A general needlework training phantom, created using 3D printing and ballistics gel molding for the purpose of simulating ultrasound-guided needle insertion. See purchasing instructions, how-to-use guide, and maintenance and assembly instructions below.
This model was developed at the Lynn & Arnold Irwin Advanced Perioperative Imaging Lab, Toronto General Hospital, University Health Network.
Fully assembled phantom and case.
To purchase this phantom, please email apil@uhn.ca and a representative will be in touch with you with more details.
A purchased phantom contains the following:
- Fully assembled APIL General Needlework Phantom (including case, tube couplings, and on/off valves)
To prepare for use, first fill the tubes with water by opening the valves on both ends and using a syringe to inject water, then closing both valves.
The phantom can now be used for ultrasound imaging. Apply an adequate amount of ultrasound gel to the surface of the phantom prior to imaging. The water-filled tubes should be visible under ultrasound, mimicking veins, and should contrast with the graphite-filled gel surrounding them (see image below). The user can practice using ultrasound imaging to locate a patient’s vein, into which they can then insert a needle.
One of the phantom's "veins" under ultrasound. A: short axis, B: short axis compressed, C: long axis, D: long axis compressed.
If the damage to the phantom is minimal and surface-level, it may be possible to recondition it by lightly melting the surface with a heat gun until the tubes are again visible under ultrasound without obstruction.
However, if the damage is more extensive—large chunks of gel missing from the surface, leaking tubes, etc—it may be necessary to recast the gel portion of the phantom. This can be done by following the mold and phantom assembly instructions below. If water is leaking from the tubes due to extensive puncturing, be sure to use new tubes when casting.
The case can be reused, unless it is damaged, in which case the manufacturing instructions for the case can be followed.
Labelled case components.
- phantom case — picc case.stl/3mf
- phantom case lid — picc case lid.stl/3mf
- 4 push-in rubber bumpers — 1/2" ID, 1” high stem — https://www.mcmaster.com/9310K16/
- 4 M3 screws
- 3D printing filament (any rigid filament can be used; ex. PLA, PETG, etc)
- 3D printer (a Prusa i3 MK3 printer was used here)
- Drill
- Tube couplings, 2 per tube (for 1/4” tube ID, https://www.mcmaster.com/51525K216)
- On-off valves, 2 per tube (male x female, https://www.mcmaster.com/7033T24)
- Silicone tubing (1/4" ID, 3/8" OD, https://www.mcmaster.com/5236K512/)
- Ballistics gel (https://www.clearballistics.com/shop/20-ballistic-gelatin-nato-block-16x6x6/, https://humimic.com/product/gelatin-4-medical-gel-by-the-pound/)
- Graphite powder
- Crock pot
- 3D print out the intermediate mold components using any rigid filament. Clamp them together and cast with silicone.
- Laser cut the wooden pieces. Initially there are enough holes cut for 2 veins, however extra vein holes can be drilled if desired.
- Attach the bottom wooden component to the bottom of the silicone component with 4 screws.
- Attach the corner components to the long wooden side components with screws, then screw that to the sides of the silicone mold. Then screw the corner components into the bottom of the silicone mold.
- Slide the shorter side components into the gaps between the corner pieces and the silicone mold, and screw into place.
- Print both components.
- Insert a rubber bumper into each hole.
CAUTION: Use appropriate heat-proof gloves when working with liquefied ballistic gel and/or heat gun.
CAUTION: Work only in a very well ventilated area. A fumehood is highly recommended.
- Cut silicone tubing and insert across the mold through each set of holes in the wood. Leave enough tubing outside the holes to be able to insert tube couplings later on.
- Melt roughly 650 g of ballistics gel (here, a roughly 2:1 mixture of 20% ballistics gel and Humimic Medical Ballistics Gel #4 was used) in a crockpot at 105C - 115C (approx. 225F - 240F).
- Stir graphite powder into liquefied gel until saturated and uniformly distributed.
- Pour liquefied gel into mold until the gel is flush with the top of the mold.
- Once cooled, remove from mold by unscrewing the corner components and pulling the mold apart until the phantom and the wood pieces can be removed. Then pull the wood pieces off of the tubes. If there are any pockets or uneven areas on the surface of the phantom that are interfering with ultrasound visibility, use a heat gun to melt the surface until these areas smoothen out.
- Insert a tube coupling into each end of each tube. Attach a valve to each coupling.
- Place phantom inside the case, with the tubes sticking out at either end, and screw the lid in place with four M3 screws.