CN117771567A - Force touch stimulation system and force touch stimulation method based on focused ultrasound - Google Patents
Force touch stimulation system and force touch stimulation method based on focused ultrasound Download PDFInfo
- Publication number
- CN117771567A CN117771567A CN202311722252.0A CN202311722252A CN117771567A CN 117771567 A CN117771567 A CN 117771567A CN 202311722252 A CN202311722252 A CN 202311722252A CN 117771567 A CN117771567 A CN 117771567A
- Authority
- CN
- China
- Prior art keywords
- stimulation
- focused ultrasound
- channel
- ultrasonic
- module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000000638 stimulation Effects 0.000 title claims abstract description 159
- 238000002604 ultrasonography Methods 0.000 title claims abstract description 45
- 238000000034 method Methods 0.000 title claims description 30
- 230000003321 amplification Effects 0.000 claims abstract description 16
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 16
- 230000005540 biological transmission Effects 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims abstract description 6
- 230000001953 sensory effect Effects 0.000 claims description 24
- 230000035807 sensation Effects 0.000 claims description 12
- 230000006870 function Effects 0.000 claims description 10
- 210000003811 finger Anatomy 0.000 claims description 8
- 230000037152 sensory function Effects 0.000 claims description 7
- 210000000245 forearm Anatomy 0.000 claims description 4
- 210000001617 median nerve Anatomy 0.000 claims description 4
- 210000003205 muscle Anatomy 0.000 claims description 4
- 210000003813 thumb Anatomy 0.000 claims description 4
- 230000009977 dual effect Effects 0.000 claims 2
- 230000000694 effects Effects 0.000 abstract description 7
- 230000035515 penetration Effects 0.000 abstract description 3
- 238000012360 testing method Methods 0.000 description 16
- 230000008447 perception Effects 0.000 description 10
- 210000003491 skin Anatomy 0.000 description 10
- 238000002474 experimental method Methods 0.000 description 6
- 230000006978 adaptation Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 5
- 230000003993 interaction Effects 0.000 description 5
- 210000004556 brain Anatomy 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 230000004044 response Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000001976 improved effect Effects 0.000 description 3
- 230000001965 increasing effect Effects 0.000 description 3
- 230000007774 longterm Effects 0.000 description 3
- 210000005036 nerve Anatomy 0.000 description 3
- 210000000578 peripheral nerve Anatomy 0.000 description 3
- 238000002560 therapeutic procedure Methods 0.000 description 3
- 208000006011 Stroke Diseases 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 210000003710 cerebral cortex Anatomy 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000004064 dysfunction Effects 0.000 description 2
- 210000003414 extremity Anatomy 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 230000007659 motor function Effects 0.000 description 2
- 230000001537 neural effect Effects 0.000 description 2
- 238000010079 rubber tapping Methods 0.000 description 2
- 210000000697 sensory organ Anatomy 0.000 description 2
- 210000004092 somatosensory cortex Anatomy 0.000 description 2
- 210000001519 tissue Anatomy 0.000 description 2
- 210000000707 wrist Anatomy 0.000 description 2
- 206010008190 Cerebrovascular accident Diseases 0.000 description 1
- 208000008238 Muscle Spasticity Diseases 0.000 description 1
- 206010033799 Paralysis Diseases 0.000 description 1
- 208000030886 Traumatic Brain injury Diseases 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000036982 action potential Effects 0.000 description 1
- 108091008698 baroreceptors Proteins 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000031018 biological processes and functions Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000003925 brain function Effects 0.000 description 1
- 239000002775 capsule Substances 0.000 description 1
- 210000003169 central nervous system Anatomy 0.000 description 1
- 208000015114 central nervous system disease Diseases 0.000 description 1
- 230000002490 cerebral effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 210000003780 hair follicle Anatomy 0.000 description 1
- 210000004247 hand Anatomy 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000010365 information processing Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000007794 irritation Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000004807 localization Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000028161 membrane depolarization Effects 0.000 description 1
- 210000000716 merkel cell Anatomy 0.000 description 1
- 230000004118 muscle contraction Effects 0.000 description 1
- 230000004220 muscle function Effects 0.000 description 1
- 210000004126 nerve fiber Anatomy 0.000 description 1
- 230000004007 neuromodulation Effects 0.000 description 1
- 210000002569 neuron Anatomy 0.000 description 1
- 206010033675 panniculitis Diseases 0.000 description 1
- 230000037361 pathway Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 210000001774 pressoreceptor Anatomy 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 108020003175 receptors Proteins 0.000 description 1
- 102000005962 receptors Human genes 0.000 description 1
- 238000007634 remodeling Methods 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 210000001044 sensory neuron Anatomy 0.000 description 1
- 230000021317 sensory perception Effects 0.000 description 1
- 230000031893 sensory processing Effects 0.000 description 1
- 210000002265 sensory receptor cell Anatomy 0.000 description 1
- 108091008691 sensory receptors Proteins 0.000 description 1
- 102000027509 sensory receptors Human genes 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 208000018198 spasticity Diseases 0.000 description 1
- 210000000278 spinal cord Anatomy 0.000 description 1
- 208000020431 spinal cord injury Diseases 0.000 description 1
- 238000007619 statistical method Methods 0.000 description 1
- 210000004304 subcutaneous tissue Anatomy 0.000 description 1
