Leidos-Developed Device Could Change Diabetes Treatment

Disposable Skin Patch Could Change Course of Diabetes Treatment

A microsystem developed by Leidos, in collaboration with Georgetown University, could change the course of diabetes treatment by automating blood sugar monitoring with a painless, disposable skin patch.

The patch, developed under contract to the Defense Advanced Research Projects Agency (DARPA), is designed to rapidly provide blood glucose readings without conventional lancets, finger-sticks, test strips, and blood sugar monitors, and transmit readings directly to an enabled cell phone.

Leidos estimates that the microsystem, known as BFIT (biofluidic integrable transdermal microsystem), could be manufactured and ready for testing in as little as two years.

Leidos and Georgetown are in active discussions with at least one potential licensee that could manufacture these microsystems.

A Different Kind of Skin Patch

Conventional skin patches are generally used to deliver a controlled dose of medication through the dermal layer of skin (hence the name transdermal). The BFIT patch is different.

At roughly the size of a Band-Aid® and not much thicker, the patch is designed to work by using a minute electrical current to burn an extremely tiny hole in the outermost layer of skin, known as the stratum corneum. The hole would be on the order of 25 microns in diameter and depth (25 microns equals about one-tenth the diameter of the smallest gauge hypodermic needle).

This is intended to enable access to interstitial fluid. That fluid makes up about a quarter of the body's liquid content, and carries, among other things, chemical byproducts, or analytes, of bodily processes. One of those is blood sugar, or blood glucose.

In addition to the sophisticated package of electronics that BFIT has been designed to carry, it will carry a saline solution that mixes with tiny amounts of interstitial fluid. BFIT would mix on-board saline solution with tiny amounts of interstitial fluid. It is this mixture that could be drawn into the BFIT for analysis. A process known as capillary action - the same sort of process that enables the flow of sap in trees - helps to draw the mixed fluids into the patch for analysis.

The Impetus Behind the Patch

Leidos's Robert "Robb" White, a senior scientist, was one of the "serial inventors" who developed the technology. The microsystem grew out of a series of encounters White had with a new program manager who, when asked what he was interested in, pointed to a wristwatch-like device intended to measure blood sugar levels, but which had since been discontinued. That prompted White to get a team together with Georgetown to make such a device.

Patch Designed to Get Beneath the Skin, Painlessly

White pulled together a team with Leidos expertise in micro-electro-mechanical systems (MEMS), electro-chemical detection techniques and systems integration, and Georgetown expertise in transdermal drug delivery and transdermal extraction, and MEMS.

DARPA wanted to be able to remotely measure soldiers' stress reactions in battle. The initial design for DARPA measured more analytes in interstitial fluid than just blood sugar, which, along with stress hormones (adrenaline, for example) and other chemicals, can be an indicator of stress.

As stress manifests itself in a number of biochemical reactions, one of DARPA's requirements was that the patch itself did not induce stress. If it did, then it would render the readings useless. So the patch was designed to be minimally invasive and painless.

Additional Potential Uses for the Patch

White explained that with this kind of DARPA research "you don't have specifications and requirements, but you have some top-level - what DARPA calls 'blue sky' - goals or a mission." To meet those goals, White noted that a lot of non-recurring engineering is done, which has led to a number of other possible uses for the technology.