Table 3.

Comparison of the most commonly used sensors for quantification and monitoring of tremor ^*.

	Assessment of kinematics**			EMG Surface EMG (SEMG) Needle electrodes Fine-wire electrodes Long-term recordings	Force transducers and force-feedback devices (haptic devices)
	Accelerometer	Gyroscope	Video
Gravity effect influence	yes	no	no	no	no
Accuracy of frequency information	good	good	may be low	good	good
Signal-to-noise ratio	low to high	high	variable	high	high
Electrical contacts with subjects	no	no	no	yes	yes
Size	small	small	relatively large	small	Large
Painful	no	no	no	yes (needle EMG)	no
Cost	cheap	cheap	cheap to expensive	variable	expensive
Easy to use	yes	yes	yes	variable	relatively difficult
Data processing required	yes	yes	yes	yes	yes
Measurement of tremor amplitude	calculation from time/acceleration	measurement of inertial angular rate	from calibrated video frames	no	from force/mass or position encoder

^*Emerging sensors include wearable textiles with integrated sensors, sensors based on the fusion approach and hybrid sensors.

^**Includes also flexible angular sensors/goniometers and laser-based devices.