Spinelli J C, Valentinuzzi M E
Med Prog Technol. 1983;9(4):239-45.
An impedance cardiograph (so-called cardioimpedance meter) with the following characteristics is described: preadjustable current generator range of 0-4 mA rms at 100 kHz, crystal-controlled; sensitivity up to 50 V/omega with a resolution of 2 m omega; maximum nonlinearity of 2%; 0.7 microA arms of maximum leak current at 50 Hz; flat frequency response between 0 and 19 Hz. The instrument is self-balanced, using Arenson's bridge [1] with minor modifications, and is also able to operate as a plethysmograph, respirograph, and as an intracardiac Z-meter. Preliminary test as an impedance cardiograph yielded a correlation coefficient better than 0.8 when the stroke volume was evaluated by Kubicek's method and compared with values obtained using thermodilution.
描述了一种具有以下特性的阻抗心动图仪（所谓的心阻抗仪）：在100kHz时，晶体控制的预可调电流发生器范围为0 - 4mA rms；灵敏度高达50V/Ω，分辨率为2mΩ；最大非线性为2%；50Hz时最大泄漏电流为0.7μA rms；0至19Hz之间频率响应平坦。该仪器采用经过微小修改的阿伦森电桥[1]进行自平衡，还能够作为体积描记器、呼吸描记器以及心内Z测量仪运行。作为阻抗心动图仪进行的初步测试表明，当采用库比切克方法评估每搏输出量并与热稀释法获得的值进行比较时，相关系数优于0.8。
