BIOPAC® Systems, Inc. Logo

Constant Voltage Stimulator – Unipolar Pulse

Request More Info
Constant Voltage Stimulator  - Unipolar Pulse
Part #: STM200

The Constant Voltage Stimulator – Unipolar Pulse (STM200) has digital display, a keyed range switch (remove key for added safety), and software-controlled pulse width and repetition, with fully arbitrary pulse sequence. It can be used with an MP Research System to stimulate any preparation or subject, including

  • pain and stress studies that require lower voltages and wider pulse widths
  • trigger the stimulator from a visual presentation system such as SuperLab®, E-Prime®, DirectRT®, MediaLab®, Inquisit®, and other visual presentation programs
  • tissue baths (up to 100 V range at 0.1-200 ms pulse width)
  • nerve or muscle stimulation that requires higher energy than a STMISOC/D/E can deliver
  • MRI animal applications (for human-safe MRI stim, see STM100C/STMISOC)

If  using Touchproof electrodes for stimulation, add CBL207 to interface to Touchproof leads.

See More...

Unipolar Pulse Constant Voltage Stimulator
View Spec PDF

Are You Looking for These?

Part #: STM200
Categories: Stimulation - Research
Subcategories: Stimulators - Research

Alternatives
For the same Platform

Details

Compatibility


MRI safe hardwareFor MRI applications, the STM200 is suitable for animal use only. Do not use on human subjects inside the MRI chamber.

For a human-safe MRI stimulation solution, see the STM100C and STMISOC.

The Current Feedback Monitor Cable (CBLCFMA) is recommended for use with any voltage stimulator; to isolate CBLCFMA output, use INISO and HLT100C. Always make sure to place the electrodes on the participant at least 10 minutes before starting any electrical stimulation. Use a CBLCFMA to monitor and record the actual current delivered to the participant at ALL times. A large enough change in current delivered to the participant will alter the subjective perception of the stimulation. Thus, an unpleasant shock may become painful if more current starts being delivered or become ineffectual if less current is being delivered than during threshold identification. Changes in the levels of delivered current are due to changes in impedance. Changes in impedance could be due to a number of factors: gel saturating the skin over time; gel drying up – over longer period of times; hydration level of participant; sweating; decoupling of electrodes and skin due to motion artifacts; etc.

IMPORTANT Comprehensive Safety Guidelines for Performing Electrical Stimulation on Subjects: read Application Note 257 – Safe Use of Electrical Stimulators

Controls & Connections

Front Panel

Range

Establishes the stimulus pulse output level range in Volts (.025-10 Volts or .12-100 Volts).

  • Turn right to select a range up to 10 Volts.
  • Turn left to select a range up to 100 Volts.
  • Remove the key for added safety and control.

If the Range is changed before recording begins, the scaling must also be changed (MP menu > Set Up Channels) to maintain direct Level recordings.

If the Range is changed during recording, the user should manually enter a software marker to note the change (F9 on Windows or Esc on Mac). The pulse Level could then be determined by (mentally) moving the decimal place to the right or left, depending on how the Range was changed.

Refers to the pulse width of the signal on the Reference Output (on the back panel).

  • Actual reflects the actual output width.
  • Fixed (15 ms) establishes a pulse width of 15 ms, regardless of the actual pulse width.

 The Reference control only affects the pulse width; in either case, the pulse level reflects the actual output level.

Level
Level is used in conjunction with Range to set the stimulus pulse output level. Turn the Level control (right to increase, left to decrease) to establish the desired Level, as indicated on the digital display.
Output
Standard BNC connector to output the stimulus pulse to external electrodes or other devices.
  • For Touchproof electrodes, add CBL207: BNC (m) to 2 x 1.5 mm TP (m)

LCD light

The red LCD is activated when the DC adapter is plugged in and the power switch on the back panel is turned ON, and flashes when the stimulus pulse is active.

Back Panel

Power
Rocker switch for turning the STM200 power ON and OFF.
Fuse
If the fuse blows and must be replaced, use a screwdriver to open (counterclockwise) and close (clockwise) the fuse cap.
DC Input
Socket for DC adapter (AC300A or equivalent).
Trigger
This cable terminates in a 3.5 mm mono plug for connection to the UIM100C Analog Output 0 or the STM100C 50Ω output.
Manual Test
Used to diagnose problems with the STM200 stimulator unit. Disconnect the “Trigger” cable from the MP System and press the Manual Test button to initiate a stimulus with a fixed pulse width of 1 millisecond.
Reference Out
This output cable terminates in an RJ-11 plug for connection to the HLT100C. The cable reports the stimulator marker pulse to the MP System, via the channel it is connected to. A marker pulse will be generated each time the stimulator generates a pulse. The front panel Reference switch determines the marker amplitude:
  • Actual varies between 0-1 V and maps to 0-100 V or 0-10 V
  • Fixed is 15 ms

Support

Application Notes

Applications

Downloads/Resources

Knowledge Base

Recommended Items

Spotlight On
continuous NIR spectroscopy (NIRS) module

fNIR Imaging Systems

fNIR Imaging Systems are stand-alone functional brain imaging solutions for continuous NIR spectroscopy (NIRS). They provide an in-lab cognitive function assessment and eliminate a great many of the drawbacks of a functional MRI. fNIR optical imaging technology measures neural activity and hemodynamic response in the prefrontal cortex. Subjects wear an fNIR sensor (IR light sources […]

View All
Latest News

Alan Macy Answers Proust Questionnaire

BIOPAC co-founder and R&D Director, Alan Macy, was interviewed recently by Roger Durling for the Santa Barbara Independent. The article, “The S.B. Questionnaire: Alan Macy,” provided a background excerpt of the Santa Barbara entrepreneurs’ past as well as his answers to the Proust Questionnaire. The biomedical technology developed at BIOPAC reflects an ambitious understanding of the natural and […]

New Citations | Research in Motion

Physiological researchers have been studying the lower body through examining impacts of training, movement instruction, and innovative research measurements on an individual’s well being. The following articles represent recent developments in physiological research, moving our understanding of lower limbs and the body as a whole forward, one step at a time. The Importance of Form Improper […]

Read All
Request a Demonstration
Request a Demonstration