The Constant Current or Constant Voltage Isolated Linear Stimulator (STMISOL) will connect to any analog output signal drive (±10 V input) and has two functional modes:
Voltage and current stimulator (unipolar or bipolar)—the STMISOL connects directly to the STM100C (50
output port) or the UIM100C (Analog Output 0 or 1 port) associated with the MP1X0 system.
Linear stimulator—the STMISOL can be used to generate stimulation signals that can have arbitrary waveshape (not compatible with MP36/35). Typically, stimulators can only generate simple unipolar or bipolar pulses. The STMISOL, however, can output unipolar or bipolar arbitrary waves such as pulse (single or train), square, sine, triangle, exponentially decaying, modulated envelopes, and fully user-specified types.
The STMISOL can output either voltage or current waveforms.
Voltage (V) mode—the STMISOL multiplies the Control Input Voltage by a factor of 20, to present that amplified signal at the STMISOL output.
In the case of a maximum ±10 V Control Input Voltage, the STMISOL will output a ±200 V signal, with a current compliance of ±100 ma.
Current (I) mode—the STMISOL multiplies the Control Voltage by a factor of (10 ma/V) to present that associated output current at the STMISOL output.
In the case of a maximum ±10 V Control Input Voltage, the STMISOL will output a ±100 ma current signal, with a voltage compliance of ±200 V.
Isolation characteristics—The STMISOL isolates the Control Input Voltage signal from the stimulus output to 1500 VDC HiPot and approximately 90 pF of coupling capacitance.
This very high degree of input/output isolation helps ensure subject safety and helps considerably to substantially reduce, or eliminate, stimulus artifact.
Stimulus artifact results when some percentage of electrical current from the stimulation site is directed to the recording site due to electrical leakage paths intrinsic to the stimulation/recording equipment. In the case of the STMISOL, the leakage conductances and capacitances that permit this artifact to occur are reduced to extremely small values.
Power ON Safety—When you Power ON the STMISOL, you must also hold Reset for at least 3 seconds. This forces the unit into an "operational but no output state" and protects the subject if accidentally connected to electrodes on power-up.
IMPORTANT Comprehensive Safety Guidelines for Performing Electrical Stimulation on Subjects: read Application Note 257 - Safe Use of Electrical Stimulators