AU2021107212A4 - Electrophysiological test method for auditory brainstem implant and recording electrode used by method - Google Patents

Abstract

of the Disclosure The present invention relates to the field of medical devices, and relates to an electrophysiological test method for an auditory brainstem implant (ABI) and a recording electrode used therein. According to the method of the present invention, there is no need to subcutaneously place an additional recording electrode for a patient, which simplifies preoperative preparation. Moreover, the method has advantages of a high signal-to-noise ratio, a fast response speed, a short recording time, and a large anti-interference ability, thus can effectively improve efficiency of intraoperative electrode test. The method is suitable for use in an auditory brainstem implantation surgery. Besides, the present invention enables the auditory brainstem implantation to be located more accurately, thereby expanding a scope of application. B c A PC2 eABR(D waveform 'd1°1°81 e1°1°1 g°s° recording B Determine and draw a figure 2. Record Two-dimensional plan figure of ABI electrode PC IABI I Stimulate and register Patient positioninformation stimulation 4. Feed back 5. Adjust C Audiologist positions Table of ABI stimulation parameter Surgeo information C FIG. 1 PC2 eABR waveform matching and recording, and automatic determination Record PClI ABI StimulatePain stimulation biologist AElectrode sheet position A positions information fed back in a 3D visualization manner FIG. 2 1/9

Description

B c A PC2 eABR(D waveform 'd1°1°81 e1°1°1 g°s° recording B Determine and draw a figure 2. Record Two-dimensional plan figure of ABI electrode

PC IABI I Stimulate and register Patient positioninformation stimulation 4. Feed back

5. Adjust C Audiologist positions Table of ABI stimulation parameter Surgeo information C

FIG. 1

PC2 eABR waveform matching and recording, and automatic determination

Record

PClI ABI StimulatePain stimulation

biologist AElectrode sheet position A positions information fed back in a 3D visualization manner

FIG. 2

1/9

Title

ELECTROPHYSIOLOGICAL TEST METHOD FOR AUDITORY BRAINSTEM IMPLANT AND RECORDING ELECTRODE USED BY METHOD

Background of the present invention

Field of Invention

The present invention relates to the field of medical devices, specifically to an

electrophysiological test method for an auditory brainstem implant (ABI), and a recording electrode

used therein.

Description of Related Arts

An ABI is favorable for a patient who is not suitable for a cochlear implantation due to

undeveloped cochlea, cochlear ossification, lack of an auditory nerve, and the like. The ABI, which

has not been widely used domestically, has a broad application prospect. Good intraoperative

monitoring guarantees the effect of postoperative auditory reconstruction.

An ABI device includes two parts: an extracorporeal apparatus and an intracorporeal

apparatus. The extracorporeal apparatus includes an electroacoustic transducer, a voice processor,

and a connecting wire. The intracorporeal apparatus includes a receiver, an electrode wire, and an

electrode array (namely, an auditory brainstem electrode array). A working principle of the ABI is,

by placing the electrode array on a surface of a cochlear nucleus in a recess of a fourth ventricle, to

directly stimulate a cochlear nucleus complex across a cochlea and an auditory nerve, to produce

speech perception and recognition. An ABI implantation surgery is a craniotomy. During the surgery,

an implantation area is fully exposed, to well locate the cochlear nucleus. The cochlear nucleus is

located in a brainstem and is surrounded by many other nerve nuclei, including a facial nerve

nucleus, a trigeminal nerve nucleus, a glossopharyngeal nerve nucleus, etc. Therefore, an accurate

implantation of the electrode array is crucial. Any incorrect stimulation to the surrounding structure

can result in serious consequences.

At present, electrically-evoked auditory brainstem responses (eABR) is conventionally used

for detection after the ABI implantation. The eABR is a far-field potential recording. The electrode

array of the ABI emits electrical stimulations. A recording electrode is placed at a top of a head or a

mastoid, a reference electrode is placed at two earlobes or a mastoid, a forehead electrode is

grounded, and a preamplifier is supposed to be placed close to a subject. A typical response of the

eABR occurs within 10 milliseconds after a pulse stimulation, and usually, thousands of average

scans are required to obtain a sufficient signal-to-noise ratio. Since the ABI crosses the cochlea and

auditory nerve, and accordingly the electrode array directly stimulates the cochlear nucleus, the

recording of only partial waves including wave III (cochlear nucleus), wave IV (olive nucleus), and

wave V (lateral lemniscus nucleus) can be obtained, which appears 1 to 2 milliseconds (ms) earlier

than the recording in a case of using a cochlear implant.

It is important to monitor auditory responses when the electrode array is implanted, which

not only indicates a position of the electrode array, but also indicates auditory effect after the

implantation. One or more response waves help to confirm that the electrode is implanted correctly,

but a process of obtaining eABR is relatively cumbersome. Typically, an external system used for

recording is provided and must then be connected/synchronized with a stimulation system.

Moreover, various recording electrodes need to be placed on a patient, positions of which may be

easily affected by the patient's movement.

