before being used to reconstruct the circle corresponding to the iris. - For each eye, a pupil detection algorithm determines the width, height, and center of the ellipse corresponding to the pupil for each image and records it as a time series, - A signal processing algorithm cleans the time series, removing outliers, replacing them by interpolation, and applying smoothing using a time-varying moving average window. - A time series analysis algorithm determines several parameters of the pupil response of each eye to the stimulus created by at least one first visible light source - recording pupil data in a database by associating it with the user detected by the user identification device. According to one embodiment of the invention, the data consists of the pupil time series and the parameters deduced from it.

[0025] Preferably, the user identification step, when the user identification device is a fingerprint sensor, consists first of detecting the user's fingerprint, then comparing it with the fingerprints already stored in the internal memory, and finally, if the fingerprint is known, initiating the measurement sequence. According to one embodiment of the invention, if the fingerprint is not known by the fingerprint sensor, it is recorded and associated with a new user according to a new user registration procedure.

[0026] The pre-processing step of the measurement consists of determining whether the user had the device on their face during the measurement and whether they blinked. Preferably, the pre-processing step verifies whether the user blinked during a critical period of the measurement. According to one embodiment of the invention, the critical period of the measurement is between t=3s and t=8s, and preferably between t=3.5 and t=7s. The pre-processing step consists of the following steps: - detection via an algorithm of the position of the two eyes on the video. According to one embodiment of the invention, the verification is carried out only on the first 50 images of the video, preferably on the first 30 images of the video. According to one embodiment of the invention, each image of the video is separated into 2 parts along a vertical axis located in the middle of the image, and the algorithm for detecting the position of the two eyes is then applied to each part independently. - Pupil detection via a second algorithm for each frame of the video. Each frame in which no pupil is found increments one or more counters which, when they reach a certain threshold, trigger the return of an error to the output of the pre-processing stage. In one embodiment, a first counter checks the number of consecutive frames without pupil detection. In another embodiment, a second counter checks the number of frames without pupil detection across the entire video. In another embodiment, a third counter checks the number of frames without pupil detection over a critical period. The critical measurement period is between t=3s and t=8s, and preferably between t=3.5 and t=7s.According to one embodiment of the invention, each image of the video is separated into 2 parts along a vertical axis located in the middle of the image, and the pupil detection algorithm is then applied to each part independently.

[0027] According to one embodiment of the invention, the calibration procedure is carried out as follows: - a calibration tool is placed at a known distance from the opening facing the camera at a possible position of a user's eye. - at least one first infrared light source and at least one second infrared light source are switched on - A video acquisition is performed using the infrared camera; during the video acquisition, the calibration tool is placed at at least 3 different distances from the camera along the length of the portable pupillometer - A step to determine a conversion factor to convert measurements from pixels to millimeters using the calibration tool. This step involves using an algorithm to detect reflections from at least one and at least one second infrared light source on the measuring tool. The difference between at least two reflections is then determined in pixels. The size of the tool, or a portion of the calibration tool whose size in millimeters is known, is then measured. This allows for the creation of a conversion table to associate the pixel value of the difference between the reflections with a value in millimeters. According to one embodiment of the invention, the calibration tool includes an eye template whose position relative to the camera can be adjusted along the x, y, and z axes. According to another embodiment of the invention, the calibration tool includes a conversion portion at the center of the eye template whose size is known; this portion is used during the step of determining a conversion factor.

[0028] A method for determining the fatigue state of a user, characterized in that it comprises the following steps: - a step of measuring the dynamic pupillometry characteristics of a user according to the dynamic pupillometry characteristic measurement procedure described previously - A step in which the user enters information about their personal condition and training. This personal condition information includes: sleep duration and quality, stress level, muscle soreness level, perceived recovery level, travel time, illness, and alcohol consumption. Training information includes: duration, type of activity, GPS data, heart rate or power sensor data, and the athlete's perceived exertion level during the activity. According to one embodiment of the invention, the training information is retrieved via one or more API requests to one or more physical activity tracking applications or can be entered directly by the user using a web interface that saves it in a database. - a step of determining a user's fatigue score using pupillary response parameters and user-provided information as input variables in a machine learning model. According to one embodiment of the invention, the time series of pupil area is used directly as input to a machine learning model, and preferably in combination with user-related information. - a step where the user can visualize their fatigue score using a web interface

[0029] The charging station's second connection means are spring-loaded electrical contact pins, thus eliminating the need for any action by the user to recharge the portable pupillometer when it is on its base. The walls are sufficiently fitted to guide the positioning of the portable pupillometer on the base and ensure proper connection between at least one second connection means of the charging station and at least one receiving means of the portable pupillometer.

