A disc designed to improve the transmission of acoustic waves.

Abstract

The invention relates to a pellet (200) for improving the transmission of acoustic waves between a device for locating a blood vessel in a limb of a living being and said limb, the pellet being configured to be placed between the locating device and a skin surface covering the blood vessel of said limb, the device comprising means for determining the location of the blood vessel based on the emission of acoustic waves, characterized in that it comprises a support layer (201) coated with at least one adhesion layer (202, 203) intended to be in contact with the skin surface or with a surface of the locating device, and in that the support layer (201) is made of polyurethane. Figure for the abstract: Fig. 2

Description

Description Title of the invention: Pastille intended to improve transmission acoustic waves Technical field of the invention

[0001] — The present invention relates generally to techniques for lo- calization of blood vessels, and in particular the corresponding devices. Technical background

[0002] = Blood gas analysis (or blood gas analysis) is called "blood gas". When From such an analysis, the practitioner measures the acidity of the blood and the quantities of oxygen and of carbon dioxide in the blood. Blood is preferably taken from a artery.

[0003] … The examination allows pulmonary exchanges to be assessed and changes to be detected concentrations of oxygen and carbon dioxide in arterial blood and especially in the blood which flows to the tissues. Indeed, for example, when the blood passes through the lungs, it becomes richer in oxygen and poorer in dioxide carbon.

[0004] = Blood gas analysis also allows the acid-base balance of a patient to be assessed. patient.

[0005] — During the examination, a blood sample is taken from an artery. In general This is the radial (wrist), humeral (arm) or femoral (groin) artery. Once the Once the sample has been taken, a gauze or cotton compress must be placed and compressed the puncture site firmly for a few minutes.

[0006] Therefore, it would be advantageous to accurately determine the location of the artery by non-invasive means before taking blood, and provide the practitioner a visual indication of the location of the artery to facilitate blood sampling.

[0007] — In particular, it would be interesting to display the location of the artery on a sufficient length to allow the practitioner to determine the orientation of the artery, so that the needle or stylet can be positioned to cut the artery along its axis. It is generally desirable to cross the artery at an angle between approximately 30 degrees and 45 degrees. When the artery is properly located, the The practitioner can then align the needle at an appropriate angle for insertion into the Blood vessel.

[0008] — Systems of the prior art, for example systems for locating a vessel blood, have been described.

