Researchers from the University of Calgary have demonstrated that tremors can be accurately diagnosed and assessed using a smartwatch.
It’s estimated that essential tremor affects 10 million patients in the United States alone. Another 10 million patients are affected by Parkinson’s disease worldwide. Clearly, the burden of disease is large and the impact on day-to-day life for many of these patients is significant.
Accurate diagnosis and the ability to monitor the effectiveness of therapy is critical. Wile et al sought to use a smartwatch specifically to distinguish between essential tremors and Parkinson’s disease in patients with a known diagnosis. We’ve previously described use of an iPhone and a smartphone peripheral in the diagnosis of tremors.
Wile et al enrolled 29 patients, 14 with essential tremor and 15 with Parkinson’s disease. In 10 patients, they collected simultaneous measurements with an analog triaxial accelerometer to validate the smartwatch assessments. In that part of the study, they found near perfect concordance in assessment of tremor frequency and relative power of harmonics.
In all patients, they collected 3-6 minutes of data with the hand at rest and then outstretched. The device used was the WIMM One from WIMM labs which was acquired by Google nearly two years ago. Using the measured mean harmonic peak power, they were able to derive a threshold that correctly identified Parkinson’s disease patients with a sensitivity of 91% and specificity of 100%; area under the ROC curve was 0.981.
In addition to diagnostics, there are apparent, if theoretical, therapeutic applications as well. If they can capture a precise assessment of tremors using a commercially available, connected smartwatch then it could be feasible to monitor effects of therapy objectively. In conjunction with a subjective assessment of symptoms, that capability could improve the ability to prescribe medications and other therapies.
It would be important to demonstrate that such a strategy actually improves outcomes like symptom control above just titrating medications to patient-reported symptom control.
Regardless, this study demonstrates an interesting and innovative application of the flood of consumer-directed wearable devices like smartwatches.