[0030] The charging station includes an energy storage device so as to increase the autonomy of the portable pupillometer when moving without immediate proximity to an electricity network without impacting the weight and use of the device with an excessively large internal energy storage system in the portable pupillometer. Brief description of the drawings

[0031] [Fig-1] Front view of the portable pupillometer according to the invention

[0032] [Fig.2] Top view of the portable pupillometer according to the invention

[0033] [Fig.3] Rear view of the portable pupillometer according to the invention

[0034] [Fig.4] Cross-sectional view of the charging station

[0035] [Fig. 5] Top view of the rear of the portable pupillometer

[0036] [Fig. 6] Step diagram of the measurement sequence

[0037] [Fig.7] Step diagram for carrying out a measurement

[0038] [Fig.8] Step diagram for determining user fatigue Detailed description

[0039] Figure 1 is a three-quarter view of the portable pupillometer. The pupillometer consists of an opaque housing (2) with an opening at the front and a removable face opposite the opening. The opacity of the housing (2) isolates the interior of the housing from external light. The housing (2) is obtained by additive manufacturing of a thermoplastic polymer material, resulting in a lightweight, low-cost, and rapidly produced housing (2).

[0040] A mask body (7) is attached to the opening of the housing (2). It is also opaque to maintain a controlled measurement environment in the area between the housing opening (2) and the user's face during a measurement. To ensure complete light isolation between the mask body (7) and the user's face, it has two concave portions that conform to the user's facial contours, one at the top of the face and the other in the central part where the user's nose is located. To improve light isolation during measurement and user comfort, a deformable foam (8) is placed on the outer surface of the housing opening. When the user rests their face on the foam (8), it deforms and conforms to the user's facial features.Like the casing (1), the mask body (7) is made using additive manufacturing from a thermoplastic polymer material.

[0041] A panel (6) is arranged in the width of the case and separates a front portion from a rear portion, the panel (6) allows to isolate a measurement area, from an area where several components of the portable pupillometer (1) are located.

[0042] The panel (6) has an opening opposite which is located an infrared camera (5). The opening is the same size and shape as the camera to ensure light isolation between the front and rear parts of the housing (2). The opening can be positioned opposite the user's eye when taking a measurement, in cases where only one camera (5) is present and the measurement of pupil variations in only one eye is desired. If both eyes are to be measured using two cameras, the panel (6) has two openings, each containing a camera (5), and each opening is positioned opposite one of the user's eyes. Measuring both eyes provides additional information about the user's condition based on the difference between the reactions of each pupil to the light stimulus.

[0043] If the camera (5) is equipped with a wide-angle lens, it is possible to measure both eyes using a single camera (5). The aperture is then located in the center of the panel (6). To improve the quality of the infrared acquisition of the camera (5), it is equipped with a high-pass filter that only allows wavelengths above 850 nm to pass through. Thus, the video acquisition of the eye does not include reflections from light sources emitting in the visible range.

[0044] The panel (6) is a printed circuit board on which several light sources are fixed.

[0045] Several first visible light sources (9) are fixed to the panel (6) on one face facing the opening of the housing (2). They are arranged so as to be distributed over the surface of the panel (6) to ensure complete and homogeneous illumination of the area between the panel (6) and the user's face. These first visible light sources (9) are white LEDs and are used to produce a controlled light stimulus on the user's pupil. The first visible light sources (9) can also be arranged as an LED strip on the upper part of the face facing the opening of the panel (6), and a light diffuser can be placed over the first visible light sources (9).