[0009] — For example, US patent application NO. US2018325448A1 discloses a artery locating device that includes a sensor network configured to be attached to a skin surface covering a target artery. The sensor array is an array of detectors, for example pressure detectors configured to generate signals responsive to pressure or a change in pressure. A display device is disposed on the sensor array. A controller circuit is configured to receive signals generated by the sensor array, to identify from the received signals periodic pressure pulses that have a frequency in a predetermined frequency range corresponding to a pulsatile frequency and that define an elongated path through at least a portion of the sensor array, and to display on the display device an image that overlays the elongated path through the sensor array, such that the display shows a projection of the two-dimensional position of the artery below the display. However, such a location device based on a sensor network does not have sufficient sensitivity to detect arteries under all conditions of use of the device. In addition, slight movements of the location device relative to the limb on which it is placed lead to a reduction in the accuracy of the location measurement. Furthermore, with such a conventional device, the patient's "capillarity", that is to say, the curvature of the skin and its surface condition (for example, cracking of the skin related to the patient's age) prevents good conductivity of the waves. Summary of the invention Based on this problem, the present invention therefore aims to improve the sensitivity of the measurement of the location of a blood vessel. The invention, according to some of its embodiments, also aims to provide such a measurement whose accuracy is improved. The invention, according to some of its embodiments, also aims to provide such a measurement which is easy and quick to implement. According to one embodiment, the invention relates in particular to a patch intended to improve the transmission of acoustic waves between a device for locating a blood vessel of a limb of a living being and said limb, the patch being configured to be arranged between the locating device and a skin surface covering the blood vessel of said limb, the device comprising means for determining the location of the blood vessel based on the emission of acoustic waves. According to one embodiment of the invention, the patch comprises a support layer coated with at least one adhesion layer intended to be in contact with the skin surface or with a surface of the locating device and in that the support layer is made of a material that conducts acoustic waves. According to one embodiment of the invention, the support layer is made of polyurethane. According to one embodiment of the invention, the support layer is made of a material having a rigidity of between 85 Shores À and 95 Shores À measured according to the ASTM D2240 test method. Thus, the pellet makes it possible to preserve the transmission of acoustic waves between a device for locating a blood vessel in a limb of a living being. The locating device can be used to locate any type of blood vessel such as veins, capillaries or arteries. It can be advantageously used on humans but can also be used on animals (veterinary applications). Preferably, the location device according to the invention is used to locate an artery as part of an arterial blood test. According to one embodiment of the invention, the patch comprises, on one of its faces, an adhesion layer intended to be in contact with the skin surface. According to one embodiment of the invention, the adhesion layer is a layer that conducts acoustic waves. According to one embodiment of the invention, the adhesion layer is made of silicone. According to one embodiment of the invention, the patch comprises, on one of its faces, a silicone adhesion layer intended to be in contact with the skin surface. According to one embodiment of the invention, the pellet comprises, on one of its faces, an acrylic adhesion layer intended to be in contact with the surface of the location device. According to one embodiment of the invention, the patch comprises on one of its faces, a silicone adhesion layer intended to be in contact with the skin surface and on the other of its faces, an acrylic adhesion layer intended to be in contact with the surface of the location device. According to one embodiment of the invention, one of the adhesion layer(s) has an adhesive outer surface and a protective coating is provided on the adhesive outer surface. According to one embodiment of the invention, each of the adhesion layers has an adhesive outer surface and a protective coating is provided on said adhesive outer surface. The invention according to at least one of its embodiments also relates to a use of a pellet according to the invention as previously described. According to one embodiment of the invention, the use is a use for improving (or preserving) the transmission of acoustic waves between a device for locating a blood vessel of a limb of a living being and said limb, the pellet being arranged between the locating device and a skin surface covering the blood vessel of said limb, the device comprising means for determining the location of the blood vessel based on the emission of acoustic waves. According to one embodiment of the use according to the invention, the location device comprises a main body, the main body comprising a first finger in contact with a first portion of skin of the limb and a second finger in contact with a second portion of skin of the limb and said pad is arranged at least between one of the first and second fingers and the limb. According to one embodiment of the use according to the invention, the pad is arranged between each of the first and second fingers and the limb. According to one embodiment of the use according to the invention, a first pad according to the invention is arranged between the first finger and the limb and a second pad according to the invention is arranged between the second finger and the limb. According to one embodiment of the use according to the invention, the location device comprises at least one acoustic wave transmitter configured to emit acoustic waves - hereinafter emitted acoustic waves - into the limb through the skin surface, at least one acoustic wave receiver configured to receive the acoustic waves reflected by the limb - hereinafter reflected acoustic waves, a module for measuring