Summary of the present invention

The present invention provides an automated electrophysiological test method for an ABI,

including the following steps: step 1, performing, by a stimulation generator, electrical stimulations

on a plurality of ABI electrodes; step 2, sequentially and correspondingly generating, by each of the

ABI electrodes, an electrical stimulation signal to stimulate a central auditory system, to generate

eABR, and sequentially recording, by a recording electrode in a body of a patient, the generated

eABR; and step 3, receiving, by a signal receiving apparatus that is respectively connected to a

signal acquisition apparatus and a signal processing apparatus, the eABR recorded by the recording

electrode and acquired by the signal acquisition apparatus, and determining, by the signal processing apparatus, whether an eABR target waveform appears at a corresponding ABI electrode through signal superimposition and automatic waveform recognition, to obtain response results of all of the

ABI electrodes and display the response results in a three-dimensional image manner.

The present invention further provides an electrophysiological test method for an auditory

brainstem implant based on cochlear nucleus action potentials (CNAP), including the following

steps: Si, implanting an ABI electrode array; S2, using any one of to-be-tested ABI electrodes on

the ABI electrode array as a stimulating electrode to emit an electrical stimulation; S3, using,

according to different simulation modes, any other one of the ABI electrodes on the ABI electrode

array as a recording electrode of the stimulating electrode, the recording electrode being configured

to receive an electrical stimulation signal transmitted by the stimulating electrode and record

electrically-evoked cochlear nucleus action potentials; S4, determining whether an

electrically-evoked cochlear nucleus action potential target waveform is obtained from a recording

result, if the electrically-evoked cochlear nucleus action potential target waveform is obtained in a

recorded result, the stimulating electrode being correctly placed, and if the electrically-evoked

cochlear nucleus action potential target waveform is not obtained, the stimulating electrode being

incorrectly placed, performing fine-tuning on a position of the stimulating electrode, and performing

steps S2 to S4 after the fine-tuning, until the target waveform is obtained from the recording result;

and S5, determining whether all of the to-be-tested ABI electrodes on the ABI electrode array have

been tested: if all of the to-be-tested ABI electrodes on the ABI electrode array have been tested,

ending an electrophysiological test process; and if not all of the to-be-tested ABI electrodes on the

ABI electrode array have been tested, performing step S2, and testing a next one of the to-be-tested

ABI electrodes until all of the to-be-tested ABI electrodes have been tested.

The present invention further provides a non-invasive nerve clamp recording electrode,

including: a misaligned and complementary clip, including two clip pieces, front ends of the two

clip pieces being misalignedly opened to form an opening at a head of the clip, or the two clip pieces

being complementarily closed to form a complete closed loop structure; a plurality of electrodes

exposedly arranged at an inner side of the closed loop structure, electrically connected to an external

signal generator and/or a signal receiver through a wire; two pressing sections, respectively

extending outward from a tail of the clip, and providing a first force for making the clip open by transmitting an external pressing force applied to the two pressing sections; a first elastic body, arranged at rear ends of the clip pieces that are at the tail of the clip and at the pressing sections, an elastic force of the first elastic body being used as a second force for making the clip close; and a second elastic body, arranged at the tail of the clip, two ends of the second elastic body respectively abutting against the two clip pieces, and an elastic force of the second elastic body being used as a third force for making the clip open.

The present invention further provides a cochlear nucleus recording electrode, including: an

electrode array, including a body and a plurality of first test electrodes distributed on the same

surface of the body; a wire, passing through the body, being connected to the first test electrodes

correspondingly, and extending outside the body from a tail of the electrode array to receive an

electrical stimulation signal; and a first clampable member, arranged on the wire extending from the

tail of the electrode array. Optionally, the cochlear nucleus recording electrode further includes one

or more movable electrodes. Each of the movable electrodes is provided with a lead to transmit an

electrical stimulation signal, an end of the lead is connected to a second test electrode, and the other

end of the lead is arranged at the wire extending from the tail of the electrode array. The lead of each

of the movable electrodes is provided with a second clampable member.

Brief Description of the Drawings

Fig. 1 is a schematic diagram of an electrophysiological test method for an auditory

brainstem implant in a related art.

Fig. 2 is a schematic diagram of an automated electrophysiological test method for an

auditory brainstem implant consistent with the present invention.

Fig. 2a is a schematic diagram of waveforms in a case that an ABI electrode has a good

response consistent with the present invention.

Fig. 2b is a schematic diagram of waveforms in a case that an ABI electrode has a normal

response consistent with the present invention.

Fig. 2c is a schematic diagram of waveforms in a case that an ABI electrode has a poor response consistent with the present invention.

Fig. 3 is a schematic diagram of a relationship between an electrode array and a cochlear

nucleus consistent with the present invention.

Fig. 4 is a flowchart of an electrophysiological test method for an auditory brainstem

implant based on a CNAP consistent with the present invention.

Fig. 5 is a schematic diagram of a principle of an ABI electrode array performing an

electrical stimulation and recording consistent with the present invention.

Fig. 6 is a schematic diagram of a recording result of positive and negative waves caused by

the present invention.

Fig. 7 is a top view of a non-invasive nerve clamp recording electrode in a case that a clip is

closed consistent with the present invention.

Fig. 8 is a top view of a non-invasive nerve clamp recording electrode in a case that a clip is

open consistent with the present invention.

Fig. 9 is a side view of clip pieces in a non-invasive nerve clamp recording electrode being

complementarily closed consistent with the present invention (other parts of a clip are omitted).

Fig. 10 is a side view of clip pieces in a non-invasive nerve clamp recording electrode being

misalignedly open consistent with the present invention (other parts of a clip are omitted).

Fig. 11 is a schematic diagram of a first elastic body in a non-invasive nerve clamp

recording electrode being a torsion spring consistent with the present invention.

