A nuclear magnetic compatible haptic stimulation device

Abstract

The application discloses a kind of nuclear magnetic compatible tactile stimulation devices, comprising: drive control system and multichannel tactile stimulation system, the drive control system with the multichannel tactile stimulation system electrically connected;The drive control system is used to control the reciprocating tactile stimulation module of corresponding position on the multichannel tactile stimulation system generates tactile stimulation output, adjusts the frequency of output, output displacement and output force size, control stimulation time length;The multichannel tactile stimulation system is used to apply contact mechanics tactile stimulation to the hand of subject, tactile stimulation area covers whole hand, stimulates position, stimulation output displacement, force and regulates and controls stimulation duration.The present application tactile stimulation has high time and space resolution, output displacement, stimulation frequency is stable and adjustable, tactile coverage area is wide, and it is beneficial to tactile brain topological function diagram research.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of functional brain topography of touch, and particularly relates to a nuclear magnetic compatible touch stimulation device. BACKGROUND

[0002] In the field of brain science, because of the lag in the development of instruments for studying the brain function of touch, the study of the brain function of touch is relatively lagging behind the development of the study of the brain functions of vision, spatial cognition, etc. Touch is to take objective things as objects, generate different action potentials through touch receptors on the skin, convert physical quantities in the external world into nerve signals, and transmit them to the somatosensory cortex of the brain to stimulate the brain function of touch, thereby producing a complex process of sensation and cognition. The brain function area of touch is mainly located near the central sulcus of the brain, which is complex in shape and interwoven with other functional areas, which leads to the fact that, compared with the brain functions of other sensory organs, touch has a very important significance to human production and life. When a person touches an object with his hand, the touch receptors on the hand obtain touch information and transmit it to the somatosensory cortex of the brain through the touch nerves, and then integrate and recombine the information obtained by each part of the palm (touch perception brain function topography), and finally recognize the shape of the touched object. However, this brain cognitive process is still unclear. At present, human understanding of the brain function of touch is still only a tip of the iceberg, and how to create a brain function map of touch is the most urgent scientific problem to be solved, and is also the most concerned topic in brain disease diagnosis. The creation of the brain function map of touch perception can not only reveal the quantitative functional mapping relationship between human touch perception and the somatosensory cortex of the brain, but also help us explore the mystery of the brain and realize the early diagnosis of brain diseases, and provide a brain science basis for artificial intelligence and intelligent manufacturing. Functional magnetic resonance imaging, abbreviated as fMRI, is a new neuroimaging method, which measures the changes in blood flow caused by neuron activity by using magnetic resonance imaging. Since fMRI has the advantages of non-invasiveness and no radiation, it has been widely used in the study of the functional structure and brain atlas of human visual, auditory, somatosensory cortex and parietal cortex since the 1990s.

[0003] However, due to the lack of high-precision tactile brain activity stimulation terminal system, the research on human brain tactile brain activity is greatly limited, and the main problems of the high-precision tactile brain activity stimulation terminal system are the stimulation terminal configuration in the limited space and the compatibility of the equipment in the strong magnetic field. The stimulation generation methods of the stimulation providing device in the prior art mainly include pneumatic type and piezoelectric ceramic type. The pneumatic transmission method mainly includes the following: 1, providing stimulation by vibrating a diaphragm; 2, fixing a nozzle directly on the stimulation site to generate stimulation by air injection; 3, air is pushed to generate reciprocating motion of the air cylinder through the control of the reversing valve, so as to drive the reciprocating vibration of the guide wire to realize the stimulation of the target position. Due to the limitation of the compression coefficient of the gas, the pneumatic stimulation method can provide a low stimulation frequency, and the experimental frequency available for selection is less in the experiment. The piezoelectric ceramic type mainly relies on the inverse piezoelectric effect of the piezoelectric ceramic to convert electrical energy into mechanical energy and then generate mechanical vibration to provide tactile stimulation. However, the current piezoelectric ceramic sheet has a large volume, low resolution in arrangement, and relatively small displacement. Therefore, under the trend of increasingly precise tactile stimulation requirements, it is necessary to develop a tactile stimulation device that has high stimulation frequency and spatial and temporal accuracy, and also has the ability to cover the full terrain of the human skin. SUMMARY

[0004] The purpose of the present application is to provide a nuclear magnetic compatible tactile stimulation device, which has high spatial and temporal resolution, stable and adjustable output displacement and stimulation frequency, and wide tactile coverage area, which is beneficial to the study of tactile brain topology function map.

