具有触觉和滑觉的肌电假手研究

触觉和滑觉是人非常重要的信息来源,给肌电手安装合适的传感器,使肌电手具有某些触、滑觉功能,可以提高肌电手工作的智能化程度.通过提出一种触觉和滑觉的复合传感器完成触觉信号、滑觉信号的采集、转换和输出 ,实现肌电控制假手对易碎物体的无损伤抓取 ,使抓取物体更自然,控制更灵活.     

具有触觉和滑觉的肌电假手研究

触觉和滑觉是人非常重要的信息来源，给肌电手安装合适的传感器，使肌电手具有某些触、滑觉功能，可以提高肌电手工作的智能化程度。通过提出一种触觉和滑觉的复合传感器完成触觉信号、滑觉信号的采集、转换和输出，实现肌电控制假手对易碎物体的无损伤抓取，使抓取物体更自然，控制更灵活。     

高位颈髓损伤致四肢瘫患者肌电控制式神经假肢的抓握功能

<正> 一种有表面电极的四通道功能性电刺激系统使C_4和C_5位脊髓损伤致完全性四肢瘫患者完成抓握功能成为可能。这个系统的优势是:①恢复丧失的抓握功能;②自然且方便地训练手打开和收拢;③抓握力量的平稳调节;④患者可利用自然控制策略控制神经假肢;⑤并入一个微控制器很容易控制疼痛。试验表明这个方法有效地增加了受试者完成日常生活     

国产新型电生理刺激反馈仪DS21在无创筛查糖尿病中的初步应用

目的:初步评判国内最新研制的电生理刺激反馈仪DS21无创筛查糖尿病的稳定性、有效性及安全性。方法:46例受试者根据口服葡萄糖耐量试验(OGTT)及既往病史分为健康组(n=17)、糖调节受损组(n=15)和糖尿病组(n=14)。受试者签署知情同意书,接受常规体检及采集病史及生化检查,对受试者进行3次电生理刺激反馈仪DS21测试,得到3个电导值,通过计算平均偏差,判断检测结果的稳定性、有效性,同时观察不良反应。结果:46例受试者电导值平均偏差最大值为4.4,最小值为0.2,均小于5.0;46例受试者中健康组、糖调节受损组和糖尿病组受试者的电导值分别为77.9±5.2、70.4±5.7、54.7±11.4,趋势为健康组糖调节受损组糖尿病组,组间差异有统计学意义(P0.01);校正了性别、年龄、体质指数(BMI),3组人群电导值依然存在上述趋势(P0.01)。入组受试者均未发生不良事件。结论:国产电生理刺激反馈仪DS21在不同糖代谢人群中存在不同的电导值,有助于评判糖尿病风险,且稳定、安全,值得进一步以应用于临床。     

智能假手控制研究

０引言假手的发展与不断完善，为残肢患者带来福音。其经历了装饰假手、机械假手、肌电假手几个阶段。目前广泛使用的肌电假手，改善了残肢者的生活自理能力，使用也方便，但其最大的缺陷，一是控制准确性问题，再是握物时无法有针对性地调整握力与速度。本文探讨一种具有感知能力的智能肌电假手的控制模式，它装有力敏和滑敏复合传感器，可以感知握力及手指与被握物的相对滑动信息，实现握力与速度的适应性调节，使抓取物体更灵活自然。１智能假手功能要求和控制模式具有握力与滑觉感知能力的智能肌电假手应具有如下特点：（１）具有较高的…     

短时程非强直性低频超强神经电刺激对脑卒中患者脊髓运动神经元兴奋性的影响

目的:研究非强直性低频超强神经电刺激对脊髓运动神经元兴奋性的影响,为完善脑卒中后外周神经电刺激治疗参数提供参考。方法:分别比较脑卒中患者和健康人群在0.5Hz低频F波检测中最初5次和最终5次超强刺激下F波次数,潜伏期和F波幅/M波幅(F/M)的变化情况。F波检测通过刺激腓骨头下腓总神经完成,记录肌肉为胫骨前肌和腓骨肌。结果:在脑卒中患者和健康人群,超强低频腓总神经电刺激前后胫骨前肌和腓骨肌F波出现次数、F/M值、潜伏期均无明显变化。结论:短时程非强直性低频超强周围神经电刺激不改变脑卒中患者和健康人群脊髓运动神经元的兴奋性;在超强刺激强度下,不同刺激频率可能对脊髓运动神经元兴奋性产生差异性影响。     

肌电控制前臂假手握力反馈装置

本文研究了利用电阻应变片测量假手握力及采用电刺激方法实现假手握力反馈的原理与反馈装置的实现,并对如何达到良好的反馈效果及实际应用的问题进行了讨论。实验结果表明:本文所采用的方法简便易行,反馈信号的特征明显,反馈效果良好。本文所述方法可应用于各种类型的电动假手,构成感觉反馈系统。     