Fig. 12 is a schematic diagram of a second elastic body in a non-invasive nerve clamp

recording electrode being a coil spring consistent with the present invention.

Fig. 13 is a schematic diagram of a second elastic body in a non-invasive nerve clamp

recording electrode being a serpentine spring consistent with the present invention.

Fig. 14 is a schematic diagram of a cochlear nucleus recording electrode provided with a

clampable member consistent with the present invention.

Fig. 15 is a schematic diagram of an electrode array in a cochlear nucleus recording electrode having different colors to assist in distinguishing an electrode orientation consistent with the present invention.

Fig. 16 is a schematic diagram of a cochlear nucleus recording electrode provided with a movable electrode consistent with the present invention.

Fig. 17 is an exemplary structural schematic diagram of a clampable member in a cochlear nucleus recording electrode consistent with the present invention.

Detailed Description of the Preferred Embodiments

To make the objectives, technical solutions, and advantages of the embodiments of the present invention more comprehensible, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention.

To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some embodiments of the present invention rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the disclosed embodiments without creative efforts shall fall within the protection scope of the present invention.

The present invention provides an automated electrophysiological test method for an ABI. As shown in Fig. 2, the method includes the following operations:

Si. Before a surgery, first an electrode group for detecting eABR is placed at a patient's head by an audiologist, the electrode group including a reference electrode placed at a top of the head (a preferred position), a ground electrode placed on a chest skin (a preferred position), and one or more recording electrodes placed in front of both ears (preferred positions). The recording electrode is not limited to being placed at the top of the patient's head, but may also be placed at other parts of the head or at a forehead. Besides, positions of the recording electrodes and the reference electrode may be changed according to an implanter's condition.

S2. During the surgery, a surgery area is exposed by a surgeon, and an eABR detecting is started after auditory brainstem electrodes (ABI electrodes) have been implanted.

Step S2 further includes the following operations:

S21. First, a stimulation generator performs an electrical stimulation on each connected ABI electrode.

In step S21, a first computer 1 (PC) is electrically connected to the stimulation generator, to control the stimulation generator. The stimulation generator receives a stimulation control signal from the PC Iand transmits an electrical stimulation signal to an ABI electrode.

Generally, there are 12 to 22 ABI electrodes that have been implanted. Each electrical stimulation is only used to stimulate one ABI electrode. An electrical stimulation process of each ABI electrode is performed sequentially until the electrical stimulation processes of all ABI electrodes have been completed. Besides, in an embodiment, a quantity of to-be-tested ABI electrodes is determined by an expert system (for example, a surgeon).

S22. Each ABI electrode correspondingly receives an electrical stimulation signal, and stimulates a central auditory system to generate local potential, so as to obtain eABR.

In step S22, the eABR is one kind of an auditory evoked potential. The eABR can be recorded by the recording electrode placed on the patient. That is, the to-be-tested ABI electrodes are tested sequentially, and the same recording electrode is responsible for all the recording.

S23. Since the eABR have a low signal-to-noise ratio, a signal receiving apparatus is connected to a signal acquisition apparatus, to receive the eABR generated by the central auditory system in the patient's head, which are recorded by the recording electrode and acquired by the signal acquisition apparatus. The signal receiving apparatus is connected to the second computer 2 (PC2, a computer used to match and record eABR waveforms). The PC2 performs filtering, superposition, and other processing (for example, 100 to 1000 times) on the eABR, to form a relatively stable and characteristic target eABR waveform. The "stable" refers to that the eABR waveform after the superimposition has a stable baseline, and basically maintains a consistent form, latency, and amplitude. The "characteristic" refers to that the eABR wave after the superimposition always exists, with a wave crest becoming larger as a stimulus amount is increased and the wave crest becoming smaller as the stimulus amount is decreased. The signal acquisition apparatus is connected to the recording electrode.

In step S23, the eABR waveform is automatically recognized by a software recognition

algorithm module in the second computer 2. A starting point of the eABR waveform generally

appears within 1I ms, and an entire eABR waveform time limit is approximately within 3 ms, so the

software recognition algorithm module can automatically recognize the waveform within the eABR

waveform time limit. The software recognition algorithm module also performs a differential

calculation to calculate a slope of data points on the eABR waveform, so as to find a starting point, a

wave crest, and a wave trough of the waveform, thereby locating and recognizing the entire eABR

waveform, and further automatically calculating a latency, amplitude, time limit of the eABR

waveform.

S23. In a case that the PCI controls the stimulation generator to apply a minimum amount

of an electrical stimulation to a certain ABI electrode, if the PC 2 recognizes the stable and

characteristic target eABR waveform, the ABI electrode is determined to have a good response; if

the PC 2 fails to recognize the eABR waveform, the PC I automatically increases the amount of the

electrical stimulation, steps S21 to S23 are repeated until the stable and characteristic eABR

waveform appears, and then the ABI electrode is considered to have a normal response; and if the

amount of the electrical stimulation reaches a maximum amount, but there is still no target eABR

waveform that can be recognized by the PC 2, the ABI electrode is considered to have no response.

Fig. 2a shows waveforms in a case that an ABI electrode has a good response, from which

it can be seen that the same stimulation intensity always causes waveforms with similar crest values

in the same latency, an abscissa indicating a time and an ordinate indicating an amplitude. Fig. 2b

shows waveforms in a case that an ABI electrode has a normal response, from which it can be seen

that the same stimulation intensity causes similar waveforms in the same latency, but with different

crest values. Fig. 2c shows waveforms in a case that an ABI electrode has a poor response, from

which it can be seen that there is no relatively stable and characteristic target waveform.

