A sinusoidal load generator for use in cycle ergometry.
We have modified an electromagnetically braked cycle ergometer to provide a sinusoidally varying work load. This was accomplished by applying a low-frequency sinusoidal voltage at the inputs of the electromagnets using a sinusoidal potentiometer, whose shaft was driven by a variable-speed motor, and a voltage-programmable power supply to amplify the signal. The frequency range is currently 0.0017-0.3 Hz. This technique for sinusoidal work loads allow the period, amplitude, and mean position to be easily changed from a console, even during a test if required.
D004581:Electronics; D006801:Humans; D010101:Oxygen Consumption; D005082:Physical Exertion; D010827:Physiology / Q000295:instrumentation*; D011199:Potentiometry