[0046] Several first infrared light sources (10) are also fixed to the panel (6) on the face opposite the opening of the housing (2). The first infrared light sources are distributed on the panel (6) so as to allow uniform infrared illumination of the area between the panel (6) and the user's face when taking a measurement. The first infrared light sources (10) are LEDs emitting at a center wavelength of 850 nm. Thus, although these LEDs emit the majority of their signal in the infrared range, they also emit a portion in the visible range, which helps to ensure of their proper functioning to the naked eye and to simplify the maintenance of the portable pupillometer.

[0047] A second visible light source (14) is fixed to the panel (6) on the side facing the opening of the housing (2). This second visible light source (14) is used as a visual reference to fix the user's gaze during the measurement and to ensure that the pupil is clearly visible and directed towards the camera (5). The second visible light source (14) is positioned near the opening of the panel (6). The second visible light source (14) is an RGB LED, thus allowing it to emit several colors in a controllable manner to transmit information to the user during the measurement.

[0048] A mounting bracket (27) is fixed to the panel (6) on one face opposite the opening of the housing (2). The mounting bracket (27) extends in the direction of the opening of the housing (2) and has at its end a support on which a second infrared light source (28) is fixed. This mounting bracket (28) is positioned on a lateral portion of the panel (6) on the side where the opening of the panel (6) is located. This positioning and its extension towards the user allow the user's eye to be illuminated from the side, thus providing better contrast between the different parts of the eye and improving the acquisition of the measurement data. If it is desired to measure the reaction of both eyes, the portable pupillometer (1) has two mounting brackets (28), each positioned on one side of the panel (6) to allow for better contrast on each eye.

[0049] Figure 2 is a top view of the portable pupillometer (1). A control device (21) is positioned on the upper face of the housing (2). It consists of a control body (22) to which four deformable fins (23) are connected at the center of the control body. The control device is produced by additive manufacturing of a thermoplastic polymer material. A push button is located under each deformable fin (23). When the user presses a deformable fin (23), its deformation activates the push button located below it. Each deformable fin (23)-push button pair activates a function of the portable pupillometer (1). To differentiate each button, they are identified by color markings. A charge level indicator (30) surrounds the control device (21) on the upper face of the housing (2). This indicator of a charge level (30) is a luminous ring.The luminous ring emits in the visible spectrum and emits light of a different colour depending on the state or mode in which the device is located. The different pairs are associated respectively with the following functionalities:

[0050] - to turn the portable pupillometer (1) on / off; switching is done via a brief press whereas a sustained press of 4 seconds is required to turn off the Portable pupillometer (1). This prevents the portable pupillometer (1) from being inadvertently switched off by a user. When the portable pupillometer is switched on but not in a specific mode or taking a measurement, the light ring indicates the power supply unit's charge level. The light is blue when the portable pupillometer is switched on but not charging, and green when the portable pupillometer is switched on and charging on the charging station. When the charge level is below 5%, a red light is emitted to warn the user that the charge level is low.

[0051] - Entering / exiting a standby mode, this mode allows the device to limit its Energy consumption is reduced by switching off several components: the second visible light source (14) and the user identification device (11). The programmable processing unit (13) also limits its consumption by stopping most of its ongoing processes. When the device is in standby mode, the light ring (30) is switched off to reduce the energy consumption of the portable pupillometer (1).

[0052] - enter a “user registration” mode, this mode allows registration The user's fingerprint is captured on the user identification device (11), and the identifier associated with that fingerprint is sent to the server for that portable pupillometer (1). This method allows a user's fingerprint to be associated with each portable pupillometer (1) with a different identifier on each one, while ensuring that the data is correctly associated with the same user on the server. In this mode, the light ring emits an intermittent yellow light to indicate to the user that they are in this mode.

[0053] - enter a “connection” mode, this mode allows the portable pupillometer (1) to add a Wi-Fi network to connect to. Adding can be done using the infrared camera (5), which captures a QR code for the connection, or by requesting the network's parameters from the server. This mode also allows the user to check the server for available updates for the portable pupillometer (1) and, if so, install them. In this mode, the light ring emits an intermittent purple light to indicate to the user that they are in this mode.

[0054] The upper face of the housing (2) has a dome (19) at the location of the user identification device (11). This dome (19) serves to guide the user in positioning their finger on the user identification device (11) and also to isolate it from external light in order to improve fingerprint detection. To assist the user in positioning their finger, the housing (2) also has grooves external (20) on the outer face of the latter opposite the opening of the dome (19) and towards a lateral face of the housing (2).

