VIBRATION AND COMPLIANCE EFFECTS ON SCALPEL INCISION FORCES

Open Access
Author:
Barrett, Jessica Price
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Jason Moore, Thesis Supervisor
  • Sean Brennan, Honors Advisor
Keywords:
  • Vibration
  • Compliance
  • Scalpel
  • Incision Force
  • Ultrasonic
  • Surgical Tools
Abstract:
The success of many invasive, surgical procedures is dependent on precise scalpel incisions. Deviations from the intended scalpel cut path and depth can cause severe harm to the patient including additional surgeries, excessive bleeding, and other complications. This thesis work investigates methods of reducing scalpel incision forces including the application of vibrations, and the introduction of compliance to scalpels. Fixtures were machined to perform three specific experiments, each demonstrating the effects of different methods. All experiments involved a piezoelectric transducer and an attached scalpel cutting through a polyvinyl chloride (PVC) tissue simulant. Experiment 1 involved applying vibrations to scalpels at 0 Hz, 500 Hz, 700 Hz, and 900 Hz during the scalpel incision, and determined that vibrations of 500Hz resulted in the lowest insertion force, and 700Hz vibrations resulted in the lowest steady cut force. Experiment 2 introduced the concept of compliance, and the effects of three compliant scalpels and vibrations of 500Hz on the incision forces were determined. Compliant scalpel 2 had a compliant slit 7.64mm from the scalpel tip, and was found to cause the largest reduction in both the scalpel insertion force and steady cut force when no vibration was applied. From Experiment 3, the effects of ultrasonic vibration and compliant scalpel shafts were investigated. It was found that the application of ultrasonic vibration and compliance failed to reduce the total forces when cutting through PVC phantom. With further investigation and development of related work, incision forces can be reduced thereby improving patient safety in invasive surgical procedures.