Imagine having a watch that would give you a constant reading of your blood glucose levels without having to prick your finger.
Development of a system called the GlucoWatch by Mark C. Shults and Dr. Stuart J. Updike of the University of Wisconsin-Madison may help bring this futuristic concept to you.
As described in the August, 1994 issue of Diabetes Care, the process involved in the GlucoWatch consists of a glucose monitoring device implanted under the skin which is attached to an implanted radio transmitter that sends frequent readings to the watch, much like a pager does.
Though by definition this device is not non-invasive since it requires implantation, once fully developed the monitor may be able to last for up to a year before it needs to have the sensors replaced. The implantation procedure is a minor operation done under local anesthesia on an outpatient basis.
At this point, the sensors have been shown to be effective for three months in animal models. The researchers are trying to develop the technology so that the sensors would last a minimum of 6 months to make them more appealing to the public and to companies that produce biomedical products. The process of developing this technology was described in the May, 1994 issue of Analytical Chemistry. Research is set to begin in 1995 on human subjects to demonstrate a 6-12 month sensor lifetime.
The implanted device, which is about the size of a matchbox, would have to be removed every ten years to replace the batteries. A description of the monitoring device telemetry was published in the October 1994 issue of the Journal of International Electric and Electronic Engineers.
The researchers feel that the GlucoWatch will have many advantages over other proposed non-invasive methods such as near infrared spectroscopy in that it provides a continuous display, provides a surveillance alarm for low blood sugars, and tells the wearer if blood sugars are going up or down.
It also may have advantages over other types of non-invasive technology including the transdermal patch. The wearer must calibrate the patch daily, and the device may not be as effective during exercise, nervousness, fever or in the shower. The GlucoWatch would need to be calibrated only once a week, or less, and would be waterproof.
Bringing the product to the market will require several things, including: millions of dollars to manufacture the longer lasting devices, and finding a wrist watch manufacturer interested in making the receivers.