- 238000001356 surgical procedure Methods 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 210000000658 ulnar nerve Anatomy 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Landscapes
- Percussion Or Vibration Massage (AREA)
Abstract
The invention discloses a force touch stimulation system based on focused ultrasound, which comprises: the ultrasonic waveform generation module is used for generating ultrasonic waveforms; the power amplification module is connected with the ultrasonic waveform generation module and used for carrying out signal conversion and transmission on ultrasonic waveforms; and the stimulation module is connected with the power amplification module, receives signals of the power amplification module and outputs stimulation to the outside. The force touch stimulation system based on the focused ultrasound, disclosed by the invention, has the characteristics of noninvasive, focused and deep penetration on skin by utilizing the mechanical effect of the focused ultrasound, and can be used for avoiding the problem that the sense acuity is reduced along with the increase of the stimulation duration or the times.
Description
Technical Field
The invention belongs to the technical field of rehabilitation engineering, and particularly relates to a focused ultrasound-based force touch stimulation system and a focused ultrasound-based force touch stimulation method.
Background
The skin is the largest sensory organ of the body, and there are a variety of sensory receptors in the skin, including merkel cells, peripheral nerve fibers, subcutaneous tissue, hair follicles, etc., which are very sensitive to different tactile stimuli. When the skin is subjected to tactile stimuli, receptors at the sensory nerve endings convert these stimuli into nerve impulses. These nerve impulses are transmitted through sensory nerve fibers to the central nervous system, where the spinal cord plays a key role in primary information processing, responsible for the transmission and preliminary processing of basic sensory information. These signals then continue to be transmitted to different areas of the cerebral cortex, such as the somatosensory cortex, for further sensory processing and perception. Further, sensory information is processed and integrated at multiple levels in the brain to create a sensory experience with respect to the touch, including integration of sensory information for determining characteristics of the stimulus, such as shape, hardness, temperature, texture, and the like. Ultimately, the haptic information is used by the brain to identify objects, perceive external environments, and guide the corresponding reactions. Such as grasping, touching or avoiding irritation.
For typical sensory dysfunction such as reduced sense of touch and loss of sense of touch caused by central nervous system diseases such as stroke, brain trauma, spinal cord injury, etc., tactile stimulation is one of the therapeutic methods used clinically to restore the sensory function of patients. Clinically, the touch feeling such as pressure, vibration, temperature and the like is mainly transmitted to the skin or other sense organs of a human body in a physical, mechanical or electrical mode, so that the information perception and fine action control of the environment of a patient are improved, and the human body sense function is effectively recovered. In addition, haptic stimulation has been widely studied and applied in the field of human-computer interaction such as virtual reality, robotic control, tele-teleoperation, and the like.
Currently, the methods for realizing human body tactile function reconstruction by physical stimulation of the periphery are mainly divided into two types: mechanical stimulation and electrical stimulation. The mechanical stimulus comprises vibration stimulus and pressure stimulus, wherein the vibration stimulus adopts a miniature direct current motor, a voice coil or a solenoid and the like as a stimulus unit (vibrator), and the vibrator is controlled to generate mechanical vibration so as to transmit low-frequency vibration stimulus to the skin of a user; the pressure stimulus is to control the piezoelectric material, gas or liquid capsule cavity to produce mechanical displacement, and the probe is perpendicular to the skin, so as to apply pressure stimulus to the skin of the user. The university of hong Kong university research team uses textile to monitor the response of mechanical stimulus to cerebral cortex, which they consider to significantly activate the sensory-motor area of the brain. The mechanical stimulus tactile feedback-based novel tactile sensor array manipulator is successfully developed by the university of hong Kong city, and the control speed and the degree of freedom of the manipulator are improved through the tactile feedback of baroreceptors. The electric stimulation stimulates neurons by using electric current, triggers action potential propagation to activate a sensory-motor pathway to stimulate muscle contraction, thereby causing depolarization of peripheral sensory-motor nerves and achieving the purpose of repairing sensory-motor functions. With the explosive development of flexible sensing technology in recent years, there is increasing evidence that non-invasive electrical stimulation therapy significantly improves the tactile function of sensory dysfunction patients and has a positive effect on pain relief, spasticity and enhancement of motor function. North Carlai Luo Nada research team successfully induced multiple haptics in multiple phantom finger areas of forearm amputees by applying electrical stimulation to an electrode array distributed near the median and ulnar nerves. The John Hopkins university research team found that electrical stimulation-based haptic feedback could alter the dynamic brain connection of the amputee's somatosensory cortex, improving the ability of the affected side limbs to feel. In rehabilitation of motor functions after cerebral apoplexy, research team in Shanghai university of traffic finds that haptic feedback based on electrical stimulation plays an important role in improving the control capacity of affected limbs of hemiplegic patients and promoting brain function remodeling.