[0005] To achieve the above purpose, the present application provides a nuclear magnetic compatible tactile stimulation device, comprising: a driving control system and a multi-channel tactile stimulation system, the driving control system is electrically connected with the multi-channel tactile stimulation system;

[0006] The driving control system is used for controlling the reciprocating tactile stimulation module at the corresponding position of the multi-channel tactile stimulation system to generate tactile stimulation output, adjusting the frequency, output displacement and output force of the output, and controlling the stimulation time length.

[0007] The multi-channel tactile stimulation system is used for applying contact mechanical tactile stimulation to the hands of the subjects, covering the whole hand with tactile stimulation area, stimulating position, stimulating output displacement, force and regulating stimulation time.

[0008] Optionally, the driving control system comprises a single-chip microcomputer control circuit module and a voltage amplification circuit module, the single-chip microcomputer control circuit module transmits signals to the single-chip microcomputer through USB, the signals include the output channel of the tactile stimulation, the output displacement, the output force and the output time of the corresponding channel, the single-chip microcomputer decodes and outputs a low-voltage square wave signal of a corresponding frequency to the voltage amplification circuit module through the corresponding pin of the corresponding channel.

[0009] The voltage amplification circuit module is configured to amplify the signal voltage after receiving the low-voltage square wave signal generated by the single-chip microcomputer control circuit module, and output a high-voltage square wave signal of the same frequency to a piezoelectric bimorph on the multi-channel stimulation system.

[0010] Optionally, the single-chip microcomputer control circuit module comprises a USB-micro interface, a USB-UART data conversion, an LDO chip, an MCU single-chip microcomputer, and a plurality of FPC interfaces.

[0011] The MCU single-chip microcomputer communicates with a PC through the USB-micro interface.

[0012] The PC signal is converted by the USB-micro interface, converted by the USB-UART data conversion, and stepped down by the LDO chip, and is transmitted to the MCU single-chip microcomputer for decoding, and is transmitted to the voltage amplification circuit module through the FPC interface after decoding.

[0013] Optionally, the single-chip microcomputer control circuit module and the voltage amplification circuit module are connected in communication through an FPC line; the voltage amplification circuit module comprises a plurality of FPC interfaces, a triode amplification circuit, and a DB15 interface; the triode amplification circuit amplifies the low-voltage square wave signal into a high-voltage driving signal of the same frequency, and transmits the high-voltage driving signal of the same frequency to the piezoelectric bimorph of the multi-channel haptic stimulation system through the DB15 interface, to drive the multi-channel haptic stimulation system to generate haptic stimulation.

[0014] Optionally, the triode amplification circuit comprises a triode element and a protection current limiting circuit, configured to amplify the low-voltage control signal and protect the circuit.

[0015] Optionally, the multi-channel haptic stimulation system comprises a hand conforming fixing device and a reciprocating haptic stimulation module, the reciprocating haptic stimulation module is arranged on the hand conforming fixing device, and the reciprocating haptic stimulation module is in sliding connection with the hand conforming fixing device.

[0016] Optionally, the hand conforming fixing device comprises a signal line storage box, a palm base, a finger sliding slot, a palm sliding slot, a thumb moving pair, a thumb rotating pair, a thumb sliding slot, a thumb support, a finger support and a palm support, all signal lines of the piezoelectric bimorph are fixed by the signal line storage box, the palm base is fixedly connected to the signal line storage box, the finger sliding slot is detachably connected to the sliding slot of the palm base, the palm sliding slot is detachably connected to the sliding slot of the palm base, the thumb moving pair is detachably connected to the sliding slot of the palm base, the thumb rotating pair is detachably connected to the thumb moving pair, the thumb sliding slot is flange-structured with the thumb rotating pair, and the thumb support, the finger support and the palm support are respectively clamped with the thumb sliding slot, the finger sliding slot and the palm sliding slot.

