A Sensorized Instrument for Skills Assessment and Training in Minimally Invasive Surgery

Minimally invasive surgers (MIS) is carried out using long narrow instruments and significantly reduces trauma to the body postoperative pain and recovery time unfortunately the restricted access conditions limited instrument motion and degraded sense of touch inherent in MIS result in new perceptual motor relationships which are unfamiliar to the surgeon and require training to overcome Current training methods do not adequately address the needs of surgeons interested in acquiring these skills Although a significant amount of research has been focused on the development of sensorized systems for surgery there is still a need for a system that can be used in any training scenario (laparoscopic trainer animal laboratories or real surgery) for the purpose of skills assessment and training A sensorized laparoscopic instrument has been designed that is capable of noninvasively measuring its interaction with tissue in the form of forces or torques acting in all five degrees of freedom (DOFs) available during MIS Strain gauges attached to concentric shafts within the instrument allow the forces acting in different directions to be isolated An electromagnetic tracking system is used for position tracking Two prototypes of the sensorized instrument were constructed Position calibration shows a maximum root mean square (RMS) error of 1 3 mm The results of the force calibration show a maximum RMS error of 0 35 N for the actuation force 0 07 N in the x and v directions and 1 5 N mm for the torque calibration with good repeatability and low interests Axial measurements were significantly affected by draft noise and coupling leading to high errors in the readings Novel sensorized instruments for skills assessment and training have been developed and a patient has been field for the design and operation. The instruments measure forces and torques acting at the tip of the instrument corresponding to all five DOFs available during MIS and provide position feedback in six DOFs The instruments are similar in shape size and weight to traditional laparoscope instruments allowing them to be used in any training environment Furthermore replaceable tips and handles allow the instruments to be used for a variety of different tasks