[0055] Figure 3 is a rear view of the portable pupillometer (1). Several openings are located on the removable face of the housing (2) to allow the passage of the second connection means (36) of the charging station (31) in order to connect to the receiving means of the portable pupillometer (1). The removable face is fixed by means of screws and an insert located in the housing (2).

[0056] Figure 4 is a cross-sectional view of the charging station (31). It consists of a base (33) which serves as the structure for the charging station (31), and a first connection means (32) for connecting the charging station (31) to an external power source. An energy storage device (34) and its support (35) are positioned in a lower part of the base (33). The energy storage device (34) is a battery and increases the operating time of the dynamic pupillometry measurement system when used away from a power source, without increasing the weight of the portable pupillometer (1). The upper part of the base has a cavity (38) adapted to receive the portable pupillometer (1) with its removable face facing the bottom of the cavity (38).Secondary connection means (36) are located in the bottom of the cavity (38) opposite the openings in the removable front of the housing (2). These are spring-loaded electrical contact pins which then make contact with receiving means (37) of the portable pupillometer (1). Thus, the connection between the charging station (31) and the portable pupillometer (1) is immediate and requires no action from the user once the portable pupillometer (1) is positioned on the charging station (31).

[0057] Figure 5 is a top view of the rear of the portable pupillometer (1) when the removable front panel of the housing (2) is removed and the sliding plate is partially extended. A sliding plate (4) is inserted into two internal grooves (3) of the housing (2). This plate (4) has a bracket (24) for mounting the infrared camera (5), a bracket for the user identification device (17), and also serves as a mounting point for the panel (4) on its front portion and for a printed circuit board (15) on its rear portion. The programmable processing unit (13) and the power supply unit (12) are also mounted on this plate (4). Mounting all these components on the plate (4) facilitates the assembly and maintenance of the portable pupillometer (1).The user identification device support (17) includes pressure means (18) to allow vertical movement of the user identification device (11) and bring it into a so-called disassembly position where it is possible to remove the plate (4) from the housing (2). Connection elements consisting of cables and connectors ensure connections between the programmable processing unit (13) and the infrared camera (5), the power supply unit (12). the user identification device (11), and the visible (9,14) and infrared (10,28) light sources.

[0058] Figure 6 is a step diagram of the measurement procedure performed by a user. The first step is to place the portable pupillometer (1) on the user. To do this, the user must bring their face against the foam (8) of the mask body (7) with their eyes positioned facing the opening of the housing (2). They must then bring a finger, the fingerprint of which has been previously registered on the user identification device (11), into contact with it.

[0059] The user identification step is triggered as soon as a finger is detected by the user identification device (11). The device then compares the detected fingerprint with known fingerprints, and if it is recognized, it initiates the next step. The user identification device (11) also transmits the fingerprint identifier to the programmable processing unit (13), which records it for transmission to the server along with the video acquisition data.

[0060] The “measurement sequence” step is broken down into several phases:

[0061] Following recognition of the user's fingerprint, the first and second infrared light sources (10, 28) illuminate and remain illuminated throughout the video acquisition. The second visible light source (14) illuminates at a minimum intensity so as not to influence the measurement and remains illuminated throughout the video acquisition, as it serves as a reference point for the user to fixate on. The infrared camera (5) begins recording video from the start of this phase. The purpose of this phase is to allow the user's pupil time to stabilize in response to the measurement environment.

[0062] The second phase corresponds to the delivery of a visual stimulus to the user's pupil. For this, the first visible light sources (9) illuminate after a predetermined delay. The duration for which the first visible light sources (9) remain illuminated is predetermined but must be greater than the pupil's reaction time and short enough to ensure that the pupil's reaction to the stimulus remains reflexive and is not disrupted by any action from the user. A duration between 0.4 s and 1.4 s is optimal for this phase. The first visible light sources (9) turn off at the end of this phase.

[0063] Next, a phase is observed in which the light sources (10, 28, and 14) are illuminated in the same manner as in the first phase. The purpose of this phase is to observe the return of the pupil to a stable state following the cessation of the light stimulus. The end of this phase marks the end of video recording.

