Sustained skeletal muscle power for cardiac assist devices: implications of metabolic constraints.
Sustained skeletal muscle power for cardiac assist devices: implications of metabolic constraints.
复制标题
心脏辅助装置的持续骨骼肌力量：代谢限制的影响。
DOI：
10.1097/00002480-200109000-00029
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Hill,JD
中科院分区：
文献类型：
--
作者：
Reichenbach,SH;Egrie,GD;Marinache,SM;Gustafson,KJ;Farrar,DJ;Hill,JD
一种利用骨骼肌线性收缩产生的能量的装置正在开发中。这种应用需要持续的功率水平，这取决于肌肉力学和代谢特性。一个生物力学肌肉模型和代谢模型构建的实验数据被用来预测最大功率可在一个可持续的区域的负荷和刺激条件。用TELECTRONICS肌刺激器对4只山羊的背阔肌（LD）进行了10周的原位预处理。将LD插入重新连接到液压加载系统，允许等长和等张收缩进行生物力学表征。通过基于热敏电阻的肌热技术测量代谢利用。工作等张收缩的简短疲劳测试揭示了与持续功率相关的刺激条件。结果表明，代谢利用率取决于收缩持续时间，速率，力量和中风。持续收缩的区域持续时间为0.1至0.6秒，速率为10至120 bpm。代谢利用率的恒定值很好地近似了可持续功率区域的边界。恒定占空比（收缩周期持续时间比）也接近持续功率，但在较短的收缩持续时间内相差高达30%。结果表明，机械肌肉模型可以预测最大持续功率时，操作条件被约束到一个可持续的范围内确定的代谢模型。此外，代谢约束影响骨骼肌动力辅助装置设计中所需的持续动力的最佳条件。
A device to harness power from skeletal muscle contracting in a linear configuration is under development. This application requires a sustained level of power that is dependent upon muscle mechanics and metabolic properties. A biomechanical muscle model and a metabolic model constructed from experimental data were used to predict maximum power available in a sustainable region of loading and stimulation conditions. Latissimus dorsi (LD) of four goats were evaluated in vivo after a 10 week in situ conditioning protocol with an implanted Telectronics myostimulator. The LD insertion was reconnected to a hydraulic loading system, allowing isometric and isotonic contractions for biomechanical characterization. Metabolic utilization was measured by a thermister based myothermic technique. Brief fatigue tests of working isotonic contractions revealed stimulation conditions associated with sustained power. The results show metabolic utilization was dependent on contraction duration, rate, force, and stroke. The region of sustainable contractions was found for a range of durations of 0.1 to 0.6 sec and rates of 10 to 120 bpm. The boundary for the sustainable power region was well approximated by a constant value of metabolic utilization. A constant duty cycle (contraction to cycle duration ratio) also approximated the sustained power but differed by as much as 30% during the shorter contraction durations. The results demonstrate that a mechanical muscle model can predict maximum sustained power when the operating conditions are constrained to a sustainable range determined by a metabolic model. Furthermore, metabolic constraints influence the optimum conditions for sustained power needed in the design of skeletal muscle powered assist devices.