K.Gardiola, J. Perez, Y. Huang, B. G. Crawford, M. Phillips, R. Cabrera, S. Paul, J. Hryb

Department of Engineering

Quinnipiac University

In the fall of 2016, Quinnipiac University’s Engineering Department were approached with a senior project opportunity by the Minimal Invasive Therapies Group of Medtronic. The project entailed developing a portable version of one of their current testing devices that performs reliability and functional tests on several of their minimally invasive surgical instruments. This device will provide the biggest impact for Medtronic’s R&D Team throughout their ongoing product development efforts. The device could also be largely used by Medtronic’s Quality and Testing department in the near future upon Medtronic’s discretion. 

This project opportunity was undertaken as a Mechanical Engineering Senior Design Capstone by a team of three senior ME students and two faculty advisors, as well as a team of engineers from Medtronic. After an introductory meeting about the requirements and limitations of the project, as well as a series of literature reviews, the team proposed the following problem statement to Medtronic during a Preliminary Design Review:

Design and manufacture a device that will be able to measure and output the loads applied on the surgical instrument. The device must replicate the functional test of the current A3 tester. The device should be high quality in design and constructed using robust materials. It must be precise, portable, reusable and comply with all Medtronic safety standards. A functioning Portable A3 Tester must be delivered NLT April 23^rd.

The current A3 tester was too big to be moved from room to room which made it difficult for testing in different departments. The team had to reduce its size while maintaining all its primary functions. Due to the nature of the devices the Portable A3 Tester would be used on, the precision of the measurements had to be very high in order to comply with the strict medical regulations. Throughout the test, there must be minimal digression from the loading profile of the device tested, or else it could prove to be unreliable The portable A3 also needs to be capable of use inside Medtronic’s clean room, where production of their surgical instruments takes place. This meant that the material used for the manufacturing of this device had to be clean-room compatible and anodized.

The final design uses load cells, linear potentiometer position sensors and two electrohydraulic actuators (EHAs) to simulate and measure medical device displacement and applied loads, all of which feed into a close loop control system programmed using LabVIEW software.  Position is measured to an accuracy of +/- 0.0001 inch and force is measured and controlled to an accuracy of +/-15 lbf.  The EHA used in the system is capable of exerting loads of up to 1200 lbf in both tension and compression. The tester simulates the loading profile the surgical instruments undergo doing their life cycle by linearly displacing the EHAs while the applied force is controlled by the measured displacement. A laptop is used to control and set the parameters for the test, as well as where record and store test data.

Corresponding Authors: Kyzer Gardiola, Kyzer.Gardiola@quinnipiac.edu; Jose Perez, Jose.Perez@quinnipiac.edu; Yihao Huang, Yihao.Huang@quinnipiac.edu