ABSTRACT:Negative Pressure Wound Therapy (NPWT) is a treatment that promotes healing of chronic wounds. Despite high prevalence of chronic wounds in Low- and Middle-Income Countries (LMICs), NPWT devices are not available nor affordable. This study aims to improve chronic wound care in LMICs by presenting the Wound Care (WOCA) system, designed for building, testing and use in LMICs. Design requirements were formulated using input from literature, ISO standards, and wound care experts. The WOCA design was developed to provide safe, portable, user-friendly and affordable NPWT to patients in LMICs. The design features an adjustable operating pressure ranging from −75 to −125 mmHg, a battery for portability, a 300 ml canister, overflow protection, and system state alarms. An Arduino controls the pressure and monitors the system state. Three prototypes were developed and built in Nepal, and their performance was evaluated. Pressure control was 125 ± 10 % mmHg, internal leakage was 7.5 ± 4.3 mmHg/min, reserve capacity was 189 ± 16.9 ml/min, and overflow protection and alarm systems were effectively working. Prototype cost was approximately 280 USD. The WOCA demonstrates to be a locally producible NPWT device that can safely generate a stable vacuum. Future research will include clinical trials situated in LMICs.-------PUBLICATION:A. J. Knulst et al., “The WOCA negative pressure wound therapy device designed for low resource settings,” HardwareX, vol. 21, no. e00620, Dec. 2024, doi: https://doi.org/10.1016/j.ohx.2024.e00620.-------REVISION HISTORY:Version 2: Published versionVersion 1: Submitted draft for review

ABSTRACT:Negative Pressure Wound Therapy (NPWT) is a treatment that promotes healing of chronic wounds. Despite high prevalence of chronic wounds in Low- and Middle-Income Countries (LMICs), NPWT devices are not available nor affordable. This study aims to improve chronic wound care in LMICs by presenting the Wound Care (WOCA) system, designed for building, testing and use in LMICs. Design requirements were formulated using input from literature, ISO standards, and wound care experts. The WOCA design was developed to provide safe, portable, user-friendly and affordable NPWT to patients in LMICs. The design features an adjustable operating pressure ranging from −75 to −125 mmHg, a battery for portability, a 300 ml canister, overflow protection, and system state alarms. An Arduino controls the pressure and monitors the system state. Three prototypes were developed and built in Nepal, and their performance was evaluated. Pressure control was 125 ± 10 % mmHg, internal leakage was 7.5 ± 4.3 mmHg/min, reserve capacity was 189 ± 16.9 ml/min, and overflow protection and alarm systems were effectively working. Prototype cost was approximately 280 USD. The WOCA demonstrates to be a locally producible NPWT device that can safely generate a stable vacuum. Future research will include clinical trials situated in LMICs.-------PUBLICATION:A. J. Knulst et al., “The WOCA negative pressure wound therapy device designed for low resource settings,” HardwareX, vol. 21, no. e00620, Dec. 2024, doi: https://doi.org/10.1016/j.ohx.2024.e00620.-------REVISION HISTORY:Version 2: Published versionVersion 1: Submitted draft for review

Negative Pressure Wound Therapy (NPWT) is an effective treatment that aids the healing of chronic wounds. However, high treatment cost of commercial systems has limited its use and availability in developing countries. Here, we introduce the Wound Care (WOCA) Pump, a portable and affordable vacuum pump system design for use in low-resourced settings. It features a simple interface for smooth operation and monitoring. It also allows treatment pressure adjustments from 70 to 125 mmHg that is automatically controlled by the system. A rechargeable battery supplies power throughout a treatment cycle and enables portability of the device. 3D printed custom parts and widely available components are used to guarantee future repair and maintenance of the device. A standard laboratory bottle, which can be cleaned and reused, is used as a canister. The only consumable in the system is the bacterial filter that needs to be periodically replaced. Future modification, such as matching of different dressing sets, would be easily achievable with the design files shared online. Testing results shows minimal air leakage, optimal pressure control, and functional safety mechanisms for the system. Hereby, we hope this detailed documentation could contribute a small step in narrowing existing global healthcare gaps.