a parameter of the reflected acoustic waves or a difference in value of a parameter between the reflected acoustic waves and the emitted acoustic waves and a module for obtaining the location of the blood vessel as a function of said parameter or of said difference in value of said parameter. The invention according to at least one of its embodiments also relates to a method of applying a pellet according to the invention as previously described. According to one embodiment of the invention, the method comprises the following steps: - removal of a first part of the protective coating from the adhesive outer surface of the acrylic adhesion layer; - installation of the part of the pad, acrylic adhesion layer side, corresponding to the part removed from the protective coating on the surface of the location device; - removal of the remaining protective coating from the adhesive outer surface of the acrylic adhesion layer; - placing the rest of the pad, acrylic adhesion layer side, on the surface of the location device; - applying pressure to smooth the pad placed on the surface of the locating device; - removal of the protective coating from the adhesive outer surface of the silicone adhesion layer; - place the location device on the skin surface, pellet side. The invention also relates, according to at least one of its embodiments: Preferably, the blood vessel is an artery, the living being a human being, and the limb a wrist. Of course, the limb can also be a forearm. Brief description of the figures Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the appended drawings in which: [Fig.1] schematically shows a locating device and a pad positioned on the wrist of a patient according to one embodiment of the invention; [Fig.2] shows schematically the pellet of [Fig.1]; [Fig.3] schematically shows a top view of the locating device of [Fig.1]. Detailed description of the invention Described below are various aspects of various embodiments of a patch intended to improve the transmission of acoustic waves between a device for locating a blood vessel of a limb of a living being and the limb, the patch being configured to be disposed between the locating device and a skin surface covering the blood vessel of said limb. For example, according to one embodiment of the invention, the localization device is for example used to detect and locate the radial artery in the wrist of a human patient. Of course, according to other embodiments, any other locating device according to the invention can be used to locate any blood vessel such as capillaries or veins or arteries for any living being such as a human being or an animal. Likewise, they can be used for such detection in any limb such as for example the wrist, the arm, the groin, and the leg or the paw. In the present embodiment of the invention, the locating device is used by a caregiver or practitioner as part of an arterial blood test to perform a blood gas analysis of the patient. Thus, in the present example, the target artery is the radial artery of the patient's wrist. [Fig. 1] schematically shows a locating device 10 and at least one patch 200 positioned on the wrist of a patient according to one embodiment of the invention. As described below in relation to [Fig. 3], in the context of the present embodiment, the locating device 10 comprises a main body with two fingers, each of the fingers facing the skin. It is therefore desirable to implement two pads 200 according to the invention, each being arranged between a finger and the skin. In relation to [Fig. 2] a pad 200 is presented for improving the transmission of acoustic waves between the device 10 for locating a blood vessel (for example, in the context of the present embodiment, the radial artery) of a limb (for example, in the context of the present embodiment, the wrist) of a living being (for example, in the context of the present embodiment, the patient) and the limb which is the wrist of the patient. According to one embodiment, the pad is configured to be arranged between the locating device 10 and a skin surface covering the radial artery of the wrist, the locating device 10 comprising means 1 for determining the location of the radial artery based on the emission of acoustic waves.According to one embodiment of the invention, the patch comprises a support layer 201 coated with at least one adhesion layer 202, 203 intended to be in contact with the skin surface or with a surface of the location device and the support layer 201 is made of polyurethane. In fact, the use of polyurethane for the support layer has the following advantages: very good capacity for transmitting acoustic waves which allows to increase the sensitivity and efficiency of the location device; it is a biomaterial increasingly used for medical applications; It is less allergenic than latex. Preferably, such a pad 200 ensures contact between the locating device and the skin. For example, the pad has a length of 60mm and a width of 16mm (in another example, the pad has a length of 72mm and a width of 24mm). It can also have any other pair of dimensions suitable for the location device. Preferably, the pad 200 comprises, on one of its faces, a silicone adhesion layer 203 intended to be in contact with the skin surface. Indeed, the use of silicone has the following advantages: it allows good maintenance of contact between the skin and the polyurethane of the support layer; it is particularly useful as a skin contact surface; It adheres well to dermal surfaces but does not adhere significantly- ficative to the moist surfaces of wounds: it therefore causes less or no pain and / or irritation upon removal; it is biocompatible: ISO 10993 standard (sensitization and cyto- toxicity). For example, the pellet comprises, on one of its faces, an adhesion layer in acrylic 202 intended to be in contact with the surface of the locating device 10. Indeed, the use of acrylic has the following advantages: it allows the maintenance of contact between the polyurethane and the loca- device lization; it is a particularly high-performance adhesive; it offers very good adhesion to the material of the locating device. The material of the locating device is for example made of an assembly of polyurethane and acrylonitrile butadiene styrene. According to a variant of the present embodiment, the material of the locating device is for example made of an assembly of polyurethane and polycarbonate. According to a variant of the present embodiment, the material of the