Tactile robot for tumor detection

Late summer a Canadian group reported on the first prototype of a palpation robot setup for tumor identification.

"Malignant tissue is usually stiffer than the surrounding tissue. Oncologists use scanning techniques such as MRI and CT scanning pre-operatively to identify lesions. But tissues may shift during surgery, making it hard to rely on the position identified by the scan. So instead surgeons use gentle pressure (palpation) to confirm where the tumor is, or to locate further tumors not picked up through scanning. But in MIS this can be very tricky due to access difficulties - as the surgeon must attempt to feel for harder tissue using long, slim instruments via a very small incision. Using tactile MIS sensing instruments under robotic control reduces the maximum force applied to the tissue by over 35% compared to a human controlling the same instrument. Accuracy in detecting the tumors was also far greater with the robot - between 59 and 90% depending on the robot control method used for palpation." /Source: surgicalproductsmag.com/

"The 10 mm incisions used in minimally invasive cancer surgery prevent the direct palpation of internal organs, making intraoperative tumor localization difficult. A tactile sensing instrument (TSI), which uses a commercially available sensor to measure distributed pressure profiles along the contacting surface, has been developed to facilitate remote tissue palpation. The objective of this research is to assess the feasibility of using the TSI under robotic control to reliably locate underlying tumors while reducing collateral tissue trauma. The performance of humans and a robot using the TSI to locate tumor phantoms embedded into ex vivo bovine livers is compared. An augmented hybrid impedance control scheme has been implemented on a Mitsubishi PA10-7C to perform the force/position control used in the trials. The results show that using the TSI under robotic control realizes an average 35% decrease in the maximum forces applied and
a 50% increase in tumor detection accuracy when compared to manual manipulation of the same instrument. This demonstrates that the detection of tumors using tactile sensing is highly dependent on how consistently the forces on the tactile sensing area are applied, and that robotic assistance can be of great benefit when trying to localize tumors in minimally invasive surgery. /Source: The International Journal of Robotic Reseearch/"