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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 Surgery Columbia University, New York. Outline. Motivation Introduction Proposed Solution Prototype Device I and II
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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 Surgery Columbia University, New York
Outline • Motivation • Introduction • Proposed Solution • Prototype Device I and II • Animal Tests • Results and Conclusion • Contributions and Future Work • Acknowledgement
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. Karl Storz Endoscope Flexible Endoscope Pill camera Gao et al., 1998 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 • 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) Design of 5-DOF insertable camera device
Single Camera Prototype I Diameter: 22 mm; Length: 190 mm Camera opening: 58 mm 3 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.
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.
Laparoscopic Procedures Video Appendectomy Running (measuring) the bowel Suturing Nephrectomy
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 grant 1R21EB004999-01A1.