发射式植入刺激器的研制及其在截瘫猗排尿功能障碍时的…

介绍一种体外发射式植入刺激器的结构和电路原理。该机不但体积较小,耗电少,且可选择较强刺激电压,其植入部分的生物相容性较好,并初步观察了用此刺激器刺激骶神经以恢复截瘫狗排尿功能的情况。     

一种基于可穿戴器件触觉感知信息的盲人虚拟视觉导航系统

目的 全球视力受损或失明人数已超2亿,长期以来各类人工视觉系统被广泛研究。人工视觉系统的研发主要有两种技术路径,第一种是各类植入式人工视觉装置,第二种是各类非植入式、可穿戴装置。本文展示了一种非植入式、基于可穿戴头部触觉激发装置的系统原型,能够帮助盲人和视觉障碍者完成行走等复杂任务。方法 该系统采集受试者周边环境图像信息并无线传输到后台,操作人员分析处理图像信息后,将指令以触觉编码形式无线传输到头套等可穿戴装置,由驱动电路激发多点位头部触觉,从而为受试者提供准确的行动指令。系统并辅助以语音信息,让其了解更多道路状况和环境信息。结果 用原型系统对5名（2男3女）在读大学生健康志愿者和1名年轻盲症患者（男）进行实验。结果表明,原型系统充分利用了头部对前后左右的天然区分能力和对触觉的快速反应,具备直行、左右调整、转弯等明确指令功能。受试者对指令的响应时间约0.5 s,直线行走约7 m距离的偏差量标准差平均值相比未佩戴装置的情况下降低到（16±10）cm。结论 该系统可隐蔽、准确地提供环境图像信息,有效帮助视觉障碍人士完成行走、避让障碍物、上台阶、进入咖啡厅等公共场所、桌上取物等日常活动,达到了预期目标。今后对原型系统作进一步完善,特别是小型化、智能芯片化,把触觉装置制成颈环、腰带、手环、脚环等,将能够广泛应用于盲人出行辅助、夜间野外旅行、深海潜水等多种工作场景。     

一种用于自由活动动物的微型多模式遥控刺激器

本文采用集成有射频功能的片上系统(nRF24E1),研制了一种用于自由活动小动物的微型多模式遥控刺激器。刺激参数的设置及结果分析均由10 m外的个人计算机进行。通过离体实验,即刺激蛙坐骨神经干时产生动作电位并可观察到伪迹;及在体大鼠的训练操作性条件反射的行为学实验,即在Y臂迷宫中训练大鼠听到不同声音完成左右运动,如果完成正确给予前脑内侧束以电刺激,我们观察到5 d内大鼠的正确率增加3倍,达到93．5％。上述实验都验证了该刺激器的有效性与稳定性。本系统具有体积小(18 mm×28 mm双层线路板)、重量轻(不含电池5 g)、简单、实用、可靠等特点,能有效地用于自由活动小动物的实验研究。为基于电刺激的小动物行为训练(动物机器人)及相关神经生理学实验研究,提供了新的实验条件和实验手段。     

发射式植入刺激器的研制及其在截瘫狗排尿功能障碍时的应用

介绍一种体外发射式植入刺激器的结构和电路原理。该机不但体积较小,耗电少,且可选择较强刺激电压,其植入部分的生物相容性较好,并初步观察了用此刺激器刺激骶神经以恢复截瘫狗排尿功能的情况。     

人手指柔性触觉感知的记忆特性

触觉再现技术是当前虚拟现实和远程操作机器人领域的前沿,而柔性触觉则是其重要的研究内容。触觉再现接口的设计需要充分研究人手的触觉感知特性。本文在柔性触觉装置上研究了人手指柔性触觉记忆特性。先通过回忆性实验确定人手指的柔性触觉记忆容量,在记忆容量范围内又进行了再认性实验,对人手指的柔性触觉记忆反应时间进行分析。本实验方法简单有效,得出的结论不仅可以用来改进触觉再现装置的设计,而且为触觉再现技术的研究提供了生理学依据。     

鼹鼠的美味触觉

当鼹鼠在地下遇到一只昆虫后,它会迅速将其吞入口中。但是这种几乎没有视觉的啮齿动物究竟是如何区分一只蚂蚁和一枚橡树果的呢?答案可能就在一种蜂窝状的细胞团——艾玛氏器中,它位于啮齿动物鼻腔的边缘。从19世纪开始,这类     