locating device is for example made of an assembly of polyurethane, polycarbonate and acrylonitrile butadiene styrene. For example, the patch 200 comprises on one of its faces, a silicone adhesion layer 203 intended to be in contact with the skin surface and on the other of its faces, an acrylic adhesion layer 202 intended to be in contact with the surface of the location device 10. Preferably, at least one of the adhesion layers 202, 203 has an adhesive outer surface and a protective coating 204, 205 is provided on the adhesive outer surface. For example, each of the adhesion layers 202, 203 has an adhesive outer surface and a protective coating 204, 205 is provided on the adhesive outer surface. The invention also relates to a use of a pellet 200 according to the invention to improve the transmission of acoustic waves between the artery locating device 10 and the wrist. The invention also relates to a method of applying the pellet 200, the method comprising the following steps: - removing a first portion of the protective coating 204 from the adhesive outer surface of the acrylic adhesion layer 202; - laying the part of the pellet 200, acrylic adhesion layer 202 side, corresponding to the part removed from the protective coating on the surface of the calization device 10; - removing the remainder of the protective coating 204 from the adhesive outer surface of the acrylic adhesion layer 202; - placing the remainder of the pad 200, acrylic adhesion layer 202 side, on the surface of the location device 10; - applying pressure to smooth the pad 200 placed on the surface of the locating device 10; - removal of the protective coating 205 from the adhesive outer surface of the silicone adhesion layer 203; - placing the location device 10 on the skin surface with the 200 pellet side. [Fig.3] schematically shows a top view of the locating device 10 of [Fig.1]. According to this embodiment of the invention, the location device 10 comprises a main body 41 comprising means for determining the location 1 of the blood vessel, the main body 41 being designed to be positioned so as to place the means for determining the location 1 opposite the skin surface covering the blood vessel of the limb. The location device 10 may also comprise means for securing the main body to the patient's wrist (for example, a second branch designed to hold the first branch 41 against the limb or any other means, for example an elastic strap or a leather strap which is secured to the main body 41 and which holds the main body against the wrist). For example, the location device 10 comprises means for supplying electricity to the means 1 for determining the location of the artery. For example, these power supply means are a rechargeable battery. For example, the battery is positioned in the first branch. Of course, the battery or more generally, any means for supplying electricity to the location device 10 or to the means 1 for determining the location of the location device 10 can be located in any part of the location device 10 or even outside the location device 10 and in this case the electrical energy can be brought to the location device 10 by any means such as an electric cable or wire or by induction or by any other means. For example, a portion of the main body 41 has a substantially arc-shaped shape so as to match the morphology of the limb. According to one embodiment of the present invention, the main body 41 comprises a first finger 411 in contact with a first portion of skin of the wrist and a second finger 412 in contact with a second portion of skin of the wrist. For example, the pad 200 is disposed at least between one of the first and second fingers and the wrist. According to one embodiment of the invention, the pad 200 is disposed between each of the first 411 and second 412 fingers and the wrist. According to one embodiment of the invention, a first pad according to the invention is disposed between the first finger 411 and the wrist and a second pad according to the invention is disposed between the second finger 412 and the wrist. According to one embodiment of the invention, the means 1 for determining the location of the artery comprise at least one acoustic wave transmitter configured to emit acoustic waves - hereinafter emitted acoustic waves - in the member through the skin surface, at least one acoustic wave receiver configured to receive the acoustic waves reflected by the member — hereinafter reflected acoustic waves, a module for measuring a parameter of the reflected acoustic waves or a difference in value of a parameter between the reflected acoustic waves and the emitted acoustic waves and a module for obtaining the location of the blood vessel as a function of said parameter or said difference in value of said parameter. Of course, the determination means 1 may implement any other blood vessel location technology. For example, they may implement optical waves emitted and received (for example, emitted by diodes, lasers or any other light sources and, received, by photodiodes or any other light detection devices). For example, they may implement detection by pressure measurement, by emission of radio frequency waves or any other technology. For example, they may only implement means for detecting optical, acoustic, radio frequency or pressure waves without means for emitting such waves or pressure. The determination means 1 are configured to be arranged substantially opposite a skin surface covering the wrist artery. According to one embodiment of the invention, the determination means 1 are configured to be arranged substantially in contact with a skin surface covering the wrist artery. However, according to variants of this embodiment of the invention, the determination means 1 may be provided to be arranged at a distance (for example a few millimeters or a few centimeters) from the skin surface. For example, the first finger 411 comprises at least one first acoustic wave transmitter and at least one first acoustic wave receiver and the second finger 412 comprises at least one second acoustic wave transmitter and at least one second acoustic wave receiver. For example, the determining means 1 comprise at least one acoustic wave transmitter configured to transmit acoustic waves (hereinafter emitted acoustic waves) into the limb through the skin surface, at least one acoustic wave receiver configured to receive the acoustic waves reflected by the wrist (hereinafter reflected acoustic waves). For example, the