[Evaluation of fatigue by using acceleration plethysmography].
Yamaguti, Kouzi·Nihon rinsho. Japanese journal of clinical medicine·2007
Researchers tested a new device called acceleration plethysmography to measure fatigue in ME/CFS patients. This device tracks tiny blood vessel changes and nervous system activity in the fingertip. The study found that fatigue levels were connected to specific patterns in these measurements, suggesting this tool might help doctors objectively measure ME/CFS fatigue in the future.