The broad long term goal of this project is to develop a low-cost, miniature, fully implantable wireless glucose sensor that is easy to implant and extract and can empower diabetic patients (type I and type II) manage their disease in a seamless manner. Diabetes affects more than 400 million people worldwide with an estimated increase of about 205 million by the year 2035. Therefore, development of a low-cost and effective device that allows close monitoring of glucose level and managing the disease is of high relevance to public health. We have prototyped a novel, miniature (size of a poppy seed), completely wireless and extremely low-cost glucose sensing system using complementary metal oxide semiconductor (CMOS) technology. It consists of an electronic microchip which can sense glucose owing to an on-chip integrated electrochemical solid-state sensor. This device is injected subcutaneously using a proprietary needle-based applicator and wirelessly communicates the glucose data to an external transmitter which enables cloud-based data storage and processing using a smartphone reader application. We are currently working on development of reliable and scalable processes to enable high-yield manufacturing of the sensor with long-term in-vivo operation. In this Phase I project, we propose to change the current IMS sensor to an even more user friendly format that makes implantation/extraction pain-free, cause less tissue damage both during implantation/extraction and while being in the body by reshaping the implant into a needle shape (2.5mmx0.8mmx0.1mm) which reduces the applicator needle size (from gauge 16 for current design (1.4mmx1.4mmx0.2mm) to gauge 20 for proposed new design). Furthermore, we are proposing to optimize wireless link operation to minimize erroneous readouts which sometime occur with the current system and can result in incorrect output signals. This involves the optimization of the wireless power transfer system, the communication link and the solid-state sensor and readout electronics for the new design as well as designing and prototyping a proprietary applicator and extractor device to ultimately enable self-administration of the new design using a fine needle. These design and fabrication efforts will be followed by rigorous in-vitro validations and in-vivo verification to identify system performance metrics and different optimization factors to incorporate them in the final design for clinical testing of this technology.
Diabetes is a chronic disease affecting around 400 million people worldwide and is growing at epidemic proportions. Diabetes management requires a good control on patient's glucose level throughout their daily life. Current glucose measurement systems involve home glucose meters requiring blood drops from finger pricks to measure patient's glucose level, 5-6 times a day. Another mode of measurement is through the use of transcutaneously implanted sensors which have a fine needle and wire assembly going through skin and are connected to an external electronics system which measures glucose levels continuously. These devices pose infection and skin irritation risks. Hence, their lifetime is short (14 days maximum) resulting in poor patient adoption. Completely wireless long-term implants are a solution to this problem and have been the focus of many research efforts. In this proposal, we present a first of its kind, extremely small, low-cost and modern sensor technology enabled through advance nanofabrication techniques that can perform continuous measurements for several months. We have demonstrated the functionality of this sensor through extensive in-vitro and preliminary in-vivo experiments. We have built a fully-functioning prototype system consisting of the wireless sensors, an external wireless ?transmitter?, a smartphone ?reader? and a web-based data interface. Our next goal is to optimize the sensor in terms of form factor to enable seamless implantation/extraction using a proprietary applicator/extractor device, achieve communication fidelity and robustness against environment variations, and improve sensor dynamic range and signal-to-noise ratio. Furthermore, we are proposing to design applicator/extractor devices and fabricate their prototypes for ex-vivo testing. This will be followed by in-vitro and in-vivo validation as part of the preparation process for the product development and first-in-man clinical studies.