The main problem with mechanical stimulation for haptic reconstruction is that mechanical vibrators often require a certain spatial volume, resulting in a low spatial selectivity of the mechanical stimulation, which makes it difficult to achieve accurate stimulation of specific areas, limiting their effectiveness in some applications requiring a high localization. In addition, the traditional mechanical stimulation method generally only provides a limited information mode, mainly uses vibration or pressure as a main component, and cannot provide more complicated tactile information, such as temperature, shape and the like, so that the application of mechanical stimulation in the aspect of simulating diversified tactile feedback is limited. The electric stimulation is used for tactile reconstruction, has the advantages of simplicity, easiness, light weight, simplicity, high energy conversion efficiency, convenience in program control and the like, and is difficult to provide continuous and stable tactile stimulation. In particular, the same location for a long time or under high intensity stimulation may cause a decrease in sensory acuity, causing a phenomenon of sensory adaptation to the human body. The adaptation degree is not only related to the stimulus intensity, but also to the stimulus frequency and the stimulus duration. In short, electrotactility is not a constant and the intensity of sensation induced by it may decrease with increasing stimulation time.
Aiming at the problems of low spatial selectivity of mechanical stimulation, single feedback information mode, easy human body sensory adaptation caused by continuous electric stimulation and the like, the method for providing the multi-mode force touch stimulation with noninvasive, high spatial selectivity and stability is an important technical requirement at present. Focused ultrasound stimulation is a novel neuromodulation method based on the acoustic mechanical effect, emitting ultrasound waves (> 20 kHz) at specific frequencies and energies, delivering mechanical forces in biological tissue, thus achieving non-invasive stimulation. Low frequency focused ultrasound has been increasingly used in recent years for central nervous regulation as an emerging technique for modulating neural tissue activity. Compared with mechanical stimulation, the low-intensity focused ultrasonic stimulation can realize noninvasive tactile stimulation with high spatial selectivity, and has the advantages of high response speed, wide parameter adjustment range, controllable stimulation depth and the like. In addition, the biological action principle of the focused ultrasound is different from that of the electric stimulation, so that more stable force touch reconstruction effect can be brought. Therefore, the patent proposes to use a low-intensity focused ultrasound technology to build an ultrasonic stimulation system, and the basic frequency of a transducer is selected to adjust pulse repetition frequency, sound pressure combination and the like so as to realize the force touch reconstruction with different types, different intensities and long-term stability.
Disclosure of Invention
The first object of the invention is to provide a force touch stimulation system based on focused ultrasound, which solves the defects of low mechanical stimulation space selectivity and accuracy, reduced sense acuity caused by long-time use of electric stimulation and easy human body discomfort in the prior art.
The second object of the invention is to provide a force touch stimulation method based on focused ultrasound.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
a focused ultrasound-based haptic stimulation system, comprising:
the ultrasonic waveform generation module is used for generating ultrasonic waveforms;
the power amplification module is connected with the ultrasonic waveform generation module and used for carrying out signal conversion and transmission on ultrasonic waveforms;
and the stimulation module is connected with the power amplification module, receives signals of the power amplification module and outputs stimulation to the outside.
In the invention, the ultrasonic waveform generation module is a double-channel function signal generator.
Further, the dual-channel function signal generator comprises a first channel and a second channel; the first channel is used for designating pulse repetition frequency components of waveforms, and the second channel is used for generating sound pressure of stimulus waveforms; the first channel is a trigger input channel of the second channel.
Further, the ultrasonic waveform is a sine wave.
