阅读说明：本技术 一种在顶颞区三维均匀分布的脑电极阵列及其制备方法 (Brain electrode array evenly distributed in three-dimensional manner in apical-temporal area and preparation method thereof ) 是由 康晓洋 方涛 宋左婷 穆伟 展格格 汪鹏超 王君孔帅 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种在顶颞区三维均匀分布的脑电极阵列及其制备方法。其中所述的在顶颞头皮表面三维均匀分布是指脑电极阵列中相邻脑电极三维空间上的距离相等,在脑电极阵列覆盖的头皮范围内所有的脑电极是均匀分布的。其中所述的二维高密度脑电极阵列是指本发明的脑电极阵列是通过二维平面的微纳加工方法制作的,这些以特定坐标排列的二维脑电极佩戴到三维的头部时,则会三维变形在头皮表面实现脑电极的均匀分布。本发明形成的二维高密度脑电极阵列,在二维平面不是均匀分布,只有佩戴在顶颞头皮表面才会均匀分布,以均匀的距离对运动想象脑区的脑电信号进行记录,以便实现脑电信号记录均匀的空间分辨率。(The invention discloses a brain electrode array which is uniformly distributed in a three-dimensional manner in an apical temporal area and a preparation method thereof. The three-dimensional even distribution on the surface of the apical-temporal scalp means that the distances among the three-dimensional spaces of the adjacent brain electrodes in the brain electrode array are equal, and all the brain electrodes are evenly distributed in the scalp range covered by the brain electrode array. The two-dimensional high-density brain electrode array is manufactured by a two-dimensional plane micro-nano processing method, and when the two-dimensional brain electrodes arranged according to specific coordinates are worn on a three-dimensional head, the brain electrodes can be deformed in three dimensions and are uniformly distributed on the surface of the scalp. The two-dimensional high-density brain electrode array formed by the invention is not uniformly distributed on a two-dimensional plane, and is uniformly distributed only when being worn on the surface of the apical-temporal scalp, so that the brain electrical signals of a motor imagery brain area are recorded at uniform distance, and the uniform spatial resolution of the brain electrical signal recording is realized.)

1. A preparation method of a high-density brain electrode array which is uniformly distributed on the surface of the scalp of the apical temporal area in a three-dimensional way is characterized by comprising the following steps: the method comprises the following steps:

(1) based on a projection expansion method from three-dimensional coordinates to two-dimensional coordinates, obtaining specific coordinate arrangement of two-dimensional brain electrodes which are uniformly distributed in three-dimensional mode on the surface of the scalp when the brain electrode array is worn on the apical temporal region; the three-dimensional uniform distribution on the scalp surface of the apical temporal area means that the distances in three-dimensional spaces of adjacent brain electrodes in the brain electrode array are equal;

(2) manufacturing a two-dimensional brain electrode array with specific coordinate arrangement by a micro-nano processing method of a two-dimensional plane;

(3) the manufactured two-dimensional brain electrode array arranged in specific coordinates is worn on a three-dimensional head, and a high-density brain electrode array which is deformed in a three-dimensional manner and realizes three-dimensional uniform distribution of brain electrodes on the surface of the scalp in the apical temporal region is obtained.

2. The preparation method according to claim 1, wherein in the step (1), the three-dimensional coordinates are first converted into two-dimensional coordinates by arranging an electrode array on the scalp surface of a Magnetic Resonance Imaging (MRI) template and then by a projection expansion method of the three-dimensional coordinates into two dimensions; the Projection expansion method from three-dimensional coordinates to two-dimensional coordinates adopts an Azimuth Equisistant Projection AEP azimuth equidistance Projection method.

3. The preparation method according to claim 1, wherein the distance of the adjacent brain electrodes in the three-dimensional space when the brain electrodes are worn on the temporocele region in step (1) is 0.1-12 mm.

4. The method for preparing a brain electrode according to claim 1, wherein in the step (2), the two-dimensional brain electrode array is composed of a conductive material and an insulating material, wherein the conductive material is used for forming the brain electrodes and transmitting brain electrical signals; the insulating material forms a structure of the brain electrode array and is used for selectively insulating the conductive material to prevent signal crosstalk; the diameter of the brain electrode in the two-dimensional high-density brain electrode array is 0.02-8 mm.

