| Chronic wounds, which do not heal in a timely manner like regular wounds, are a serious problem for patients and heath care providers around the world. Chronic wounds may take years to heal, or may never heal at all. They are very painful, and are a significant threat to older patients or individuals who are obese or diabetic. Studies have shown the associated annual costs of treating chronic wounds in the United States is substantial, and this cost is expected to increase exponentially in coming years as the number of diagnosed cases of chronic wounds grows. There are several treatments for chronic wounds, from the use of antibiotics to maggot therapy. One of the more clinically successful therapies is negative pressure wound therapy (NPWT). This is a technique where a slight vacuum is applied over the wound. However the cost is prohibitive and therefore generally approved by insurance companies only as a last resort. Additionally, the external pumps used in the device are heavy, and require large batteries to run. To solve this problem, a micro pump has been invented that is low cost, highly energy efficient, and is small enough to discreetly fit inside a typical bandage, battery included. The design utilizes micromanufacturing techniques, to develop piezo actuated valves with novel silicone o-rings to reduce valve leakage. This along with reduced dead volume optimizes the pumps ability to generate vacuum. Ultimately 15 kPa was generated, which is the required pressure for NPWT. Additionally, the pump was used in vitro and in vivo. It was shown that there was an increase in cell migration (p < 0.0003), Wnt/beta-catenin mRNA and protein expression (p < 0.007 and p < 0.0004 respectively) in response to NPWT. |
