Cuff-type pneumatic stimulator for studying somatosensory evoked responses with fMRI.

For quantitative somatosensory testing in the clinical environment a microprocessor controlled MR-compatible stimulation device was developed. A main feature of this device is the use of an inflatable cuff allowing the application of defined test pressures (0-1000 mbar) to the skin surface. The cuff is pressurized by a piezoelectric proportional valve with embedded closed loop controller.

Personal noise ranking of road traffic: subjective estimation versus physiological parameters under laboratory conditions.

Objective: To evaluate the subjective estimation of noise-induced discomfort and its correlation to psychoacoustic and physiological parameters under laboratory conditions. To establish an effective description of sound qualities of road traffic noise, supplementing the current standards and calculation specifications.

Methods: Pass-by vehicle noise samples were binaurally recorded with a dummy head measurement system, and synthetically composed to six vehicle ensembles considering different road beds, varying speed profiles and noise barriers.

Contact force- and amplitude-controllable vibrating probe for somatosensory mapping of plantar afferences with fMRI.

Purpose: To study cerebral responses evoked from mechanoreceptors in the human foot sole using a computer-controlled vibrotactile stimulation system.

Materials And Methods: The stimulation system consisted of two stationary moving magnet actuators with indentors to gently contact and vibrate the foot sole during functional MRI (fMRI) experiments. To allow independent settings of contact force (0-20 N) and intensity of vibration (frequency range=20-100 Hz) the actuators were controlled by a digital servo loop.

Human brain structures related to plantar vibrotactile stimulation: a functional magnetic resonance imaging study.

The purpose of this study was to investigate the sensorimotor cortex response to plantar vibrotactile stimulation using a newly developed MRI compatible vibration device. Ten healthy subjects (20-45 years) were investigated. Vibrotactile stimulation of the sole of the foot with a frequency of 50 Hz and a displacement of 1 mm was performed during fMRI (echo-planar imaging sequence at 1.

Evaluation of FES-induced knee joint moments in paraplegics with denervated muscles.

The pendulum test was applied to evaluate functional electrical stimulation (FES)-induced joint moments in paraplegics with denervated muscles. Therefore a manipulandum was connected to the knee joint and programmed to elicit gravity-induced leg oscillations. The FES-induced output torque was compensated for in order to keep the leg in a mean vertical position (knee angle 90 degrees ).

Functional electrical stimulation-induced surface muscle stiffness captured by computer-controlled tonometry.

A new tonometric test system to assess surface stiffness over relaxed and activated calf muscles was developed. The mechanical arrangement consists of a skin indentor driven by a torque motor (galvo-drive) that is rigidly connected to an ankle dynamometer. The indentation depth is measured by a displacement transducer.