Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Division of Pulmonary Medicine, Department of Internal Medicine and Department of Critical Care Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan.
J Biophotonics. 2019 Mar;12(3):e201800320. doi: 10.1002/jbio.201800320. Epub 2019 Feb 1.
Neuromuscular electrical stimulation (NMES) is used for preventing muscle atrophy and improving muscle strength in patients and healthy people. However, the current intensity of NMES is usually set at a level that causes the stimulated muscles to contract. This typically causes pain. Quantifying the instantaneous changes in muscle microcirculation and metabolism during NMES before muscle contraction occurs is crucial, because it enables the current intensity to be optimally tuned, thereby reducing the NMES-induced muscle pain and fatigue. We applied near-infrared spectroscopy (NIRS) to measure instantaneous tissue oxygenation and deoxygenation changes in 43 healthy young adults during NMES at 10, 15, 20, 25, 30, and 35 mA. Having been stabilized at the NIRS signal baseline, the tissue oxygenation and total hemoglobin concentration increased immediately after stimulation in a dose-dependent manner (P < 0.05) until stimulation was stopped at the level causing muscle contraction without pain. Tissue deoxygenation appeared relatively unchanged during NMES. We conclude that NIRS can be used to determine the optimal NMES current intensity by monitoring oxygenation changes.
神经肌肉电刺激 (NMES) 用于预防肌肉萎缩和增强患者和健康人群的肌肉力量。然而，目前 NMES 的电流强度通常设定为引起受刺激肌肉收缩的水平。这通常会引起疼痛。在肌肉收缩发生之前，定量测量 NMES 过程中肌肉微循环和代谢的瞬时变化至关重要，因为这可以使电流强度得到最佳调整，从而减少 NMES 引起的肌肉疼痛和疲劳。我们应用近红外光谱 (NIRS) 技术来测量 43 名健康年轻成年人在 10、15、20、25、30 和 35 mA 时的 NMES 过程中组织氧合和去氧合的瞬时变化。在 NIRS 信号基线稳定后，组织氧合和总血红蛋白浓度在刺激后立即呈剂量依赖性增加（P<0.05），直到刺激停止在引起肌肉收缩但无疼痛的水平。在 NMES 过程中，组织去氧合似乎相对不变。我们的结论是，NIRS 可以通过监测氧合变化来确定最佳的 NMES 电流强度。
