阅读说明：本技术 一种基于mems技术的脑深部刺激电极 (Brain deep stimulation electrode based on MEMS technology ) 是由 程瑜华 兰舒 王高峰 李文钧 于 2021-10-14 设计创作，主要内容包括：本发明公开了一种基于MEMS技术的脑深部刺激电极,其包括绝缘体内芯,以及包裹在绝缘体内芯上的柔性电极薄膜。柔性电极薄膜卷曲包裹在绝缘体内芯的侧面上,且两侧边缘对接在一起。柔性电极薄膜的内表面与绝缘体内芯粘接在一起。柔性电极薄膜包括绝缘外层,以及设置在绝缘外层上的金属触点和金属导线。金属导线设置在绝缘外层内表面。本发明通过MEMS技术制备出平面的柔性电极薄膜后,将其卷曲固定到绝缘体内芯上,从而通过平面制造技术加工出了,具有三维空间结构的脑部刺激到电极,大大降低了电极制造成本。此外,使用MEMS技术制备柔性电极薄膜,使得金属触点和金属导线之间实现一体化,二者的连接相较于传统工艺更加稳固。(The invention discloses a brain deep stimulation electrode based on an MEMS (micro-electromechanical systems) technology, which comprises an insulator inner core and a flexible electrode film wrapped on the insulator inner core. The flexible electrode film is coiled and wrapped on the side surface of the insulator inner core, and the two side edges are butted together. The inner surface of the flexible electrode film is bonded to the insulator core. The flexible electrode film comprises an insulating outer layer, and a metal contact and a metal lead which are arranged on the insulating outer layer. The metal wire is arranged on the inner surface of the insulating outer layer. After the planar flexible electrode film is prepared by the MEMS technology, the planar flexible electrode film is curled and fixed on the inner core of the insulator, so that the planar flexible electrode film is processed by the planar manufacturing technology, a brain with a three-dimensional space structure stimulates the electrode, and the manufacturing cost of the electrode is greatly reduced. In addition, the flexible electrode film is prepared by using the MEMS technology, so that the metal contact and the metal wire are integrated, and the connection between the metal contact and the metal wire is more stable compared with the traditional process.)

1. A deep brain stimulating electrode based on MEMS technology is characterized in that: comprises an insulator inner core (1) and a flexible electrode film wrapped on the insulator inner core (1); the flexible electrode film is coiled and wrapped on the side surface of the insulator inner core (1), and the edges of the two sides are butted together; the inner surface of the flexible electrode film is bonded with the insulator inner core (1);

the flexible electrode film comprises an insulating outer layer (2), and a metal contact (3) and a metal wire which are arranged on the insulating outer layer (2); the metal wire is arranged on the inner surface of the insulating outer layer (2); the multiple groups of metal contacts (3) are sequentially arranged at intervals along the axial direction of the insulator inner core (1); the group of metal contacts (3) comprises a plurality of metal contacts (3) which are uniformly distributed along the circumferential direction of the axis of the insulator inner core (1); the metal contact is attached to the inner core (1) of the insulator in a circular arc shape; each metal contact (3) is led out to the end part of the tail end of the insulator inner core (1) through mutually independent metal wires;

the preparation method of the brain deep stimulating electrode based on the MEMS technology comprises the following steps:

manufacturing a flexible electrode film by using an MEMS (micro electro mechanical system) technology, forming an insulating outer layer (2) embedded with a metal contact array, and respectively leading out each metal contact to a metal lead at the edge of the end part of the inner surface of the insulating outer layer (2) independently;

step two, gluing the inner surface of the flexible electrode film obtained in the step one, and wrapping the inner surface of the flexible electrode film on the outer side surface of the insulator inner core (1) in a curling manner to enable the edges of two sides of the flexible electrode film to be in butt joint; and (3) after the flexible electrode film is bonded with the insulator inner core (1), obtaining the deep brain stimulating electrode.

2. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: the metal contact is in a round corner rectangle after being unfolded.

3. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: in the first step of the preparation method, the ends of the metal leads on the finished flexible electrode film, which are positioned at the edge of the insulating outer layer (2), are respectively connected to corresponding connecting terminals.

4. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: the insulator inner core (1) is cylindrical, and a head end of the insulator inner core is provided with a hemispherical head insulating block (4); the head insulating block (4) extends out of the coverage range of the flexible electrode film.

5. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: each group of metal contacts (3) comprises two metal contacts (3) which are arranged along two sides of the insulator inner core (1) in a centering way; the corresponding central angle of one metal contact (3) is 120 degrees.

6. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: the distance between any two groups of adjacent metal contacts (3) is equal.

7. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: the material of the insulator inner core (1) is silica gel; the insulating outer layer (2) is made of poly-p-xylylene chloride; the metal contact (3) is made of platinum-iridium alloy.

8. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: each metal lead is connected to a signal output interface of the nerve stimulator.

9. The deep brain stimulation electrode based on the MEMS technology as claimed in claim 1, wherein: the diameter of the brain deep stimulating electrode is 1.27mm, the width of a single metal contact is 1.5mm, and the distance between two adjacent groups of metal contacts is 1 mm.

Technical Field

The invention belongs to the field of implantable medical devices and MEMS (micro-electromechanical systems), and particularly relates to a deep brain stimulation electrode based on an MEMS (micro-electromechanical systems) technology.

Background

Neurological diseases profoundly affect the health and life quality of human beings, and cause huge social and economic burden. The traditional treatment method of the neurological diseases comprises early-middle-stage drug treatment and late-stage surgical treatment, and the patients need to take medicines all the year round or even for the lifetime, which not only causes great economic burden to the patients, but also weakens the effect of the drug treatment along with the increase of the physiological drug resistance of the patients. With the development of scientific technology, Deep Brain Stimulation (DBS) therapy is becoming an important therapeutic means for neurological diseases.

DBS surgically implants electrodes in the brain, and this invasive therapy electrically stimulates the nerve tissue nuclei deep in the brain through electrodes. The implantation operation uses an accurate positioning technology, so that the electrode is placed at a stimulation target point, and the stimulation parameters and the stimulation mode need to be adjusted after the operation. The stimulation electrode that is mainly used today is the model 3389 electrode from mayonney, usa, which has four metal cylindrical contacts, each of which can be either positive or negative, to achieve a monopolar to tetrapolar stimulation mode. DBS has advantages and disadvantages, the stimulation parameters and stimulation modes are adjusted after surgery so as to be as small as possible, the side effect of DBS is mainly because the nerve nuclei in non-target areas are stimulated, for example, when the Subthalamic Nucleus (STN) is stimulated to treat Parkinson's disease, the nerve nuclei have a spherical shape with a diameter of 3-4 mm, and the nerve nuclei for controlling other functions of the human body are arranged around the nerve nuclei, the stimulation on the non-target areas can generate unpredictable side effects, for example, the cortex (mainly cortical spherical fibers) is close to the boundary of the STN, and the misstimulation on the cortex nuclei can cause the deterioration of speech function.

The accurate positioning of the operation and the adjustment of the stimulation parameters and the stimulation mode after the operation are to find the optimal balance point of the stimulation treatment, so as to achieve the best treatment effect and the minimum side effect. Even if the positioning error is zero, the side effects are increased at the later stage due to the relative movement of the electrode and the tissue, the magnetic resonance deviation, the change of the disease condition and the like. By adjusting the three parameters of the stimulation amplitude, the stimulation pulse width and the stimulation frequency, the optimal balance point of the treatment can be searched from the software level. In terms of hardware, the existing stimulation electrode has the disadvantages that four cylindrical metal contacts are arranged on a strip-shaped insulator cylinder, although four stimulation modes from a monopole to a quadrupole exist, the monopole mode with the minimum stimulation area can stimulate peripheral non-target nerve nuclei to generate side effects, the stimulation precision and flexibility of the existing electrode are insufficient, and the adaptability to illness states is insufficient, so that the side effects are aggravated.

In addition, the existing stimulating electrode, especially the stimulating electrode with the three-dimensional stimulation site structure, has a complex manufacturing process, the connection between the metal contact and the metal lead is poor in stability, and various unpredictable factors easily cause the connection between the two to be separated.

Disclosure of Invention

The invention aims to design a deep brain stimulating electrode based on an MEMS (micro electro mechanical system) technology aiming at the defects of the existing deep brain stimulating electrode.

The invention provides a deep brain stimulation electrode based on an MEMS (micro-electromechanical systems) technology, which comprises an inner core of an insulator and a flexible electrode film wrapped on the inner core of the insulator. The flexible electrode film is coiled and wrapped on the side surface of the insulator inner core, and the two side edges are butted together. The inner surface of the flexible electrode film is bonded to the insulator core.

