[16737524]
This machine has a serious flaw, called aliasing, that distorts the data. The unit has a low sampling rate in the display of the emg data, causing the data to appear abnormal when the data is actually normal. I realize that unless you compare the data from this unit with any other emg instrument, you will not recognize this crucial error. Sampling rate in emg instruments is in the software, not the chip. To demonstrate this crucial error, you must set the filters to 20hz-10,000hz and record a normal muscle. Then change the sweep duration to 500ms or 1s. Sweep speed muss be 50ms/div or higher. If the amplitude of the waveform is relatively constant you are seeing an instrument with a high sampling rate, a necessity in clinical electromyography. If the motor unit is variable then be assured the sampling rate is inadequate. Sadly, this is missed as no one tests a pt on 2 different instruments. What occurs with the neuromax is reduced signal amplitude resulting in a false negative diagnosis. Additionally, this unit does not utilize standard filter settings for the nerve conduction testing. Mds compare results on this unit with normative data collected with standard filter settings and again misdiagnose pts. The cart does not meet the tilt test. This unit has caused tremendous misdiagnosing of pts. A beginning engineering student would have caught this glaring error if only pt testing was performed with any other instrument.
Patient Sequence No: 1, Text Type: D, B5