手针、电针及经皮穴位电刺激调节人脑功能的功能性磁共振观察

目的:比较不同的针刺方法对人脑功能的调节作用。方法:16名健康成年被试(男8例),每名被试均参加4次实验,分别接受手针、电针、经皮穴位电刺激及触觉对照刺激,在刺激过程中同时进行功能性磁共振(血氧依赖水平,blood oxygen level dependent,BOLD)数据采集。结果:4种刺激均表现为对躯体运动感觉系统、岛叶和小脑的BOLD信号激活。此外,电针还表现为对边缘系统的BOLD信号的抑制,而经皮穴位电刺激则特异性地激活了基底核(P<0.001,uncorrected,k>22)。结论:电针和经皮穴位电刺激可模拟手针对脑BOLD信号的调节作用,表明3者有其共性,又各具特色。其生理意义有待进一步阐明。     

小腿假肢-触觉振动反馈系统的设计

摘要 目的：为了提高小腿假肢穿戴者的步态协调与对称性,降低长期穿戴假肢造成的腰背痛、膝骨关节炎等并发症,我们设计了一套小腿假肢-触觉振动反馈系统,以达到对小腿假肢穿戴者的步态进行自动识别,并根据设定的参数提供振动反馈,从而帮助提高小腿截肢者的平衡功能与行走能力,以及适应各种变化的外在环境。 方法：通过在健侧和假肢侧的大小腿位置,以及假脚的足背共安装5个陀螺仪传感器来采集肢体运动信息,控制主板进行比对数据处理,然后通过固定在假肢侧大腿前后左右的振动马达来对患者行走状态进行提醒并建立条件反射,进而达到调节小腿假肢穿戴者步态平衡性和对称性的目的。招募了6例小腿截肢者参与实验,对穿戴该系统前后的步态参数进行比对。 结果：6例小腿截肢者使用触觉振动反馈系统4周后,步速、健侧单步时长/假肢侧单步时长、健侧摆动期/假肢侧摆动期差异均有显著性意义（P≤0.05）,穿戴4周后3项指标均高于穿戴前。穿戴前后健侧步长/假肢侧步长差异无显著性意义（P=0.052）。 结论：该小腿假肢-触觉振动反馈系统可帮助提高小腿假肢穿戴者的步态对称性和平衡功能,提高假肢使用的安全性,降低跌倒风险,增加患者对假肢的接受度和依从性,具有实用性和可行性。     

前臂肌电假肢

本文介绍了一种由肌肉电控制的前臂假肢。该假肢是利用前臂截肢者残端上检测到的肌电信号来控制的,可以实现指伸屈和旋腕两种动作。介绍了获取和处理肌电信号的模拟电路,全部电路置于带有镀金电极的小型绝缘塑料盒内,使镀金电极与残端肌肉直接接触以提取肌肉电信号。对假手的机械结构和握力进行了分析,讨论了减轻假手重量和降低机械噪声的方法。能自动换速增力的机构,使假手获得了传动效率高、噪声低和握力大的效果。两年多的临床应用结果表明,假手的设计是成功的,患者反应良好。     

Grasper having tactile sensing function using acoustic reflection for laparoscopic surgery

Purpose:

In current minimally invasive surgery techniques, the tactile information available to the surgeon is limited. Improving tactile sensation could enhance the operability of surgical instruments. Considering surgical applications, requirements such as having electrical safety, a simple structure, and sterilization capability should be considered. The current study sought to develop a grasper that can measure grasping force at the tip, based on a previously proposed tactile sensing method using acoustic reflection. This method can satisfy the requirements for surgical applications because it has no electrical element within the part that is inserted into the patient’s body.

Methods:

We integrated our acoustic tactile sensing method into a conventional grasping forceps instrument. We designed the instrument so that acoustic cavities within a grasping arm and a fork sleeve were connected by a small cavity in a pivoting joint. In this design, when the angle between the two grasping arms changes during grasping, the total length and local curvature of the acoustic cavity remain unchanged. Thus, the grasping force can be measured regardless of the orientation of the grasping arm.

Results:

We developed a prototype sensorized grasper based on our proposed design. Fundamental tests revealed that sensor output increased with increasing contact force applied to the grasping arm, and the angle of the grasping arm did not significantly affect the sensor output. Moreover, the results of a grasping test, in which objects with different softness characteristics were held by the grasper, revealed that the grasping force could be appropriately adjusted to handle different objects on the basis of sensor output.

Conclusions:

Experimental results demonstrated that the prototype grasper can measure grasping force, enabling safe and stable grasping.