determining means 1 comprise a first matrix of acoustic wave transmitters and receivers located in the first finger 411 and a second matrix of acoustic wave transmitters and receivers located in the second finger 412. Of course, according to variants of the invention, the determination means 1 can comprise in the first finger 411, any number of transmitters and of acoustic wave receivers organized in a matrix or not and they can also comprise in the second finger 412, any number of acoustic wave transmitters and receivers organized in a matrix or not. For example, the determining means 1 have a substantially square or rectangular shape in top view. Preferably the distance between the first matrix in the first finger and the second matrix in the second finger is less than 2 cm and even more preferably less than 1.5 cm so that the artery can be considered as substantially rectilinear between the first matrix and the second matrix. According to one embodiment, each acoustic wave transmitter and receiver can be reconfigured respectively into a receiver and / or an acoustic wave transmitter. Of course, according to variants of this embodiment, only a portion of the transmitters and / or receivers (for example at least one of them) can be reconfigured. According to yet another variant, none of the receivers or transmitters is reconfigurable. For example, each of the acoustic wave transmitters and receivers comprises a piezoelectric element, for example a piezoelectric disc whose diameter is for example between 0.5 mm and 1 cm and more preferably still between 1 mm and 3 mm. For example, each of the piezoelectric discs has a diameter of | mm. Of course, the invention can be implemented with any other diameter value of the piezoelectric discs. Furthermore, any other form of piezoelectric element can be implemented within the scope of the invention. Furthermore, other types of transmitters and receivers than piezoelectric solutions can be implemented within the scope of the invention. For example, the determination means 1 of the location device 10 also comprise means for controlling the transmitters and receivers. These control means are for example produced in the form of an electronic circuit. Thus, according to a preferred implementation of the invention, the electronic circuit can supply power to some of the transmitters and receivers of the first and second matrices according to a determined sequence. For example, such a sequence can comprise the simultaneous implementation of the following four steps: configure the first piezoelectric disc of the first as a transmitter matrix starting from the left on the outer row of the first matrix (the line of piezoelectric discs furthest from the center of the means of determination 1); configure the first piezoelectric disc of the first as a receiver matrix starting from the left on the inner row of the first matrix (the line of piezoelectric discs closest to the center of the means of determination 1); configure the first piezoelectric disc of the second as a transmitter matrix starting from the left on the inner row of the second matrix (the line of piezoelectric discs closest to the center of the de- termination 1); configure the first piezoelectric disc of the second as a receiver matrix starting from the left on the inner row of the second matrix (the line of piezoelectric discs furthest from the center of the de- termination 1). Then, the simultaneous implementation of the same four steps with the second piezoelectric disc of each row of each matrix and so on so as to horizontally scan all the piezoelectric discs of the first matrix and second matrix. Such scanning makes it possible to measure the acoustic waves reflected by the wrist along the entire length of the piezoelectric disc arrays. For example, the length of the first and second arrays is the same and the spacing between the discs in each row is also the same. Thus, for example, each row of each array includes the same number of piezoelectric discs. For example, the length of the first array and the second array is provided in the determining means 1 so that each array in the device overhangs the artery in the wrist. The electronic circuit includes a module for measuring a parameter of the reflected acoustic waves or a difference in value of a parameter between the reflected acoustic waves and the emitted acoustic waves. The electronic circuit also includes a module for obtaining the location of the blood vessel based on the parameter or the difference in value of the parameter. Preferably, the module for measuring the parameter of the reflected acoustic waves or a difference in value of a parameter between the reflected acoustic waves and the emitted acoustic waves comprises a filter and an amplifier. According to a first embodiment of the invention, the measurement module is a module for measuring the phase shift between the reflected acoustic waves and the emitted acoustic waves. According to a second embodiment of the invention, the measurement module is a module for measuring the amplitude of the reflected acoustic waves. According to a third embodiment of the invention, the measurement module is a module for measuring the frequency difference between the reflected acoustic waves and the emitted acoustic waves. For example, the phase shift between the emitted acoustic waves and the reflected acoustic waves will be measured as a function of time t over the duration of a scan of a matrix of piezoelectric discs of the location device 10 in the context of the first embodiment mentioned above. The phase shift Af is equal to the phase difference Phi 1 - Phi between the reflected waves and the emitted waves. Thus, for example, when scanning the matrices of piezoelectric discs implemented by the electronic circuit previously described, the phase shift measuring means will measure the phase shift between the emitted waves and the reflected waves at the level of each pair of piezoelectric discs on the two lines of each matrix. Thus, for each of the first matrix and second matrix, a scan is for example implemented. In a given matrix, when the emitted acoustic waves reach or approach the artery, the phase shift between the emitted waves and the reflected waves will have one or more maximum values ​​which are characteristic of the presence of the artery (in general, a pair of maximum values ​​will be obtained which indicates that the artery is located between the pairs of discs concerned). Thus, the electronic circuit of