5. The preparation method according to claim 1, wherein in the step (2), the distance between the adjacent brain electrodes of the two-dimensional high-density brain electrode array on the two-dimensional plane is 0.05-15 mm.

6. The preparation method according to claim 1, wherein the number of brain electrode channels in the two-dimensional high-density brain electrode array in step (2) is 64 to 10240.

7. The preparation method according to claim 1, wherein, in the step (2), the thickness of the two-dimensional high-density brain electrode array is 0.01-1 mm,

the method for preparing according to claim 1, wherein, in the step (2), the circumference of a single brain electrode in the two-dimensional brain electrode array is split from other brain electrodes at an angle of 1-60 degrees.

8. A high-density brain electrode array evenly distributed in three dimensions on the scalp surface of the apical-temporal area prepared by the preparation method of claim 1.

9. The high-density brain electrode array according to claim 8, wherein the brain electrodes in the electrode array have a diameter of 0.02-8 mm; the number of brain electrode channels is 64-10240; the distance between the adjacent brain electrodes of the brain electrode array on the two-dimensional plane is 0.05-15 mm, the periphery of a single brain electrode and other brain electrodes are split, and the connecting angle is 1-60 degrees; the distance between adjacent brain electrodes in three-dimensional space is 0.1-12 mm.

Technical Field

The invention belongs to the technical field of medical instruments, biomedical engineering, artificial intelligence and micro-nano processing, and relates to a high-density brain electrode array, in particular to a brain electrode array which is uniformly distributed in a three-dimensional manner in an apical temporal region and a preparation method thereof.

Background

In recent years, reliable man-machine interaction, brain-machine interaction, medical diagnosis and auxiliary treatment means have been developed for brain-machine interfaces based on surface electroencephalogram signals, but the technology relies on recording spontaneous biopotentials of the brain from the scalp in an amplified manner, and spontaneous and rhythmic electrical activities of brain cell populations recorded by brain electrodes. The brain electrical signals triggered in the 4 th area and the 6 th area of the neocortex functional area during the movement and motor imagery of specific parts of the human body (such as the left hand, the right hand, the left foot, the right foot and the tongue) are the key for researching the motor imagery. The high-quality acquisition of the electroencephalogram signals of the areas is the basis for successfully realizing the motor imagery. The motor imagery performance based on brain-computer interfaces is thus significantly affected by the brain electrode array.

However, the density and spatial resolution of the current electroencephalogram cap or electroencephalogram electrode array are low, and the primary motor cortex of the 4 th area of the apical temporal area, the premotor cortex of the 6 th area and the auxiliary motor cortex are not optimized, so that the capacity of acquiring electroencephalogram signals of the areas is relatively poor. It is worth noting that most brain caps or brain electrode arrays are in direct three-dimensional shapes, the processing difficulty is relatively high, and a plurality of auxiliary wearing structures exist. Therefore, a two-dimensional high-density brain electrode array which can be uniformly distributed on the surface of the apical-temporal scalp in a three-dimensional manner is needed to record the electroencephalogram signals of the motor imagery brain area at a uniform distance so as to realize the uniform spatial resolution of the electroencephalogram signal recording.

According to the search findings of the prior art, Limei Tian, Benjamin Zimmerman, Aadel Akhtar et al are written in Nature biological Engineering volume 3, pages 194-205 (2019) as "Large-area MRI-compatible epipolar electronic interfaces for prosthetic control and cognitive monitoring" (Large-area MRI-compatible electronic interface for prosthetic control and cognitive monitoring), and the research indicates that the Large-area epidermal electrode can be used for recording the electroencephalogram signals on the surface of the scalp, and compared with the traditional brain electrode cap, the quality of the acquired signals is obviously improved, and more details can be acquired. However, in this study, the optimal design is not performed with respect to the distribution of the brain electrode array, and the deformation of the two-dimensional array electrode in the three-dimensional space is not considered, which is limited in practical application.

As described above, although studies on brain electrode arrays have been advanced to some extent, no two-dimensional high-density brain electrode array capable of realizing three-dimensional uniform distribution on the apical-temporal scalp surface has been reported in the literature.