     

A remote palpation instrument for laparoscopic surgery: Design and performance

This paper describes the design and performance of a prototype remote palpation instrument with tactile feedback for laparoscopic surgery. Psychophysical experiments aiming at comparing palpation with and without tactile feedback are also described. The remote palpation instrument is designed to provide the surgeon with information about size and contact force distribution. The instrument consists of a tactile sensor and a tactile display, both of which are small enough to fit onto a conventional laparoscopic grasper. Static tests showed that hardness, size and shape were successfully rendered by the tactile display. Dynamic testing showed that the bandwidth is suboptimal, but at low frequencies the output from the remote palpation instrument is useful. For the psychophysical testing, nine subjects were asked to discriminate hardness and size of objects with and without tactile feedback. The results indicated that the instrument with tactile feedback can be helpful for hardness discrimination, although the difference between the two instruments was not statistically significant for neither hardness nor size. Comparisons with earlier, similar experiments showed that the quality of the grasper and size of the forceps affected the results, indicating that there is a great potential for improving laparoscopic graspers in general.     

A laparoscopic grasper with force perception

Summary

In laparoscopic surgery, grasping instruments are the only source of force feedback to the surgeon. Therefore, the force transmission characteristics of these instruments are important features. For mechanical graspers to allow force feedback, the force transmission function should ideally be constant throughout its range of motion and be free of hysteresis. In this paper, the design of a laparoscopic grasping instrument with outstanding force transmission characteristics is presented, which satisfies these demands to a large extent. The mechanical efficiency of the prototype amounts to 96% whereas the non-constancy is only 3% approximately. With these forceps, several physiological properties, such as stiffness of tissue and the pulse of arteries, can be clearly perceived.     

A brain-computer interface with vibrotactile biofeedback for haptic information

Background  

It has been suggested that Brain-Computer Interfaces (BCI) may one day be suitable for controlling a neuroprosthesis. For closed-loop operation of BCI, a tactile feedback channel that is compatible with neuroprosthetic applications is desired. Operation of an EEG-based BCI using only vibrotactile feedback, a commonly used method to convey haptic senses of contact and pressure, is demonstrated with a high level of accuracy.     

Evaluation of a Neural Network-Based Control Strategy for a Cost-Effective Externally-Powered Prosthesis

ABSTRACT

This paper presents a control strategy that compensates for the nonlinearity in the inexpensive sensors and hardware of a cost effective prosthetic hand. The control strategy uses neural network-based force control and sensory feedback to detect disturbance induced by slippage. The neural network approach is chosen over other nonlinear models because it is easy to implement and it offered the additional advantage of having its parameters easily adjusted over the life span of the device. The proposed strategy was evaluated on a functional multi-digit underactuated prosthetic hand. The initial and incremental forces exerted from each finger were adjusted to balance the amount of disturbance and the deformation of the objects. Experiments were conducted to test the performance of the protocol in situations encountered in activities of daily living. The displacement of each object under three grasping configurations was measured as a performance criterion while the object's mass was changed. The results showed that with the adjusted parameters for each grasping configuration, the control strategy was able to detect the dynamic changes in mass of the object and was also able to successfully adjust the grasping force before the object drops from the hand.     

Discrete bandwidth visual feedback increases structure of output as compared to continuous visual feedback in isometric force control tasks

BACKGROUND: Performance variability measures provide a partial picture of force control ability. Nonlinear analyses can reveal important information related to the randomness and complexity of the data, providing a more complete picture of the physiological process. METHODS: We investigated the effects of visual feedback on the structure and performance of the force output from isometric force control tasks. Twelve young volunteers completed isometric force control tasks using two types of visual feedback: discrete bandwidth (+/-4% maximal voluntary contraction) and continuous line matching. We determined force signal variability (standard deviation), self-similarity (fractal dimension), and complexity (approximate entropy). Analyses of variance (feedback x muscle group x force level) were conducted and P values less than 0.05 were considered significant. FINDINGS: The force signal in discrete bandwidth feedback, compared to continuous line matching, had significantly a higher standard deviation (P=.000): 2.18 Nm (SD 1.98) vs. 0.99 Nm (SD 0.91); lower fractal dimension (P=.000): 1.07 (SD 0.04) vs. 1.16 (SD 0.04); and lower approximate entropy (P=.000): 0.12 (SD 0.07) vs. 0.26 (SD 0.09). INTERPRETATION: The greater self-similarity (lower fractal dimension) and greater regularity (lower approximate entropy) of the discrete bandwidth, compared to the continuous line matching, may indicate a process that required more kinesthetic (intrinsic) feedback to modulate force. Clinicians may choose to employ visual feedback paradigms that target the use of intrinsic feedback during rehabilitation. Discrete bandwidth feedback may be useful for delineating impairments in motor skill and measuring outcomes of intervention programs.     

Artificial tactile sensing in minimally invasive surgery - a new technical approach.

