Human Hand (human + hand)

Distribution by Scientific Domains

Selected Abstracts

RAPA: a novel in vitro method to evaluate anti-bacterial skin cleansing products

S. A. Ansari
Synopsis Development of efficacious anti-bacterial skin cleansing products has been limited by the availability of a pre-clinical (in vitro) method to predict clinical efficacy adequately. We report a simple and rapid method, designated as rapid agar plate assay (RAPA), that uses the bacteriological agar surface as a surrogate substrate for skin and combines elements of two widely used in vivo (clinical) methods (Agar Patch and Cup Scrub). To simulate the washing of the human hand or forearm skin with the test product, trypticase soy agar plates were directly washed with the test product and rinsed under running tap water. After air-drying the washed plates, test bacteria (Staphylococcus aureus or Escherichia coli) were applied and the plates were incubated at 37°C for 18,24 h. Using S. aureus as the test organism, anti-bacterial bar soap containing triclocarbanilide showed a strong linear relationship (R2 = 0.97) between bacterial dose and their per cent reduction. A similar dose-response relationship (R2 = 0.96) was observed for anti-bacterial liquid hand soap against E. coli. RAPA was able to distinguish between anti-bacterial products based on the nature and level of actives in them. In limited comparative tests, results obtained by RAPA were comparable with the results obtained by clinical agar patch and clinical cup scrub methods. In conclusion, RAPA provides a simple, rugged and reproducible in vitro method for testing the relative efficacy of anti-bacterial skin cleansing products with a likelihood of comparable clinical efficacy. Further testing is warranted to improve the clinical predictability of this method. Résumé Le développement des produits de nettoyage de peau antibactérienne efficace a été limité par la disponibilité d'une méthode (in vitro) préclinique pour prévoir en juste proportion l'efficacité clinique. Nous rapportons une méthode simple et rapide, indiquée comme analyse rapide de plat d'agar (RAPA) ce des utilisations la surface bactériologique d'agar comme substrat de remplacement pour la peau et combinons des éléments de deux méthodes (cliniques) in vivo employées couramment (correction d'agar et la tasse frottent). Pour simuler le lavage de la peau humaine de main ou d'avant-bras avec le produit d'essai, des plats de l'agar de soja de trypticase ont été directement lavés avec le produit d'essai et rincés sous l'eau du robinet courante. Après l'air séchant les plats lavés, les bactéries d'essai (S. doré Ou Escherichia coli) étaient appliquées et des plats ont été incubées au °C 37 pendant 18,24 heures. Utilisant S. doré Comme organization d'essai, le triclocarbanilide contenant du savon de barre antibactérienne a montré un rapport linéaire fort (R2 = 0.97) entre la dose bactérienne et leur réduction de pour cent. On a observé un rapport semblable de réponse à dose donnée (R2 = 0.96) pour le savon liquide antibactérien de main contre E. coli. RAPA pouvait distinguer les produits antibactériens basés sur la nature et le niveau des actives dans eux. Dans les essais comparatifs limités, résultats obtenus par RAPA étaient comparables aux résultats obtenus par la correction clinique d'agar et la tasse clinique frottent des méthodes, en conclusion, RAPA fournit à une méthode in vitro simple, raboteuse et reproductible pour examiner l'efficacité relative des produits de nettoyage de peau antibactérienne la probabilité de l'efficacité clinique comparable. Davantage d'essai est justifié pour améliorer la prévisibilité clinique de cette méthode. [source]

Blood Flow in Snake Infrared Organs: Response-Induced Changes in Individual Vessels