Further, the pulse duration of the ultrasonic waveform is set by adjusting the number of cycles of each pulse on the second channel; the stimulation duration is set by adjusting the number of pulses on the first channel.
In the invention, the power amplification module is a power amplifier.
Further, the power amplifier is a linear radio frequency amplifier.
In the invention, the stimulation module is an ultrasonic transducer.
Furthermore, the ultrasonic transducer is a magnetic resonance compatible gas matrix piezoelectric composite ultrasonic transducer and is provided with a collimator. By adjusting the geometric shape and the position of the collimator, parameters such as surface energy, surface sound pressure, focal zone energy, focal zone sound pressure and the like are adjusted, so that the stimulation quantity matching at different fundamental frequencies at the focus point is realized to the greatest extent.
Studies have shown that low frequency focused ultrasound with fundamental frequencies between 0.2MHz and 2.67MHz is more prone to induce peripheral nerve sensations, while the fundamental frequency of the ultrasound transducer directly affects the focal zone size and stimulation depth. In the invention, the fundamental frequency of the ultrasonic transducer is 0.2-2.67MHz.
Further, the fundamental frequency of the ultrasonic transducer is 0.2-1MHz.
A focused ultrasound-based haptic stimulation method, comprising the steps of:
selecting a stimulation site as a target sensory area, evaluating the sensory function of the target sensory area, and determining the target stimulation area; and placing the target stimulation area above a stimulation module of the force touch stimulation system, selecting safe stimulation parameters to act on the stimulation site, and performing force touch stimulation.
In the invention, the stimulation sites comprise the wrist bending muscle of the forearm corresponding to the median nerve, the thumb and palm muscle of the palm, and the index finger, middle finger and thumb.
In the invention, the sensory function of the target sensory area is evaluated by methods such as hairbrush, tuning fork skin vibration qualitative inspection and the like.
Further, the sensory functions include touch, pressure, vibration, and two-point discrimination.
In the invention, the stimulation parameters comprise fundamental frequency, duty ratio, stimulation duration, pulse repetition frequency and sound pressure of the ultrasonic transducer.
Further, the stimulation parameter is a combination of sound pressure, pulse repetition frequency and duty ratio. Through tests, the pulse repetition frequency, the sound pressure and the duty ratio are important factors influencing the sound field distribution. The pulse repetition frequency and the sound pressure are directly key parameters affecting the feeling type and the intensity, different force touch feeling can be generated by adjusting different pulse repetition frequencies, and different force touch feeling intensity can be generated by different sound pressures. These two parameters were thus tested in combination to induce different intensity force haptics for different sensory types. The two parameters are first combined and the subject is allowed to adapt to the stimulus level at the determined reference stimulus level using classical two-stage methods. Subsequently, after the adaptation phase, a less or more varying stimulus is introduced, requiring the subject to determine whether this variation is perceptible. The response of the subjects was recorded, including their judgment as to whether a change was felt, and if so, the extent of the change was confirmed.
Further, according to the combination of the sound pressure and the pulse repetition frequency, four force touch senses, namely, weak vibration sense, strong vibration sense, weak touch pressure sense and strong touch pressure sense, are obtained.
Further, the pulse repetition frequency is 8Hz-86 Hz, and the sound pressure is 250mvpp-700mvpp.
Further, the repetition frequency of the weak vibration sense pulse is 8-12Hz, and the sound pressure is 250-450mvpp; the repetition frequency of the strong vibration sense pulse is 18-26Hz, and the sound pressure is 500-700mvpp; the repetition frequency of the weak touch pressure sense pulse is 46-56Hz, and the sound pressure is 250-450mvpp; the repetition frequency of the strong touch pressure sense pulse is 72-86Hz, and the sound pressure is 500-700mvpp.
Further, the weak vibration sensation PRF is 10Hz,350mvpp; the strong vibration sense is 20Hz,550mvpp; the weak touch pressure sense is 50Hz,350mvpp; the sense of strong touch pressure is 80Hz,550mvpp.
In the invention, the duty cycle is 1% -3%.
The invention has the following beneficial effects:
(1) The force touch stimulation system based on the focused ultrasound, disclosed by the invention, has the characteristics of noninvasive, focused and deep penetration on skin by utilizing the mechanical effect of the focused ultrasound, and can be used for avoiding the problem that the sense acuity is reduced along with the increase of the stimulation duration or the times.