In step S23, the amount of the electrical stimulation (such as the minimum amount of the

electrical stimulation, the amount of an electrical stimulation increased each time, and the maximum amount of the electrical stimulation) is determined by an expert system (such as an audiologist).

S24. Perform electrical stimulations on all required ABI electrodes sequentially according

to the above steps S21 to S23, and perform automatic recognition and determination. ABI electrodes

with good responses or normal responses or no response are obtained by the PC 2 in an automatic

determination manner.

S25. The PC 2 may also automatically simulate and draw a figure of positions of the ABI

electrodes (electrode array position information in a 3D visualization structure) based on

information about the obtained eABR and the eABR waveform, and display the figure on an

interface of the PC 2, to facilitate subsequent use in a process of adjusting the positions of the ABI

electrodes by a surgeon.

S26. A surgeon may also perform an adjustment on the position of the ABI electrode with a

normal response or no response according to result information imaged by the PC 2 (the electrode

array position information in the 3D visualization structure), and after the adjustment, the above

steps S21 to S23 are repeated until a most suitable position of the ABI electrode has been found, to

obtain a good position of the entire electrode array.

In an embodiment, the good position of the entire electrode array is determined by an expert

system (for example, a surgeon).

Besides, the PC 1 connected to the stimulation generator, and the PC 2 used to match and

record eABR waveforms in the present invention may be implemented by one computer, that is, the

stimulation generator and the signal receiving apparatus are both connected to the computer.

Fig. 3 shows a schematic diagram of a relationship between an electrode array and a

cochlear nucleus. In the electrode array on the left half of the figure, twelve electrodes (indicated by

Al) have good responses and good positions, four electrodes (indicated by BI) have normal

responses and normal positions, and five electrodes (indicated by C1) have no response and poor

positions. The electrode array after position adjustment becomes as shown in the right half of the

figure, in which sixteen electrodes (indicated by A2) have good responses and good positions, two

electrodes (B2) have normal responses and normal positions, and three electrodes (C2) have no

response and poor positions.

In addition, the forgoing automated electrophysiological test method consistent with the

present invention is also applicable to a cochlear implant, which is not detailed herein.

The automated electrophysiological test method for an ABI consistent with the present

invention uses the eABR waveform automatic determination manner, and automatically records

relevant stimulation information and matched eABR waveforms, automatically simulates and draws

an electrode position figure (electrode array position information in a 3D visualization structure),

which can replace the conventional manual recording approach. The present test method can

effectively improve the efficiency of an audiologist performing electrode testing during a surgery,

thereby saving labor. In addition, according to the displayed electrode array position information in

the 3D visualization structure, the efficiency of a surgeon adjusting the electrode array position can

be improved, which shortens surgical time, reduces surgical risk, and improves patient prognosis.

Good intraoperative detection guarantees the effect of postoperative auditory reconstruction; thus

the method of the present invention has a broad application prospect.

The present invention further provides an electrophysiological test method for an ABI

based on electrically-evoked cochlear nucleus action potentials (CNAP). As shown in Fig. 4, the

method includes the following operations:

Sl'. During a surgery, exposing, by a surgeon, a surgery area, and implanting an auditory

brainstem implant (ABI).

In step Sl', the ABI includes an ABI electrode array (also called an electrode array), a

reference electrode, and a ground electrode, used for subsequent detecting of the electrically-evoked

cochlear nucleus action potentials. The reference electrode is placed at a top of a head (a preferred

position), and the ground electrode is placed on a chest skin (a preferred position). During the

surgery, the ABI electrode array is placed on a surface of a cochlear nucleus in a recess of the fourth

ventricle according to an anatomy, and subsequently the electrophysiological test method is used to

check whether the ABI electrode array is correctly placed.

As shown in Fig. 5, the ABI electrode array includes a body and a plurality of to-be-tested

ABI electrodes distributed on the same surface of the body.

S2'. Emitting an electrical stimulation by using a certain ABI electrode (a certain to-be-tested ABI electrode) on the ABI electrode array as a stimulating electrode.

S3'. Using any adjacent electrode of the stimulating electrode as a recording electrode, to

receive an electrical stimulation signal transmitted by the stimulating electrode, to record cochlear

nucleus action potentials.

In step S3', the recording electrode is connected to a signal acquisition apparatus, for

transmitting a cochlear nucleus action potential signal recorded by the recording electrode to a signal

processing apparatus.

S4'. Determining whether an electrically-evoked cochlear nucleus action potential target

waveform is obtained from a recording result in step S3': if the electrically-evoked cochlear nucleus

action potential target waveform is obtained, it indicates that the stimulating electrode is correctly

placed; if electrically-evoked cochlear nucleus action potential target waveform is not obtained, it

indicates that the stimulating electrode is incorrectly placed, and the position of the stimulating

electrode needs to be fine-tuned. The electrophysiology test is performed again after the fine-tuning,

that is, steps S2' to S4' are repeated until the target positive and negative waveform is generated,

which indicates that the stimulating electrode is correctly placed. Fig. 6 shows a schematic diagram

of a recording result of positive and negative waves generated by the present invention.

