In-Vivo Pan/Tilt Endoscope with Integrated Light Source

Tie Hu, Ph. D*, Peter K. Allen, Ph. D*, Dennis L. Fowler, M.D.***Department of Computer Science

**Department of SurgeryColumbia University, New York

Outline Motivation Introduction Proposed Solution Prototype Device I and II Animal Tests Results and Conclusion Contributions and Future Work Acknowledgement

Minimally Invasive Surgery

Limitations of Standard Endoscope Paradigm of pushing

long sticks into small openings. Narrow angle imaging. Limited workspace. Counter intuitive

motion. Assistants needed to

control the camera. Additional incisions

for other laparoscopic instruments.

Robotic Surgery Robotic surgery is future of surgery.

Increase the dexterity and fine motion capabilities of surgeon.

Decrease the tremor of surgeon’s hand. Enable remote operation.

Current surgical robot. Enormous size. Extremely high cost. Multiple assistants needed. Multiple incisions needed as non-robotic MIS.

Compact and inexpensive surgical robot is needed.

In-Vivo Imaging Devices Rod-lens by Hopkins and cold light source of

fiber optics by Karl Storz. Flexible endoscope using fiber optics to

delivery light and transmit image. Pill camera without locomotion. Endoscope with rotating mirror. Endoscope positioned by multilink arm with

piezoelectric actuators.

Gao et al., 1998

Pill camera

Karl Storz Endoscope

Flexible Endoscope

Ikuta et. al., 2002

Proposed Solution An insertable surgical robot platform with sensors and

effectors in the body cavity where they can perform surgical & imaging tasks unfettered by traditional endoscopic instrument design.

A prototype of a novel insertable Pan/Tilt endoscope with integrated light source.

The incision port is left open access, allowing for single port surgery.

Prototype Device I

Design of 5-DOF insertable camera device

Stereo camera with 6 DOF are desirable – full mobility

Difficult to achieve in small actuated package

Compromise – 3 DOF per camera Cameras share tilt axis

(1 DOF) Independent translation

(2 DOF) Independent pan (2

DOF)

Single Camera Prototype IDiameter: 22 mm; Length: 190 mmCamera opening: 58 mm3 DOF: Pan: 120°; Tilt: 130°; Translation: 50 mm

Video

Improvements Needed for Prototype II

Much reduced size: Smaller diameter Reduce length

Needs light source Make imaging head modular design Tradeoff: Degrees-of-freedom for

compactness

Prototype II 110 mm in length and 11

mm in diameter. 120 degrees Pan/ 90 degrees

Tilt. Integrated 8 LED light

source and miniature camera module.

Package to protect the delicate electronics and fragile wires from body fluid and moisture. Fully sealed camera

module. Joint sealed by rubber boot.

Joystick control.

Prototype II (Cont.)

LED Light Source Light-emitting diode (LED) as

a light source in laparoscopy: Lower power Higher efficiency Compact package Longer lifespan Lower cost

Luxeon portable PWT white LED(LXCL_PWT1) 2.0 X1.6 X 0.7 mm 26 lumens of light at 350 mA

8 PWT LED in a printed circuit board with 9mm diameter. 208 lumens light at 8.4 w

Camera Module

Pin hole lens (PTS 5.0 from Universe Kogaku America) Focal length 5.0 mm. F number 4. Angle of view D-H-V(85.4-68.3-50.9 ).

6.5 mm CCD camera sensor. NET USA Inc, CSH-1.4-V4-END-R1. 450 TV lines in horizontal resolution and 420 TV lines in vertical resolution.

Protective window by sapphire.

Pan/Tilt Mechanism

Miniature Brushless DC motor (0513G, Faulhaber Group). 25mNm output torque. 5.8 mm in diameter.

Miniature worm gear (Kleiss Gear Inc.) Gear ratio 16:1. Compact size. Increased torque.

Sleeve bearing to reduce the friction of tilt motion.

Working Device in the Animal Test

Laparoscopic Procedures

Running (measuring) the bowel Appendectomy

Suturing Nephrectomy

Video

Timing of Each Procedures for Laparoscope and our device

Procedure Laparoscope(minutes)

Robot(minutes)

Running Bowel 4:20 3:30

Appendectomy 2:20 2:20

Suturing 5:00 4:00

Conclusion Easier and more intuitive to use than a

standard laparoscope. Joystick operation requires no specialized

operator training. Field of view and access to relevant regions

of the body were superior to a standard laparoscope using a single port.

Time to perform procedures was better or equivalent to a standard laparoscope.

Contributions and Future Work Contributions

Built an insertable camera with Pan/Tilt and integrated LED light source.

Accomplished a series of standard laparoscopic procedures( appendectomy, running (measuring) the bowel, suturing, and nephrectomy) by laparoscopic surgeon using the device.

Future Work Camera with zoom and auto-focusing capabilities. Stereo camera in one package. Function with tool or organ tracking.

Acknowledgement

We thank Nancy Hogle for her help in project development and lab support.

This work was supported by NIH grant1R21EB004999-01A1.