the determination means 1 can identify, from the measured phase shift, maximum values ​​which are characteristic of the presence of the artery under the pairs of piezoelectric discs concerned in the wrist. In the second embodiment, the amplitude of the reflected waves is measured instead of the phase shift and, in the same way, the maximum value of the amplitude is characteristic of the presence of the artery. In the third embodiment, the frequency difference between the reflected waves and the emitted waves is measured instead of the phase shift and, in the same way, the maximum value of the frequency difference is characteristic of the presence of the artery. The electronic circuit also comprises a module for obtaining the location of the artery as a function of the phase shift measured in the first embodiment mentioned above (or as a function of the amplitude of the reflected acoustic waves in the second embodiment mentioned above or as a function of the frequency difference between the reflected waves and the emitted waves in the third embodiment mentioned above). This module will therefore identify the maximum phase shift measured by the phase shift measurement module in the first embodiment (or the maximum amplitude of the reflected acoustic waves in the second embodiment or the maximum frequency difference in the third embodiment) during the scanning on each of the first and second matrices, which allows it to determine which pairs of piezoelectric discs are concerned by the maximum at the level of each of the first and second matrices. This allows it to locate the artery at two points: one at the level of the first matrix and the other at the level of the second matrix. Then, for example, the module for obtaining the location of the artery performs a linear interpolation between the two points and determines a location of a portion of the artery between these two points. Thus, as described previously, the location device 10 and in particular its determination means 1 implement: a scan by the transmitters and receiver of the first matrix in order to identify the two pairs of transmitters / receivers of the latter which have the most significant response (e.g. phase shift) (the artery is therefore located between these two pairs). Once these two pairs have been identified, for example depending on the delay and reception strength between these two couples, the device can calculate the distance between the artery and each couple. Thanks to this information it is possible to know the position of the artery in the reference frame of the first matrix (location of a first point of the artery). the same scan is carried out with the second matrix which makes it possible to obtain the location of a second point of the artery. According to the present embodiment, the location device 10 also comprises means 100 for projecting at least one image 50 of the location of the artery onto the skin surface. For example, an artery location image 50 includes at least one of the following images: - information representative of the depth of the artery in the wrist; - a representation of a portion of the artery. For example, the location image(s) 50 is / are projected onto the skin surface so that it / they are located substantially directly above the artery. For example, the projection means 100 comprise at least one projector and a tilting mirror. According to one embodiment of the invention, an artery location image 50 is a portion of the artery which is constructed from a first location determined from the location of the artery at two points using the first and second matrices as indicated above. For example, a location image 50 according to the invention also comprises a number (or even any other information representative of the depth) arranged in proximity (in the location image 50) to the portion of the artery (mentioned above- above) which is the depth of the artery in the wrist. Of course, according to variants of this embodiment, the image 50 may only include the depth or only a portion of the artery. Thus, the location information (e.g. the locations of the first and second points mentioned above) is transmitted to the image projection means. At the level of the image projection means, a program will transpose the artery location information obtained into a virtual matrix representing a display area (in which the image is displayed) by assigning coordinates to it. Indeed, because the first matrix and the second matrix are fixed relative to the display area, the location information is transposed there. Once this location information (e.g. the first and second points mentioned above) has been transposed into the display area, the location device draws a straight line between these two points. This straight line represents the course of the radial artery in the working area. Once this is done, the image formed is projected onto the wrist For this, a projector is placed in the upper part of the device and a mirror angle is used to redirect the image into the final projection area. According to one embodiment of the invention, the location device 10 comprises means for detecting a movement of the artery. For example, the means 1 for determining the location of the artery and the projection means 100 are activated by the means for detecting a movement of the artery. Thus, according to one embodiment of the invention, a loop can be implemented which aims to correct any displacement of the artery not in relation to the image projected on the wrist, for example during the intervention by the practitioner on the artery (during the procedure). For example, according to such a loop, if the artery does not move, then no correction of the image is made. On the other hand, if the device detects a displacement of the artery in relation to the image, then the location of the artery is again sought (as described above) using the first and second matrices (for example based on the three pairs of transmitters / receivers generating the strongest response). In this way, a new image representative of the new location of the artery is projected. This makes it possible to continuously monitor the radial artery and to update the information provided to the operator. List of reference signs 1 means of localization 200 lozenges 201 support layer 202 acrylic adhesion layer 203 silicone adhesion layer 204 protective coating 205 protective coating 41 main body 411 first finger 412 second finger 50 images 10 location devices 100 projection means

