Instrument-free point-of-care diagnostics
Many human diseases can be diagnosed by biochemical analysis of blood, saliva, urine, or other fluids that can be easily collected. Samples are typically sent to a centralized lab where the analysis is performed by a trained human using an expensive machine. While waiting for the diagnosis, the patient may get worse, spread the disease, or incubate drug-resistant organisms. The problem is especially important in low-income regions, where sophisticated labs are less accessible, and locating a patient to deliver a delayed diagnosis may be difficult. We aim to create portable “laboratories” that can rapidly diagnose disease in low-resource settings. In several projects, we take advantage of the wicking ability of paper-like materials to move sample and reagents, and we “program” the materials to carry out the steps normally done in the lab. In another project, we are using a cell phone audio jack connected to a microfluidic card to control the diagnostic test and detect the results. These projects exploit simple physical principles to design new diagnostic devices. Applications include HIV, malaria, dengue fever, MRSA, and influenza.

Devices to drain fluid from the brain
In 2010, I was approached by a pediatric neurosurgeon who had a “plumbing” problem. Half of his surgeries involved placing or replacing one type of implantable device that had a notorious reputation for unexpected failure. The device, call a “shunt”, has been used since the 1950’s to treat hydrocephalus (‘water + ‘head’), which results from an inability to reabsorb the cerebrospinal fluid that we all produce constantly in our brains. These devices are remarkably common (1 in 500 live births) and fail at a very high rate (40% by two years). After viewing a surgery I was hooked on the problem, and we set out to develop improved technologies to treat hydrocephalus and related drainage problems. Our projects are problem-driven and focused on short-term outcomes, including attention to translational issues of intellectual property, regulatory approval, and commercialization.