is such an electrical circuit possible?

[azg]

Hello all

I want a small coil of wire (solenoid) to vibrate at different frequencies with a mean frequency of about 1 Hz, the interval between vibrations should last a random length of time between 100 and 3000msec and the vibration at each frequency should be about 10msec long.

Is this possible to do?

Thanks for any help at all.

[pebe]

I think your mean frequency of 1Hz must be a mistake. Can you confirm what it should be?

[azg]

Thanks for the reply.

I want to create a device as was done in this study (http://www.jneurosci.org/content/20/4/1597.full). Briefly, it found that variable frequency stimulation applied to finger tips in human subjects results in improvement in spatial discrimination ability.

The relevant section regarding the specifics of the device,
"The timing of the coactivation protocol was the same as that in our previous neurophysiological study. To prevent habituation during the long-lasting stimulation over several hours, we presented the applied stimuli at eight different interstimulus intervals (ISIs) between 100 and 3000 msec in pseudorandomized order, resulting in a mean stimulation frequency of 1 Hz (Godde et al., 1996). The duration of each pulse was 10 msec. This protocol was used for a group of 11 subjects. The remaining subjects were tested with a slightly modified protocol, in which ISIs were randomized between 8 and 1761 msec, resulting in a mean frequency of 1.7 Hz. Because the outcome of the experiments was unaffected by the slight differences in average frequency, we pooled the data for further analysis."

Mean stimulation frequency was 1 Hz in standard protocol and 1.7 Hz in the modified protocol, with no change in outcome of the experiment. I wonder how they did it.

[pebe]

I can never understand why people cannot write articles in plain English. Most of the nebulous terms used in the article went over my head.

But I gather from it that the stimuli is a train of eight 10ms pulses, spaced between 100ms and 300ms apart, and repeated continuously. I did not see any reference to the amplitude of the pulses, unless it is embedded somewhere in the text. The stimulii are applied through two needles.

If you apply that sort of signal to a solenoid, it will pulse - rather than vibrate.