The flexible electrode film comprises an insulating outer layer, and a metal contact and a metal lead which are arranged on the insulating outer layer. The metal wire is arranged on the inner surface of the insulating outer layer. The multiple groups of metal contacts are sequentially arranged at intervals along the axial direction of the inner core of the insulator. The group of metal contacts comprises a plurality of metal contacts which are uniformly distributed along the circumferential direction of the axis of the inner core of the insulator; the metal contact is in a circular arc shape and attached to the inner core of the insulator. And all the metal contacts are led out to the tail end position of the insulator inner core through mutually independent metal leads.

The preparation method of the brain deep stimulating electrode based on the MEMS technology comprises the following steps:

step one, manufacturing a flexible electrode film by using an MEMS technology, forming an insulating outer layer embedded with a metal contact array, and respectively leading out each metal contact to the edge of the end part of the inner surface of the insulating outer layer.

And step two, gluing the inner surface of the flexible electrode film obtained in the step one, and wrapping the inner surface of the flexible electrode film on the outer side surface of the insulator inner core in a curling manner, so that the two side edges of the flexible electrode film are butted. And (5) after the flexible electrode film is bonded with the inner core of the insulator, obtaining the brain deep stimulating electrode.

Preferably, the metal contact is in a round corner rectangle after being unfolded.

Preferably, in step one of the preparation method, only the ends of the metal wires on the finished flexible electrode film at the edge of the insulating outer layer are respectively connected to the corresponding connecting terminals.

Preferably, the insulator inner core is cylindrical, and a head insulating block in a hemispherical shape is arranged at the head end of the insulator inner core. The head insulating block extends out of the coverage range of the flexible electrode film.

Preferably, the set of metal contacts each includes two metal contacts centrally disposed along both sides of the insulator core. One metal contact corresponds to a central angle of 120.

Preferably, the spacing between any two adjacent sets of metal contacts is equal.

Preferably, the material of the insulator inner core is silica gel. The insulating outer layer is made of poly-p-xylylene monochloride. The metal contact is made of platinum-iridium alloy.

Preferably, each metal lead is connected to a signal output interface of the neurostimulator.

Preferably, the deep brain stimulation electrode has a diameter of 1.27mm, a width of a single metal contact of 1.5mm, and a pitch between two adjacent metal contacts of 1 mm.

The invention has the beneficial effects that:

1. after the planar flexible electrode film is prepared by the MEMS technology, the planar flexible electrode film is curled and fixed on the inner core of the insulator, so that the planar flexible electrode film is processed by the planar manufacturing technology, a brain with a three-dimensional space structure stimulates the electrode, and the manufacturing cost of the electrode is greatly reduced. In addition, the flexible electrode film is prepared by using the MEMS technology, so that the metal contact and the metal wire are integrated, and the connection between the metal contact and the metal wire is more stable compared with the traditional process.

2. The metal contacts are uniformly distributed on the outer side of the cylindrical electrode in an array shape, the utilization rate of the surface of the electrode is high, and a plurality of stimulation points can be integrated on the small-size electrode, so that more flexible electrical stimulation is realized.

3. The electrode metal contact is a curved rounded rectangle, compared with the charge density at the sharp corner of a conventional rectangular electrode, the charge density of the rounded corner is smaller, the charge density of the whole metal contact is more uniform, and the stimulation effect on the brain is easier to control. In addition, the electrode tip provided by the invention is provided with the hemispherical head insulating block at the end position, so that the injury to brain tissues during surgical implantation can be reduced.

4. The stimulation electrode is communicated with the stimulator, the stimulator controls the stimulation electrode to switch and select stimulation channels, and the position and the size of a stimulation area can be more accurately adjusted, so that more accurate and three-dimensional stimulation area and more flexible and variable stimulation mode combination are realized.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a side schematic view of the present invention.

FIG. 3 is a schematic view of the outer surface of the flexible electrode film of the present invention after deployment.

FIG. 4 is a schematic view of the inner surface of the flexible electrode film of the present invention after it has been unrolled.

Fig. 5 is a schematic view of the invention in different cross-sections.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings.

As shown in fig. 1, 2, 3, 4 and 5, the deep brain stimulation electrode based on the MEMS technology has an overall cylindrical shape, and specifically includes an insulator core 1 and a flexible electrode membrane wrapped on the insulator core 1. The flexible electrode film is rectangular under the condition of unfolding, and two side edges are butted together after being curled, so that the flexible electrode film is cylindrical. The inner surface of the flexible electrode film is bonded with the outer side surface of the insulator core 1. The insulator core 1 provides physical support for the flexible electrode membrane.

