282 – Subject Electrical Stimulation in fMRI and MRI

This application note is concerned with the implementation of subject electrical stimulation in the fMRI and MRI for the purposes of psychophysiological research. The setup presented physically limits the stimulation energy to be less than 300 mJ under all operating conditions and restricts the electrical stimulation pulse widths to be 2 ms or less. The setup only supports fully programmable, voltage-controlled, voltage stimulation.

Topics

• Operation of STMEPM Configured for fMRI
• EPI-Generated Artifact Stimulation
• Phantom Testing
• Subject Testing
• Recommendations for Electrical Stimulation in the fMRI and MRI

BIOPAC Hardware

• MP160 System Data Acquisition System (includes HLT100C or AMI100D High-level Transducer Module) OR MP150 System Data Acquisition System (includes UIM100C Universal Interface Module)
• STMEPM-MRI Programmable Stimulation System for E-Prime – consolidated equipment, configured for fMRI
  • STM100C Stimulator Amplifier Module
  • STMISOC Stimulus Isolator
  • IPS100D Isolated Power Supply Module
  • MECMRI-STMISO MRI Cable/Filter System to STMISO Series
  •  Interface Cables: CBLEPM for E-Prime; CBL100 3.5 mm, CBL122 RJ
    • E-Prime to analog out of IPS100D via CBL122+CBL100+CBLEPM
  • CBLCFMA Current Feedback Monitor Cable (1 V = 10 ma)
    • Note If other modules will be connected between MP150 System and subject, the CBLFMA output will need to run through an INISO Input Signal Isolator and HLT100C/AMI100D High-level Transducer Module (instead of through the UIM100C). The MP160 System includes the HLT100C/AMI100D High-level Transducer Module in lieu of UIM100C.
  • LEAD108C MR Conditional Carbon Fiber Electrode Leads
  • EL509 Disposable RT Dry Electrodes
  • GEL104 Salt-free and chloride-free electrically conductive gel

Associated Applications

• Psychophysiology - Record and analyze BP, ECG, HRV, EDA, EMG, EEG, EOG, RSP, etc. Interface to stimulus presentation programs...use automated analysis routines to easily score and analyze data.
• Magnetic Resonance Imaging with BIOPAC Equipment - Electrodes, electrode leads, transducers, and stimulus options for safe data acquisition in the MRI. Record biopotentials, temperature, respiration, EDA, dynamometry, blood pressure, etc.