In order to make for easy charging, our transmitter slides in and out of its mounting base for a secure fit. The end of the rail is widened to allow you to easily align the shaft and hole. This feature is beneficial, especially for elderly diabetics with limited dexterity.

I. Bluetooth & Display

In order to make for easy charging, our transmitter slides in and out of its mounting base for a secure fit. The end of the rail is widened to allow you to easily align the shaft and hole. This feature is beneficial,

First, in order to reduce the amount of equipment needed, our CGM will function with Bluetooth transmission to a phone application. The innovated CGM will have a separate transmitter and probe, similar to the eversense® in order to allow for a longer transmitter life. The probes will be shipped pre-calibrated in the factory to also reduce the need for reagent strips and glucometers.

II. Adhesive

The adhesive of our new CGM must be biocompatible and longer-lasting than that of the Freestyle Libre’s 14 days in order to be a true improvement. The adhesive should be made possible to attach to the skin, which is an organic material, and a possibly inorganic material located where the transmitter base will be at. Plant-derived high-performance biocompatibility appears to be optimal. Our group would test out a plant-derived mussel-mimetic glue [23]. Mussels are known to form strong bonds between organic and inorganic surfaces, and utilizing a synthetic adhesive modeled after natural and effective substance aids in the challenge of biocompatibility. 3,4-dihydroxy phenyl-L-alanine (DOPA) is a substance produced by mussels. The presence of catechol groups is attributed to the adhesive properties of the substance. Caffeic acid, which can be polymerized, produces DHCA which has a similar structure to DOPA [23]. DHCA when tested against instant super glue was found to have higher shear adhesion strength on several materials, including carbon. DHCA can be produced in the form of Adhesive sheets, which can be utilized in the application of our CGM [23]. The sheer strength promises of biocompatibility, waterproofing, heat resistance, and reversibility make this a proper material for our innovative CGM [23].

III. Hydrogel

Since we intend to have a CGM with longer wear, we need to account for any immune response by the body. As such, our new CGM would include a hydrogel coating around the probe to mitigate immune response and aid in glucose diffusion. Hydrogels such as pHEMA are systems of polymers designed to hold water without evaporation and offer a similar environment to skin. These hydrogels can also be customized to determine the size of pores and can allow for specified diffusion of glucose. These hydrogels show promise in fully encapsulated sensor implants and thus have an application in our surface CGM [24]. A limitation would be the thickness of the coating, and if it causes conflicts either in needle insertion and/or comfortable wearability.

IV. Wireless Charging Transmitter

The transmitter is made of a lithium battery [25] and a device that utilizes Bluetooth to send glucose levels from the sensor to the display [26]. Currently, the transmitter is clunky and inconveniencing as it must be recharged every three to five days [27]. Currently, lithium-ion batteries are the most efficient type of battery as they are compact while providing a tremendous amount of power for their size, so the size of the battery cannot be improved [28]. In spite of that, we can reduce the size of the transmitter by eliminating the charging port of the battery and innovating the transmitter to wirelessly charge.

Our wireless charging design will be based on a wireless phone charger as CGM transmitters and modern phones both use Lithium batteries. Therefore, recharging them should be relatively similar [29]. Wireless phone chargers take advantage of Lenz’s law which states that “the direction of an induced current is always such as to oppose the change in the circuit or the magnetic field that produces it” [30]. Wireless chargers use two inductors: one inside the battery and one connected to a power source. By inducing a current in the inductor connected to a power source, a magnetic field is generated which induces a current on the other inductor, this current recharges the Lithium battery inside of the transmitter [31].

This creates another problem as to how the charger would remain anchored to the transmitter as without a port the charger has nowhere to hold onto. To solve this, we propose a small magnet inside of the transmitter and another magnet inside of the wireless charger. This will allow a stable anchor between the two and allow slight mobility of the patient during charging; this, however, has not been tested and may negatively affect the glucose readings.

V. Immunosuppression & Sensor Evaluation

On the sensor of a CGM system, there are immunosuppressants, metals, and enzymes that cause the sensor to stop functioning after 5-7 days [32]. In order to increase the usage of a sensor, we proposed to evaluate each of these components to see if they can be further used or replaced. In order to measure the amounts of immunosuppressants on the sensor after use, we have proposed to add a nontoxic fluorescent stain to the sensor [33]. By adding this stain, we can detect how much chemical solution there is on the sensor initially and how much is left after it is removed based on the brightness of the fluorescent color. In order to reuse the sensor, the patient will need to reapply the chemical mixture with a machine that sterilizes the sensor with ultraviolet rays and reapply the mixture by pipetting the appropriate amount onto the sensor. The disinfecting part of the system will be similar to a lab hood, but dramatically smaller. The reapplying part of the system will be similar to an automated pipette as it will add enough of the chemical solution to guarantee the sensor is not rejected.

This method could work in coordination with the formerly presented hydrogels to measure the chemical mixture leftover after use. The hydrogel is a separate entity and can also reduce the need for the proposed chemical mixture. In production, we plan on doing comparisons to see if these new systems would be more cost-effective than traditional CGM systems.

VI. Platinum & Enzymes

The sensor measures glucose levels by converting blood glucose into hydrogen peroxide, the glucose reacts with glucose oxidase to form hydrogen peroxide, and then the hydrogen peroxide reacts with the Platinum inside of the sensor yielding an electric current that can be translated by the sensor into a glucose level [26]. It is unrealistic to refill the glucose oxidase because of how small the sensor is. In production, this product is assembled with tweezers and microscopes [32]. Therefore, a patient will be unable to do this. Additionally, there is no way for a patient to measure enzyme level due to how compact the device is. Initially, we considered running an electric current through the enzyme solution, however, the electrode would conflict with this method. The amount of glucose oxidase cannot be measured conveniently for the patient using common household tools.

It is possible to measure how much Platinum is built up in the sensor (as Platinum is the cathode). This can be done by calculating the moles gained (for consumer convenience, there will be a system that converts volume to mass using density, and then by using the mass, the system can estimate the moles). Although this system allows a large error in the calculation of moles of Platinum, the amount of Platinum can be estimated to have a general idea of how much was used. Using this information, the patient can use a program that will tell them if this is a safe amount.