Development of an artificial feedback system with abdominal electrical stimulation for treatment of orthostatic hypotension

我们开发了一种无创的腹部电刺激人工反馈系统原型，并评估了其治疗直立性低血压的疗效。频率反应可识别，阶跃反应函数显示动脉压对刺激反应迅速，在20秒内达到稳态反应的90%。稳态增益为0.2±0.07毫米汞柱/赫兹。在此基础上，将Kp设置为1.0，将Ki设置为0.01，从而使伺服系统能够快速有效地抑制外部扰动的影响。该系统可以将自主神经性直立性低血压患者的倾斜时间从2.3分钟延长到3.2分钟。此外，用40毫米汞柱的气裤按压双腿，可以延长到4.4分钟。

We developed prototype of a noninvasive artificial feedback system with abdominal electrical stimulation, and evaluated an efficacy for treatment of orthostatic hypotension. The frequency responses were identifiable and the step response function showed arterial pressure quickly responded to the stimulation and reached 90% of the steady-state response in 20 seconds. The steady state gain was 0.2+-0.07 mmHg/Hz. On the basis of these results, Kp was set at 1.0, and Ki was set at 0.01, so that the servo system could quickly and effectively attenuate the effect of the external disturbance. The system could prolonged a tilting time in patients with autonomic orthostatic hypotension from 2.3 minutes to 3.2 minutes. Moreover, it could extend to 4.4 minutes by pressing lower limbs with air pants of 40mmHg.