In step S4', the signal processing apparatus receives the cochlear nucleus action potential

signal, and determines whether the electrically-evoked cochlear nucleus action potential target

waveform, namely the relatively stable and characteristic electrically-evoked cochlear nucleus

action potential waveform, appears at the corresponding stimulating electrode through signal

superimposition and automatic waveform recognition. The target waveform refers to a waveform

having an obvious crest value within a certain time range, as shown in Fig. 6, an abscissa indicating

a time and an ordinate indicating an amplitude. The signal processing apparatus includes a software

recognition algorithm module for automatically recognizing the electrically-evoked cochlear nucleus

action potential target waveform.

S5'. Determining whether all the to-be-tested ABI electrodes on the ABI electrode array

have been tested, if all the to-be-tested ABI electrodes on the ABI electrode array have been tested,

ending an electrophysiological test process; and if not, performing step S2', and continuing a test process of a next ABI electrode until the electrophysiological test process of all the ABI electrodes have been completed.

Generally, there are 12 to 22 electrodes in the implanted ABI electrode array. Referring to

the above steps S2' to S4', each ABI electrode is used as the stimulating electrode to emit an

electrical stimulation, and its adjacent electrode serves as the recording electrode to record action

potentials, so as to check whether each ABI electrode is correctly placed, until the electrode

stimulation processes of all the ABI electrodes have been completed.

For example, a quantity of the to-be-tested ABI electrodes is determined by an expert

system (such as a surgeon).

An electrode that is not adjacent to the stimulating electrode of the present invention may

be used as the recording electrode. In a preferred embodiment, the recording electrode is adjacent to

the stimulating electrode, which provides a best effect without additional connection to other

apparatus. Therefore, different from the conventional eABR test method in which an electrode needs

to be subcutaneously placed for a patient, the method of the present invention simplifies

preoperative preparation, thereby providing an easier application.

Compared with the related art, the electrophysiological test method of the present invention

has the following beneficial effects: (1) the present invention uses the test method in which the

electrically-evoked cochlear nucleus action potentials (CNAP) replace the conventional eABR, and

has no need to subcutaneously place a recording electrode for a patient, which simplifies

preoperative preparation and has advantages of a high signal-to-noise ratio, a fast response speed, a

short recording time, and a large anti-interference ability, thereby effectively improving efficiency

of intraoperative electrode test; (2) the CNAP consistent with the present invention has advantages

as a near-field technology, by using which a signal with a larger amplitude can be observed, and

fewer average scans is needed to obtain a satisfactory waveform; and (3) the present invention is

also suitable for use in auditory brainstem implantation surgery, which has an easier application.

The electrophysiological test method for an ABI based on CNAP consistent with the

present invention has a high signal-to-noise ratio, a fast response speed, a greatly shortened

recording time, and a strong anti-interference ability, thus can be used as a standard test method for determining whether an electrode array is correctly placed at a cochlear nucleus. The present invention can also be used to assist post-operative programming of an implantable auditory apparatus. The present invention not only can complete auditory electrophysiological test after an auditory brainstem implant is implanted, but also is more in line with surgical habits, which can shorten surgery time, reduce surgery risk, and improve patient prognosis. The CNAP has advantages as a near-field technology, by using which a signal with a larger amplitude can be observed, and fewer average scans is needed to obtain a satisfactory waveform.

The present invention provides a non-invasive nerve clamp recording electrode. Referring

to Figs. 7 to 10, a body of the non-invasive nerve clamp recording electrode includes a misaligned

and complementary clip. That is, two clip pieces 10 are provided, which may be misalignedly

opened (Fig. 8 and Fig. 10), or may be complementarily closed to form a complete closed loop

structure (Fig. 7 and Fig. 9). An exemplary closed loop structure has a hollow cylindrical shape.

At a head of the clip, in a case that front ends of the two clip pieces 10 are misalignedly

opened to a set angle (or beyond the set angle), the clip can clamp a nerve to be monitored. The

closed loop structure formed by the two clip pieces 10 embraces the clamped nerve. Unless the two

clip pieces 10 are misalignedly opened again to the set angle or beyond the set angle, it is difficult

for the nerve to escape from the closed loop structure, which realizes a reliable clamping and fixing.

Several electrodes 40 are exposedly arranged on an inner side of the closed loop structure

(Fig. 7), and can be in close contact with the clamped nerve, to transmit an excitation signal to the

nerve and/or receive a feedback signal in an electrophysiological monitoring of nerve functions.

The electrodes 40 are electrically connected to an external signal generator and/or a signal

receiver through a wire 30. For example, the electrodes 40 may be embedded in or attached to inner

sides of the clip pieces 10, so that at least parts of the electrodes 40 are exposed to the inner sides of

the clip pieces 10. The wire 30 is firmly connected to the clip pieces 10. For example, the wire 30

may pass through the clip pieces 10, and may also be embedded in or attached to the inner sides or

outer sides of the clip pieces 10 (parts where the wire 30 is fixed to the clip pieces 10 and connected

to the electrodes 40 are omitted in Fig. 7 and Fig. 8).

The entire closed loop structure may include one or more electrodes 40. In a case that there are a plurality of electrodes 40, the electrodes 40 may be only arranged on one of the clip pieces 10, or arranged on two clip pieces 10, respectively. The electrodes 40 may be symmetrically or asymmetrically distributed. The present invention does not limit the shape and a quantity of the electrodes 40, nor their positions on the clip pieces 10 or the fixing manner.

