Motion Accuracy of Pneumatic Stepper Motor-Driven Robotic System Developed for MRI-Guided High-Intensity Focused Ultrasound Treatment of Prostate Disease

Table 2

Positional accuracy of transducer in linear motion along Z-axis.

Direction	Linear error (mm)
	Mean ± SEM	SD
Forward	0.00 ± 0.03	0.20
Backward	−0.13 ± 0.04	0.22

Mean, SEM, and SD were obtained from 40-time sampling error distribution.