摘要:

The testing of prosthetic heart valves under pulsatile conditions is still a subject for debate among researchers and competent standardization bodies. The laboratory of Biomedical Engineering of the Istituto Superiore di Sanitàin Rome, has reproduced the current inter-laboratory situation with several test apparatuses, focusing on the definition of significant measurement parameters and procedures to obtain reasonably comparable data. The laboratory is also equipped With a Laser Doppler Anemometer (LDA) and a High-speed Cinematographic system (HSC). A 29 mm tilting disc valve model, was mounted in the aortic position. Under tightly controlled system conditions the analyses performed on two pulse duplicators (PDs) may be deemed consistent for the valve model tested. Useful results, on the same valve specimen, are reported concerning velocity profiles and turbulent shear stress values (TSS). Furthermore valve motion on the Sheffield PD was monitored during the closing phase, and related cinematic data reported. The applied methodologies can provide relevant data to support surgeon decision making.

ISSN:0309-1902    

DOI:10.3109/03091909509012416

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Spinal mobilization or manipulation techniques are frequently used by physiotherapists in the treatment of musculoskeletal disorders. Many of these techniques involve the application of a varying force to the affected joint. Despite the routine use of these techniques, there are no objective measures to quantify their use. This paper describes the principles of the instrumentation of a mobilization couch to enable measurement of thc forces applied during mobilization of the lumbar spine. The couch was linked to a personal computer with a 286 processor and data card for data collection. The system was found to be reliable and sensitive over the range of forces applied during mobilization. It has potential for use in many situations where measurements of forces applied to the patient are required.

ISSN:0309-1902    

DOI:10.3109/03091909509012417

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

The physical strain and mechanical efficiency of manual wheelchair propulsion using handrim and hubcrank propelled racing wheelchairs were studied during a submaximal wheelchair exercise test on a stationary roller ergometer. Ten healthy male able-bodied subjects conducted two exercise tests in a random order and measurements of physical strain (oxygen uptake, minute ventilation, respiratory exchange ratio, heart rate) and gross mechanical efficiency were obtained. During the experiment torque data, speed and power output were determined at a sample frequency of 0·1 Hz. Analysis of variance for repeated measures (p<0·05) was used to establish differences. The hubcrank propulsion mechanism showed a significantly lower physical strain and higher gross mechanical efficiency in comparison with the handrim propulsion mechanism. The lower strain and higher efficiency in propelling the hubcrank partly seems to be due to the continuous biphasic cyclic propulsion movement, which allows both push and pull forces to be exerted, This involues flexor and extensor muscles around elbow and shoulder, leading to a reduced tendency to fatigue in individual muscles in the upper extremity. The more natural and neutral wrist-hand orientation also seems to diminish finger flexor activity and wrist-stabilizing muscle activity, and will thus reduce physical strain both with respect to the cardiorespiratory and musculoskeletal systems. The latter may influence the tendency to develop carpal tunnel problems positively. The reduced strain of the hubcrank propulsion mechanism clearly has a number of advantages over handrims for the human engine in the short and long run. However, technical innovation should address current practical problems of steering and braking. Clearly, hubcrank can be used in low-seated wheelchairs (i.e. racing wheelchairs) only, and in subjects with a sufficiently large range of motion in the upper extremity. Moreover, the increased width is a drawback of hubcranks. Care should be taken while negotiating door posts.

ISSN:0309-1902    

DOI:10.3109/03091909509012418

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

ISSN:0309-1902    

DOI:10.3109/03091909509012419

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

摘要:

Laser Doppler: Edited by Gianni V. Belcaro, Ulrich Hoffman, Alfred Bollinger and Andrew N. Nicolaides, MED-ORION, London, 1994,£75.00, pp. 293. ISBN 9963–592–53–8.Interfacing the IBM-PC to medical equipment. The art of serial communication: By R. W. D. Nickalls and R. Ramasubramanian, Cambridge University Press, Cambridge, 1995,£37.50, pp. 402. ISBN 0521, 16280 0.Introduction to Medical Electronics Applications: By D. Jennings, A. Flint, B. C. H. Turton and L. D. M. Noakes (Edward Arnold, London, 1995), pp.222.£24.99. ISBN 0 340 614579.

ISSN:0309-1902    

DOI:10.3109/03091909509012420

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

ISSN:0309-1902    

DOI:10.3109/03091909509012421

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

ISSN:0309-1902    

DOI:10.3109/03091909509012422

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor

ISSN:0309-1902    

DOI:10.3109/03091909509012423

出版商:Taylor&Francis    

年代:1995

数据来源: Taylor