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A simple calf muscle ergometer for use in a standard whole‐body mr scanner
Author(s) -
Quistorff BjøRn,
Nielsen Steen,
Thomsen Carsten,
Jensen Karl Erik,
Henriksen Ole
Publication year - 1990
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910130311
Subject(s) - isometric exercise , cycle ergometer , work (physics) , isotonic , work output , contraction (grammar) , biomedical engineering , kilogram , scanner , rowing , mathematics , computer science , simulation , physics , physical therapy , medicine , physical medicine and rehabilitation , blood pressure , engineering , mechanical engineering , heart rate , archaeology , quantum mechanics , artificial intelligence , history , body weight
A calf muscle ergometer, designed for use in a standard whole‐body MR scanner, is described. The instrument allows isotonic or isometric calf muscle exercise over a continuous range of work loads from 0 to individual maximum work output. Work output may be recorded on a strip chart recorder. A sound encoding provides an effective guidance for the subject tested to accurately reproduce his performance in each contraction cycle at a given work load. The FID recording may be triggered from the ergometer at any point during the contraction cycle. Nonmetal materials are used for the instrument construction in order to eliminate potentially disturbing eddy currents. The force resistance of the ergometer is obtained by a combined hydraulic‐pneumatic system, which is loaded by coupling to an outside source of compressed air equipped with a suitable pressure regulator. When varying the time of data sampling within a repeated 6‐s contraction cycle it was found that the recorded P i /PCr ratio remained essentially constant at low and moderate work loads. However, at work loads at or above 70% of individual V max a pronounced dependence of the time of sampling with the contraction cycle was observed.