Fig 1.
a) Assembled OI implant with the prosthetic hoof; b) example of a sheep forelimb with a surgically inserted OI implant and prosthetic hoof (from a separate IACUC-approved study); and c) proposed aBL device prototype containing two semi-circular halves situated around the adapter screw. The blue dashes represent LEDs.
Fig 2.
Device 1.0–12 LEDs were soldered onto two semi-circular PCBs and mounted onto an aluminum base.
Two bases were connected via small screws which fit securely around the adapter screw.
Fig 3.
1) LED array, 2) aluminum plate bridges, 3) Peltier modules, 4) fan-cooled heat sinks.
Fig 4.
Simplified thermal schematic of active cooling system.
Fig 5.
Device 3.0 with LEDs tilted 30° towards the center of the device.
Fig 6.
Left, side view and right, top view. Sheep jacket was used to hold the aBL device in place and minimize the sheep’s ability to damage it.
Fig 7.
3D printed mold to create thermoformed plastic covers used to cover the LED PCBs.
Fig 8.
Thermoforming process: Dental plastic was held by a wooden frame and heated under hot coils until the plastic began to sag (left). Plastic was quickly transferred to a vacuum table where the plastic was vacuumed down to fit the shape of the 3D printed mold (right).
Fig 9.
Transparent cover with excess plastic trimmed away and holes drilled through for attachment purposes.
Fig 10.
Device 2.1 LEDs, using PCBs with three different wire terminal orientations (black rectangles).
This limited the ease of PCB replaceability.
Fig 11.
Device with 3D-printed wire covers and LED PCBs with vertically positioned wire terminals.
A single LED PCB could be inserted into any of the six possible positions.
Fig 12.
Device 4.0 that was placed on a study animal using the sheep jacket.
The aBL device attached around the prosthetic hoof and the cords were threaded up through the zippered pocket on the leg sleeve. The cords were connected to a control panel located in the right-side pocket (pictured). Another cord then connected the device to a 48 V (1000 mAh) battery inserted into a pocket on the left shoulder.
Fig 13.
Results of Device 1.0 heat test.
Fig 14.
Optical power output was recorded at 0.5 cm increments across the diameter of the Device 2.0 and Device 2.1 –flat and tilted geometries respectively.
Fig 15.
a) No fins; 196°C LED surface temperature, b) Short plate fins; 92.4°C LED surface temperature, c) Pin fins; 100°C LED surface temperature, and d) Three cm long plate fins; 37°C LED surface temperature.
Fig 16.
Device 4.0 with 3 cm long plate fins and small fans.
Fig 17.
Device 4.0 heat test results overlaid on results from Device 1.0.