[0017] Optionally, the reciprocating tactile stimulation module comprises a fixing frame, a piezoelectric bimorph, a guide rail, a rocker, a sliding rod, a sliding block and a stimulation array, the fixing frame is slidably connected to the hand conforming fixing device, the piezoelectric bimorph is inserted into the mounting hole of the fixing frame and placed side by side, the guide rail is fixedly connected to the two side guide rail mounting holes of the fixing frame, one end of the rocker has a slot and is splicedly connected to the piezoelectric bimorph, the other end of the rocker has a hole, the sliding rod is inserted into the hole of the rocker, the sliding block is connected to the guide rail through the through hole on the sliding block, and the stimulation array is splicedly connected to the sliding block through the bottom trapezoidal sliding slot.

[0018] Optionally, the piezoelectric bimorph is a sheet, each side of the sheet has a piezoelectric ceramic, after two sides are applied with square wave voltage signals at the same frequency, the piezoelectric bimorph bends left and right at the same frequency to form oscillation, and the piezoelectric bimorph is the original power drive of the nuclear magnetic compatible tactile stimulation device.

[0019] The technical effect of the present application is that the nuclear magnetic compatible tactile stimulation device is disclosed, the multi-channel tactile stimulator of the stimulation output end is designed to be nuclear magnetic compatible, the selected driver is a piezoelectric bimorph, and other structural members are all ABS engineering plastics 3D printed and processed, and the selected signal line is a pure silver shielding line. After the prototype is processed, a water film experiment is carried out in a 3T nuclear magnetic environment, and it is verified that the output performance is excellent in the nuclear magnetic environment, and the signal acquisition is basically not affected. The hand conforming fixing device can carry 23 channels of tactile stimulation modules, and can simultaneously perform precise tactile stimulation on the whole hand. The hand conforming fixing device can adjust the position of the stimulation module according to the size and shape of the test hand, so as to realize precise and wide coverage, high spatial resolution tactile stimulation. The magnetic resonance compatible tactile stimulation module is a full-terrain adaptive tactile stimulation device, which can be flexibly arranged and stimulate any position on the surface of the human skin. The stimulation array can be replaced, and can be customized according to the test hand shape and skin surface curvature, or can be designed into different stimulation shapes or different number of stimulation points, so as to meet the paradigm requirements of various tactile stimulation experiments. The output force of the tactile stimulation module is adjustable and controllable. By adjusting the output square wave voltage of the piezoelectric bimorph through the amplification circuit unit, the stimulation force of the tactile stimulation module can be controlled. The post-circuit at the output end of the amplification circuit module protects the transistor circuit and also plays a role in energy storage for the piezoelectric ceramic output. The introduction of inductance and current limiting resistance protects the transistor circuit affected by the reverse impact current generated by the piezoelectric ceramic capacity, and in addition, the inductance solves the problem of phase lag of the piezoelectric ceramic capacity and also serves as an energy storage element to improve the output force potential of the tactile stimulation module. The present application is a nuclear magnetic compatible, full-terrain conforming, wide tactile coverage area, stable and adjustable and controllable physical tactile stimulation device. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the present application illustrated in the drawings and their descriptions are used to explain the present application and do not limit the present application. In the drawings:

[0021] Figure 1 The piezoelectric bimorph parameter diagram for the embodiment of the present application is shown in the figure;

[0022] Figure 2 The reciprocating tactile stimulation module schematic diagram for the embodiment of the present application is shown in the figure;

[0023] Figure 3 The hand conforming fixing device schematic diagram for the embodiment of the present application is shown in the figure;

[0024] Figure 4 The single-chip microcomputer control circuit unit circuit diagram for the embodiment of the present application is shown in the figure;

[0025] Figure 5 The voltage amplification circuit unit circuit diagram for the embodiment of the present application is shown in the figure;

[0026] Figure 6 Structure diagram of a nuclear magnetic resonance compatible tactile stimulation device according to an embodiment of the present application.