Claims

Claims

1. A pellet intended to improve the transmission of acoustic waves between a device (10) for locating a blood vessel of a limb of a living being and said member, the pellet being configured to be disposed between the locating device and a skin surface re- covering the blood vessel of said member, the device (10) comprising means for determining (1) the location of the blood vessel based on the emission of acoustic waves, characterized in that it comprises a support layer (201) coated with at least one adhesion layer (202, 203) intended to be in contact with the surface of skin or with a surface of the locating device and in that the support layer (201) is made of a wave-conducting material acoustic, for example polyurethane.

2. Lozenges according to claim 1, characterized in that they comprise, on one of its faces, a wave-conducting adhesion layer acoustic, for example silicone (203), intended to be in contact with the skin surface.

3. A lozenge according to any preceding claim, ca- characterized in that it includes, on one of its faces, a layer acrylic adhesion (202) intended to be in contact with the surface of the tracking device.

4. Lozenges according to claim 1, characterized in that they comprise on one of its faces, a silicone adhesion layer (203) intended to be in contact with the skin surface and on the other of its faces, a acrylic adhesion layer (202) intended to be in contact with the surface of the locating device.

5. Lozenges according to any one of claims 2 to 4, characterized in that one of the adhesion layer(s) (202, 203) has a adhesive outer surface and in that a protective coating (204, 205) is provided on the adhesive outer surface.

6. A lozenge according to claim 4, characterized in that each of the adhesion layers (202, 203) have an adhesive outer surface and in that a protective coating (204, 205) is provided on said adhesive outer surface.

7. Use of a pellet (200) according to any one of the claims- previous instructions to improve wave transmission acoustics between a location device (10) of a vessel blood of a member of a living being and said member, the pellet (200) being disposed between the locating device and a skin surface covering the blood vessel of said member, the device (10) comprising means for determining (1) the location of the blood vessel based on the emission of acoustic waves.

8. Use according to the preceding claim, characterized in that the locating device (10) comprises a main body (41), the body main (41) comprising a first finger (411) in contact with a first portion of skin of the limb and a second finger (412) in contact of a second portion of skin of the limb and in that said patch is arranged at least between one of the first and second fingers and the limb.

9. Use according to any one of claims 7 and 8, characterized in that the locating device (10) comprises at least one acoustic wave transmitter configured to emit waves acoustic - hereinafter acoustic waves emitted - in the member to through the skin surface, at least one acoustic wave receiver configured to receive acoustic waves reflected by the limb — hereinafter reflected acoustic waves, a measuring module of a parameter of reflected acoustic waves or a difference in value of a parameter between reflected acoustic waves and waves emitted acoustics and a module for obtaining the location of the blood vessel depending on said parameter or said difference in value of said parameter.

10. A method of applying a pellet according to claim 6, characterized in that it includes the following steps: - removal of a first part of the protective coating (204) from the adhesive outer surface of the acrylic adhesion layer (202); - installation of the part of the pellet (200), acrylic adhesion layer side (202), corresponding to the removed part of the protective coating (204) on the surface of the locating device (10); - removal of the remainder of the protective coating (204) from the outer surface adhesive of the acrylic adhesion layer (202); - installation of the rest of the pad (200), acrylic adhesion layer side (202), on the surface of the locating device (10); - applying pressure to smooth the pad (200) placed on the surface of the locating device (10); - removal of the protective coating (205) from the adhesive outer surface of the silicone adhesion layer (203); - place the location device on the skin surface, side of the pad (200).