ABSTRACT Objective: In the past the microkinetics of blood flow in the infrared pit organs of pit vipers has been studied with Doppler flowmetry using various infrared stimuli such as a human hand or soldering iron at various distances, lasers of various wavelengths, etc. Quick-acting variations in blood flow were recorded, and interpreted as a cooling mechanism for avoiding afterimage in the infrared receptors. However, the Doppler measurements provided only the summation of blood flow in a number of vessels covered by the sensing probe, but did not give data on flow in individual vessels. Methods: In the present work the authors introduced into the bloodstream of Gloydius and Trimeresurus pit vipers fluorescent microspheres labeled with fluorescein isothiocyanate (FITC) contained in a solution of FITC-dextran in physiological saline. They observed the passage of the microspheres through individual pit organ vessels with a fluorescent microscope to which was attached a high-speed video camera and image intensifier. Output of the camera was recorded before, during, and after stimulus with a 810-nm diode laser. Recording was done at 250 frames/s on high-speed video apparatus and downloaded to a hard disk. Disk files were loaded into proprietary software and particles were tracked and average velocities calculated. The data were then tested for significance by ANOVA with post hoc tests. Results: A significant (p < .05) increase in blood velocity was found at the focal point of the stimulus laser, but not anywhere removed from this point. Proximal severing of the pit sensory nerves caused degeneration of the pit receptor terminals and abolished stimulus-induced blood flow changes, but did not affect normal blood flow. Conclusions: The authors conclude that the receptors themselves are directly and locally controlling the smooth muscle elements of the blood vessels, in response to heating of the receptors by infrared radiation. They speculate that the heavy vascularization constitutes a cooling system for the radiation-encoding receptors, and further that the agent of control may be a volatile neuromediator such as nitric oxide. [source]

A reconstructed digit by transplantation of a second toe for control of an electromechanical prosthetic hand

MICROSURGERY, Issue 1 2002
Zhong Wei Chen M.D.
The treatment options for the loss of an entire human hand and part of the forearm are currently limited to the transplantation of toe(s) to the amputation stump or a Krukenberg's bifurcation hand, and using a cosmetic or functional prosthesis. The functional prosthetic hand, such as the prevailing myoelectrically controlled prosthetic hand, has an action accuracy that is affected by many factors. The acceptance rate of the three planes freedom myoelectronic hand by the patients was 46,90% because of poor function caused by the weakness of signal and strong external interference. In this report, the left second toe was transplanted to the patient's forearm amputation stump. Mandates from the brain are relayed by the action of this reconstructed digit, to control a special designed multidimension freedom electronic prosthetic hand. After rehabilitation and adaptation training, the correct recognition rate of the electronic prosthetic hand controlled by this reconstructed digit is a remarkable 100%. © 2002 Wiley-Liss, Inc. MICROSURGERY 22:5,10, 2002 DOI 10.1002/micr.22002 [source]

The Mechanical Stability for the Hand-Arm System

Aurora Felicia Pop
The present paper contains a study regarding importance stability in the mechanical systems, mechanical systems are emerging under mechanical vibrations action, it referring especially to the human hand,arm system. Mechanical systems stability is directly influenced of the dumper and the elasticity factors. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Human tactile perception as a standard for artificial tactile sensing,a review

J Dargahi
Abstract In this paper, we examine the most important features of human skin tactile properties with special emphasis on the characteristics which are vital in the design of artificial systems. Contrary to the visual and auditory senses, the touch signal is not a well-defined quantity. As a result, the researchers of this field are still dealing with the basics of collecting the most relevant data. Following this, mimicking the sense of touch by producing artificial tactile skin is a challenging process. Although the sense of touch is widely distributed all over the human body, the tactile perception in the human hand is of great importance in terms of surgical and medical robotics applications. In this study, the role of various mechanoreceptors in the human hand, such as, RA, SA I, SA II, and PC units are discussed in relation to the stimuli like force, position, softness, and surface texture. Taking human hand as a suitable tactile model, the necessary engineering features of an artificial tactile sensor, such as, spatial and temporal resolutions, force sensitivity, and linearity, are being reviewed. In this work, we also report on the current and possible future applications of tactile sensors in various surgical procedures. Copyright © 2004 Robotic Publications Ltd. [source]

Study of the Different Types of Actuators and Mechanisms for Upper Limb Prostheses

Vanderlei O. Del Cura
Abstract: Research in the area of actuators and mechanisms has shown steadily growing technological advances in externally activated upper limb prostheses. From among the actuators, advances include the use of piezoelectric materials, special metal alloys, polymers, and new motor applications, while the advances in mechanisms include mechanical designs based on the anatomy of the human hand and improvements in the way these components are combined. These efforts are aimed at meeting the need for anthropomorphic and functional prosthetic devices that enable patients to carry out basic daily tasks more easily and reduce the rejection rate of prostheses. This article technically discusses the several types of actuators and mechanisms, listing their main characteristics, applications, and advantages and disadvantages, and the current state of research in the area of rehabilitation of upper limb functions through the use of active prostheses. Comparisons of these devices are made with regard to the main criteria of construction and operation required to achieve optimal prosthetic performance. [source]