Open source surgical fracture table for digitally distributed manufacturing

Abstract

Roughly a third of the surgical procedures the World Bank is prioritizing as essential and cost-effective are orthopedic procedures. Yet in much of the developing world, prohibitive costs are a substantial barrier to universal access. One area where this is clear is surgical fracture tables, which generally cost >US$200,000 new. With the advent of 3-D printing, a new way to reduce medical equipment costs is to use open source hardware licensed designs to fabricate digitally-distributed manufactured medical hardware. That approach is applied here to make surgical tables more accessible. This study describes the design and manufacture of an open source surgical fracture table that uses materials that are widely available worldwide with specialty components being 3-D printed. The bill of materials and assembly instructions are detailed and the fracture table is validated to perform mechanically to specifications. Using an open source desktop RepRap-class 3-D printer, the components can be printed in a little over a week of continuous printing. Including the 3-D printed parts, the open source fracture table can be constructed for under US$3,000 in material costs, representing a 98.5% savings for commercial systems, radically increasing accessibility. The open source table can be adjusted 90-116 cm in height, tilted from +/-15 degrees, the leg height ranges from 31 to 117 cm, the arm supports and foot holder both have a 180-degree range, the foot position has a 54 cm range, and the legs can be adjusted from 55 to 120 degrees. It is mechanically adjusted so does not require electricity, however, surgical staff need to be trained on how to perform needed adjustments during surgery. The open source surgical table has verified performance for mechanical loading over 130 kg, geometric flexibility to allow for wide array of common surgeries, is radiolucent in surgical zones, and is modular and upgradeable.

Fig 1. Design flow chart.

Fig 2. Adding four Base 3in Pipes to the corners of the Base Panels.

Fig 3. Total 3_INCH_PVC_to_HDPE_Sheets_Outside on each Base 3in Pipe.

Fig 4. Addition of bottom of support structure to the base.

Fig 5. Addition of Jack top HDPE to center of base assembly.

Fig 6. Addition of one side Jack insert.

Fig 7. Completing the base support structure by adding the Top Support Structure.

Fig 8. Finishing the addition of Lower_Arc_for_Table_Bracket’s.

Fig 9. Attaching two Lower_Arc_for_Table_Angle to Lower_Arc_for_Table_Bracket.

Fig 10. Adding two Upper_Arc_for_Table to both Lower_Arc_for_Table_Angle.

Fig 11. Final view of both Table Top Support components.

Fig 12. Final attachments of table top bracket.

Fig 13. Completing the Table Top assembly by adding the Table Top.

Fig 14. Addition of Arm Attachments to Table Top.

Fig 15. Final two arm-rest_mounting_pin holding Arm Rests in place.

Fig 16. Addition of Distancing Brace through the Table Top Support.

Fig 17. Addition of Leg Multi Pivot to Leg Pivot X-Axis.

Fig 18. Addition of final component Pelvic Post Mount Pin into Leg Attachment Assembly.

Fig 19. Addition of Peroneal Support to the Table Top Support.

Fig 20. Addition of Peroneal Brace to the Peroneal Support.

Fig 21. Addition of pelvic_post_mount to Peroneal Brace.

Fig 22. Addition of Peroneal Post Cover around the pelvic_post_mount.

Fig 23. Insertion of 3in PVC to Leg vertical positioner.

Fig 24. Addition of both vertical_pvc_leg_support_new to 1.25in pipe.

Fig 25. Addition of leadscrew_handle to the Lead Screw for Foot Pedestal.

Fig 26. Addition of Foot-Rest to leg assembly.

Fig 27. Final Table Assembly without cover and straps.

Fig 28

a) The final assembly with no pads. b) The final assembly with pads flat. c) The final assembly with pads tilted towards head (Trendelenburg position). d) The final assembly with the pads tilted towards feet (reverse Trendelenburg).

Fig 29. Details of wrench used to control heights of motor cycle jack and thus the table surface.

Fig 30. Details of arm support.

Fig 31. Details of one leg straight and one leg straight down (scissored).

Fig 32. Details of one leg straight and the other flexed and abducted.

Note that the leg positioner could have been abducted for this position.

Fig 33. Table tilted down and both legs bent with no post.

Fig 34. Patient on side.

Fig 35. Table with simulated patient when table extension is inserted.

Fig 36. Simple diagram illustrating the applied force on PP in worst case scenario.

Fig 37

Pressure applied on the PP (left) and PVC pipe (right) in Abaqus.

Fig 38

FEM analysis results for the maximum pressure (P), tolerable by a) PP for PETG manufacture’s specification, b) PP made with poor 3-D printing and c) PP with PVC pipe.