The loss of tactile sensation is a commonly known drawback of minimally invasive surgery (MIS). Since the advent of MIS, research activities in providing tactile information to the surgeon are still ongoing, in order to improve patient safety and to extend the indications for MIS.We have designed a tactile sensor system comprising a tactile laparoscopic grasper for surgical palpation. For this purpose, we developed a novel tactile sensor technology which allows the manufacturing of an integrated sensor array within an acceptable price range. The array was integrated into the jaws of a 10mm laparoscopic grasper. The tactile data are transferred wirelessly via Bluetooth and are presented visually to the surgeon. The goal was to be able to obtain information about the shape and consistency of tissue structures by gently compressing the tissue between the jaws of the tactile instrument and thus to be able to recognize and assess anatomical or pathological structures, even if they are hidden in the tissue. With a prototype of the tactile sensor system we have conducted bench-tests as well as in-vitro and in-vivo experiments. The system proved feasibility in an experimental environment, it was easy to use, and the novel tactile sensor array was applicable for both palpation and grasping manoeuvres with forces of up to 60N. The tactile data turned out to be a useful supplement to the minimal amount of haptic feedback that is provided by current endoscopic instruments and the endoscopic image under certain conditions.     

The effect of lower leg sensory impulses on the force sense of knee extensor muscles in healthy adults: The accuracy of sense-of-force studies

BackgroundProducing the target force of a muscle group by using visual feedback and reproducing the same force fully blind are regarded as a common approach for quantifying the sense of force. Force sense error is considered to be the difference between the produced target force and reproduced force. The present study aimed to evaluate the effects of tactile sensory feedback in the lower leg on the perceived magnitude of force sense.Methods and materialsIn this cross-sectional study, 18 healthy men (mean age 24.31 ± 3.94 years) were selected based on a simple randomized method. First, the quantity of force sense error of the knee extensor muscle group was measured before and after manipulating the tactile inputs of the leg. Then, methods A, B, and C were applied to measure force sense errors. In addition, the tactile impulses were manipulated in methods B and C by placing a piece of thick foam between the distal portion of lower leg among the subjects and the dynamometer. The tactile inputs remained intact during method A.ResultsThe accuracy of the reproduced target force was significantly affected following the disturbance of tactile inputs in the lower leg in methods B and C, compared to method A (p < 0.05).ConclusionAltering tactile inputs in the lower leg can affect the force sense of the knee extensor muscles. The received somatosensory inputs across the lower leg can affect the whole process of force perception at this joint.     

Artificial tactile sensing in minimally invasive surgery – a new technical approach

The loss of tactile sensation is a commonly known drawback of minimally invasive surgery (MIS). Since the advent of MIS, research activities in providing tactile information to the surgeon are still ongoing, in order to improve patient safety and to extend the indications for MIS.

We have designed a tactile sensor system comprising a tactile laparoscopic grasper for surgical palpation. For this purpose, we developed a novel tactile sensor technology which allows the manufacturing of an integrated sensor array within an acceptable price range. The array was integrated into the jaws of a 10mm laparoscopic grasper. The tactile data are transferred wirelessly via Bluetooth and are presented visually to the surgeon. The goal was to be able to obtain information about the shape and consistency of tissue structures by gently compressing the tissue between the jaws of the tactile instrument and thus to be able to recognize and assess anatomical or pathological structures, even if they are hidden in the tissue. With a prototype of the tactile sensor system we have conducted bench‐tests as well as in‐vitro and in‐vivo experiments. The system proved feasibility in an experimental environment, it was easy to use, and the novel tactile sensor array was applicable for both palpation and grasping manoeuvres with forces of up to 60N. The tactile data turned out to be a useful supplement to the minimal amount of haptic feedback that is provided by current endoscopic instruments and the endoscopic image under certain conditions.     

Visuomotor behaviors and performance in a dual-task paradigm with and without vibrotactile feedback when using a myoelectric controlled hand

ABSTRACT

Prosthesis users allocate visual attention to their prosthetic hand while performing activities of daily living (ADLs), due to absence of sensory feedback. Dual-task assignments present competition for visual attention and may affect the performance of ADLs. Vibrotactile feedback (VTF) is a frequently-used method to provide prosthesis users with tactile feedback. However, the effect of adding VTF on visual attention and performance in a motor dual-task paradigm has not been investigated. Our aim was to compare visual attention and performance during ADLs in a motor dual-task paradigm when using binary VTF and without using VTF. Forty-three able-bodied subjects (age 26 ± 6.6 years) had a myoelectric-controlled hand attached to their right hand. The dual task comprised of a computer game played with the left hand, while manipulating objects with the artificial hand. This was performed with and without VTF in a counter-balanced order of two conditions. An eye-tracker monitored visual attention, while time to complete each task and the time the virtual car went off-road were recorded. No significant differences were found in visual attention or in performance time between the two conditions. Further examination of adding VTF to prosthesis users is recommended, with disrupted visual feedback and basic grasping tasks.