Laparoscopy accounts for more than two million surgical procedures each year in the U.S.. While it has brought many benefits in terms of cost reduction and safety, one drawback of this approach is the lack of tactile feedback for the surgeon. To address this problem, a team of engineers from Science and Technology of Robotics in Medicine (STORM) Lab at Vanderbilt University have developed a small, wireless capsule which aims to restore tactile feedback to the physician during laparoscopic surgery.
The prototype capsule is equipped with a pressure sensor, wireless transmitter, accelerometer, magnetometer and battery, all housed within a 0.6 inch x 2.4 inch cylindrical plastic capsule.The capsule can be inserted through an existing laparoscopic access port and easily manipulated with a gripper or endoscope to allow the surgeon to palpate the target tissue.
As the surgeon moves the capsule, the pressure of the tissue is measured using the head of the capsule. Simultaneously, the accelerometer and magnetometer provide corresponding localization data in a 3D co-ordinate plane. All of this data is collected at a sampling frequency of 200Hz and transmitted wirelessly to a PC which builds a visual 3D pressure map of the target tissue.
Collaborator and Associate Professor of urologic surgery at Vanderbilt University School of Medicine, S. Duke Herrell, explains:
The hope behind something like this capsule is that the surgeon will be able to place it inside the body through an existing incision and leave it in a position where it can be easily grasped and used to map out the stiffness or density of the tissue when needed, much like he or she would palpate it with by hand in open surgery.
While the capsule has not yet been used to drive a haptic actuator for direct tactile feedback to the surgeon, the data is available to do so. The prototype has so far performed well in early animal tests and the team has published their detailed design and validation results in the journal IEEE Transactions in Biomedical Engineering.
IEEE Transactions in Biomedical Engineering: Wireless Tissue Palpation for Intraoperative Detection of Lumps in Soft Tissue…
Press release: Restoring surgeons’ sense of touch during minimally invasive surgeries…