Closed-loop control of carbon dioxide concentration and pressure improves response of room respiration calorimeters.
Closed-loop control of carbon dioxide concentration and pressure improves response of room respiration calorimeters.
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二氧化碳浓度和压力的闭环控制提高了室内呼吸热量计的响应。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
N. Butte
中科院分区：
文献类型：
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作者：
Jon K. Moon;F. Vohra;Omar S. Valerio Jimenez;M. Puyau;N. Butte
大房间量热计能够快速测量，通常在通风橱或小房间中进行。我们评估了四个量热计的性能增益与现代控制系统，样气制备和数据处理。对量热计和仪器进行了现场校准，可追溯到国际标准。通过输注N2-CO2气体和243个24小时个体研究评估性能。我们的研究对象包括体重20公斤的儿童和从事剧烈运动的成年人。24小时输注测量（n = 23）的耗氧率误差为-0.34 +/- 1.24%，二氧化碳产生率误差为0.11 +/- 0.98%。热量计90%响应时间在100至> 4000 mL/min的耗氧率范围内为2至6 min。供应和排气流量的闭环控制提供了一致的24 h平均CO2水平（0.39 +/- 0.015%）和压力（13.2 +/- 4.4 Pa）。以闭环控制操作的室内热量计可用于精确测量各种个体的能量消耗率动态。
Large room calorimeters are capable of rapid measurements that are usually made in hoods or small rooms. We evaluated the performance gains of four calorimeters constructed with modern control systems, sample gas preparation and data processing. Calibration of the calorimeters and instruments was performed in place, with traceability to international standards. Performance was evaluated by infusion of N2-CO2 gas and 243 24-h studies of individuals. Our subjects included children weighing 20 kg and adults engaged in heavy exercise. Errors for 24-h infusion measurements (n = 23) were -0.34 +/- 1.24% for oxygen consumption rate and 0.11 +/- 0.98% for carbon dioxide production rate. Calorimeter 90% response times were 2 to 6 min over a range of oxygen consumption rates from 100 to > 4000 mL/min. Closed-loop control of supply and exhaust air flows provided consistent 24-h mean CO2 levels (0.39 +/- 0.015%) and pressures (13.2 +/- 4.4 Pa). Room calorimeters operated with closed-loop control can be used for accurate measurement of energy expenditure rate dynamics for a wide range of individuals.