Department of Electrical Engineering and Information Technology (DIETI)University of Naples Federico II Naples 80125 Italy.
Department of Electrical Engineering and Information TechnologyChemnitz University of Technology Chemnitz 09107 Germany.
IEEE J Transl Eng Health Med. 2024 Jul 8;12:533-541. doi: 10.1109/JTEHM.2024.3425269. eCollection 2024.
The equivalent electrical circuit approach is explored to improve a bioimpedance-based transducer for measuring the bioavailability of synthetic insulin already presented in previous studies. In particular, the electrical parameter most sensitive to the variation of insulin amount injected was identified. Eggplants were used to emulate human electrical behavior under a quasi-static assumption guaranteed by a very low measurement time compared to the estimated insulin absorption time. Measurements were conducted with the EVAL-AD5940BIOZ by applying a sinusoidal voltage signal with an amplitude of 100 mV and acquiring impedance spectra in the range [1-100] kHz. 14 units of insulin were gradually administered using a Lilly's Insulin Pen having a 0.4 cm long needle. Modified Hayden's model was adopted as a reference circuit and the electrical component modeling the extracellular fluids was found to be the most insulin-sensitive parameter. The trnasducer achieves a state-of-the-art sensitivity of 225.90 ml1. An improvement of 223 % in sensitivity, 44 % in deterministic error, 7 % in nonlinearity, and 42 % in reproducibility was achieved compared to previous experimental studies. The clinical impact of the transducer was evaluated by projecting its impact on a Smart Insulin Pen for real-time measurement of insulin bioavailability. The wide gain in sensitivity of the bioimpedance-based transducer results in a significant reduction of the uncertainty of the Smart Insulin Pen. Considering the same improvement in in-vivo applications, the uncertainty of the Smart Insulin Pen is decreased from [Formula: see text]l to [Formula: see text]l.Clinical and Translational Impact Statement: A Smart Insulin Pen based on impedance spectroscopy and equivalent electrical circuit approach could be an effective solution for the non-invasive and real-time measurement of synthetic insulin uptake after subcutaneous administration.
采用等效电路方法改进了一种基于生物阻抗的传感器，用于测量之前研究中已提出的合成胰岛素的生物利用度。特别是，确定了对注射胰岛素量变化最敏感的电参数。茄子被用来模拟人体在准静态假设下的电行为，这种假设通过与估计的胰岛素吸收时间相比非常低的测量时间来保证。使用 EVAL-AD5940BIOZ 通过施加幅度为 100 mV 的正弦电压信号并在 [1-100] kHz 的范围内获取阻抗谱来进行测量。使用具有 0.4 厘米长针的 Lilly's Insulin Pen 逐渐给予 14 个单位的胰岛素。采用改进的 Hayden 模型作为参考电路，发现建模细胞外液的电元件是对胰岛素最敏感的参数。该传感器实现了 225.90 ml1 的最新灵敏度。与之前的实验研究相比，灵敏度提高了 223%，确定性误差降低了 44%，非线性度降低了 7%，重复性提高了 42%。通过将其对实时测量胰岛素生物利用度的智能胰岛素笔的影响进行预测，评估了该传感器的临床影响。基于生物阻抗的传感器的灵敏度大幅提高，显著降低了智能胰岛素笔的不确定性。考虑到在体内应用中同样的改进，智能胰岛素笔的不确定性从[公式：见正文]l 降低到[公式：见正文]l。临床和转化影响声明：基于阻抗谱和等效电路方法的智能胰岛素笔可能是一种有效的解决方案，可用于非侵入性和实时测量皮下给药后合成胰岛素的吸收。