(2) The invention combines the minimum perceived difference of the physical indexes and the Weber score, successfully realizes 4 highly-distinguished power touch sensations by carefully designing and accurately controlling the pulse repetition frequency and the sound pressure parameter of ultrasonic stimulation, and respectively corresponds to different intensity degrees of vibration and intensity changes of touch pressure, and each touch sensation can be stably induced for a long time. The innovative research provides an important experimental basis for the field of haptic perception, deepens understanding of haptic sensation, and provides powerful guidance and inspiring for future perception research and engineering application.
(3) According to the invention, a psychological and physical experiment design method is adopted to design a subjective experiment for distinguishing the stimulus type in a short time, the accuracy of ultrasonic touch stimulus is counted, and the accuracy and the stability of the experimental result are further verified by respectively counting the number of recognition errors of 4 tests according to the result of each test.
Drawings
The technical scheme of the invention is further described below with reference to the specification, the drawings and the specific embodiments.
FIG. 1 is a schematic diagram of an ultrasonic stimulation system constructed in accordance with the present invention;
FIG. 2 is a graph of minimum perceived difference index analysis for selecting pulse repetition frequencies;
FIG. 3 is a graph of minimum perceived difference index analysis of selected sound pressures;
FIG. 4 is a graph of ultrasound stimulation parameter combinations;
FIG. 5 shows subjective test accuracy (ES is electrical stimulation, other ultrasonic stimulation at different fundamental frequencies);
FIG. 6 is a graph showing the number of recognition errors for different test runs in subjective testing;
reference numerals in the drawings are as follows: 1. an ultrasonic waveform generation module; 2. a power amplification module; 3. a stimulation module; 4. a first channel; 5. and a second channel.
Detailed Description
The invention firstly constructs a force touch stimulation system based on focused ultrasound, and the system can complete the generation and the transmission of the ultrasound. In addition, the invention provides a focused ultrasound-based force touch stimulation method, which is based on a focused ultrasound-based force touch stimulation system, optimizes ultrasonic transducer fundamental frequency selection, and reconstructs force touch with different intensities and types by adjusting various ultrasonic stimulation parameters. The method carries out force touch stimulation by adjusting pulse repetition frequency and sound pressure, and combines 2 psychophysical indexes: the minimum perceived difference (Just Noticeable Difference, JND) and Weber Factor (WF) are used as the sensitivity and discrimination capability in different sensing tasks to find the optimal stimulation parameter combination, and realize the long-term stable induction method of different types of force touch under two intensities.
Example 1
A focused ultrasound based haptic stimulation system as shown in fig. 1, comprising:
an ultrasonic waveform generation module 1 for generating an ultrasonic waveform;
the power amplification module 2 is connected with the ultrasonic waveform generation module 1 and is used for carrying out signal conversion and transmission on ultrasonic waveforms;
and the stimulation module 3 is connected with the power amplification module 2, receives the signal of the power amplification module 2 and outputs stimulation to the outside.
In this embodiment, the ultrasonic waveform generation module 1 is a dual-channel function signal generator. The two-channel function signal generator comprises a first channel 4 and a second channel 5; the first channel 4 is for designating a pulse repetition frequency component of the waveform, and the second channel 5 is for generating sound pressure of the stimulus waveform; the first channel 4 is the trigger input channel of the second channel 5. The ultrasonic waveform is a sine wave. The pulse duration of the ultrasonic waveform is set by adjusting the number of cycles per pulse on the second channel 5; the stimulation duration is set by adjusting the number of pulses on the first channel 4.
The power amplification module 2 is a power amplifier, which is a linear radio frequency amplifier. The stimulation module 3 is an ultrasound transducer. The ultrasonic transducer in this embodiment is a magnetic resonance compatible gas matrix piezoelectric composite ultrasonic transducer, and is provided with a collimator (not shown in the figure). By adjusting the geometric shape and the position of the collimator, parameters such as surface energy, surface sound pressure, focal zone energy, focal zone sound pressure and the like are adjusted, so that the stimulation quantity matching at different fundamental frequencies at the focus point is realized to the greatest extent. The fundamental frequency of the ultrasonic transducer is 0.2-2.67MHz. Studies have shown that low frequency focused ultrasound with fundamental frequencies between 0.2MHz and 2.67MHz is more prone to induce peripheral nerve sensations, while the fundamental frequency of the ultrasound transducer directly affects the focal zone size and stimulation depth. More preferably, the fundamental frequency of the ultrasonic transducer is 0.2-1MHz.
Example 2
A focused ultrasound-based haptic stimulation method, comprising the steps of:
selecting a stimulation site as a target sensory area, evaluating the sensory function of the target sensory area, and determining the target stimulation area; and placing the target stimulation area above the stimulation module, selecting safe stimulation parameters to act on the stimulation site, and performing force touch stimulation.