Disclosure of Invention

Aiming at the actual requirements of the brain electrode array and the defects in the prior art, the invention aims to provide the two-dimensional high-density brain electrode array which is applied to recording brain electrical signals in motor imagery and can be uniformly distributed on the surface of the scalp of the temporalis area in a three-dimensional mode. The three-dimensional even distribution on the surface of the apical-temporal scalp means that the distances among the three-dimensional spaces of the adjacent brain electrodes in the brain electrode array are equal, and all the brain electrodes are evenly distributed in the scalp range covered by the brain electrode array. The two-dimensional high-density brain electrode array is manufactured by a two-dimensional plane micro-nano processing method, and when the two-dimensional brain electrodes arranged according to specific coordinates are worn on a three-dimensional head, the brain electrodes can be deformed in three dimensions and are uniformly distributed on the surface of the scalp.

The invention provides a preparation method of a high-density brain electrode array which is uniformly distributed on the surface of the scalp of an apical temporal area in a three-dimensional way, which comprises the following steps: the method comprises the following steps:

(1) based on a projection expansion method from three-dimensional coordinates to two-dimensional coordinates, obtaining specific coordinate arrangement of two-dimensional brain electrodes which are uniformly distributed in three-dimensional mode on the surface of the scalp when the brain electrode array is worn on the apical temporal region; the three-dimensional uniform distribution on the scalp surface of the apical temporal area means that the distances in three-dimensional spaces of adjacent brain electrodes in the brain electrode array are equal;

(2) manufacturing a two-dimensional brain electrode array with specific coordinate arrangement by a micro-nano processing method of a two-dimensional plane;

(3) the manufactured two-dimensional brain electrode array arranged in specific coordinates is worn on a three-dimensional head, and a high-density brain electrode array which is deformed in a three-dimensional manner and realizes three-dimensional uniform distribution of brain electrodes on the surface of the scalp in the apical temporal region is obtained.

In the invention, in the step (1), the distance between the adjacent brain electrodes in the three-dimensional space when the brain electrodes are worn on the temporocele area is 0.1-12 mm.

In the invention, in the step (2), the two-dimensional high-density brain electrode array is composed of a conductive material and an insulating material, wherein the conductive material is used for forming an electrode and transmitting an electroencephalogram signal; the insulating material forms a structure of the brain electrode array and is used for selectively insulating the conductive material to prevent signal crosstalk; the diameter of the brain electrode in the two-dimensional high-density brain electrode array is 0.02-8 mm.

In the invention, in the step (2), the distance between the adjacent brain electrodes of the two-dimensional high-density brain electrode array on the two-dimensional plane is 0.05-15 mm.

In the present invention, in the step (2), the number of brain electrode channels in the two-dimensional high-density brain electrode array is 64 to 10240.

In the invention, in the step (2), the thickness of the two-dimensional high-density brain electrode array is 0.01-1 mm,

in the invention, in the step (2), the periphery of a single brain electrode in the two-dimensional brain electrode array is split from other brain electrodes, and the connecting angle is 1-60 degrees, so that the two-dimensional high-density brain electrodes can be deformed in a three-dimensional space to adapt to the three-dimensional shape of the head.

In the invention, in the step (3), after the two-dimensional electroencephalogram electrode array is worn, the distance between adjacent electroencephalograms in a three-dimensional space is 0.1-12 mm.

The invention provides a high-density brain electrode array which is uniformly distributed on the surface of the scalp of the temporocele area in a three-dimensional manner and is prepared by the preparation method. Preferably, the diameter of the brain electrodes in the electrode array is 0.02-8 mm; the number of brain electrode channels is 64-10240; the distance between the adjacent brain electrodes of the brain electrode array on the two-dimensional plane is 0.05-15 mm, the periphery of a single brain electrode and other brain electrodes are split, and the connecting angle is 1-60 degrees; the distance between adjacent brain electrodes in three-dimensional space is 0.1-12 mm. The center distance of adjacent brain electrodes of the traditional brain electricity cap in three-dimensional space is generally not less than 16 mm. According to the high-density brain electrode, the distance between adjacent brain electrodes in a three-dimensional space is 0.1-12 mm, so that the spatial resolution of electroencephalogram signals recorded on the surface of the scalp of the apical-temporal area is remarkably improved.