[0064] The next phase of the measurement sequence is a pre-processing carried out by the programmable processing unit (13) and aims to verify the conformity of the video acquisition; for this purpose, detection of the presence of an eye and a pupil is performed and Non-presence thresholds allow the video acquisition to be characterized as either valid or invalid. The detection of the presence of an eye in the video is performed on the first few seconds using a recognition algorithm. When measuring both eyes, each eye is independently detected. Pupil detection is then performed on each video frame, and each frame where the pupil is not detected increments several counters based on the point in the measurement during which the pupil is not detected. The critical measurement phase, where minimal non-detection is required to ensure usable results, extends from the few frames before the start of the light stimulus until 3 seconds after the visual stimulus stops. The counter associated with this video acquisition period has a low non-conformity threshold, while the counters corresponding to the times before and after this critical period have higher thresholds.

[0065] When the video is deemed compliant following the pre-processing phase, it is transferred to the server by the programmable processing unit (13) via a Wi-Fi connection but can also be done via a wired connection with a computer.

[0066] Once the video is on the server, this triggers the start of the video analysis phase.

[0067] The steps of the analysis phase are detailed in the step diagram in [Fig. 7]. An eye detection algorithm is first applied to reduce each image to a region of interest corresponding to the eye's location. This algorithm is applied only to the first few seconds of the video since the user does not move during the measurement. This step is performed independently on each eye if a measurement of both eyes is taken, and two regions of interest are then defined.

[0068] A pixel / mm conversion step then takes place, its purpose being to obtain a conversion factor to go from 1 pixel to a metric value. Since the same user does not always position their face identically on the mask body (7), it is necessary to be able to convert pupil values ​​and areas from pixels to a metric value in order to compare several measurements. To this end, a reflection detection algorithm linked to the illumination of a first infrared light source and a second infrared light source is applied. The difference between the reflections is determined in pixels and serves as input to the application of a conversion function whose transformation coefficients are obtained by calibrating the portable pupillometer beforehand. This conversion function returns as output the conversion factor to go from pixel to millimeter.This conversion step can also be performed by detecting the diameter of the individual's iris. Since the size of the iris is constant for a given individual, it can serve as a reference. to compare the measurements. The contours of the iris are detected using several image processing techniques before being used to reconstruct the circle corresponding to the iris.

[0069] The next step is pupil detection as part of a measurement of both eyes. An algorithm is used to detect, for each eye, the area and the various parameters of the ellipse (height, width, center) corresponding to the pupil in each image of the video. This information is recorded as a time series.

[0070] A signal processing step is performed on these time series to enable their future use. Anomalous values ​​are detected and replaced by interpolation; the same processing is applied to missing values ​​due to pupil non-detection to reconstruct a complete time series. Finally, smoothing using a moving average with a time window that varies over time is applied to reduce the impact of small variations related to the accuracy of the detection algorithm.

[0071] The next step is a time series analysis to determine several parameters of the pupil's response to a light stimulus. The parameters concern the maximum and minimum area values ​​at different times during the measurement, the velocities associated with the changes in pupil area, and the times between the different phases of the pupil's reaction.

[0072] Finally, the data are recorded in one or more tables of a database and are associated with the user profile corresponding to the identifier detected by the user identification device (11). The recorded data include the processed time series and the parameters deduced from them.

[0073] Figure 8 is a step diagram of the process for determining a user's fatigue level. Two parallel steps are used to retrieve the data necessary for this process: a step measuring the characteristics of dynamic pupillometry according to the measurement method described above, and a step where the user enters information about themselves. This information concerns their personal condition and includes: sleep duration and quality, stress level, muscle soreness level, perceived recovery level, journeys completed, illness, alcohol consumption, heart rate variability measurement, and also their training: duration and type of activity, speed, pace, perceived exertion level, data from power meters, and heart rate. The user enters the data concerning their condition using a web interface.Training data is obtained via API requests to one or more physical activity tracking applications. A user's fatigue level is determined through a combination of the information provided. The combined data from user input and measurements of dynamic pupillometry characteristics are used as input variables in a Leaming machine model. According to another embodiment of the invention, the time series of pupil area is used directly as input to a Leaming machine model. The user's web interface for entering data about their condition is also used to allow them to view their fatigue score at any time.

