WO2014207050A1

WO2014207050A1 - Electrophysiological measurement device for the head of an animal

Info

Publication number: WO2014207050A1
Application number: PCT/EP2014/063420
Authority: WO
Inventors: Hugo COUSILLAS; Claire PETTOELLO; Martine HAUSBERGER
Original assignee: Universite De Rennes I; Cnrs - Centre National De La Recherche Scientifique
Priority date: 2013-06-28
Filing date: 2014-06-25
Publication date: 2014-12-31
Also published as: FR3007633B1; FR3007633A1; EP3013226A1

Abstract

The invention relates to an electrophysiological measurement device (2) for the head of an animal, said device comprising a helmet that can be arranged on the head of said animal and comprises electrophysiological measuring means. According to the invention, said helmet comprises a first and a second strap (212, 211) to be placed around the head of said animal, respectively in front of and behind the ears (12) of said animal (1), said first and second straps (212, 211) being connected by a third and a fourth strap (207, 208) to be placed respectively beneath each ear of said animal.

Description

Electrophysiological measuring device for the head of an animal

1. TECHNICAL FIELD OF THE INVENTION

The invention relates to the field of electrophysiology.

The invention more particularly relates to a device for collecting electrical biological signals on an animal, such as in particular, but not exclusively, a horse. Such signals are for example electroencephalographic signals.

2. SOLUTIONS OF THE PRIOR ART

Itinerant veterinarians specializing in the care of farm animals (cattle, sheep, etc.) and / or recreational animals (horses, ponies) generally have diagnostic aids that are transportable and easy to use in conditions often binding.

However, it is not uncommon for the animal to be moved to a veterinary center (eg a veterinary school) which is equipped with diagnostic aids, such as fixed electroencephalographic appliances, magnetic resonance imaging (MRI), and scanners. These devices are certainly powerful, but they have the disadvantage of being expensive and energy-intensive.

Electroencephalography, for example, has been practiced in a veterinary clinic for many years. It provides information on the state of cerebral health of an animal.

Such an examination, however, is relatively cumbersome to implement when the animal is a large animal, such as a horse.

Indeed, it is necessary to constrain the horse during the electroencephalographic examination and to resort to anesthesia. However, anesthesia does not measure the level of vigilance of the horse. I

There is a long-felt need to propose an electrophysiological measuring device, in particular measuring electroencephalographic, adapted to perform measurements in the field, that is to say in the living environment of the horse.

However, the solutions known to date are not entirely satisfactory.

Indeed, to know the functional state of the horse's brain, it is known to use self-adhesive electrodes connected by a wire to a computer. This solution, however, requires local shaving of the skull of the horse to ensure good contact of the electrode with the skin of the animal. In addition, the wired link limits the horse's movements.

In other words, the measurements obtained by means of these known devices are not really relevant since the electroencephalography is not implemented under conditions close to reality, that is to say when the horse is free of his movements.

It is also known portable electroencephalographic devices that operate by telemetry but their range is reduced (they are not suitable for horses).

Another problem to take into account is that the anatomy of the horse's head is particular and very different from that of the man.

Indeed, as illustrated schematically in Figure 1, the horse head 1 has an elongate profile and has multiple bumps and depressions, the eyes 11 being positioned on the side of the head.

On the other hand, the horse's brain is situated between its ears 12 at the top of the head (the ears 12 are thus close to the brain 13), and is small compared to the brain of the adult man.

More specifically, the horse's brain 13 comprises two left and right cerebral hemispheres (each hemisphere having a length of 12 to 13 cm and a width of 5 cm), and a cerebellum (weighing about 70 g, length equal to 5.5 cm and width equal to 6 cm). By way of comparison, the brain of the adult man weighs about 1500 g, and measures about 15 cm from the front to the back of the cerebral hemispheres.

The electroencephalographic measuring devices for humans are therefore perfectly inadequate for large animals, such as horses. 3. OBJECTIVES OF THE INVENTION

The invention particularly aims to overcome these disadvantages of the prior art.

More specifically, an objective of the invention, in at least one embodiment, is to propose an electrophysiological measuring device for an animal, such as a horse, which is non-invasive, easily positionable, comfortable, not very constraining, light and stable.

Another objective of the invention, in at least one embodiment, is to propose an electrophysiological measuring device for an animal that is inexpensive, efficient and adapted for use by an itinerant veterinarian.

Yet another object of the invention, in at least one embodiment, is to propose an electrophysiological measuring device for an animal which allows the animal to remain free of its movements and which allows precise measurements, under close conditions. reality.

