YOU CAN BUILD THE WOUND THERAPY PUMP RICH HOSPITALS HAVE, FOR 280 EUROS
Arjan Knulst and colleagues at TU Delft published a build for the wound pump that rich hospitals have and poor ones do not.
by Arjan J. Knulst, Salome Berger, Jorijn van den Boom, Inge Bosch, Noa Nicolai, Suraj Maharjan, Eileen Raaijmakers, Chang-Lung Tsai, Lisa van de Weerd, Jenny Dankelman, Jan-Carel Diehl
HealthOpen-hardware
Built withArduino3D printing
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- CC-BY-4.0
- repo
- repo FINISHED0 stars
●●●●○ · a weekend-plus · CC-BY-4.0 · 0 stars · repo FINISHED
WHAT YOU’LL NEED
Jump to section
COMPAREE VERDICT
WOCA is a published academic build for a negative pressure wound therapy pump that costs about 280 euros in parts, where the paper puts commercial devices at 7,500 to 12,000 dollars. The design is documented in a peer-reviewed HardwareX paper with CAD, Arduino code, a full BOM and bench-test results from three prototypes built in Nepal. The pump holds a gentle, adjustable vacuum (75 to 125 mmHg) on a sealed wound to draw out fluid and support healing — standard care in wealthy hospitals, often absent in low-resource ones. The build is a 3D-printed housing, a small vacuum pump, a 300 ml canister with a bacterial filter and overflow protection, a pressure sensor, an Arduino Nano, a battery, and alarms. The paper names the 3M ActiV.A.C. Therapy Unit as the closest commercial analog. The hardest part is not the build itself — it is the clinical context: this is research hardware, clinical trials are still future work, and it is not a certified medical device. If you are a maker looking to treat your own wound, this is not the project. If you are a clinician or researcher in a low-resource setting looking for a documented open-source alternative, this is exactly what it claims to be. Any part substitution needs the pressure control and alarms re-tested.
IN THE REPO
GOOD TO KNOW
- —All CAD, firmware, and assembly instructions are in the HardwareX paper under Creative Commons Attribution 4.0 — commercial use is allowed.
- —This is research hardware presented for building and testing, not a certified medical device.
- —The bill of materials is detailed, but some components (the vacuum pump, the bacterial filter, the battery) are sourced from suppliers named in the paper and may not be available everywhere.
- —Three prototypes were built in Nepal and bench-tested (pressure control, leakage, reserve capacity, alarms). There are no clinical trials yet and no claim of equivalence to commercial systems.
- —The authors explicitly state this is for low and middle income settings where commercial systems are not available — not a hobbyist project.
- —The Arduino code, CAD and BOM are in the source file repository linked from the paper (Mendeley Data, doi.org/10.17632/r95wgtmffn).
Parts to buy
12 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
More builds like this
All projectsGallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the HardwareX paper (Open access DOI 10.1016/j.ohx.2024.e00620 — all documentation, CAD, firmware, and BOM are in the paper and supplementary materials)
- 2.Download the STLs and firmware from the supplementary materials(The files are in the paper's Mendeley Data repository: https://doi.org/10.17632/r95wgtmffn)
- 3.Source the vacuum pump, bacterial filter, and other BOM components(The BOM names specific parts and suppliers — some may not be available in all regions)
- 4.Print the enclosure and canister holder(The paper recommends PET-G for shock resistance and chemical stability; PLA or ABS also work if that is what you have.)
KNOWN ISSUES
- The BOM names specific parts and suppliers in the Netherlands and Europe; local equivalents may differ, and any substitution (especially the pump, pressure sensor or bacterial filter) needs re-testing of pressure control and alarms.
- This is research hardware presented for clinical use in low-resource settings, not a hobbyist project — do not build this to treat your own wound.
- The firmware is a single Arduino sketch in the paper's Mendeley Data repository (doi.org/10.17632/r95wgtmffn). You will need to adapt it if you substitute components.
- WOCA has not been through clinical trials or regulatory certification. If you deploy it clinically, you are responsible for validation and safety.
- The cost estimate of 280 euros assumes you can source the parts the paper names — in some regions that will not be possible.
- The alarm buzzer is critical for safe operation — the paper documents failure modes, and you need to test them before any clinical use.
Can I build this to treat my own wound?
No. This is a research prototype for low-resource clinical settings, it has not yet been through clinical trials, and it carries no regulatory certification. If you have a wound that needs negative pressure therapy, see a clinician.
How does it compare to the 3M ActiV.A.C.?
The paper names the 3M ActiV.A.C. as the closest commercial analog but does not claim clinical equivalence. WOCA costs about 280 euros versus thousands for commercial units. Three prototypes were built in Nepal and bench-tested for pressure control, leakage and reserve capacity; clinical trials are planned future work.
Where is the firmware repository?
The Arduino code, STL files and BOM are in the paper's source file repository on Mendeley Data: https://doi.org/10.17632/r95wgtmffn
Can I use a different vacuum pump?
The BOM names a specific pump model. If you substitute it, you will need to validate that the system can hold the target pressure range and that the alarm logic still works.
What is the licence?
Creative Commons Attribution 4.0 — commercial use is allowed, but you must credit the authors and this is not a certified medical device.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
Three prototypes built in Nepal, about 280 euros each, and stable vacuum on the bench — but clinical trials are still to come. If you work in a low-resource clinical setting, what is the single biggest barrier to building and using this?
Arjan J. Knulst, Salome Berger, Jorijn van den Boom, Inge Bosch, Noa Nicolai, Suraj Maharjan, Eileen Raaijmakers, Chang-Lung Tsai, Lisa van de Weerd, Jenny Dankelman, Jan-Carel Diehl
Arjan Knulst and colleagues in the Department of Biomechanical Engineering at Delft University of Technology built WOCA with partners in Nepal for low and middle income settings where commercial negative pressure wound therapy systems are not available. The project was published in HardwareX in 2024.
Keep building — related projects
Same category or platform, picked by how close they are to this build.
FULL CADA mouse you control with your lips, for people who cannot use their hands
Open-hardwareFor intermediate builders
FULL CADFlex a muscle and the hand obeys — you can 3D print this bionic hand
Open-hardwareFor expert builders
FULL CADAn open-source hearing aid you build yourself and program in your own ear
HealthFor advanced builders
NO CAD FILESYou can build the instrument sterilizer that runs off a car battery
HealthFor advanced builders
FULL CADYou can build the box surgeons practise keyhole surgery in, for under 150 dollars
HealthFor intermediate builders
FULL CADHospital retinal cameras cost 10,000 dollars and up. This open-source build aims to do it for under 400
HealthFor advanced builders
DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM22d agoedited
Practical notes from our verification: this is a clear example of open medical hardware — the paper (HardwareX, CC BY 4.0) documents the design, and the source files, including the Arduino code, are on Mendeley Data (DOI 10.17632/r95wgtmffn). The build cost is approximately 280 euros according to the paper, and it relies on commonly available electronic, mechanical and 3D-printed parts: a vacuum pump, a bacterial filter and a reusable canister, with PET-G preferred for printing (PLA and ABS also work). The canister filter is the only consumable. Three prototypes were built in Nepal and bench-tested — pressure held at 125 mmHg within tolerance, and the overflow protection and alarms worked — but clinical trials are listed as future research, and the paper does not discuss regulatory certification. If you are a maker looking for a weekend project, this is not it; if you are a clinician or researcher in a setting where commercial negative pressure wound therapy is not available, it is a well-documented starting point. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.