Table 6.

Studies classified by sensor type (N=72).

Sensor type		Sensor measurement	Application settings			References
			Technology-based therapy setting	Home setting
Body-worn sensor
	Accelerometer	Acceleration of upper limb segments and trunk	[89]	[60,64,65,83]	[27,28,60,64,65,82,83,85,89]
	IMUa	Original IMU signals or Euler angles of upper limb segments and trunk	[25,31,42,59,70]	[25,43,44,81]	[21,22,25,31,42-44,59,68,70,73,81,90]
	Strain sensors	Electrical resistance of sensors printed on the stretched parts	N/Ab	[78,79]	[78,79]
	CyberGlove	Finger angles	N/A	N/A	[34]
Marker-based motion capture system
	Optical motion capture system	3D coordinates of the markers placed on the upper body	[24,26,31-33,38,39,42,45-47,59,62,63,87]	N/A	[24,26,31-33,36,38-40,42,43,45-47,57-59,62,63,66,72,87]
	Electromagnetic motion capture system	3D coordinates of the markers placed on the upper body	N/A	N/A	[34]
	Ultrasound 3D motion capture system	3D coordinates of the markers placed on the upper body	N/A	N/A	[86]
Marker-free vision sensor
	Microsoft Kinect depth sensor	Upper body joint positions in 3D space (x-y-z) coordinates	[23,41,48-52]	N/A	[20,23,41,48-52,61,69,86]
	Simple camera	Video	[74,84]	[67]	[27,28,67,69,74,84]
Physiological signal sensing technology
	EMGc	sEMGd signals of upper limb and trunk muscles	[29,30,33,39,54,84]	N/A	[29,30,33,39,53,54,77,84]
	EEGe	EEG signals	[33]	N/A	[33,80]
	fMRIf	fMRI images	N/A	N/A	[72]
Sensors embedded in the training system	Force sensor or piezoelectric sensor or others	Force exerted by upper limbs, finger force, upper limb joint position, or orientation	[31,35,42,59,75,76,84,88]	N/A	[31,35,42,59,75,76,84,88]
Ambient sensor
	Pressure distribution mattress	Force distribution	[45,54,91]	[45,54,91]	[45,54,91]
	Position sensor	Upper limb and trunk position	N/A	[55]	[55,56]

^aIMU: inertial measurement unit.

^bN/A: not applicable.

^cEMG: electromyogram.

^dsEMG: surface electromyogram.

^eEEG: electroencephalogram.

^ffMRI: functional magnetic resonance imaging.