The specific process is as follows:
aiming at the characteristics of noninvasive, focusing and deep penetration of ultrasonic stimulation, the wrists and palms of the forearms and the index finger, the middle finger and the thumb corresponding to the median nerve are respectively selected as stimulation sites. The above stimulation sites are used as target sensory areas (the affected side of a patient is used as a stimulation area), and firstly, the sensory functions of the target sensory areas such as touch sense, pressure sense, vibration sense and two-point discrimination sense are evaluated by methods such as hairbrush and tuning fork skin vibration sense qualitative examination, and the target stimulation areas are determined. And then placing the target stimulation area on a film covered above an ultrasonic transducer of a force touch stimulation system stimulation module, selecting safe stimulation parameters to act on a stimulation site, and performing force touch stimulation. The stimulation parameters comprise fundamental frequency, duty ratio, stimulation duration, pulse repetition frequency and sound pressure of the ultrasonic transducer. The optimal stimulation site is determined based on subjective experiences of the subject.
The method provides scientific basis for the design of the tactile stimulus, combines two psychophysical indexes of JND (minimum perceptible difference) and WF (Weber score), and can more accurately determine the perception discrimination and comfort of the tactile stimulus. Parameters that cause the ultrasound stimulus to induce a sensory change include ultrasound transducer fundamental frequency, duty cycle, stimulus duration, pulse repetition frequency, sound pressure, etc. Wherein pulse repetition frequency, sound pressure and duty ratio are important factors influencing sound field distribution. Through tests, the pulse repetition frequency and the sound pressure are directly key parameters affecting the feeling type and the intensity, different force touch feeling can be generated by adjusting different pulse repetition frequencies, and different force touch feeling intensities can be generated by different sound pressures. These two parameters were thus tested in combination to induce different intensity force haptics for different sensory types. Firstly, combining the two parameters to obtain four force touch senses, namely weak vibration sense, strong vibration sense, weak touch pressure sense and strong touch pressure sense, and using a classical two-stage method to enable a subject to adapt to the stimulus level under the determined reference stimulus level. Subsequently, after the adaptation phase, a less or more varying stimulus is introduced, requiring the subject to determine whether this variation is perceptible. The response of the subjects was recorded, including their judgment as to whether a change was felt, and if so, the extent of the change was confirmed. Through multiple experiments, enough data are collected to calculate JND, i.e. a discernable threshold. And analyzing the JND data by using a statistical analysis method to determine the perception threshold under different tactile stimulation parameters. Finally, the parameter range of JND reaching more than 75% is included in the experimental range. In addition, subjects were guided to experience various tactile stimuli and were asked to subjectively evaluate the comfort of each stimulus. The objectivity of the evaluation results is ensured using standardized comfort assessment tools, such as visual analog scales. The comfort scores of the subjects were recorded and asked for their feelings under different stimulation conditions. And carrying out enough experiment times to obtain reliable comfort degree data. JND diagrams of pulse repetition frequency and sound pressure are obtained, and are shown in fig. 2 and 3. According to the selection of the above parameters, the preferred parameter ranges of the four force haptics (including weak and strong) are finally determined as shown in table 1 and the optimal parameters are shown in fig. 4.
TABLE 1 stimulation parameter combinations for different haptic types
| Haptic type | Pulse repetition frequency (Hz) | Sound pressure (mvpp) |
| Weak vibration | 8-12 | 250-450 |
| Weak touch pressure | 46-56 | 250-450 |
| Strong vibration | 18-26 | 500-700 |
| Strong touch pressure | 72-86 | 500-700 |
The combination of the 4 optimal stimulation parameters of the force touch sense is that the PRF (pulse repetition frequency) of the weak vibration sense is 10Hz and the sound pressure is 350mvpp; the strong vibration sense PRF is 20Hz, and the sound pressure is 550mvpp; the weak touch pressure sense PRF is 50Hz, and the sound pressure is 350mvpp; the high touch pressure sense PRF is 80Hz and the sound pressure is 550mvpp. In the above-described combination of pulse repetition frequency and sound pressure, the present embodiment can select a duty ratio of 1% -3%, and a better stimulation effect can be obtained.
