When we mentioned to the developer of the LiftPulse app that the frequency of the OT tremor often exceeded the 15hz threshold on the current LiftPulse app, Anupam Pathak of Lift Labs Design quickly responded and said that he would increase the test to 20hz to accomodate the OT tremor.
Well... version 2 of LiftPulse was just released, and with it the ability to track the faster OT tremor, - many thanks to Anupam!
And - it's still free.
here's the info from the developer:
What's New in Version 2.0
This is a major update for the Lift Pulse. We now have a versatile, free app that can help you track and manage tremor. Using this app will now help obtain valuable information to learn more about Essential Tremor and Parkinson's Disease. New features include:
* Tremor history -- track and chart your tremor over time
* Record life factors (stress, exercise, sleep)
* Journal your medications/treatments
* Accurate tremor readings
A link to LiftLabs
that describes some of the "how-to", although this is for the older version it is still relevant.
You might try placing your smartphone in a knee sock, or possibly a better reading would be with the phone tucked in a band around your upper leg muscle (quadriceps). This could be an "ace bandage" or similar elastic wrap bandage. After you record your tremor (while standing) you will see a frequency spectrum. Your tremor measurement should appear as a peak between 13 and 18 Hz*. The LiftPulse app automatically finds this peak and integrates it to calculate your overall tremor amplitude in centimeters.
OT would "typically" have a finer or faster frequency and a lower amplitude. And this is why it is often not recognized as a tremor. Compared to the slower frequency and the higher amplitude of essential tremor (4-12 Hz - beats per second). The amplitude or distance traveled is why Essential Tremor is also more visible. Parkinsons would have an even slower frequency and a greater amplitude.
*13-18Hz is the most common range of frequency for OT (think of frequency as the rhythm of the tremor, faster or slower)
The degree of linear or angular displacement of the limb or body part, or the tremor amplitude, is generally measured in millimeters or degrees. Tremor amplitude can be accurately assessed using accelerometers or gyroscopes (note - such as used those used in iphones/smartphones). reference - clinical tremor assessment
A quick look at the LiftPulse screen below will show:
A spike along the "Frequency" axis, this should indicate how many tremors per second. 13Hz would be 13 tremors per second
Amplitude - this would indicate how far the limb moved, LiftPulse averages and calculates amplitude in centimeters.