Rear ends of the two clip pieces 10 are connected or integrated at a tail of the clip. The tail

of the clip further extends outward, and is provided with two pressing sections. By relatively

pressing the two pressing sections, the front ends of the two clip pieces 10 can be misalignedly

opened.

The softness and shape of the entire recording electrode also decide the open/close state of

the clip to a certain extent. An O-shaped opening with a slit (Fig. 7) of the clip in the close state

becomes a C-shaped (Fig. 8) opening in a case an internal force increasing, and then becomes a

U-shape (not shown) in a case of the internal force continuing to increase, which makes the opening

to be larger (a larger open angle). For example, a material of the two pressing sections is relatively

hard, while a material of the two clip pieces 10 is relatively soft.

Preferably, lengths of the two pressing sections are different. The wire 30 of the electrodes

is tightly connected to a first pressing section 21 that is relatively long. For example, the wire 30

may pass through the first pressing section 21 or be embedded in a surface of the first pressing

section 21. This can avoid a direct pressing on the wire 30, thereby providing a certain protective

effect on the wire 30. A second pressing section 22 is relatively short, which can prevent it from

blocking a surgical field of vision during an actual application, thereby not affecting surgical

operations.

A first elastic body 51 is provided. The first elastic body 51 may be a torsion spring (Fig.

11). A spiral part of the torsion spring is arranged inside the rear ends of the two clip pieces 10, and

two torsion arms connecting the spiral part are respectively located in the two pressing sections. An

elastic force of the first elastic body 51 makes the clip close.

A second elastic body 52 is provided. The second elastic body 52 may be a coil spring 52'

(Fig. 12), a serpentine spring 52" (at least one set; Fig. 13), an elastic sheet, or the like, which is

arranged in the two clip pieces 10, and fixed on the same axis 53 together with the first elastic body

51. The second elastic body 52 is bent as a whole, with two ends respectively abutting against the

two clip pieces 10. An elastic force of the second elastic body 52 is used to make the clip open. The

second elastic body 52 may be bent in accordance with a curvature of the clip pieces 10, or the

curvature of the second elastic body 52 may be adaptively adjusted according to the elasticity, so

that when the clip is in the close state the second elastic body 52 has been deformed to generate a

certain elastic force (which is insufficient to open the clip).

Preferably, the first elastic body 51 and the second elastic body 52 are arranged inside the

clip (indicated by dashed lines in Fig. 8), so that they are not exposed to the inner sides of the clip

pieces 10, to avoid influence on the electrodes 40 in the clip pieces 10. For example, the second

elastic body 52 is mainly arranged at the tail of the clip, with no part or only a small part extending

to the head of the clip.

The wire 30 of the electrodes 40 is not directly related to the second elastic body 52.

Through an adjustment of a design structure and a limited number of tests, the first elastic body 51,

the second elastic body 52, and a gravity force of the clip itself may realize:

1) In a case that the pressing sections are pressed to a certain extent, the clip is opened to a

set angle that is just for a nerve to enter and exit: in this case, an opening angle of the clip is

consistent with a state in which the second elastic body 52 is not deformed, accordingly the elastic

force of the second elastic body 52 does not work; at the same time, the first elastic body 51 has not

been deformed or an elastic force generated by its deformation is insufficient to actually make the

clip close. In other words, there exists a clip opening angle range (namely, the set angle) where the

elastic forces of the two elastic bodies do not work, allowing the nerve to enter and exit.

A principle of the above situation is briefly described as follows: before the pressing

reaches a certain extent, the clip continues to open as the pressing force increases, and the second

elastic body 52 gradually recovers from a deformed state when the clip is closed to a non-deformed

state, with its elastic force being gradually reduced. When the clip is opened to the set angle, the clip

is out of a space range where the second elastic body 52 works, and the second elastic body 52 is not

deformed; in this case, even if the pressing force is removed, the second elastic body 52 does not

exert a force on the clip pieces 10. In the above pressing process, the first elastic body 51 has not

been deformed or the elastic force generated by its deformation is insufficient to actually close the clip; and if the pressing is removed after the set angle is exceeded, since the first elastic body 51 is sufficiently deformed, its elastic force will actually make the clip close.

The above situation, without considering the influence of the gravity of the clip itself, is

applicable to scenarios where the clip is placed horizontally on an object such as a table and is

supported by the object; or scenarios where the clip is hold by a user and pressed by the user.

2) Without considering the pressing force, in a case that the clip is in a vertical position, the

gravity of the clip itself and the elastic force of the second elastic body 52 work together to make the

two clip pieces 10 close (in this case, the first elastic body 51 is not deformed and no force is

generated). The vertical position may be defined by an opening direction of the clip that is vertically

downward. In this example where the clip is arranged vertically, the two pressing sections are

upward (but in other examples, the vertical position of the clip may not be defined by the opening

direction, and the pressing sections may be oriented in other directions, which are not limited by the

present invention).

3) Without considering the pressing force, in a case that the clip is changed from a vertical

position to a position deviated from the vertical position (preferably to a horizontal position), the

effect of the gravity is weakened (or the effect of the gravity of the clip itself disappears in the

horizontal position), and the second elastic body 52 exhibits an obvious effect (the first elastic body

51 at this time is still not deformed, and no force is generated). In this case, by pulling the wire 30 of

the electrodes 40 to drive the clip pieces 10 to move, the clip can be opened to the set angle to

release the nerve with the assistance of the second elastic body 52.