[0027] Figure 7 Circuit diagram of a piezoelectric bimorph wiring method according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0029] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown.

[0030] As shown in Figures 1-7 The present embodiment provides a nuclear magnetic resonance compatible tactile stimulation device, which comprises a driving control system and a multi-channel tactile stimulation system, wherein the driving control system is electrically connected to the multi-channel tactile stimulation system.

[0031] The driving control system is configured to control the reciprocating tactile stimulation modules at corresponding positions on the multi-channel tactile stimulation system to generate tactile stimulation output, adjust the frequency, output displacement and output force of the tactile stimulation output, and control the stimulation time length.

[0032] The multi-channel tactile stimulation system is configured to apply contact mechanical tactile stimulation to the hands of a subject, wherein the tactile stimulation area covers the whole hand, and the stimulation position, stimulation output displacement, force and stimulation time length are adjustable.

[0033] The driving control system is a control circuit configured to transmit a control signal to the multi-channel tactile stimulation system, so that the multi-channel tactile stimulation system generates tactile stimulation output. The driving control system is placed outside the nuclear magnetic resonance chamber, generally in the nuclear magnetic resonance control chamber, and the multi-channel tactile stimulation system is placed inside the nuclear magnetic resonance chamber.

[0034] The driving control system comprises a single-chip microcomputer control circuit unit and a voltage amplification circuit unit, and the two units are connected and communicate through FPC lines.

[0035] The single-chip microcomputer control circuit unit comprises: an MCU single-chip microcomputer STM32F407VET6, a USB-micro adapter, an LDO chip AMS1117, a USB-UART conversion chip FT232RL and an FPC interface, the MCU single-chip microcomputer communicates with a PC through the USB-micro, PC signals are converted by the USB-micro adapter, the LDO chip and the USB-UART conversion chip in sequence, and are transmitted to the MCU single-chip microcomputer for decoding, and the decoded signals are transmitted to the FPC through the GPIO pin of the single-chip microcomputer and are transmitted to the voltage amplification circuit unit through the FPC. The MCU can output 64-channel GPIO signals at most, and the single-chip microcomputer control circuit unit is provided with eight FPC interfaces, each of which is responsible for transmitting eight-channel signals.

[0036] The voltage amplification circuit unit comprises: an FPC interface, an 8-way transistor amplification circuit and a DB15 adapter. The single-way transistor amplification circuit comprises three transistor elements and a protection current limiting circuit. The transistor amplification circuit can amplify the low-voltage control signals transmitted by the single-chip microcomputer control circuit unit into high-voltage driving signals of the same frequency, and transmit the high-voltage driving signals to the piezoelectric bimorph of the multi-channel tactile stimulation system through the DB15, so that the piezoelectric bimorph is driven to generate tactile stimulation. The high-voltage level of the high-voltage driving signal can be adjusted by adjusting the voltage adjusting knob on the power supply, so as to adjust the output force and output displacement of the multi-channel tactile stimulation system.

[0037] The single-chip microcomputer control circuit unit and the voltage amplification circuit unit inside the driving control system are arranged separately, which separates the strong and weak electricity and plays a protective role, and is conducive to channel expansion.

[0038] The multi-channel tactile stimulation system comprises: a hand conforming fixing device and a reciprocating tactile stimulation module. The reciprocating tactile stimulation module is arranged on the hand conforming fixing device and is fixed to the sliding groove of the hand conforming fixing device through the bottom sliding block and the threaded structure.

[0039] The hand conforming fixing device comprises:

[0040] A signal line storage box in which all signal lines of the piezoelectric bimorph are arranged;

[0041] A palm base which is fixed to the signal line storage box by buckling;

[0042] A finger sliding groove which is connected to the sliding groove of the palm base by screwing and can move left and right on the sliding groove, and there are four of them corresponding to the four fingers of the subject;

[0043] A palm sliding groove which is connected to the sliding groove of the palm base by screwing and can move forward and backward on the sliding groove, and there are three of them which can cover the whole palm of the subject;

[0044] The thumb moving pair is connected to the palm base through a sliding groove and can move forward and backward on the sliding groove;

