The final design is a titanium implant with an insulin reservoir and two batteries. The device will use the following materials in its function: A titanium outer shell & insulin reservoir, PVDF coating (a type of polyelectrolyte hydrogel), poly(ethylene glycol) (PEG) hydrogel, watch batteries, insulin, a refilling port [1], glucose sensing probe [2], wires, a board and a Bluetooth transmitting device. The orifice that opens to deliver insulin is based on polymeric artificial muscles that surround and control micrometer-sized holes that open to release drug [3]. The polymeric ring expands or contracts in response to an electrical signal transmitted through a conducting polymer that contacts a swell-able hydrogel [3]. Polyelectrolyte hydrogels are stable in the body’s temperature, pH, and are known to be biocompatible. They have shown to have high durability in the body along with short response time to electric signals. Because polyelectrolyte hydrogel can absorb water to over a thousand times its size, the porous gel will cover the orifice of ideally 1 mm, opening and closing based on the delivery of 1-5 V [4]. Constant low voltage is required to maintain the hydrogel in its swelled state when insulin is not being delivered. Poly(vinylidene fluoride) (PVDF) has been chosen to surround the pores in the hydrogel due to its “mechanical and chemical resistance, thermal stability, and suitable mechanical properties,”[4]
The end users of this project are people with Type I diabetes, specifically children. Important user needs include convenience, comprehensive, cheap, long term, reliable, and painless. The device dramatically decreases patients’ involvement in treatment, reducing the time, energy, stress, and pain involved in the process. Because the device is a onetime purchase, it is more affordable in comparison to traditional methods such as a pump or injections. This lessens the financial burden on caregivers who are responsible for purchasing diabetes treatment for someone. Additionally, because insulin is refilled every two weeks, the batteries are replaced every year, and all data regarding treatment is communicated through our app, the time involved in treatment is dramatically reduced, leaving patients and caregivers more time and energy for their jobs and other activities, improving productivity and potentially income. Children afflicted with Type I diabetes can focus on school, friends, and playing with friends.
Comparing our device to traditional treatment options, the market currently has several options for treatment, such as insulin injections, insulin inhalers, and insulin pumps. Insulin injections can cause irritation and possibly a possible allergic reaction when administered. Insulin inhalers are not comprehensive and must be paired with insulin injections. The insulin pump is another option available for Type I diabetics, but it remains outside of the body, forcing the patient to be cautious and always aware of its presence. Each of these treatment options requires a significant amount of time and energy.
Image of the SOLIDWORKS model
User Interfacing
References:
[1] M. Zaki AJ et al, “Implantable Drug Delivery System: A Review,” International Journal of PharmTech Research, vol. 4, no. 1, pp. 280-292, ISSN: 0974-4304
[2] H. Yoon et al, “Wearable, robust, non-enzymatic continuous glucose monitoring system and its in vivo investigation,” Biosensors and Bioelectronics, vol. 117, pp. 267-275, Oct. 2018, doi: 10.1016/j.bios.2018.06.008
[3] A. Kumar, J. Pillai, “Implantable Drug Delivery Systems: An Overview.” Nanostructures for
the Engineering of Cells, Tissues and Organs, William Andrew Publishing, 23 Feb. 2018, https://www.sciencedirect.com/science/article/pii/B9780128136652000132.
[4] Claus, Johanna, Andreas Brietzke, Celina Lehnert, Stefan Oschatz, Niels Grabow, and Udo
Kragl. “Swelling Characteristics and Biocompatibility of Ionic Liquid Based Hydrogels for Biomedical Applications.” PLOS ONE15, no. 4, April 2020. https://doi.org/10.1371/journal.pone.0231421.