The flexible electrode film includes an insulating outer layer 2, a metal contact 3, and a metal wire 5. The insulating outer layer 2 is wrapped on the outer side of the insulating inner core 1 in a cylindrical shape. The metal wire 5 is disposed between the insulator inner core 1 and the insulating outer layer 2. The head end of the insulator inner core 1 is integrally formed with a head insulating block 4 in a hemispherical shape. The head insulating block extends out of the insulating outer layer 2. And a plurality of groups of metal contacts 3 which are sequentially arranged at intervals along the axis direction of the electrode are arranged on the insulating outer layer 2. The group of metal contacts 3 comprises two arc-shaped metal contacts 3 which are symmetrically arranged on two sides of the axis of the electrode. In this embodiment, the metal contacts 3 are four groups, eight pieces in total, to form a metal contact array.

The insulator inner core 1 and the head insulating block 4 which are integrally formed are made of silica gel. The insulating outer layer 2 is made of poly-monochloro-p-xylene with biocompatibility. The metal contact 3 is made of platinum-iridium alloy with biocompatibility, high corrosion resistance and low contact resistance. The diameter a of the brain deep stimulation electrode is 1.27mm, the width b of a single metal contact is 1.5mm, and the distance c between two adjacent groups of metal contacts is 1 mm; the total width d of the entire metal contact array is 9 mm.

The flexible electrode film is divided into an inner layer and an outer layer, the outer surface of the flexible electrode film is unfolded and tiled to form a rectangle as shown in fig. 3, and the width e of the unfolded flexible electrode is 4mm (namely the perimeter of the brain deep stimulation electrode is 4 mm). The metal contact 11 is in a rounded rectangle after being unfolded, and the length f after being unfolded is 1.33 mm. After the deep brain stimulating electrode is implanted into the brain of a human body, the outer surface of the flexible electrode film is directly contacted with brain tissues.

The inner surface of the flexible electrode film is unfolded and laid flat as shown in fig. 4, and the metal contact penetrates through the insulating outer layer 2; the metal wire 513 is located on the inner surface of the insulating outer layer. Each metal contact 15 is led out from the tail end of the insulator core 1 through a separate metal wire 513 and connected to a neurostimulator. The metal conductors 513 are separated by an insulating outer layer 2. The insulating outer layer 2 realizes the isolation of the metal wire 513 from the brain tissue; the metal contacts 18 contact the brain tissue to perform the stimulation function.

The preparation method of the brain deep stimulating electrode based on the MEMS technology comprises the following steps:

step one, manufacturing a flexible electrode film by using an MEMS technology, forming an insulating outer layer 2 embedded with a metal contact array, and respectively leading out each metal contact to a metal lead 5 at the edge of the end part of the inner surface of the insulating outer layer 2. The ends of the metal wires 5 at the edges of the insulating outer layer 2 are each connected to a corresponding terminal. The film deposition process can be carried out at normal temperature, and the preparation process of the flexible electrode film is very convenient and fast due to the relatively simple processing process.

And step two, gluing the inner surface of the flexible electrode film obtained in the step one, and wrapping the inner surface of the flexible electrode film on the outer side surface of the insulator inner core 1 in a curling manner, so that the edges of two sides of the flexible electrode film are butted to form a cylinder. And (3) after the flexible electrode film is bonded with the insulator inner core 1, obtaining the deep brain stimulating electrode. The insulator core 1 is previously made using a biocompatible silicone rubber.

When in use, the part of the deep brain stimulation electrode with the metal contact array is implanted into a position in the brain, which needs electrical stimulation; and the wiring terminal at the tail end of the brain deep stimulation electrode is led out to the nerve stimulator. Therefore, the invention can be used for deep brain stimulation therapy for treating neurological diseases, and the brain needs to be implanted into the brain through an operation, so that the metal contact array at the front end of the whole stimulating electrode directly contacts with the nerve nuclei of related diseases to perform current stimulation on the nuclei. When the stimulation electrode is implanted in an operation, the metal contact array of the stimulation electrode is accurately placed by utilizing a stereotactic technology. Through the control program of the stimulator, the stimulation channels can be adjusted according to the reaction condition of the patient, and the optimal stimulation combination mode is selected to achieve the optimal treatment effect and the minimum side effect.