DEVICE FOR COLD OR HOT THERMAL STIMULATION AND METHOD FOR CONTROLLING AND ADJUSTING SAME

Abstract

The present invention relates to a control and command method for a device for thermal stimulation of animal or human tissue (1), said method being characterised in that it includes: determining a neutral temperature applied to the tissue (1), thermally adjusting the neutral temperature by activating a control loop, determining a cold or hot thermal stimulation temperature to be applied to the tissue (1), in alternation with the neutral temperature; determining a duration and a frequency of the thermal stimulations; in the case of an instruction to initiate the stimulation temperature by activating a control loop and by deactivating the control loop on the neutral temperature; and synchronising a physiological recording with the thermal stimulation.

Claims

1. A device for cold and/or hot thermal stimulation of an animal or human tissue, comprising: a stimulation head designed to come into contact with said tissue, a thermal control and regulating circuit for generating a stimulation temperature, a thermal inertia mass comprising an end face, micro-Peltier components integral with the end face of the thermal inertia mass to form an end in contact with the tissue, the micro-Peltier components comprising hot and cold faces, a thermal dissipator, at least one Peltier module sandwiched between the inertia mass and the thermal dissipator, at least one temperature sensor attached to a free face of a micro-Peltier component, the sensor being connected to the thermal control and regulating circuit, an electric power supply for the micro-Peltier components controlled by the thermal control and regulating circuit to produce the hot and/or cold faces in contact with the thermal inertia mass, the control and regulating circuit thus allowing a thermal stimulation regulating loop to be performed to generate the cold and/or hot stimulation temperature, and an electric power supply for the Peltier module controlled by the control and regulating circuit to arrange its hot face in contact with the thermal dissipator or in contact with the thermal inertia mass, thus allowing a neutral temperature regulating loop for maintaining the thermal inertia mass at a neutral temperature by evacuating the thermal energy of the thermal inertia mass during a cold thermal stimulation phase or by compensating for the thermal energy drawn off during a hot thermal stimulation phase.

2. The device according to claim 1, wherein the temperature sensor is a thermocouple.

3. The device according to claim 1, wherein the control and regulating circuit comprises a microcontroller, the microcontroller comprising a connection interface for a computer and another connection interface for a physiological parameter recorder.

4. The device according to claim 1, wherein the micro-Peltier components, separate from each other and arranged in an array, are soldered to the end face of the thermal inertia mass, and wherein the device further comprises an electrical and thermal insulating material filling the free spaces located between the micro-Peltier components.

5. The device according to claim 1, further comprising an additional temperature sensor configured to continuously read the temperature of the thermal inertia mass.

6. A method for testing and controlling the device of claim 1, the method comprising: determining the neutral temperature to be applied to the tissue, carrying out thermal regulation of the neutral temperature by activating the neutral temperature regulating loop, determining the cold and/or hot thermal stimulation temperature to be applied to the tissue in alternation with the neutral temperature, determining a duration and a frequency for the application of the cold and/or hot thermal stimulation temperature, if an instruction is given to apply the cold and/or hot thermal stimulation temperature, regulating the cold and/or hot thermal stimulation temperature by activating a thermal stimulation regulating loop and deactivating the neutral temperature regulating loop, synchronising the triggering of a physiological parameter recorder with the application of the cold and/or hot thermal stimulation temperature, and reactivating the neutral temperature regulating loop after each application of the cold and/or hot thermal stimulation temperature.

7. The method of claim 5, the method comprising: determining a neutral temperature to be applied to the tissue, carrying out thermal regulation of the neutral temperature by activating a neutral temperature regulating loop, determining a cold and/or hot thermal stimulation temperature to be applied to the tissue in alternation with the neutral temperature, determining a duration and a frequency for application of the cold and/or hot thermal stimulation temperature, if an instruction is given to apply the cold and/or hot stimulation temperature, regulating the cold and/or hot thermal stimulation temperature by activating a thermal stimulation regulating loop, and synchronising the triggering of a physiological parameter recorder with the application of the cold and/or hot thermal stimulation temperature.

8. The method of claim 7, further comprising continuously reading the temperature of the thermal inertia mass with the additional temperature sensor.

9. The method of claim 6, further comprising using micro-Peltier components to generate the cold and/or hot thermal stimulation temperature.

10. The method of claim 6, further comprising using a thermal inertia mass and a thermal dissipator associated with a Peltier module to generate the neutral temperature.

11. The method of claim 9, further comprising using the thermal inertia mass to evacuate thermal energy given off by the micro-Peltier components during the cold thermal stimulation phases.