Claims

1. Demands Portable pupil meter (1) characterized in that it comprises: - an opaque housing (2) having an opening at the front and a removable face opposite the opening. The housing has two internal grooves (3) running lengthwise and a sliding plate (4) disposed in these internal grooves (3). The internal grooves (3) extend from the removable face for at least 50% of the length of the housing (2). - an infrared camera (5) oriented towards the opening of the housing and fixed to the sliding plate (4) - a panel (6) fixed to the front of the plate (4) and extending across the width of the housing (2), the panel (6) completely separating a front portion of the housing (2) from a rear portion. The panel (6) has an opening the size of the infrared camera (5) to allow the infrared camera (5) to film in the direction of the opening. - an opaque mask body (7) fixed to the opening of the housing (2), the mask body (7) has two concave portions and a foam (8) on the face facing outwards from the portable pupillometer (1). - at least one first visible light source (9) fixed to the panel (6) on one face facing the opening - at least one first infrared light source (10) fixed to the panel (6) on one face facing the opening - a user identification device (11) attached to the sliding plate (4) - a power supply unit (12) fixed on the sliding plate (4), the power supply unit is a battery. - a programmable processing unit (13) connected to the infrared camera (5), the power supply unit (12), the user identification device (11), at least one first infrared light source (10) and at least one first visible light source (9). - a second visible light source (14) is fixed to the panel (6), at a distance of less than 2 cm from the opening For the camera (5), on the side facing the opening. The second visible light source (14) is connected to the programmable processing unit (13). A printed circuit board (15) is fixed to the rear face of the sliding plate (4) opposite the removable face of the housing (2). The printed circuit board (15) includes at least one receiving means (37) for connecting to an external power source for the portable pupillometer (1) and is connected to the programmable processing unit (13) as well as to the power supply unit (12) of the portable pupillometer (1). The removable face of the housing (2) has at least one opening opposite at least one receiving means (37).

2. According to claim 1, the portable pupil meter (1) has a user identification device (11) that is a fingerprint sensor comprising internal memory and is attached via a user identification device holder (17) to the sliding plate (4). An upper face of the housing (2) has an opening opposite the user identification device (11) to allow the user to place a finger on it. The user identification device holder (17) has pressure means (18) for bringing the user identification device (11) into contact with the opening in the housing (2). The upper face of the housing (2) has a dome (19) above the opening to isolate the user identification device (11) from external light.The opening is located on a lateral portion of the upper face of the housing (2), in an area between the edge and one-third of the width of the upper face of the housing (2). The upper face of the housing (2) has, extending from the opening towards the adjacent lateral face, at least one external groove (20) designed to guide the user in positioning their finger on the user identification device (11). The external grooves (20) continue onto the lateral face adjacent to the side of the opening.

3. Portable pupillometer (1) according to claim 2, the housing (2) having an opening in the center of its upper face. A The control device (21) is positioned in this opening. The control device (21) comprises: - a circular control body (22) disposed on the outer face of the control device (21) divided into 4 deformable fins (23) connected to each other at the center of the control body (22), - a threaded rod extending under the control body (22) through the opening in the housing (2) and towards the inside of the housing (2), - a nut disposed on the inner part of the upper face of the housing (2), - at least one push button positioned under at least one deformable fin (23).

4. Portable pupil meter (1) according to any one of claims 1 to 3, in which at least one mounting tab (27) is fixed to the panel (6) on the face facing the aperture. The mounting tab (27) extends in the direction of the aperture into the area of ​​the mask body (7). The mounting tab (27) has at its end a support on which at least one second infrared light source (28) is fixed. This at least one second infrared light source (28) is connected to the programmable processing unit (13).

5. A portable pupil meter (1) according to any one of claims 1 to 4, comprising at least 3 first visible light sources (9) arranged uniformly in an upper portion of the panel (6). A light diffuser (29) is fixed over the at least 3 first visible light sources (9) to allow homogeneous illumination of the aperture when the at least 3 first light sources are switched on (9).