The resulting 4 touches (including weak and strong) were subjectively tested and non-stimulated, respectively, and the stability of the force haptic reconstruction was evaluated. The subjective experiment contained a total of 4 small tests, each containing 4 tactile stimuli and no stimulus, of 5 types. Wherein each stimulus lasts for 2s respectively and is at rest for 5s after the stimulus is ended. Test 1 and test 2, test 3 and test 4 are each 5 minutes apart, while test 2 and test 3 are each 20 minutes apart. The tested report the stimulation type after each stimulation, wherein 0 is no stimulation, and 1-4 respectively represent four touch feeling of tapping, re-tapping, light pressing and heavy pressing. The final statistics of the accuracy of distinguishing different haptic types to be tested and the number of recognition errors under each test are shown in fig. 5 and 6.
According to the invention, 16 subjective report data tested under the completion of an ultrasonic touch stimulation experiment are used, and the results of each stimulation type are analyzed, so that the accuracy is slightly reduced under high-frequency high-intensity stimulation, and the range of other stimulation parameters is kept high. The results of each test also prove that the number of recognition errors is increased under the high-frequency high-intensity stimulation parameters, and the number of recognition errors in other stimulation ranges is lower. The ultrasonic stimulation has good stability in the optimal stimulation range, and the sensory acuity does not decrease with the increase of the stimulation times.
The invention mainly provides a stimulation system and a stimulation method for inducing different types and different strength of force touch based on focused ultrasonic stimulation. The noninvasive, accurate and long-term stable low-intensity focused ultrasonic force touch stimulation device is constructed, the ultrasonic transducer with the optimal fundamental frequency is selected, the focused ultrasonic stimulation position selection and positioning are optimized, and the ultrasonic pulse repetition frequency, the sound pressure, the duty ratio and other stimulation parameter combinations are adjusted so as to induce force touch of different types (pressing and tacting) and different intensities (weak and strong) of fingers. Compared with a force touch reconstruction method based on mechanical stimulation and electric stimulation, the depth and spatial resolution of force touch stimulation can be improved through sound field modulation, and non-invasive and accurate force touch stimulation on hands is realized. The invention is hopeful to be applied to man-machine interaction scenes requiring force touch feedback such as virtual reality, medical simulation, rehabilitation and the like, can improve the sense of reality of hand task operation, and is also beneficial to improving the dexterity and stability of man-machine interaction operation.
The invention has the following purposes:
1) Perception study: the invention can be used for deeply researching the perception mechanism of the human tactile system. By adjusting stimulation parameters such as frequency, intensity and pattern, the threshold of haptic perception, differential perceptibility, perception variability, etc. can be studied. This is important to reveal the neurophysiologic and psychological basis of haptic perception.
2) Rehabilitation medicine: the invention can be used for improving the effect of rehabilitation. By simulating different tactile stimuli, the rehabilitation patient can be helped to reestablish sensory and motor control, for example, to help paralyzed patients improve muscle function in rehabilitation therapy.
3) Telemedicine: the invention can be used in telemedicine applications to provide tactile feedback by way of a teleoperation enabling a physician to perceive and manipulate the body of a remote patient. This is of great potential value for tele-surgery and diagnostics.
4) Man-machine interaction: in the field of human-computer interaction, the method and the device can be used for improving the touch screen technology and the user experience of the control equipment. This may enhance the connection between the user and the digital interface, providing more vivid haptic feedback
The foregoing disclosure is illustrative of the present invention and is not to be construed as limiting the scope of the invention, which is defined by the appended claims.
Claims (10)
1. A focused ultrasound-based haptic stimulation system, comprising:
the ultrasonic waveform generation module is used for generating ultrasonic waveforms;
the power amplification module is connected with the ultrasonic waveform generation module and used for carrying out signal conversion and transmission on ultrasonic waveforms;
and the stimulation module is connected with the power amplification module, receives signals of the power amplification module and outputs stimulation to the outside.
2. The focused ultrasound-based haptic stimulation system of claim 1, wherein the ultrasound waveform generation module is a dual channel function signal generator.
3. The focused ultrasound based haptic stimulation system of claim 2, wherein the dual channel function signal generator comprises a first channel and a second channel; the first channel is used for designating pulse repetition frequency components of waveforms, and the second channel is used for generating sound pressure of stimulus waveforms; the first channel is a trigger input channel of the second channel.
4. The focused ultrasound-based haptic stimulation system of claim 3, wherein the power amplification module is a power amplifier; the stimulation module is an ultrasonic transducer.
5. The focused ultrasound-based haptic stimulation system of claim 4, wherein the ultrasound transducer fundamental frequency is 0.2-2.67MHz.
