CNIM Practice Test questions with correct answers

Chassis leakage less than 100uA Max leakage current (to the patient) less than 10uA differential input impedance 100Mohms Common Mode Rejection 10,000:1 or 80dB Minimum Bandpass 0.1-15,000Hz Horizontal Resolution 20uS/data point (sampling rate 50,000) Vertical Resolution a minimum of 8 bits Ground System 1kohm at 60Hz must measure less than 20mV Obligate Waveform for PTN SEPs LP, N34, P37 Obligate peak generators (PTN) LP - stationary lumbar potential from spinal cord, N34 - subcortically generated far-field response from the brainstem/thalamus P37 - primary medial cortical somatosensory area PTN stimulus intensity peripheral responses should be maximized. PTN stimulus duration 100-300uS PTN stim rate 3-5Hz (clinical), 2-10Hz (intraop) PTN bandpass cortical and spinal 1-30 to 250-3000, 100-200 to PTN sweep (analysis time) 75-150mS PTN averages 500-2000 MN stimulus intensity peripheral responses should be maximized MN pulse duration 100-300uS MN stim rate 3-5Hz (clinical), 2-8Hz (intraop) Bandpass Cortical: 1-30 to 250-3000, Spinal: 100-200 to Hz MN sweep: 30-100mS MN averages 500-2000