[0045] The thumb rotating pair is connected to the thumb moving pair through a screw thread and can rotate around the screw hole;

[0046] The thumb sliding groove is connected to the thumb rotating pair through a flange structure and a screw thread structure;

[0047] The thumb moving pair, the thumb rotating pair and the thumb sliding groove together realize the conforming of the device to the position of the thumb of the subject;

[0048] The thumb support, the finger support and the palm support are fixedly connected to the thumb sliding groove, the finger sliding groove and the palm sliding groove through clamping grooves, and together hold up the hand of the subject to facilitate the skin of the hand of the subject to receive the tactile stimulation.

[0049] The hand conforming fixing device is made of ABS engineering plastic, and the screws and nuts are made of nylon material without any metal, which is compatible with magnetic resonance.

[0050] The reciprocating tactile stimulation module comprises a fixed frame connected to the hand conforming device through a sliding groove structure, which serves as the base of the reciprocating tactile stimulation module and adjusts the position of the tactile stimulation by sliding on the hand conforming device;

[0051] The piezoelectric bimorph is inserted into the mounting hole of the fixed frame and has a cantilever beam structure, which generates vibration of corresponding frequency and amplitude after receiving a high-voltage driving square wave signal, and two are placed side by side;

[0052] The guide rail is fixedly connected to the guide rail mounting hole on both sides of the fixed frame and is made of carbon fiber;

[0053] The rocker has two ends, one end has a slot and is connected to the free end of the piezoelectric bimorph, and the other end has a hole;

[0054] The sliding rod is inserted into the holes of the two rockers and swings with the piezoelectric bimorph, and is made of carbon fiber;

[0055] The sliding block is connected to the guide rail through the through hole thereon and can move up and down along the guide rail, and a 45° sliding groove is provided thereon, the left and right sliding of the sliding rod in the 45° sliding groove is converted into the up and down vibration of the sliding block, and the displacement is equal;

[0056] The stimulation array is connected to the sliding block through the bottom trapezoidal sliding groove and the sliding block moves up and down together, and the upper surface is a skin contact surface, which can be customized according to the shape of the skin surface of the subject, and can be designed as an array electric stimulation type or a shape contact type.

[0057] All the materials and driving devices selected in the multi-channel tactile stimulation system are nuclear magnetic compatible materials. The signal lines are pure silver lines. The processing material of the adaptive fixing device is ABS engineering plastic, which has excellent heat resistance, dimensional stability, impact resistance, and excellent processing fluidity. Therefore, it can be applied to thin-walled and complex-shaped products to maintain their excellent performance and formability of plastic and ester materials. The driver of the reciprocating tactile stimulation module is selected as a piezoelectric bimorph. The piezoelectric bimorph is the core element of the design, and its performance parameters are the basis for subsequent mechanism design. The piezoelectric bimorph is mainly composed of upper and lower piezoelectric ceramics and an intermediate layer of a substrate. Since the mechanical structure part needs to be placed in the nuclear magnetic chamber as a whole, the substrate of the piezoelectric bimorph can only be selected from non-magnetic glass fiber or carbon fiber materials. Because of the multi-channel requirement of the device, the existing mature products are considered to reduce the manufacturing cost and the maintenance cost. After consulting materials and comparing products from multiple companies, the QDT52-7.1-0.68-1 type long piezoelectric bimorph of Nanjing Ran Creative Company is finally selected.

[0058] During the experiment, the subject lies flat in the nuclear magnetic machine, and one hand is placed on the hand adaptive fixing device of the multi-channel tactile stimulation system. The experimenter sends the experimental paradigm command in the nuclear magnetic control room, and the reciprocating tactile stimulation module in the hand adaptive fixing device generates corresponding tactile vibration stimulation.

[0059] The multi-channel tactile stimulation system is composed of a hand adaptive fixing device and a reciprocating tactile stimulation module.

[0060] The driving part of the reciprocating tactile stimulation module is a piezoelectric bimorph. The piezoelectric bimorph is the core element of the design, and its performance parameters are the basis for subsequent mechanism design. The piezoelectric bimorph is mainly composed of upper and lower piezoelectric ceramics and an intermediate layer of a substrate. Since the mechanical structure part needs to be placed in the nuclear magnetic chamber as a whole, the substrate of the piezoelectric bimorph can only be selected from non-magnetic glass fiber or carbon fiber materials. The driving ceramic is loaded with 200V driving voltage on both ends of the bimorph according to the driving frequency, which drives the slider designed in the upper section to make reciprocating linear motion to form tactile stimulation. The piezoelectric bimorph wiring method is as follows Figure 7The positive electrode of one end of the piezoelectric sheet is connected to a 200V voltage, the negative electrode of the other end is grounded, and the remaining positive and negative electrodes on both sides are connected together and controlled by a driving signal. When the driving signal is 200V, that is, the driving voltage is in the yellow line, the voltage difference between the positive and negative electrodes of the upper end ceramic of the piezoelectric bimorph is 0V, and the voltage difference of the lower end is 200V. The ceramic at the lower end of the piezoelectric bimorph contracts, causing the piezoelectric bimorph to bend downward. When the driving voltage is in the blue line, the voltage difference between the positive and negative electrodes of the upper end ceramic of the piezoelectric bimorph is 200V, and the voltage difference of the lower end is 0V. The ceramic at the upper end of the piezoelectric bimorph contracts, causing the piezoelectric bimorph to bend upward. In this way, the position of the piezoelectric bimorph can be controlled by controlling the driving voltage. When the driving voltage fluctuates according to the set parameters, the bimorph will also vibrate according to the parameters and drive the slider and the carbon fiber to stimulate the reciprocating movement of the guide wire to form a tactile stimulation.

[0061] The reciprocating tactile stimulation module is composed of a base, a piezoelectric ceramic, a guide rail, a rocker, a slider, and a stimulation array. The piezoelectric ceramic, the base, the guide rail, and the rocker are fixedly connected. The piezoelectric ceramic can produce a transverse vibration with an amplitude of 2mm after receiving a 0V / 200V square wave. The slider and the guide rail, rocker are slidingly connected, the slider and the stimulation array are fixedly connected through a sliding groove, and the stimulation array can be designed and replaced according to experimental requirements and connected through the sliding groove and the slider. The slope-rail mechanism on the slider converts the transverse displacement vibration generated by the piezoelectric ceramic into vertical direction displacement vibration with the same displacement, and transmits it to the subject's hand through the stimulation array, thereby forming a reciprocating tactile stimulation. The stimulation array can be replaced and customized according to the subject's hand shape and skin surface curvature. It can also be designed into different stimulation shapes or different number of array stimulation points, meeting the paradigm requirements of various tactile stimulation experiments.

[0062] The hand conforming fixation device includes a signal line storage box, a palm base, a finger sliding groove, a palm sliding groove, a thumb moving pair, a thumb sliding groove, a thumb rotating pair, a thumb support, a finger support, and a palm support. The finger root sliding groove is a magnetic resonance compatible tactile multi-channel stimulator rack, which is provided with a sliding groove and is slidingly connected with a finger adjusting device, a palm adjusting device, and a thumb moving pair. The thumb moving pair and the thumb rotating pair are threadedly connected, and the thumb rotating pair is connected with the thumb adjusting device through a flange structure. This structure can conform to different palms.

[0063] In addition, the reciprocating tactile stimulation module can also be flexibly arranged on the whole body to realize tactile stimulation on the trunk, limbs and other parts.

[0064] The piezoelectric bimorph high-voltage driving module is mainly composed of a single-chip microcomputer for decoding a driving signal and a piezoelectric bimorph driving circuit. A 200V driving voltage is provided by a stabilized power supply and connected to the piezoelectric bimorph high-voltage driving module. The main function of the driving control circuit is to control the circuit to realize 3.3V small voltage control of the IO port to 200V driving voltage. Two triode switching circuits are designed as the control circuit. When the IO port is in the high level position, the triode Q1 is turned on. At the same time, the triode Q2 is in the off state, and the triode Q3 is in the on state, and the output port is grounded with a voltage of 0V. When the IO port is in the low level position, the triode Q1 is in the off state, and the triode Q2 is in the on state, and the output port is connected to the 200V power supply with a voltage of 200V. The driving circuit composed of the above principle diagram can be arranged on the piezoelectric bimorph high-voltage driving module according to the number of IO ports of the single-chip microcomputer to exert the driving control ability of the single-chip microcomputer as much as possible. In addition, according to the relationship between the output force and the control voltage by the inverse piezoelectric effect, the size of the driving voltage (200V) can be adjusted to achieve the function of adjusting the output force of the stimulation module.

[0065] Since the piezoelectric ceramic is in a low-frequency working state in the application, it can be approximated as a capacitor. According to the technical manual QDT52-7.1-0.68-1, the equivalent capacitance of the piezoelectric bimorph is 45-60nF. However, the equivalent capacitance of the piezoelectric ceramic will generate a reverse impact current under repeated high and low level inputs, which is easy to damage the triode element. In addition, the capacitor will generate a phase lag phenomenon, which affects the time response ability of the device output. In view of the above two points, current limiting resistors Ro and Ro2 and inductors Lo are introduced at the voltage output end. The introduction of inductors on the one hand weakens the reverse impact current, so that the reverse impact current will not damage the triode device, and on the other hand solves the phase lag phenomenon caused by the capacitor. A current limiting resistor Ri is added between the triode amplification circuit and the single-chip microcomputer pin to protect the single-chip microcomputer.

[0066] In order to facilitate channel expansion, circuit upgrade and safety consideration of strong and weak current separation, the driving control system circuit is divided into a single-chip microcomputer driving circuit unit and a voltage amplification circuit unit.

[0067] The single-chip microcomputer driving circuit unit is equipped with an STM32F407VET6 single-chip microcomputer, which has a total of 100 pins and can provide 64 channel GPIO outputs, that is, it can simultaneously and independently control 64 channels of reciprocating tactile stimulation modules. The basic working unit of the voltage amplification circuit unit is the above-mentioned triode amplification circuit, and eight triode amplification circuits are arranged on a single amplification unit circuit board.

[0068] The overall control scheme of the drive control part is shown in the figure. The host computer PC and the lower computer STM32 communicate through the serial port USART. The lower computer STM32 is located in the drive control circuit unit. The drive control unit has 64 channels of control voltage output. It is connected through the FPC line and the amplification circuit unit. One drive control circuit unit PCB can connect 8 method circuit unit PCB boards. The amplification circuit unit is connected with the device haptic stimulation output actuator through the DB15 cable. The drive control circuit unit and the amplification circuit unit communicate with the lower computer through the serial port UART of the host computer PC to send the haptic stimulation output parameters. The lower computer decodes and outputs the corresponding frequency 3.3V square wave signal through the corresponding single chip microcomputer pin. The signal is transmitted to the corresponding circuit of the amplification circuit unit through the FPC line. The signal is amplified and boosted to the same frequency 200V square wave signal. The movement of the piezoelectric ceramic is triggered, and the haptic stimulation is generated.

[0069] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A nuclear magnetic compatible haptic stimulation device, characterized in that, include: A drive control system and a multi-channel tactile stimulation system, wherein the drive control system is electrically connected to the multi-channel tactile stimulation system; The drive control system is used to control the reciprocating tactile stimulation module at the corresponding position on the multi-channel tactile stimulation system to generate tactile stimulation output, adjust the output frequency, output displacement and output force, and control the stimulation time. The multi-channel tactile stimulation system is used to apply contact-type mechanical tactile stimulation to the subject's hand, with the tactile stimulation area covering the entire hand, and the stimulation position, stimulation output displacement, force, and stimulation duration can be adjusted. The multi-channel tactile stimulation system includes a hand conformal fixation device and a reciprocating tactile stimulation module. The reciprocating tactile stimulation module is disposed on the hand conformal fixation device and is slidably connected to the hand conformal fixation device. The reciprocating tactile stimulation module includes: a fixed frame, piezoelectric bicrystalline wafers, a guide rail, a rocker arm, a slider, a slider, and a stimulation array. The fixed frame and the hand conformal fixing device are slidably connected. The piezoelectric bicrystalline wafers are inserted into the mounting holes of the fixed frame and placed side by side. The guide rail is fixedly connected to the guide rail mounting holes on both sides of the fixed frame. One end of the rocker arm has a groove for splicing with the piezoelectric bicrystalline wafers, and the other end of the rocker arm has a hole. The slider is inserted into the hole of the rocker arm. The slider is connected to the guide rail through a through hole on the slider. The stimulation array is spliced ​​with the slider through a trapezoidal groove at the bottom.

2. The NMR-compatible tactile stimulation device as described in claim 1, characterized in that, The drive control system includes a microcontroller control circuit module and a voltage amplifier circuit module. The microcontroller control circuit module transmits signals to the microcontroller via USB. The signals include the output channel of tactile stimulation, the corresponding channel output displacement, output force and output time. The microcontroller decodes the signals and outputs a low-voltage square wave signal of the corresponding frequency to the voltage amplifier circuit module at the corresponding pin of the corresponding channel. The voltage amplification circuit module is used to amplify the signal voltage after receiving the low-voltage square wave signal generated by the microcontroller control circuit module, and output a high-voltage square wave signal of the same frequency to the piezoelectric bicrystalline chip on the multi-channel stimulation system.

3. The NMR-compatible tactile stimulation device as described in claim 2, characterized in that, The microcontroller control circuit module includes: a USB-micro adapter, a USB-UART data converter, an LDO chip, an MCU microcontroller, and several FPC interfaces; The MCU microcontroller communicates with the PC via a USB-micro adapter. The PC signal sequentially passes through the USB-micro adapter, the USB-UART data converter for data conversion, and the LDO chip for voltage reduction before being transmitted to the MCU for decoding. After decoding, it is transmitted to the voltage amplifier circuit module through the FPC interface.

4. The NMR-compatible tactile stimulation device as described in claim 3, characterized in that, The single-chip microcomputer control circuit module is in communication connection with the voltage amplification circuit module through FPC line; the voltage amplification circuit module comprises: several FPC interfaces, a triode amplification circuit and a DB15 adapter; the triode amplification circuit amplifies the low-voltage square wave signal into a high-voltage driving signal of the same frequency, and transmits the high-voltage driving signal of the same frequency to the piezoelectric bimorph of the multi-channel tactile stimulation system through the DB15 adapter, so as to drive the multi-channel tactile stimulation system to generate tactile stimulation.

5. The nuclear magnetic resonance compatible tactile stimulation device of claim 4, wherein, The triode amplification circuit comprises a triode element and a protection current limiting circuit, which is used for voltage amplification of the low-voltage square wave signal and protection of the circuit.

6. The nuclear magnetic resonance compatible tactile stimulation device of claim 1, wherein, The hand conforming fixing device comprises: a signal line storage box, a palm base, a finger sliding groove, a palm sliding groove, a thumb moving pair, a thumb rotating pair, a thumb sliding groove, a thumb support, a finger support and a palm support, all signal lines of the piezoelectric bimorph are fixed by the signal line storage box, the palm base is fixedly connected to the signal line storage box, the finger sliding groove is detachably connected to the sliding groove of the palm base, the palm sliding groove is detachably connected to the sliding groove of the palm base, the thumb moving pair is detachably connected to the sliding groove of the palm base, the thumb rotating pair is detachably connected to the thumb moving pair, the thumb sliding groove is connected to the flange structure of the thumb rotating pair, and the thumb support, the finger support and the palm support are respectively clamped to the thumb sliding groove, the finger sliding groove and the palm sliding groove.

7. The MRI-compatible haptic stimulation device of claim 1, wherein, The piezoelectric bimorph is a thin sheet, each side of the thin sheet has a piezoelectric ceramic, after square wave voltage signals of the same frequency are applied to both sides, the piezoelectric bimorph bends left and right at the same frequency to form oscillation, and the piezoelectric bimorph is the original power drive of the nuclear magnetic resonance compatible tactile stimulation device.

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