6. A focused ultrasound-based haptic stimulation method, comprising the steps of: selecting a stimulation site as a target sensory area, evaluating the sensory function of the target sensory area, and determining the target stimulation area; placing a target stimulation area over a stimulation module of the force sense stimulation system of any of claims 1-5, selecting safe stimulation parameters to act on the stimulation site, and performing force sense stimulation.
7. The focused ultrasound-based force tactile stimulation method of claim 6, wherein the stimulation sites comprise the writhing muscle of the forearm corresponding to the median nerve, the metacarpal muscle of the palm, and the index finger, middle finger and thumb.
8. The focused ultrasound-based haptic stimulation method of claim 6, wherein the stimulation parameters include ultrasound transducer fundamental frequency, duty cycle, stimulation duration, pulse repetition frequency, sound pressure.
9. The focused ultrasound-based haptic stimulus method of claim 7, wherein four haptic sensations, namely, a weak vibration sensation, a strong vibration sensation, a weak touch pressure sensation, and a strong touch pressure sensation, are obtained based on a combination of sound pressure and pulse repetition frequency.
10. The focused ultrasound-based haptic stimulation method of claim 9, wherein the pulse repetition frequency is 8Hz-86 Hz and the sound pressure is 250mvpp-700mvpp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311722252.0A CN117771567A (en) | 2023-12-14 | 2023-12-14 | Force touch stimulation system and force touch stimulation method based on focused ultrasound |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311722252.0A CN117771567A (en) | 2023-12-14 | 2023-12-14 | Force touch stimulation system and force touch stimulation method based on focused ultrasound |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117771567A true CN117771567A (en) | 2024-03-29 |
Family
ID=90382577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311722252.0A Pending CN117771567A (en) | 2023-12-14 | 2023-12-14 | Force touch stimulation system and force touch stimulation method based on focused ultrasound |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117771567A (en) |
-
2023
- 2023-12-14 CN CN202311722252.0A patent/CN117771567A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Khan et al. | Review on motor imagery based BCI systems for upper limb post-stroke neurorehabilitation: From designing to application | |
| US6839594B2 (en) | Actuation and control of limbs through motor nerve stimulation | |
| CN105307719B (en) | Local nerve stimulation instrument | |
| JP2020124609A (en) | Patterned stimulation intensity for neural stimulation | |
| CN101574297B (en) | Rehabilitation system for disabled persons based on virtual reality | |
| D’Alonzo et al. | HyVE—hybrid vibro-electrotactile stimulation—is an efficient approach to multi-channel sensory feedback | |
| CN107440887B (en) | Full-bionic brain-like intelligent hand electromechanical exoskeleton and comprehensive control system thereof | |
| US11020188B2 (en) | System, method, and GUI for treating skin and underlying tissues for improved health, function and/or appearance | |
| WO2013169363A2 (en) | Ultrasound modulation of the brain for treatment of stroke, brain injury, and other neurological disorders | |
| Zhou et al. | Electrotactile perception properties and its applications: A review | |
| KR102515448B1 (en) | bio stimulator | |
| Wang et al. | Effective evaluation of finger sensation evoking by non-invasive stimulation for sensory function recovery in transradial amputees | |
| Wang et al. | Building multi-modal sensory feedback pathways for SRL with the aim of sensory enhancement via BCI | |
| Cardoso et al. | Soft robotics and functional electrical stimulation advances for restoring hand function in people with SCI: a narrative review, clinical guidelines and future directions | |
| CN105592789B (en) | Method and apparatus for the test of autonomic nerves system sensitive spot | |
| CN113713252B (en) | Bionic type body sense reconstruction method for prosthetic wrist and elbow joint | |
| Papaleo et al. | Integration of proprioception in upper limb prostheses through non-invasive strategies: a review | |
| CN103246348B (en) | Quantitative analysis system and method for electric touches | |
| Cho et al. | Simultaneous Sensory Feedback Strategy for Force and Position of Gripper Based on TENS | |
| CN117771567A (en) | Force touch stimulation system and force touch stimulation method based on focused ultrasound | |
| Chen et al. | An investigation of stimuli-current thresholds on the non-steady contact condition | |
| CN209253488U (en) | A kind of bionical class brain intelligent hand electric mechanical ectoskeleton and its control system entirely | |
| Cisotto et al. | An EEG-based BCI platform to improve arm reaching ability of chronic stroke patients by means of an operant learning training with a contingent force feedback | |
| Vargas et al. | Distribution of M-wave and H-reflex in hand muscles evoked via transcutaneous nerve stimulation: a preliminary report | |
| Lou et al. | Wireless master-slave FES rehabilitation system using sEMG control |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |