RU2421253C1 - Multichannel electrode with independent bundle travel of microconductors - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medical equipment, particularly, to neurophysiologic apparatuses for precision electrical stimulation and recording of bioelectric activity simultaneously of great number of neurons of human and animal brain. A multichannel electrode consists of a holder and a bundle of insulated ultrafine metal microconductors connected through contacts to a multichannel amplifier. In a central channel of the holder, there is a movable needle whereto ones of the ends of the microconductors of the bundle are attached, while the other ends are fixed in metal rods mounted in side inclined channels of the holder and independently movable and lifted to a level whereon an amplitude of the recorded bioelectric signal at an output of the related amplifier channel is maximum.

EFFECT: use of the invention shall allow higher efficiency of neurophysiologic testing due to increased simultaneously recorded cerebral neurons, enabled simultaneous micropoint brain stimulation within functionally marked nerve cells and due to decreased traumatism of cerebral tissue during neurosurgical intervention.

1 dwg

Description

FIELD OF THE INVENTION

The invention relates to medical equipment, in particular to the field of production of neurophysiological devices for precision electrical stimulation and registration of bioelectrical activity at the same time a large number of neurons of the human and animal brain.

State of the art

An analogue of the invention is a device for stimulating and diverting the discharge activity of large groups of nerve cells (the so-called “neurointerface”), consisting of a holder and a sheath of ultra-thin metal microconductors coated with insulation, connected through contacts to a multi-channel amplifier [1, 2].

With the essential features of the invention, the following combination of features of the analogue coincides: "from the holder and the sheath of superthin metal microconductors coated with insulation, connected through contacts to a multi-channel amplifier."

The disadvantage of the analogue is its low efficiency, since only the parts of the microconductors of such a beam (according to various sources, from 15% to 40%), after their introduction into the brain tissue, appear in the localization area of a particular nerve cell. Only these electrode channels in the future can be used for electrical stimulation and registration of neural activity. Replacing them with individually moving large-diameter conductors (followed by sharpening and coating each of them with a layer of insulation) [3] inevitably leads to multiple microtraumas of brain tissue and, as a result, to disrupt its normal functioning in the lead zone.

A prototype of the invention is a “modular multichannel microelectrode” [4] (J. Getke, D. Pellinen, D. Anderson. Modular multichannel microelectrode array and methods of making the same // Patent USA. WO 2007/042999 A3 (2007)).

With the essential features of the invention, the following set of features of the prototype coincides: "from the holder and the bundle of insulated metal microconductors connected through contacts to a multi-channel amplifier."

The disadvantage of the prototype is its low efficiency, namely the impossibility of obtaining at the output of each channel of the amplifier bioelectric signal of maximum amplitude.

Elimination of the disadvantage can be achieved due to the fact that a movable needle is mounted in the central channel of the holder, to which one of the ends of the beam microconductors is attached, and their other ends are fixed inside the metal rods located in the lateral inclined channels of the holder and made with the possibility of independent movement relative to each other friend and raising to a level at which the amplitude of the recorded bioelectric signal at the output of the corresponding channel of the amplifier is maximum.

SUMMARY OF THE INVENTION

The problem to which the invention is directed, is the creation of a multi-channel electrode for the effective registration of the bioelectric activity of large groups of nerve cells and their electrical stimulation.

When carrying out the invention, the following results can be obtained:

A. An increase in the number of simultaneously recorded neurons of the human and animal brain and, as a result, a significant increase in the level of effectiveness of neurophysiological testing.

B. The emergence of the possibility of simultaneous micro-point stimulation of the brain in the localization of functionally labeled nerve cells.

C. Decrease in the level of traumaticness of brain tissue during neurosurgical operations associated with the need for local stimulation of individual neurons and registration of their bioelectric activity.

These technical results are achieved due to the fact that a movable needle is installed in the central channel of the holder, to which one of the ends of the beam microconductors is attached, others are fixed inside the metal rods located in the lateral inclined channels of the holder and made with the possibility of independent movement relative to each other and lifting up the level at which the amplitude of the recorded bioelectric signal at the output of the corresponding channel of the amplifier is maximum.

The features distinguishing the invention from the closest analogue are expressed by the following combination of features: “a movable needle is installed in the central channel of the holder, to which one of the ends of the beam microconductors is attached, others are fixed inside the metal rods located in the side inclined channels of the holder and made with the possibility of independent movement relative to each other".

In order to increase the efficiency of registration and stimulation of neural activity, it is possible to independently move the microelectrodes relative to each other and raise each of them to a level at which the amplitude of the recorded bioelectric signal at the output of the corresponding amplifier channel is maximum.

Thus, the objective of the invention is solved.

Information confirming the possibility of carrying out the invention

The effectiveness of the proposed device was determined in the framework of the neurophysiological analysis of the bioelectric activity of neurons in the sensorimotor region of the cortex of rabbits in free behavior.

The drawing shows a diagram of a multi-channel electrode, which was used to register neural activity.

The circuit contains a holder 1 made of a dielectric material (fluoroplastic), in the central channel of which there is a movable tungsten needle 2, and microconductors are fixed in the side inclined holes with screws 3. Each of them is a microwire 4 in glass insulation (the diameter of the conductive core is 1-3 μm, the thickness of the glass coating insulating it is 5-7 μm), the upper part of which after removing the glass layer in hydrofluoric acid is fixed with conductive glue inside the metal rod 5 (injection needles). The lower ends of all microconductors 4 are glued with a sucrose solution to the central needle 2. The ends of the current collectors 6 (micro slots RG1N-1-5) closest to the center of the holder 1 are soldered to a microcable connected to the inputs of a multi-channel amplifier.

The device operates as follows. After trepanation of the bone of the skull over the area of registration and removal of the dura mater, the multichannel electrode is gently immersed in the brain tissue and the holder 1 is fastened to the skull bone with liquid plastic (Noracryl-100). After 15-20 minutes, which are necessary for dissolving sucrose in the brain tissue, the needle 2 is removed from the central hole and each microconductor is connected through a current collector 6 to one of the inputs of the multi-channel amplifier. Then, using (depending on the type of biological object) either a stereotactic apparatus or a micromanipulator, each of the rods 5 in the channel of the holder 1 is successively raised to a level that provides the largest amplitude of the active bioelectric signal at the output of the corresponding amplifier channel. In this position, each rod is finally fixed with a microscrew 3 in the channel of the holder 1.

The possibility of carrying out the invention with the implementation of this purpose is confirmed by the well-known means and methods of obtaining devices.

Thus, the possibility of carrying out the invention is confirmed.

The technical result of the invention is to increase the efficiency of neurophysiological testing by increasing simultaneously recorded brain neurons, the possibility of simultaneous micro-point stimulation of the brain in the area of functionally labeled nerve cells and by reducing the level of brain tissue trauma during neurosurgical intervention.

Information sources

1. V. Tsytsarev, M. Taketani, F. Schottler, Shigeru Tanaka and Masahiko Hara. A new planar multielectrode array: recording from a rat auditory cortex // J. Neural Eng. 3 (2006). 293-298.

2. Justin C. Williams, Robert L. Rennaker, Daryl R. Kipke. Long-term neural recording characteristics of wire microelectrode arrays implanted in cerebral cortex. Brain Research Protocols. 4 (1999). 303-313.

3. Steven J. Eliades, Xiaoqin Wang. Chronic multi-electrode neural recording in free-roaming monkeys // Journal of Neuroscience Methods. 172 (2008). 201-214.

4. J. Hatke, D. Pellinen, D. Anderson. Modular multichannel microelectrode array and methods of making the same // Patent USA. WO 2007/042999 A3 (04/19/2007).

Claims (1)

A multichannel electrode for recording the bioelectric activity of large groups of nerve cells and their electrical stimulation, consisting of a holder and a sheath of insulated ultra-thin metal microconductors connected through contacts to a multi-channel amplifier, characterized in that a movable needle is installed in the central channel of the holder, to which one of the ends is attached microconductors of the beam, the other ends are fixed inside the metal rods located in the side inclined channels of the holder and made x independently moveable relative to each other and raising to a level at which the amplitude of the bioelectric signal detected at the output of the corresponding amplifier is maximum.

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