第二触觉系统:编码触觉情绪成分的C纤维

过去曾认为,人类触觉信息特异地由大直径有髓(Aβ)神经纤维传导。然而最近的研究表明,哺乳动物皮肤的机械感受器不仅有Aβ纤维分布,还有大量低阈值、低传导速度的小直径无髓(C)神经纤维分布,后者对轻微的非伤害性皮肤变形反应敏感,而对快速的皮肤运动反应微弱。初级传入C纤维投射至脊髓浅层,并与脊髓板层II内的次级感觉神经元形成突触联系,再通过脊髓丘脑束投射至岛叶。功能磁共振(fMRI)研究发现,缓慢移动的触觉刺激可以明显地激活岛叶并引起愉悦感,同时还可以激活眶额叶内与愉悦味觉和嗅觉激活区域邻近的部位。这些反应的性质和所激活的部位说明,C纤维触觉主要与边缘系统的功能有关,编码触觉的情绪成分。     

温度感受器和触觉感受器的发现

2021年诺贝尔生理学或医学奖授予美国生理学家戴维·朱利叶斯(David Julius)和分子生物学家阿德姆·帕塔普蒂安(Ardem Patapoutian),以表彰他们在发现温度感受器和触觉感受器中所做出的突出贡献.机体对热、冷和机械压力等外界刺激的感知能力对于人们适应不断变化的环境至关重要,可以避免其遭受伤害.在D...     

《科学一报告》：能延伸到纳米尺度的触觉极限

2013年9月的Scientific Reports上发表的一项研究显示,人类手指能够区分有小至13纳米凸起图案的表面和没有图案的表面。这一发现表明,人类的触觉极限也许能延伸到纳米尺度。     

《神经科学杂志》：指尖大小决定触觉敏锐程度

性别差异有时并非仅仅取决于你的性别。与男性相比,女性的触觉通常会更加敏锐,然而一项新的研究表明,这其实是缘于后者的指尖往往会比前者小一些。     

A Preliminary Study of the Noninvasive Remote Control System for Rat Bio-Robot

<正> A system is described here that can noninvasively control the navigation of freely behaving rat via ultrasonic,epidermaland LED photic stimulators on the back.The system receives commands from a remote host computer to deliver specifiedelectrical stimulations to the hearing,pain and visual senses of the rat respectively.The results demonstrate that the three stimuliwork in groups for the rat navigation.We can control the rat to proceed and make right and left turns with great efficiency.Thisexperiment verified that the rat was able to reach a setting destination in the way of cable with the help of a person through theappropriate coordination of the three stimulators.The telemetry video camera mounted on the head of the rat also achieveddistant image acquisition and helped to adjust its navigation path over a distance of 300 m.In a word,the non-invasive motioncontrol navigation system is a good,stable and reliable bio-robot.     

A four-channel analysis of the tactile sensitivity of the fingertip: frequency selectivity,spatial summation,and temporal summation

Thresholds were measured for the detection of vibratory stimuli of variable frequency and duration applied to the index fingertip and thenar eminence through contactors of different sizes. The effects of stimulus frequency could be accounted for by the frequency characteristics of the Pacinian (P), non-Pacinian (NP) I, and NP III channels previously determined for the thenar eminence (Bolanowski et al., J Acoust Soc Am 84 : 1680-1694, 1988; Gescheider et al., Somatosens Mot Res 18: 191- 201, 2001). The effect of changing stimulus duration was also essentially identical for both sites, demonstrating the same amount of temporal summation in the P channel. Although the effect of changing stimulus frequency and changing stimulus duration did not differ for the two sites, the effect of varying the size of the stimulus was significantly greater for the thenar eminence than for the fingertip. The attenuated amount of spatial summation on the fingertip was interpreted as an indication that the mechanism of spatial summation consists of the operations of both neural integration and probability summation.     