6. Dynamic pupillometry measurement assembly characterized in that it comprises: - a portable pupillometer (1) according to any one of claims 1 to 3 or according to claim 5, characterized in that it also comprises the features of claim 4, including a charge level indicator (30) for the battery (12) - a charging station (31)

7. The charging station (31) includes: - a first means of connection (32) to an electrical supply network - a base (33) - an energy storage device (34) - a support for the energy storage device (35) located in a lower part of the base (33) - an upper part of the base has a cavity (38) suitable for receiving the portable pupillometer (1) oriented with its removable face towards the bottom of the cavity. - at least one second connection means (36) to at least one receiving means (37) of the portable pupillometer (1), the at least one second connection means (36) are placed in the bottom of the cavity (38) towards the outside of the base (33) and are located opposite the at least one receiving means (37) of the portable pupillometer (1) when the latter is placed on the base (33). Method for measuring the dynamic pupillometry characteristics of a user using a dynamic pupillometry measurement set according to claim 6, characterized in that it comprises the following steps: - a step of placing the portable pupillometer (1) by the user on their face, resting it against the side of the mask body (7) after removing it from the charging station (31) - a user identification step, carried out by the user identification device (11), and the launch of a measure - a measurement sequence step during which a video is recorded using the infrared camera (5) and which takes place as follows: - a phase where only the second visible light source (14) is switched on at a minimum intensity and at least one first infrared light source (10) and at least one second infrared light source (28) are switched on. The beginning of this phase corresponds to the start of video recording. a phase or at least a first visible light source (9) is switched on at a high intensity and at least a first infrared light source (10) and at least a second infrared light source are switched on (28). a phase where only the second visible light source (14) is switched on at minimum intensity and at least one first infrared light source and at least one second infrared light source are switched on. The end of this phase marks the end of the video recording. a pre-treatment phase an information phase on the measurement process for the user via the second visible light source (14) A step involving transferring the video to a server, followed by a step involving analyzing the video, determining and recording the parameters of a pupil's response in a database. This step is broken down as follows: - a step to detect the position of both eyes - a step to convert the size of a pixel to mm - a step to detect the pupil and determine its size, then record this area as a time series - a signal processing step to clean the time series - a step to analyze the time series and determine several parameters of the pupil response - a step to save the pupil data to a database

8. A method for measuring the dynamic pupillometry characteristics of a user according to claim 7, the preprocessing step of the measurement consisting of determining whether the user had the portable pupillometer (1) on their face during the measurement and whether they blinked. The preprocessing step consists of the following steps: - detection via an algorithm of the position of the two eyes - attempt to detect via a second algorithm of the pupil for each image of the video, each image or no pupil is found increments one or more counters which trigger when they reach a certain threshold the return of an error to the output of the preprocessing step.

9. Method for measuring the dynamic pupillometry characteristics of a user according to claim 7 or 8, the calibration procedure is carried out as follows: - a calibration tool is placed at a known distance from the opening facing the camera at a possible position of a user's eye. - at least one first infrared light source (10) and at least one second infrared light source (28) are switched on - a video acquisition of the calibration tool (40) is carried out using the infrared camera (5), the calibration tool is placed at at least 3 different distances from the camera (5) along the length of the portable pupillometer (1) - a step to determine a conversion factor to convert from a measurement in pixels to a measurement in millimeters using the calibration tool (40). This step involves using an algorithm to detect reflections from at least one first infrared light source (10) and at least one second infrared light source (28) on the measuring tool. The difference between at least two reflections is then determined in pixels, and the size of a portion of the calibration tool whose size in mm is known is then measured. This allows for the creation of a conversion table to associate the pixel value of the difference between the reflections with a value in mm.

10. A method for determining the fatigue state of a user, characterized in that it comprises the following steps: a step of measuring the dynamic pupillometry characteristics of a user according to the method of any one of claims 7 to 9 A step where the user enters information about their personal condition and training. This personal information includes: sleep duration and quality, stress level, muscle soreness level, perceived recovery level, travel time, illness, and alcohol consumption. Training information includes: duration, type of activity, GPS data, heart rate or power sensor data, and the athlete's perceived exertion level during the activity. a step to determine a user's fatigue score using pupillary response parameters and user-provided information as input variables in a machine learning model a step where the user can visualize their fatigue score using a web interface

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