4. SUMMARY OF THE INVENTION

The invention does not pose these problems related to the devices of the prior art.

Indeed, the invention relates to an electrophysiological measuring device for the head of an animal.

According to the invention, the device comprises a helmet adapted to be disposed on the head of said animal and carrying electrophysiological measuring means.

The invention provides an electrophysiological measuring device, in particular electroencephalographic measurement (EEG), which is adapted to be arranged around the head of an animal. To do this, the device comprises a fixing helmet for holding sensors (electrodes for example) delivering measurement signals representative of an electrophysiological measurement, for example an EEG.

It allows the measurement and recording of the electrical activity of the nervous system of an animal. It allows more generally to control and monitor the health of an animal.

The device of the invention when used in EEG provides information on the state of cerebral health of the animal and on its level of vigilance / attention. In fact, animals can undergo cerebrovascular accidents and EEG can be a quick and inexpensive way (as opposed to cerebral imaging) to detect functional abnormalities.

Furthermore, the device of the invention is transportable and is also a diagnostic aid in veterinary medicine in the field.

It is also non-invasive and does not require razing the animal, the measurement can be made despite the thick hairs of the animal (when it is a horse, for example), a conductive gel ensuring the contact between the electrode and the skin of the animal.

According to a particular characteristic, said helmet comprises a first and a second strap intended to be placed around the head of said animal, at the front and back respectively of the ears of said animal, said first and second straps being connected by a third and a fourth strap to be placed under each of the ears of said animal respectively.

According to a particular characteristic, said first and second strips are connected by at least one fifth strap intended to be placed between the ears of said animal.

The device of the invention thus makes it possible to easily and accurately position the measurement means close to the animal's brain. It also allows to maintain the measuring means in place despite the movements of the animal.

In other words, this device is easily positioned on the head of an animal, and in particular a horse, while allowing the animal to remain free of his movements.

The straps are made of a material rigid enough to adhere to the skull of the animal and flexible to not worry the latter.

According to a particular characteristic, said helmet comprises first means for adjusting the length of said fifth strap.

According to a particular characteristic, said helmet comprises second means for adjusting the length of said first and second straps.

The device of the invention is adaptable to any type of horse.

According to one particular characteristic, said first and second strips each comprise two portions connected by a connecting element. According to one particular characteristic, said measurement means comprise a plurality of electrodes.

According to a particular feature, each of said electrodes is disposed in a hole in one of said strips. The device is compact and inexpensive.

The helmet includes straps having a plurality of holes for receiving electrodes.

According to a particular characteristic, said device comprises means for holding said electrodes against the head of said animal.

According to a particular characteristic, said electrodes are dry electrodes.

According to a particular characteristic, said device comprises means for stimulating said animal carried by said helmet. The association of the EEG with stimuli (sound, visual, cognitive) also makes it possible to use the evoked potentials technique which gives precise information on the good functioning of the brain.

5. LIST OF FIGURES

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment, given as a simple illustrative and nonlimiting example, and the appended drawings, among which:

- Figure 1 shows a schematic view of the anatomy of the horse's head;

Figure 2 shows a schematic side view of an electrophysiological helmet according to a first embodiment of the invention; Figure 3 shows the electrophysiological helmet of Figure 2 when positioned on the head of a horse;

Figure 4A shows a schematic top view of the electrophysiological helmet of Figure 2;

FIG. 4B shows an electrophysiological helmet according to a second embodiment of the invention;

FIG. 5 is a diagrammatic cross-sectional view of the means for holding a helmet measuring electrode on the skin of the animal; FIG. 6 is a block diagram of the electronic means for processing and storing the signals measured by the electrodes carried by the helmet of the invention.

6. DETAILED DESCRIPTION OF THE INVENTION

Figures 1 to 3, 4A, 5 and 6 illustrate the electrophysiological measuring device 2 according to a first embodiment of the invention.

It comprises a helmet consisting of two transverse straps 211, 212 intended to be placed at the rear and the front of the ears 12 of a horse 1 (as shown in Figure 3) in substantially frontal planes. In other words, these strips 211, 212 enclose the head of the animal.

The helmet further comprises two longitudinal strips 201, 202 spaced apart and intended to be placed in parasagittal planes on each side of the forelock 14 of the horse 1, between the ears 12 of the latter. These longitudinal strips 201, 202 connect the transverse strips 211, 212 in the upper part of the helmet 2. The transverse strips 211, 212, which are spaced at the top of the helmet, are closer to the lower part of the helmet and are, for example, guided in a protective element 206 (possibly padded) coming to press against the neck of the animal.