Perception of fluids with diverse rheology applied to the underarm versus forearm skin

Little is known about the tactile–perceptual structure of fluids. Therefore, ten fluids with diverse, characterized rheologies were rated by 16 females, on 27 sensory attributes (e.g., “slippery”) and 14 emotional attributes (e.g., “enjoyable”) via five-point categorical scales. Fluids were assessed against the volar forearm and underarm, sites that commonly experience contact with fluids during the use of personal care products. Application of fluids was either by the participant to their own body (“self-applied”) or by the experimenter to the participant's body (“experimenter-applied”). Separate factor analyses of the sensory and emotional attributes for different body sites and modes of touch suggested approximately the same factorial structure in each case. Four general sensory factors emerged, labeled Lubricating, Textured, Silken, and Viscous, and two emotional factors, Comfortable and Arousing. These factors resembled those from equivalent work that used solid materials as stimuli, emphasizing that despite the differences in perceptual structure between fluid-coated and dry, solid surfaces, different body sites, and modes of touch influence the perception of fluid and dry stimuli similarly. As expected, fluids varied widely in how they scored on the factors. Site-wise differences were found, whereby stimuli assessed against the forearm were rated as more Lubricating, less Textured, more Silken, and more Comfortable than they were against the underarm. Self-applied touch was less Comfortable than experimenter-applied. The physical and perceptual were linked insofar as greater measured viscosity at low shear rates was associated with perceptions of cold and wet, whereas at high shear rates, greater viscosity was associated with greater perceived thickness.     

Frequency and site-dependent variations in vibration detection thresholds on the face

An adaptive psychophysical procedure was used to estimate the vibration detection threshold at seven spatially matched sites on the two sides of the face and at one scalp site. Repeated measurements over six testing sessions were made for stimuli vibrating at 1, 10 and 100 Hz for each of 21 neurologically healthy, young adult females. Approximately 14 stimulus trials were required to obtain each estimate of the threshold amplitude. Thresholds varied as a function of frequency ( p < 0.0001), side ( p < 0.001) and site ( p < 0.0001). Compared to stimulation at 100 Hz at which the estimates were lowest, thresholds were 3.1 times greater at 10 Hz and 5.4 times greater at 1 Hz. Thresholds were lowest on the vermilion and highest on the cheek and chin. The preauricular skin and scalp exhibited an intermediate level of sensitivity. Whereas thresholds were comparable on the two sides of the face for stimulation at 1 Hz, they averaged 1.33 times greater on the right side for stimulation at 10 and 100 Hz. Moreover, thresholds obtained during the last two sessions were 16% higher than those obtained during the first two sessions ( p < 0.02), suggesting that subjects on average became more conservative in reporting the presence of the stimulus. The sensitivity in discriminating differences in tactile function favors use of the rapidly administered testing procedure in a clinical setting.     

The frequency selectivity of information-processing channels in the tactile sensory system

The frequency selectivity of the P, NP I, and NP II channels of the four-channel model of mechanoreception for glabrous skin was measured psychophysically by an adaptation tuning curve procedure. The results substantially extend the frequency range over which the frequency selectivity of these channels is known and further confirm the hypothesis that the input stage of each of these channels consists of specific sensory nerve fibers and associated receptors. Specifically, the frequency characteristics of Pacinian nerve fibers, rapidly adapting (RA) nerve fibers, and slowly adapting Type II (SA II) nerve fibers were found to be the peripheral neurophysiological correlates of the P, NP I, and NP II channels, respectively. The finding that the tuning characteristic for a test stimulus of 250 Hz delivered through a small (0.008 cm²) contactor depended dramatically on the duration of the test stimulus whereas the detection threshold did not, provides new evidence in support of the hypothesis that separate NP II and P channels exist.     

Factors affecting tactile spatial acuity

Tactile spatial acuity on the fingerpad was measured using a grating orientation task. In this task, subjects are required to identify the orientation of square-wave gratings placed on the skin. Previous studies have shown that performance varies as a function of the width of the grooves in the gratings. In the present study, both groove width and the overall size and configuration of the contactors were varied. Sensitivity improved with wider grooves and with larger contactors. Additional measurements showed that the improved sensitivity is not the result of the increase in total area contacted, but rather is due to two other factors associated with larger contactors. One is the greater linear extent of the larger contactors. The other appears to be due to the reduction in the interference produced by the outer edge of the contactor. Specifically, as the contactor increases in size, the distance between the outer edge and the center portion of the grooves also increases. It was also shown that subjects are more sensitive to a single, continuous groove as compared with two grooves of the same total length but spatially discontinuous. Similarly, subjects are more sensitive to a contactor with a continuous groove than to a contactor in which just the end points of the groove are presented. The results are generally consistent with the results of peripheral, neurophysiological recordings. The results are discussed in terms of the way in which both spatial and intensive factors may affect sensitivity to grating orientation.