Table 1.

Summary of the technical characteristics of the eWrist

Performance metrics	Obtained values
Forearm module weight [g]	238
Upper arm module weight [g]	224
Myo armband weight [g]	94
Total weight [g]	556
Forearm module dimensions1 [mm]	200 ×120×802
Upper arm module dimensions1 [mm]	120 ×1603×1253
Output max. torque [Nm]	3.7
Output max. velocity [deg/s]	5304/5205
Output max. acceleration [deg/s2]	6’5104/7’5705
Force/torque range6 [N]/[Nm]	0-50/0-4
Force/torque resolution [mN]/[mNm]	7.3/0.58
Angular position resolution [deg]	0.058
Angular velocity resolution [rpm]	configurable
Restrained RoM [deg] (cf. Fig. 1d)	±77
Static friction7 [Nm]	<∣±0.1∣
Dynamic friction8 [Nm]	$0.00198\dot{\theta }\pm 0.0135$
Position control bandwidth [Hz]	1.74
PD steady-state error [deg]	<0.12
Autonomy9 [min]	125
Battery capacity [Wh]	11.1

¹for a 1m83 tall user

²with palm support and fastening cable

³with module fingers fully extended

⁴in extension and in restrained RoM

⁵in flexion and in restrained RoM

⁶measurable by the load cell in both directions

⁷in restrained RoM

⁸for $\dot{\theta }$ up to 250 deg/s, R²=0.995

⁹in normal use