12. The method of claim 9, further comprising using the thermal inertia mass to compensate the thermal energy drawn off by the micro-Peltier components during the hot thermal stimulation phases.

13. The method of claim 6, further comprising measuring the temperature of the tissue, at a determined frequency, and using the results of the measurement to determine or adjust the neutral temperature.

14. The method of claim 7, further comprising using micro-Peltier components to generate the cold and/or hot thermal stimulation temperature.

15. The method of claim 14, further comprising using the thermal inertia mass to evacuate thermal energy given off by the micro-Peltier components during the cold thermal stimulation phases.

16. The method of claim 14, further comprising using the thermal inertia mass to compensate the thermal energy drawn off by the micro-Peltier components during the hot thermal stimulation phases.

17. The method of claim 7, further comprising using a thermal inertia mass and a thermal dissipator associated with a Peltier module to generate the neutral temperature.

18. The method of claim 7, further comprising measuring the temperature of the tissue, at a determined frequency, and using the results of the measurement to determine or adjust the neutral temperature.

19. The method of claim 6, further comprising continuously reading the temperature of the thermal inertia mass with an additional temperature sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other characteristics and advantages of this invention will appear more clearly from the reading of the following description, referring to the attached illustrations, given as nonlimiting examples in which:

[0044] FIG. 1 is a schematic view of an embodiment example of a thermal stimulation device conforming to the invention

[0045] FIG. 2 is a schematic top view of the free end of the stimulation head of the stimulation device shown in FIG. 1,

[0046] FIG. 3 is an example of the electronic architecture of a thermal a stimulation device conforming to the invention, and

[0047] FIG. 4 is a functional flowchart illustrating the steps of an example of the implementation of a test and control method conforming to the invention,

INVENTION PRODUCTION METHOD(S)

[0048] The structurally and functionally identical components shown on several separate figures are given the same numerical or alphanumerical reference.

[0049] FIG. 1 is a schematic view of an embodiment example of a thermal stimulation device conforming to the invention. This thermal stimulation device allows the cold stimulation of animal or human tissue 1.

[0050] The thermal stimulation device conforming to the invention and described below, allows cold or hot thermal stimulation to be generated. Even if the generation of cold stimulations is described in greater detail below, the invention and especially the control and regulation method, also concern the generation of hot thermal stimulations or alternations of hot and cold thermal stimulations.

[0051] The thermal stimulation device includes a stimulation head 2 designed to come into contact with tissue 1.

[0052] The thermal stimulation device also includes a control and regulating circuit 3, generating for instance, a cold stimulation temperature at one of the ends 4 of stimulation head 2.

[0053] The stimulation head 2 comprises a thermal inertia mass 5 comprising, for instance, a block consisting of thermal conducting material. This block, weighing approximately 30 gr, is made, for instance, of copper or silver and, for instance, has a diameter of 25 mm and a thickness of 10 mm.

[0054] One end face 5a of the thermal inertia mass 5, located near the contact end 4 of the stimulation head 2, is covered with micro-Peltier components 6.

[0055] Advantageously, the micro-Peltier components 6 are made integral with the thermal inertia mass 5 by brazing.

[0056] For instance, the micro-Peltier components 6 shown in FIG. 2, are separated from one another in order to leave open spaces between the said micro-Peltier components 6, whose thickness is approximately 0.6 mm. These open spaces are advantageously filled with electric and thermal insulating material 7, such as an epoxy resin loaded with glass or phenol micro-balls. The micro-Peltier components 6, associated with insulating material 7 thus forms an end coat 8, designed to come into contact with tissue 1.

[0057] Therefore, advantageously, the end coat 8 has a thickness of approximately 0.6 mm and extremely low thermal inertia. The end coat 8 also has high thermal conductivity resulting from the component material of the micro-Peltier components 6 on the one hand, and its thinness on the other.

[0058] The distribution of the micro-Peltier components 6, of which there are for instance 16, is obtained by means of an array having four rows 6a, 6b, 6c, 6d and four columns.

[0059] The stimulation head 2 also includes a thermal dissipator 9. For instance, the latter is a passive thermal dissipator such as a high power LED dissipator. The thermal dissipator 9 can also be a natural or forced convection dissipator or a dissipator using water as a heat transfer fluid.

[0060] Each micro-Peltier component 6 has a cold active face measuring approximately 6 mm.sup.2 and a hot active face of approximately 9 mm.sup.2, used for brazing on the thermal inertia mass 5.

[0061] The array of micro-Peltier components 6, as shown in FIG. 2, advantageously has a power density in excess of 20 W/cm.sup.2, and preferably of around 80 W/cm.sup.2 or more.

