Prototyping
First Generation
Objectives of this iteration:
Use inexpensive and easily accessible materials
Determine how the funnel integrates into the outer shaft
Determine the mechanism of the suture loop
Figure 1
Side by side image of inner and outer shaft assembly with suture loop and bag deployed, along with the funnel
Figure 2
Device with funnel, loop, and bag partially deployed
Figure 3
Device with all components retracted
Materials Used for First Generation Prototype
Materials:
Shafts - PVC piping
Suture loop - Dental floss
Funnel - Paper clips to create the frame of the funnel and tape to keep them in the desired position
Bag - Blue net
Testing
Feasibility Testing
Feasibility testing was conducted using the first generation prototype at the SimPORTAL Simulation Station at the University of Minnesota Medical School.
This testing showed that we needed to improve the framing of the funnel, funnel attachment to its framing, and the deployment mechanisms of the suture loop, funnel, and retrieval bag.
Second Generation
Objectives of this iteration:
Scale down the device
Determine deployment mechanisms for suture loop, bag, and funnel
Start transitioning toward biocompatible materials
Assembled Device
All device components are shown.
Suture Loop
The suture loop is made out of nylon (size 0) suture. The loop tightens with a pull of a string at the other end of the device.
Nylon Ripstop Bag
The nylon ripstop bag contains the gallbladder and any contents that may spill out during removal.
Funnel
The funnel is comprised of nitinol wire connected by plastic packing tape. The funnel can deploy without manipulation. The blue collar implemented into this prototype iteration was included to help retain funnel orifice shape during deployment.
NOTE: The development/improvement of the retrieval bag was not in scope for this project. The funnel and the suture loop were the primary goals, as they work to elongate and linearize the gallbladder.
Materials Used for Second Generation Prototype
Materials:
Shaft - Clear PVC
Suture Loop - Nylon (size 0)
Funnel - Nitonol, clear tape
Bag - Nylon Ripstop