The invention further provides application of the high-density brain electrode array in recording the brain electric signals in motor imagery.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, by utilizing the deformation of the two-dimensional high-density brain electrodes in a three-dimensional space, parameters such as two-dimensional coordinates, electrode thickness, electrode diameter, two-dimensional distance and the like of a single brain electrode are accurately controlled through optimization, so that the high-density brain electrode array is uniformly distributed on the surface of the temporalis scalp in a three-dimensional manner. The electroencephalogram signals of the motor imagery brain area are recorded at a uniform distance, so that the uniform spatial resolution of the electroencephalogram signal recording is realized.

The invention uses the parameters of the specific combination, so that the high-density brain electrode array which originally needs three-dimensional space processing reduces the processing difficulty, and the three-dimensional brain electrode array which is relatively complex to process is converted into the two-dimensional brain electrode array which is relatively simple and convenient to process. The brain electrode array with the two-dimensional high density is utilized to realize the three-dimensional uniform distribution of the brain electrodes on the surface of the apical-temporal scalp, so that the three-dimensional structure is simplified, and the wearing of the brain electrode array is more convenient.

Drawings

Fig. 1 is a side view of a high density brain electrode array evenly distributed in three dimensions on the scalp surface of the apical temporal area, including a side view of the electrode scalp surface location and a side view of the electrode cortex location.

Fig. 2 is a top view of a high-density brain electrode array evenly distributed in three dimensions on the scalp surface of the apical-temporal area, including a top view of the electrode scalp surface locations and a top view of the electrode cortex locations.

Fig. 3 is a plan development of a two-dimensional high-density electroencephalogram array capable of being uniformly distributed in three dimensions on the scalp surface of the apical-temporal area.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1

The embodiment provides a two-dimensional high-density electroencephalogram electrode array which is applied to recording of electroencephalogram signals in motor imagery and can be uniformly distributed on the surface of the scalp of the apical temporal area in a three-dimensional mode, and specifically comprises the following steps:

(1) the high-density brain electrode array has 128 channels of independent brain electrodes;

(2) the high-density brain electrode array has a thickness of 0.02 mm;

(3) the brain electrodes in the high-density brain electrode array have a diameter of 2 mm.

(4) The periphery of a single brain electrode in the high-density brain electrode array is split from other brain electrodes, and the angle of connection is 5 degrees.

(5) The detailed two-dimensional coordinates of the 128 individual brain electrodes in the high-density brain electrode array are shown in table 1. And determining the distance of the adjacent brain electrodes on a two-dimensional plane according to the two-dimensional coordinates, and determining the distance of the adjacent brain electrodes on a three-dimensional space.

The two-dimensional coordinates are first converted to two-dimensional by arranging an array of electrodes on the scalp surface of a Magnetic Resonance Imaging (MRI) template. The three-dimensional transformation of coordinates into two dimensions is realized by an Azimuth Equivalent Projection (AEP) method, which is a drawing method similar to a world map, and is referred to Snyder, John Parr. Although this method cannot ensure that the two-dimensional electrode is designed to be worn on the three-dimensional head to be completely fitted and to adapt to different head types, the method is substantially different from the method in which the two-dimensional electrode is not specifically designed to be directly fitted on the three-dimensional head. Fig. 1 is a side view of a high-density brain electrode array with a three-dimensional uniform distribution on the scalp surface of the temporalis area, which includes a side view of the electrode scalp surface position and a side view of the electrode cortex position, wherein the size of the brain electrode in the figure does not represent the real size and is used for illustration only. Fig. 2 is a top view of a high-density brain electrode array evenly distributed in three dimensions on the scalp surface of the apical-temporal area, including a top view of the electrode scalp surface locations and a top view of the electrode cortex locations, where the dimensions of the brain electrodes are not representative of actual dimensions, but are for illustration only. As can be seen from fig. 1 and 2, the high-density electroencephalogram electrode array is uniformly distributed in three dimensions on the surface of the parietal-temporal scalp.

