Design of a low-cost device for Negative Pressure Wound Therapy in low and middle-income countries

Abstract

Many people living in low-middle-income countries (LMICs) are affected by injuries that develop into chronic wounds and, without adequate treatment, may lead to disabilities or even cause death. Negative Pressure Wound Therapy (NPWT) is currently a highly suitable manner to treat complex and chronic wounds. NPWT uses controlled negative pressure to stimulate wound healing and requires a vacuum device that is connected to a sealed vacuum dressing by a tube system. However, due to lack of resources in money and medical equipment, this treatment is still inaccessible to marginalised patients in LMICs,
The context of this research is the Green Pastures Hospital (GPH) in Nepal. This test location is typical for LMICs. In GPH a converted aquarium pump (AquaVAC) is currently used as a NPWT device. There are a multitude of complications in relation to this equipment. Therefore, the following design goal is formulated: ‘Treat chronic and complex wounds in LMICs with a device that is affordable, safe and reliable and made out of widely available, replaceable components.’

In order to design such a device, extensive context analysis, literature and expert review has been done in Phase I. It was found that international guidelines for treatment, as well as design standards and safety regulations, assume a western context or high-resources setting, and do not comply with the needs of end-users at GPH. This led to a new set of requirements and design guidance for the WOCA Wound Pump in Phase II.
Analysis of the market shows that NPWT systems are unnecessarily costly, due to the complexity of the devices and reliance on specific wound dressings. Low-cost solutions, such as the AquaVAC, show good results, however, these devices lack reliability, safety and ease of use. The design proposal of the WOCA contributes to solving these issues in several ways. Hence, the design proposal that was developed in Phase III, is based on availability, compatibility and simplicity.
The WOCA Wound Pump is a simple, cheap and robust NPWT device. The battery powered vacuum pump is portable and can be made completely from locally sourced components. The product can be disassembled with standard tools and all individual components are replaceable, which ensure a long lifespan. Special features of this design are 1) automatic pressure control, 2) compatibility with self-made dressings and standard canisters, 3) portable design with a battery that lasts for 15 hours, 4) simple interface for smooth operation and monitoring, 5) easy to repair and made from widely available components. Even so, the WOCA is affordable, the main components are purchased and produced for less than 100 USD.

To conclude, the WOCA Wound Pump has much potential in LMICs. After the evaluation of the final design, it turned out that in therapy most requirements set for a NPWT used in LMICs, were met. However, future steps have to be taken in order to fulfil its potential and make an actual contribution to the healing of chronic and complex wounds in LMICs. Firstly, the prototype needs to be finished. Design iterations should be made in order to fulfil the current dissatisfiers from the requirement list still, such as noise production, shockproof design and cleaning possibilities. Subsequently, the prototype should be validated with end-users and collaborations should be set up for funding, distribution and education. This process would probably take years, but it has the potential to profoundly improve the healthcare for chronic and complex wounds in low-resource settings.