Sensorized Cannula for Measuring Body Wall Forces During Surgery

1 Background Minimally invasive surgical (MIS) techniques, including laparoscopy, are widely known to provide many benefits for patients [1]. More recently, teleoperated surgical devices have provided clinicians the ability to perform MIS procedures with the advantages of 3D vision and more dexterous instruments, which may provide additional benefits to the patient [2]. Laparoscopic and robotic procedures are done with instruments inserted through cannulas, which create ports from the outside to the inside of the patient (Fig. 1). Some MIS procedures have resulted in post-operative port site complications including wound infections and hernias [3]. There is minimal data regarding forces applied at the port sites and possible relation to such complications. This paper focuses on a surgical device that may be useful for assessing forces applied at the body wall that could relate to port site tissue injury. A sensorized cannula was developed to monitor body wall forces during MIS procedures performed through the abdominal wall. Existing devices for measuring various forces during surgery have focused on measuring the forces exerted between instruments and tissue, or require a specially sensorized instrument in conjunction with a sensorized cannula [4-6]. It may also be possible to use an instrumented laparoscopic tool and analytically calculate the force at the body wall with well-defined boundary conditions (i.e., static forces). However, our goal was to have a force sensing tool in which any laparoscopic or robotic instrument can be inserted and used naturally.