Development and testing of a compact endoscope manipulator for minimally invasive surgery

Figures & data

Figure 1. Current prototype.

Figure 2. Current prototype schematic.

Figure 3. Endoscope manipulator in lateral position.

Figure 4. Motor control diagram.

Figure 5. Endoscope manipulator in use with instruments and keypad.

Figure 6. Endoscope manipulator kinematics in spherical and Cartesian coordinates.

Table

Mass:
Manipulator	625 g
Endoscope and camera	300–500 g typical
Backdriveability:
Torque	0.45 N-m
Backdrive force on fully  extended endoscope	1.5 N
Dimensions:
Height	75 mm
Diameter	110 mm
Motion range:
Azimuth rotation	360 + ° continuous
Inclination	to 80° from vertical
Extension	160 mm
Typical speed:
Azimuth rotation	20°/second
Inclination	20°/second
Extension	25 mm/second
Maximum torque limit:	6 N-m
Maximum force on fully extended endoscope:	20 N
Actuation hysteresis:	0.38°

Figure 7. Cable-driven prototype manipulator rotation trajectory following.

Figure 8. Cable-driven prototype manipulator inclination trajectory following.

Figure 9. Cable-driven prototype manipulator insertion trajectory following.

Figure 10. Integrated motor prototype manipulator rotation trajectory following.

Figure 11. Integrated motor prototype manipulator inclination trajectory following.

Figure 12. Integrated motor prototype manipulator insertion trajectory following.

Figure 13. Surgeon operating endoscope manipulator.

Table I.  Surgeons' evaluation of features of the endoscope manipulator.

Rating	Excellent	Good	Fair Poor
Robot to patient fixation:
Clamped to table by articulated arm	2	1	1
Sutured to skin of abdomen	–	3	1
Cable attachment to endoscope	–	2	2
Trocar clamp	2	2	–
User command interface
Voice	3	1	–
Keypad	1	3	–