Gitter A J, Stolov W C
Department of Rehabilitation Medicine, University of Washington, Seattle, USA.
Muscle Nerve. 1995 Aug;18(8):812-24. doi: 10.1002/mus.880180804.
A review of instrumentation and measurement in electrodiagnostic medicine is continued in this Part II which focuses on digital instrumentation principles, gain and sweep effects, noise, nerve stimulation, and conduction measurement limitations. With the adoption of microprocessor-based equipment, the neurophysiologic signal must undergo analog-to-digital conversion (ADC) before analysis and display on a video monitor. ADC resolution and sampling rates affect accuracy and measurement precision. Following waveform display, the visual assessment of latency and duration may be influenced by sweep and gain settings, often overlooked sources of error. Undesired signal or noise typically originates from power-line interference, electronic amplifier noise, background muscle activity, or nerve stimulation artifact. Noise often interferes with clinical studies but techniques exist to reduce noise to acceptable levels in virtually all situations. An awareness and understanding of these technical issues will lead to an appreciation of the limitations of electrodiagnostic testing and improve interpretation and clinical decision-making.
第二部分继续对电诊断医学中的仪器设备和测量进行综述，重点关注数字仪器原理、增益和扫描效应、噪声、神经刺激以及传导测量限制。随着基于微处理器的设备的采用，神经生理信号在分析并显示在视频监视器上之前必须经过模数转换（ADC）。ADC分辨率和采样率会影响准确性和测量精度。在波形显示之后，潜伏期和持续时间的视觉评估可能会受到扫描和增益设置的影响，而这些往往是被忽视的误差来源。不需要的信号或噪声通常源于电力线干扰、电子放大器噪声、背景肌肉活动或神经刺激伪迹。噪声常常干扰临床研究，但在几乎所有情况下都有将噪声降低到可接受水平的技术。对这些技术问题的认识和理解将有助于认识到电诊断测试的局限性，并改善解读和临床决策。