[0062] The stimulation head 2 also comprises a standard Peltier module 10 sandwiched between the inertia mass 5 and the thermal dissipator 9. The Peltier module 10 comprises, for instance, a power density of approximately 10 W/cm.sup.2.

[0063] The hot face of the Peltier module 10 is in contact with the thermal dissipator 9 and its cold face is in contact with the thermal inertia mass 5. The electric power supply of the Peltier module 10 can also be reversed so that its hot face is in contact with the thermal inertia mass 5 to ensure the thermal regulation of the said thermal inertia mass 5 under some conditions of use.

[0064] The Peltier module 10 and the thermal dissipator 9 also serve to evacuate the thermal energy of the thermal inertia mass 5 or to bring in thermal energy to the thermal inertia mass 5 to maintain it at a determined temperature.

[0065] The stimulation head 2 also comprises at least one temperature sensor 11 attached to a free face of a micro-Peltier component 6.

[0066] Advantageously, the temperature sensor 11 is a thermocouple having a diameter of 0.1 mm and accordingly, very low thermal inertia. The temperature sensor 11 is soldered onto the free face of a micro-Peltier component 6.

[0067] Naturally, the temperature sensor 11 is connected by any known means to the control and regulating circuit 3.

[0068] Advantageously, the thermal stimulation device conforming to the invention is associated with a computer 12 into which specific software is loaded for driving the control and regulating circuit 3.

[0069] Where applicable, various information or physical parameters can be transmitted directly by the stimulation head 2 to the computer 12 by any known type of communication link.

[0070] The stimulation head 2 and more particularly the micro-Peltier components 6 and the Peltier module 10 are connected through the control and regulation circuit 3 to an electric power supply source 13.

[0071] FIG. 3 is an example of the electronic architecture of the thermal stimulation device conforming to the invention.

[0072] The control and regulating circuit 3 includes a microcontroller 14 and a connection interface 3a to the computer 12.

[0073] Advantageously, the electric power supply source 13 can charge a battery 15 ensuring the independent operation of the thermal stimulation device.

[0074] Advantageously, the battery 15 and the control and regulating circuit 3 are incorporated in a unit 3b. The latter, for instance, is not integrated into the stimulation head 2.

[0075] In another example of an embodiment conforming to the invention, the thermal stimulation device can comprise super-capacitors accumulating energy between two cold stimulations, being supplied with power by a USB bus connected to the computer 12.

[0076] The control and regulating circuit 3, through battery 15, supplies electric voltage of approximately 40V to drive the micro-Peltier components 6 and the voltage/current regulating circuit of the said micro-Peltier components 6. Each row 6a, 6b, 6c, 6d, comprising four micro-Peltier components 6 connected in series is powered independently by electric voltage of 32 V. This limits the maximum voltage occurring at the thermal stimulation head 2 while providing for the safety of people in the event of a fault occurring in the electric insulation.

[0077] The control and regulating circuit 3 also provides a secondary electric power supply 16, producing approximately 5 Volts from battery 15 to supply the logic electronic device of the thermal stimulating device on the one hand and the Peltier module 10 on the other.

[0078] The secondary electric power supply 16 is produced advantageously using first a “step down” circuit integrated into the control and regulating circuit 3 and also the electric voltage supplied by battery 15.

[0079] The microcontroller 14 interprets the instructions received via connection interface 3a of the USB interface type and accordingly controls four current regulators 17a, 17b, 17c, 17d supplying respectively the rows 6a, 6b, 6c, 6d of the micro-Peltier components 6.

[0080] This generates the cold thermal stimulation at the end of the stimulation head 2.

[0081] Microcontroller 14 controls a complementary current regulator 18 which drives the Peltier modules 10 to ensure the stability of the neutral temperature at the thermal inertia mass 5.

[0082] Microcontroller 14 also drives the thermal stimulation device by means of temperature measurements 19 from temperature sensor 11 and, where applicable, by means of complementary measures 20 from complementary temperature sensor 21 placed directly on the tissue 1. The use of a complementary temperature sensor 21 like this facilitates the continuous adjustment of the neutral temperature to the tissue 1 temperature.

[0083] For instance, microcontroller 14 also drives triggering device 22 to generate a triggering signal designed to synchronise a physiological parameter recorded 23 with the cold thermal stimulations.

[0084] The electric supply of the micro-Peltier components 6 is therefore controlled to set up the hot faces on the thermal inertia mass 5. The control and regulating circuit 3 therefore allows a regulating loop to be performed to generate the cold stimulation temperature at the end of stimulation head 2.

