Abstract

When performing minimally invasive surgical (MIS) procedures, surgeons typically insert 3-5 specialized instruments through incisions less than 15 mm in diameter. This method has been shown to decrease patient trauma, speed healing time and provide a more appealing aesthetic result. The problem is that there is an accompanying increase in time to perform the operation and this technique has been shown, on occasion, to cause injury to the patient through repeated removal and reinsertion of tools.

The main focus of this dissertation is the mechanical design of a modular tool that would aid in decreasing the time required to change instruments by containing multiple modular tool tips within a single tool, allowing surgeons to change functionality of their instruments without removal of the tool from the patient's body.

Special design techniques (Functional Decomposition, Axiomatic Design, Quality Function Deployment) are utilized to analyze the current MIS tool paradigm, determine current shortcomings and understand the needs of MIS surgeons. The resulting 6-chamber modular MIS tool gives surgeons a wide range of functionalities without the need to remove and reinsert the tool shaft. The tool is compatible with existing MIS surgical equipment and can save approximately 13-17% of the overall time in the OR.

When using a modular tool, the possibility of wasting time selecting instruments during a procedure becomes an issue. Analysis of video of various surgical procedures by different surgeons provides data that is used in conjunction with fuzzy inference techniques to create an inference system (FIS) to optimize the arrangement of tool tips within the tool. It is shown that this FIS is able to outperform more than 60% of random tool arrangements as well as match or outperform approximately 80% of random tool arrangements using the same tool tips.

Finally, a possible application of the tool is explored. The volume and weight of the tool is determined and it is shown that if the tool were used on an extended mission to outer space, for undersea exploration or other extreme environmental conditions, it would provide space and weight savings over contemporary traditional laparoscopic tools, possibly resulting in saved lives.