Fig. 3 is a plan development of a 128-channel two-dimensional high-density electroencephalogram electrode array capable of being uniformly distributed in three dimensions on the scalp surface of the apical-temporal area. Table 1 is a two-dimensional coordinate of 128 individual brainelectrodes corresponding to the 128-channel brainelectrode array of fig. 3. Based on the two-dimensional coordinates of the electroencephalogram electrodes shown in fig. 1 and table 1, in combination with other parameters of the present embodiment, a three-dimensional uniform distribution of the high-density electroencephalogram electrode array on the surface of the apical-temporal scalp can be achieved, as shown in fig. 1.

Table 1 corresponds to the two-dimensional coordinates of the 128-channel electroencephalogram array of FIG. 3

TABLE 1

Serial number	X axis (mm)	Y axis (mm)	Serial number	X axis (mm)	Y axis (mm)
						33	-75.27	19.73	49	-46.47	8.68
34	-89.98	18.39	50	-60.80	7.79
						35	-103.97	17.68	51	-74.59	6.40
36	-119.19	15.00	52	-88.71	4.66
						37	116.34	-1.01	53	-102.91	2.52
38	100.49	2.12	54	-117.77	-0.47
						39	87.27	5.06	55	113.76	-14.10
40	74.06	6.99	56	98.84	-10.93
						41	59.94	8.03	57	85.59	-8.97
42	46.43	8.78	58	73.03	-6.69
						43	33.00	10.00	59	60.06	-5.08
44	19.68	11.17	60	46.07	-3.39
						45	5.75	11.12	61	32.66	-2.55
46	-6.85	10.47	62	19.50	-1.75
						47	-19.64	10.01	63	5.73	-1.27
48	-33.03	9.09	64	-7.00	-1.81

TABLE 1

Serial number	X axis (mm)	Y axis (mm)	Serial number	X axis (mm)	Y axis (mm)
						65	-20.00	-2.21	81	5.51	-13.43
66	-32.98	-2.89	82	-6.89	-13.99
						67	-45.43	-4.08	83	-18.90	-15.00
68	-59.27	-4.78	84	-31.39	-15.98
						69	-72.96	-7.34	85	-44.12	-16.52
70	-86.45	-10.02	86	-57.84	-18.24
						71	-99.79	-12.48	87	-71.09	-20.51
72	-113.90	-16.05	88	-83.08	-22.70
						73	110.51	-28.37	89	-96.29	-25.80
74	95.48	-24.39	90	-109.63	-30.72
						75	82.76	-22.60	91	105.39	-42.84
76	71.06	-20.01	92	-105.46	-44.22
						77	58.43	-18.03	93	-92.53	-39.12
78	44.83	-16.01	94	-79.93	-35.51
						79	32.09	-14.23	95	-68.39	-32.53
80	19.11	-13.22	96	-56.04	-30.00

TABLE 1

Serial number	X axis (mm)	Y axis (mm)	Serial number	X axis (mm)	Y axis (mm)
						97	-43.35	-28.52	113	58.53	48.91
98	-30.87	-27.54	114	-7.27	48.64
						99	-18.63	-26.44	115	-19.80	48.02
100	-6.32	-26.06	116	-33.98	47.48
						101	5.81	-25.68	117	-47.57	47.54
102	18.20	-26.12	118	-59.25	47.35
						103	30.90	-27.19	119	5.46	-33.97
104	43.40	-28.41	120	17.86	-34.44
						105	55.91	-30.08	121	30.25	-35.86
106	67.97	-32.33	122	42.93	-37.21
						107	80.09	-35.16	123	55.03	-39.75
108	92.23	-38.37	124	-6.00	-34.29
						109	5.89	50.03	125	-18.41	-35.06
110	19.11	50.37	126	-30.09	-35.93
						111	32.60	50.06	127	-42.73	-37.25
112	45.48	49.30	128	-54.73	-39.81

In summary, the two-dimensional high-density brain electrode array prepared by the method and data has the capability of recording the electroencephalogram signals of the motor imagery brain area at a uniform distance and realizing the uniform spatial resolution of the electroencephalogram signals.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.