Marble A E, Landymore R W, Church D W
Department of Electrical Engineering, Technical University of Nova Scotia, Halifax, Canada.
Med Prog Technol. 1990 May;16(1-2):19-29.
A measurement system which is capable of detecting microfibrillation in the hypothermic, arrested heart has been developed. It is shown that this system can reliably measure microfibrillation signals as low as 10 microV in amplitude. Using this system, it has been shown that even after the heart has been rendered visibly arrested using cold potassium, it may still be producing a low level of electrical activity. It has also been shown that the presence of this microfibrillation during the period of the cold potassium administration and visible arrest, is very highly correlated with the decrease in high energy phosphates (ATP), mitochondrial injury, and a decreased cardiac function post-operatively. Using the information obtained from this first measurement system, a miniature, battery powered voltmeter has been designed and fabricated. This voltmeter has been tested using the initial measurement system as reference and produces the same information concerning the small signal electrical activity (i.e.: same waveform and RMS value). Because this voltmeter is battery powered and is, therefore, completely isolated from all electrical equipment in the operating theatre, it can be used to monitor the presence, or absence, of microfibrillation in the human heart. Of greatest importance, however, is the fact that the voltmeter can serve as a monitoring device which will indicate when the potassium should be administered in order to render the heart both mechanically and electrically arrested.
一种能够检测低温停搏心脏中微颤动的测量系统已被开发出来。结果表明，该系统能够可靠地测量幅度低至10微伏的微颤动信号。使用该系统已表明，即使在使用冷钾使心脏明显停搏后，心脏仍可能产生低水平的电活动。还表明，在冷钾给药和明显停搏期间微颤动的存在与高能磷酸盐（ATP）的减少、线粒体损伤以及术后心脏功能下降高度相关。利用从这个第一测量系统获得的信息，设计并制造了一种微型电池供电电压表。该电压表已使用初始测量系统作为参考进行测试，并产生有关小信号电活动的相同信息（即：相同波形和均方根值）。由于该电压表由电池供电，因此与手术室中的所有电气设备完全隔离，可用于监测人心脏中微颤动的存在与否。然而，最重要的是，该电压表可以作为一种监测设备，指示何时应施用钾以使心脏在机械和电方面都停搏。