[0085] When it becomes necessary to generate hot thermal stimulations, it simply means modifying the direction of the electric current conducted through the micro-Peltier components 6.

[0086] The electric supply to the Peltier module 10 is controlled so that its hot face is in contact with the thermal dissipator 9 and its cold face is in contact with the thermal inertia mass 5. The control and regulating circuit 3 thus allows another final regulating loop to be performed, maintaining the thermal inertia mass 5 at a determined temperature referred to as the neutral temperature. This neutral temperature corresponds, for instance, to the temperature of tissue 1.

[0087] This invention also refers to a test and control process for a cold thermal stimulating device. The test and control method consists in determining a neutral temperature applied to tissue 1. This neutral temperature corresponds, for instance, to the ambient temperature and/or the temperature of the tissue 1 to be explored.

[0088] Advantageously, the complementary temperature sensor 21 placed directly on the said tissue 1, facilitates the adjustment of the neutral temperature. The latter is set up very quickly through the end layer 18, considering its thinness, its low thermal inertia and its high thermal conductivity.

[0089] The process then consists in carrying out thermal regulation of the neutral temperature by activating a regulating loop. This loop is performed by means of microcontroller 14 controlling the electric power supply of Peltier module 10. The regulation loop is activated by default if no cold stimulation control is issued by computer 12.

[0090] The test and control method then comprises the determination of a cold thermal stimulation temperature to be applied to the tissue 1 in alternation with the neutral temperature. A control from computer 12 then generates information requiring possible updating of the temperature, duration and frequency parameters for the cold stimulations. It is then necessary to determine, modify or confirm a cold temperature, a duration and a frequency for the cold thermal stimulations that will be applied to tissue 1.

[0091] If an instruction is given to initiate cold or hot stimulation, one carries out regulation of the cold thermal stimulation temperature by activating a regulating loop and deactivating the regulating loop controlling the neutral temperature.

[0092] The regulation of the cold stimulation temperature is obtained by microcontroller 14 driving the electric power supplies of the micro-Peltier components 6 and more specifically, each row 6a, 6b, 6c, 6d of the micro-Peltier components 6.

[0093] When the cold thermal stimulation is completed, the neutral temperature thermal regulating loop is reactivated to re-establish the neutral temperature until the next cold thermal stimulation occurs. The use of the complementary temperature sensor 21 arranged advantageously near the stimulation zone allows finer adjustment of the neutral temperature.

[0094] Since the two regulating loops use the same temperature sensor or 11, the regulating loop on the neutral temperature has to be deactivated during the cold stimulation phases. During cold stimulation, the temperature sensor 11 reads the cold temperature resulting in ordering the heating of thermal inertia mass 5 if the neutral temperature regulating loop had remained active. Overall thermal perturbation would then be inevitable.

[0095] In another example of an embodiment conforming to the invention, the thermal stimulation device could comprise a specific temperature sensor reading the temperature of the thermal inertia mass 5. In this case, there would be no need to deactivate the regulation loop for the neutral temperature during the cold stimulation phases.

[0096] The test and control method conforming to the invention would also comprise the synchronising of the initiation of a physiological parameter recording read on the tissue 1, after the initiation of cold thermal stimulation.

[0097] Implementing the test and control method conforming to the invention consists in using the thermal inertia mass 5 to evacuate the thermal energy given off by the micro-Peltier components 6 during the cold thermal stimulation phases and in using the Peltier module 10 associated with the thermal dissipator 9 to evacuate the thermal energy from the said thermal inertia mass 5.

[0098] The Peltier module 10 can therefore heat the inertia mass 5. This could be the case when at ambient temperature the stimulation device is started at around 25° C. and the temperature of the thermal inertia mass 5 has to be brought to a neutral temperature, for instance a temperature included between 30° C. and 34° C. Similarly, it may be necessary to heat the thermal inertia mass 5 to maintain the neutral temperature and thus compensate for thermal exchanges with the ambient air.

[0099] The adding of thermal energy to the thermal inertia mass 5 may also be necessary during hot thermal stimulations during which the micro-Peltier components 6 take thermal energy from the said thermal inertia mass 5.

[0100] The implementing of the method conforming to the invention then allows, without any structural modification to the device, the generation either of cold thermal stimulations or hot thermal stimulations.

[0101] The test and control method is then implemented by means of control codes, integrated into a program loaded into computer 12, specific to the various nerve fibre investigation protocols.

[0102] It is obvious that this description is not confined to the examples explicitly described but also extends to other embodiments and/or implementation methods. Accordingly, another technical characteristic described here can be replaced by an equivalent technical characteristic and a described process step can be replaced by an equivalent step while remaining in the context of this invention.