According to the non-invasive nerve clamp recording electrode of the present invention, a

misaligned and complementary clip structure is formed at the head, to clamp a specific nerve for

fixing. Besides, the second elastic body 52 is arranged to provide a guarantee mechanism to avoid

clamping too tightly. The second elastic body 52 is cooperated with the first elastic body 51 and the

gravity of the clip itself, to enable the clip to maintain a small clamping force as a whole. The clip

can be opened to the set angle by pulling the wire 30 of the electrodes 40, so that the nerve can be

released without damage. A single electrode 40 or a plurality of electrodes 40 may be provided on

the inner side of the clip, to realize various application modes. The present invention is easy to fix,

simple to operate, and accurate in recording, which is suitable for neurological monitoring during an intracranial surgery.

The present invention also provides a cochlear nucleus recording electrode for test during

an ABI surgery. An auditory brainstem implant apparatus is implanted at a cochlear nucleus, to

generate hearing by electrically stimulating the cochlear nucleus. An implantation part of the

auditory brainstem implant apparatus includes the cochlear nucleus recording electrode.

As shown in Fig. 14, the cochlear nucleus recording electrode includes an electrode array

100, a wire 200 extending from a tail of the electrode array 100, and afirst clampable member 300

arranged on the wire 200. The electrode array 100 includes a body, and a plurality of first test

electrodes 11 distributed on the same surface of the body. The wire 200 passes through the body and

is connected to the first test electrodes 11 accordingly.

The first clampable member 300 is arranged circumferentially around the wire 200, which

is equivalent to that the wire 200 extends radially outward and thereby being thickened. A material

of the first clampable member 300 is supposed to be soft enough to not cause any damage to human

tissues around an implantation site. Further, a fillet may be provided at a junction between different

surfaces of the first clampable member 300 for a smooth transition, so as to avoid sharp parts.

Besides, the first clampable member 300 needs to be made of a material with a sufficient strength, to

maintain its inherent shape or only allow a small amount of deformation. This is beneficial for a

surgical tool to clamp the first clampable member 300, and drive the electrode array 100 at the front

of the wire 200 to move to the to-be-monitored cochlear nucleus. The shape, size, and material of

the first clampable member 300 may be accordingly adjusted, to satisfy the above requirements as

much as possible.

Preferably, the first clampable member 300 has a disc shape, through which the wire 200

passes (Fig. 17). Further, a radial surface and a circumferential surface of the disc may be joined by

a fillet to realize a smooth transition. A diameter c of the disc is greater than a diameter b of the wire

200. In different examples, the diameter c of the disc may be less than, equal to, or greater than a

width a of the electrode array 100. An axial length d of the disc may be set as required, to facilitate

being held by a surgical tool. Or, in some examples, the first clampable member 300 may not be

symmetrically arranged with the wire 200 as the center for easy holding and operating during a

surgery. For example, a thickness el of the first clampable member 300 on one side of the wire 200 may be greater than a thickness e2 of the first clampable member 300 on the other side of the wire

200.

The body of the electrode array 100 on which the plurality of first test electrodes 11 are

fixed is usually transparent, so that tissues of human body can be observed through the body during

a surgery. A side where the first test electrodes 11 are exposedly arranged is called a front side of the

electrode array 100, which usually needs to be attached to a monitored part. In order to quickly

distinguish the front and back sides of the electrode array 100 during a surgery, in a preferred

example as shown in Fig. 15, an upper half part 12 and a lower half part 13 of the body of the

electrode array 100 have different colors (and still have sufficient transparencies). For example, the

upper half part 12 of the body is red, and the lower half part 13 is blue. Such color order corresponds

to a state where the front side of the electrode array 100 faces forward and the back side of the

electrode array 100 faces backward. In this way, the corresponding color order can be observed

during a surgery, and if the current order is observed to be the upper half part being blue and the

lower half part being red, which is inconsistent with the setting, the body needs to be turned over

before being used. Similarly, the left half part and right half part of the body may also have different

colors, so as to use an inherent color order (for example, the left half part is red and the right half

part is blue) to correspond to the state where the front side of the electrode array 100 faces forward.

If the color order is observed to be different, the electrode array 100 needs to be turned over.

Therefore, the present invention can use different color for identifications to assist in distinguishing

the electrode orientation.

As technologies advance, the electrode array 100 can be made very small to adapt for a

small operating space at a cochlear nucleus. The volume of the electrode array 100 can be further

reduced by appropriately reducing the quantity of the first test electrodes 11 on the body. For

example, one to four first test electrodes 11 are provided on the body of the electrode array 100.

As shown in Fig. 16, in the present invention, one or more movable electrodes 400 may be

additionally provided to satisfy various monitoring requirements, serving as a supplement for the

first test electrodes 11 on the body. A lead is arranged from the wire 200, such as from a position

near the first clampable member 300. An end of the lead is connected to a second test electrode, to

form the movable electrode 400. The second test electrode and the first test electrodes 11 on the electrode array 100 may be of the same or different types.

For example, the first clampable member 300 may be provided with a channel through

which the lead can pass, so that an initial lead-out angle for the movable electrode 400 is set. A

second clampable member 41 may be further provided on the lead of the movable electrode 400, to

facilitate intraoperative operations.

The lead of the movable electrode 400 may be one of wires, which merges with other wires

200 extending from the tail of the electrode array 100. Or, the movable electrode 400 may be

combined with the electrode array 100 as required. For example, an electrical connector is provided

at the first clampable member 300, which is internally connected to one of wires 200, and externally

connected to an electrical connector fitted at the other end of the lead, so that the movable electrode

400 can be plugged and unplugged at any time.