In the example illustrated in FIGS. 2 and 4A, the transverse strips 211, 212 each comprise two portions that are integral with the protective and joining element 206.

At least a portion of the straps of the helmet comprises one or more holes 23 through the thickness of the strap in which it is formed. The width of the strips is preferably between 10 mm and 40 mm.

It should be noted that adjustment means 205, 215 are provided on each of the longitudinal strips 201, 202 and on the transverse strips 211, 212 respectively so as to adapt the size of the helmet, and therefore the electrophysiological measuring device, to the skull of the horse. 1.

More precisely, the adjustment means 205 make it possible to adjust the spacing between the transverse strips 211 and 212. The adjustment means 215 make it possible to adjust the radius, and therefore the volume, of the helmet.

These adjustment means 205, 215 are, in this example, in the form of a loop carrying an articulated rod mounted at a first end of a strap (the strap 212 for example) and in which passes the other end of 212. The length of the strips can thus be easily adjusted by the user depending on the size of the skull of the animal. Once the helmet setting on the head of the animal is done, the rod is inserted in one of the holes 23 formed in the strap 212 so as to maintain the setting chosen by the user.

Other adjustment solutions may be envisaged, such as Velcro (trademark) fasteners, for example.

It is therefore possible to shrink or expand the volume of the helmet according to the size of the horse. The positioning of the helmet and its adaptation to the shape and dimensions of the skull of the animal are thus facilitated.

The helmet is furthermore designed to prevent inadvertent movement of the electrophysiological measuring device and to maintain the positioning of the measuring sensors (which are preferably cup-type or dry electrodes) with respect to the skull (with contact in the case of electrodes cup-type or non-contact type in the case of dry electrodes).

In the embodiment of Figure 2, the straps of the helmet comprise several rivets 22 housed in holes 23 and through the thickness of the straps.

These rivets 22 are perforated in their center so as:

to be able to mount measurement sensors, which are here electrodes 30, an electrode 30 being associated with a rivet 22, and

- To allow the injection of a conductive gel as will be seen later.

In this embodiment, the device 2 of the invention is intended to perform electroencephalographic (EEG) measurements of the horse.

To do this, the device 2 comprises at least two electrodes which are intended to be applied on either side of the head of the animal (symmetrically on each side of the skull).

In a preferred embodiment, the device 2 further comprises a posterior electrode (parieto-occipital) and a front electrode (frontal). These four electrodes are thus placed near the brain of the horse which for memory is between the ears at the top of the head. In Figure 4A, the device 2 comprises four rivets 22 (two rivets 22 are mounted on each of the longitudinal strips 201, 202) each carrying an electrode (not visible) and allows measurements to be made for each of the hemispheres of the brain of the patient. 'animal.

As illustrated in FIG. 5, in order to ensure constant contact of the electrodes 30 with the surface of the skull, a first hollow tube integral with the electrode 30 and opening into the latter is placed in a second hollow tube disposed in the opening hole of the rivet 22, the latter being fixed on the strap 211. A spring 4 is fixed firstly to the electrode 30 and secondly to the rivet 22. The first tube 5 integral with the electrode 30 is suitable to slide in the second tube 6. Thus, under the effect of the spring 4, the electrode 30 remains in permanent contact with the skin of the animal.

The electrodes 30 are, in this example, cup-type electrodes in the form of a 5 mm disc which is drilled in the center to allow the injection of a conductive gel via the inside of the first tube 5. The gel conductor improves the contact of the electrode 30 with the skin and thus optimizes the passage of the current.

The electrode 30 is covered with a thin layer of silver providing optimized electrical contact with the skin of the animal and avoiding polarization phenomena.

Each of the four electroencephalographic measuring electrodes is connected to a device for measuring and recording the cerebral activity of the horse.

The brain activity of each hemisphere is recorded separately. As illustrated in FIG. 6, the device of the invention comprises electronic means for processing and storing the bioelectrical signals measured by the electrodes 30, these electronic processing and storage means being arranged in a housing carried by the helmet . FIG. 6 is an example of implementation of the electronic circuit carried by the helmet, in which the electrodes 30 are connected by wire connection to two signal amplifiers 31 of predetermined gain (the gain being possibly adjustable), feeding an analog converter / digital (A / D) 32 for digitizing the signal and a digital data storage card, such as an SD card, 32.

Filtering means may be provided.

The SD card 32 is removable and can be read on a computer terminal once the electroencephalography is performed using the device of the invention.

