Title: Ischemia Sensing Organ Retractor
1Ischemia Sensing Organ Retractor
- THE PROBLEM
- Excessive retraction forces and time can result
in ischemic tissue damage due to cut-off oxygen
supply. - Need a way of interactively measuring tissue
oxygenation levels intra-operatively.
Babcock retractor and close-up of sensors
- THE SOLUTION
- We developed a smart retractor system that
allows for monitoring of tissue oxygen
saturation. - The device currently uses optical technology
similar to pulse oximetry. - Red and IR LEDs directed into the tissue are
sequentially pulsed - The response of the two wavelengths is measured
with photodiodes - The relative saturation of Red and IR light
varies with oxygen saturation of hemoglobin in
blood.
Retractor setup with Deaver retractor Sensing
capabilities for oxygenation and retraction forces
- THE IMPACT
- This device allows for real-time acquisition of
the tissue of interests oxygen saturation level. - Will be able to prevent tissue damage due to lack
of oxygen supply while being retracted.
Attenuation of light as a function oxygen
saturation and wavelength Figure courtesy of
Nellcor
Preliminary results of photodiode response for
Red and IR light on finger
- THE FUTURE
- Will allow for arrays of sensors to give oxygen
saturation distribution of tissue. - Determine correlation between force and time of
retraction with tissue oxygenation levels - Allows for a safe method for robotic organ
retraction. Can use to close the high level
control loop of robotic retractor based on
tissue oxygenation. - In-Vivo studies in progress.
Preliminary results from retraction of porcine
liver tissue
- PEOPLE INVOLVED
- Graduate Student Greg Fischer
- Undergrad Students Hana Chang
- Takintope Akinbiyi
- Clinicians Dr. Jason Zand
- Dr. Mark Talamini
- PUBLICATIONS
- MICCAI 2003 A Modular 2-DOF Force-Sensing
Instrument For Laparoscopic Surgery - Provisional patent for sensing surgical retractor
submitted January 2004
Porcine trials with the system in MISTIC lab
- SUPPORTED BY
- Core NSF CISST/ERC
Engineering Research Center for Computer
Integrated Surgical Systems and Technology