The wire 200 extending from the tail of the electrode array 100 may receive the electrical

stimulation signal from the stimulation apparatus in a wired or wireless manner, and then transmit

the electrical stimulation signal to the first test electrodes 11 on the electrode array 100 (and the

second test electrode on the movable electrode 400). The end of the wire 200 is directly connected to

the stimulation apparatus; or, the end of the wire 200 is connected to a signal receiving unit, which

cooperates with a signal transmitting unit of the stimulation apparatus to receive the electrical

stimulation signal.

In accordance with the cochlear nucleus recording electrode provided in the present

invention, the overall volume of the electrode array 100 is small; the movable electrode 400 is

additionally provided; the body of the electrode array 100 uses different color identifications to

assist in distinguishing the electrode orientation; and the first clampable member 300 is provided for

easy clamping. The present invention can reduce damage to an implantation site, and is applicable in

scenarios such as auditory brainstem implantation surgery and nerve monitoring with simultaneous

monitoring of eABR, eCAP and the like, thus having a wide range of applications.

Although the content of the present invention has been described in detail through the

above exemplary embodiments, it should be understood that the above description should not be

considered as a limitation on the present invention. For a person skilled in the art, various

Claims (5)

modifications and replacements to the present invention will be apparent after reading the above content. Therefore, the protection scope of the present invention should be subject to the appended claims. What is claimed is:

1. An automated electrophysiological test method for an auditory brainstem implant (ABI),

comprising:

step 1. performing, by a stimulation generator, electrical stimulations on a plurality of ABI

electrodes;

step 2. sequentially and correspondingly generating, by each of the plurality of ABI

electrodes, an electrical stimulation signal, to stimulate a central auditory system, to generate

electrically-evoked auditory brainstem responses (eABR), and sequentially recording, by a recording

electrode in a body of a patient, the generated eABR; and

step 3. receiving, by a signal receiving apparatus that is respectively connected to a signal

acquisition apparatus and a signal processing apparatus, the eABR recorded by the recording

electrode and acquired by the signal acquisition apparatus, and determining, by the signal processing

apparatus, whether an eABR target waveform appears at a corresponding ABI electrode through

signal superimposition and automatic waveform recognition, to obtain response results of all of the

ABI electrodes and display the response results in a three-dimensional image manner.

2. The automated electrophysiological test method for an ABI as in claim 1, wherein an electrode

group for detecting the eABR is placed at a head of the patient, the electrode group comprising a

reference electrode placed at a top of the head, a ground electrode placed on a chest skin, and one or

more recording electrodes placed in front of two ears.

3. An electrophysiological test method for an auditory brainstem implant (ABI) based on cochlear

nucleus action potentials (CNAP), comprising:

Si, implanting an ABI electrode array;

S2, using any one of to-be-tested ABI electrodes on the ABI electrode array as a stimulating

electrode to emit an electrical stimulation;

S3, using any other one of the ABI electrodes on the ABI electrode array as a recording

electrode of the stimulating electrode, the recording electrode being configured to receive an

electrical stimulation signal transmitted by the stimulating electrode and record electrically-evoked cochlear nucleus action potentials;

S4. determining whether an electrically-evoked cochlear nucleus action potential target

waveform is obtained: if an electrically-evoked cochlear nucleus action potential target waveform is

obtained, the stimulating electrode being correctly placed; and if an electrically-evoked cochlear

nucleus action potential target waveform is not obtained, the stimulating electrode being incorrectly

placed, performing fine-tuning on a position of the stimulating electrode, and performing steps S2 to

S4 after the fine-tuning, until the electrically-evoked cochlear nucleus action potential target

waveform is obtained; and

S5. determining whether all of the to-be-tested ABI electrodes on the ABI electrode array

have been tested: if all of the to-be-tested ABI electrodes on the ABI electrode array have been

tested, ending an electrophysiological test process; and if not, performing step S2, and testing a next

one of the to-be-tested ABI electrodes until all of the to-be-tested ABI electrodes have been tested.

4. A non-invasive nerve clamp recording electrode, comprising:

a misaligned and complementary clip, comprising two clip pieces, front ends of the two clip

pieces being misalignedly opened to form an opening at a head of the clip, or the two clip pieces

being complementarily closed to form a complete closed loop structure;

a plurality of electrodes exposedly arranged at an inner side of the closed loop structure,

being electrically connected to an external signal generator and/or a signal receiver through a wire;

two pressing sections, respectively extending outward from a tail of the clip, and providing

a first force for making the clip open by transmitting an external pressing force applied to the two

pressing sections;

a first elastic body, arranged at rear ends of the clip pieces that are at the tail of the clip and

at the pressing sections, an elastic force of the first elastic body being used as a second force for

making the clip close; and

a second elastic body, arranged at the tail of the clip, two ends of the second elastic body

respectively abutting against the two clip pieces, and an elastic force of the second elastic body

being used as a third force for making the clip open.

5. A cochlear nucleus recording electrode, comprising: an electrode array, comprising a body, and a plurality of first test electrodes distributed on the same surface of the body; a wire, passing through the body, being connected to the plurality of first test electrodes correspondingly, and extending outside the body from a tail of the electrode array to receive an electrical stimulation signal; and a first clampable member, arranged on the wire extending from the tail of the electrode array.