Optionally, a transmission unit of the bio-electrical signals is implemented in the housing, thus allowing telemetry.

These electronic means of treatment and storage are small in size so as to minimize their size and do not constitute discomfort for the animal, which could distort the measurements.

Such an electroencephalographic measuring device makes it possible to know the functional state of the brain of the animal in its environment. It is therefore not necessary to immobilize the animal.

The device of the invention can enable a veterinarian to detect a stroke or the functional consequences of a strong head injury in the field, that is to say in an equestrian center or at a training place when This is a racehorse, for example.

It is flexible depending on the size of the horse's head and is inexpensive.

Other aspects and variants

Other types of electrodes can be implemented on the device of the invention.

This may include dry electrodes which are inserted into the rivets of the helmet. In this case, it is not necessary for the electrodes dry in contact with the skin of the animal. However, a conductive gel must be placed between the dry electrode and the skin of the animal, this gel being injected via the rivet and the dry electrode which are drilled in their center. In addition, the dry electrodes must be located relatively close to the animal's brain so that EEG signals can be measured, for example. In addition,

The helmet of the device of the invention allows a fine adjustment of the positioning of the dry electrodes around the brain of the animal.

FIG. 4B illustrates a variant of the device of the invention. In this embodiment, the helmet 2 'comprises two strips 207, 208 additional to the helmet 2 of Figure 4A.

In other words, the helmet 2 'comprises four straps, two longitudinal straps 201', 202 'being intended to be placed on each side of the horse's toupee, the two other longitudinal straps 207, 208 being intended to be placed under the 12 ears of the horse 1.

All strips 201 ', 202', 207, 208, or only a portion, comprise one or more measuring electrodes, and are adjustable so as to adapt the helmet 2 'to horses of different sizes.

More generally, additional strips can be provided on each side of the ears and in front of the eyes so as to increase the number of electrodes and thus allow other types of recording, such as for example electro-occulograms (OEG ) or evoked potentials recordings (auditory, visual, cognitive) generated by acoustic and / or visual stimulation.

In other words, the number of thongs can vary, the only limiting factor being the space available on the head of the animal.

In this case, the helmet comprises one or more evoked potentials detection electrodes (these electrodes measure the electrophysiological response of the animal to a stimulus). The straps are formed of a material rigid enough to wrap the head of the animal without inadvertent deformation of the helmet, and flexible enough to not interfere with the animal.

In a particular embodiment of the invention, there is provided a plexiglass tab between the rivet 22 and the spring 4 so as to stiffen the strap and thus limit the movements of the corresponding electrode.

One can provide an elastic strap on the helmet that passes under the neck of the animal and marries the shape of the neck. Such a strap, which can be associated with the element 206, minimizes the movements of the helmet when the animal lowers his head to graze grass, for example.

Such a device can be adapted for other animal species such as dogs, cats, sheep, pigs, cows and ponies in particular.

Claims

1. Device (2) electrophysiological measurement for the head of an animal, said device (2) comprising a helmet adapted to be disposed on the head of said animal and carrying electrophysiological measuring means, said helmet comprising a first and a second strips (212, 211) intended to be placed around the head of said animal, at the front and back respectively of the ears (12) of said animal (1),

characterized in that said first and second strips (212, 211) are connected by a third and a fourth strap (207, 208) to be placed under each of said animal's ears respectively.

2. Device (2) according to claim 1, characterized in that said first and second strips (212, 211) are connected by at least one fifth strap (201, 202) to be placed between the ears (12) of said animal (1).

3. Device (2) according to claim 2, characterized in that said helmet comprises first adjustment means (205) of the length of said fifth strap (201, 202).

4. Device (2) according to one of claims 1 to 3, characterized in that said helmet comprises second adjustment means (215) of the length of said first and second strips (212, 211).

5. Device (2) according to one of claims 1 to 4, characterized in that said first and second strips (212, 211) each comprise two portions connected by a connecting member (206).

6. Device (2) according to one of claims 1 to 5, characterized in that said measuring means comprise a plurality of electrodes (30).

7. Device (2) according to claim 6, characterized in that each of said electrodes (30) is disposed in a hole in one of said strips.

8. Device (2) according to claim 6 or 7, characterized in that it comprises holding means (4) of said electrodes (30) against the head of said animal.

9. Device (2) according to one of claims 6 to 8, characterized in that said electrodes (30) are dry electrodes.

10. Device (2) according to one of claims 1 to 9, characterized in that it comprises means for stimulating said animal carried by said helmet.