Performance of a Low-Cost Insulin Pump in an STZ-Induced Diabetes Model: A Comparative Study with Commercial Device and Multiple Daily Injection

Introduction: Accessibility to continuous subcutaneous insulin infusion (CSII) systems for treating type 1 diabetes is often restricted by high costs and reliance on imported devices in many countries. To overcome this challenge, a low-cost insulin infusion pump has been developed, now at the minimally viable product (MVP) stage. Objective: To evaluate the low-cost insulin infusion pump (MVP) developed by our group through in vitro and in vivo studies, comparing its performance with a commercial insulin pump (CSII) and multiple daily injection (MDI) therapy. Methods: Male Wistar rats (n=18) were made diabetic with an injection of streptozotocin (STZ, 50 mg/Kg), and randomized into 3 groups: MVP, n=6; CSII (Accu-Chek® Spirit Combo - Roche), n=6 and MDI, n=6 (for all 3: 1.5 UI/h, fast-acting insulin, Humalog Lispro® - Eli Lilly and Company, Indianapolis, USA). Insulin was administered by those 3 different devices and were evaluated in a blood glucose-response curve, where blood glucose (BG) was measured every hour for 12h. Results: One of the key advantages of the developed MVP is its compatibility with commercial insulin pen cartridges as the pump reservoir. In in vitro tests performed according to IEC 60601-2-24 standards, the MVP demonstrated superior performance when paired with the Humalog Lispro® cartridge, with 98% of samples falling within the ±20% accuracy range, outperforming both Apidra® and NovoRapid®. In response to in vivo study performed 15 days after the onset of diabetes, initial BG was as follows: MVP: 396 mg/dL, CSII: 420 mg/dL, and MDI: 169 mg/dL. During the experiments, blood glucose reduction in the MVP, CSII, and MDI groups was 88.89%, 82.6%, and 76.33%, respectively (from hour 0 to hour 2). Final blood glucose levels were 193, 284, and 238 mg/dL, corresponding to a 29.30% decrease for MVP, and 33.49% and 13.33% decreases for CSII and MDI, respectively. The reduction of blood glucose was similar across the groups, with no statistical difference among them (p>0.05). Conclusion: The MVP showed superior performance with the Humalog Lispro® cartridge in vitro and similar blood glucose reduction in vivo in animal tests, as compared to the other devices, suggesting its potential as an effective and affordable alternative for type 1 diabetes management, particularly in resource-limited settings. Further studies will be conducted to evaluate its effects in other diabetes models, followed by human trials. CNPq 131534/2023-8, CNPq 303517/2023-9 and FAPESP 2018/22094-0. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.