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