Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
Diabetes Technol Ther. 2010 Nov;12(11):921-8. doi: 10.1089/dia.2010.0020. Epub 2010 Sep 30.
A cause of suboptimal accuracy in amperometric glucose sensors is the presence of a background current (current produced in the absence of glucose) that is not accounted for. We hypothesized that a mathematical correction for the estimated background current of a commercially available sensor would lead to greater accuracy compared to a situation in which we assumed the background current to be zero. We also tested whether increasing the frequency of sensor calibration would improve sensor accuracy.
This report includes analysis of 20 sensor datasets from seven human subjects with type 1 diabetes. Data were divided into a training set for algorithm development and a validation set on which the algorithm was tested. A range of potential background currents was tested.
Use of the background current correction of 4 nA led to a substantial improvement in accuracy (improvement of absolute relative difference or absolute difference of 3.5-5.5 units). An increase in calibration frequency led to a modest accuracy improvement, with an optimum at every 4 h.
Compared to no correction, a correction for the estimated background current of a commercially available glucose sensor led to greater accuracy and better detection of hypoglycemia and hyperglycemia. The accuracy-optimizing scheme presented here can be implemented in real time.
安培计葡萄糖传感器的准确性不理想的一个原因是存在未被计入的背景电流（在没有葡萄糖的情况下产生的电流）。我们假设，对商业可用传感器的估算背景电流进行数学修正，将比假设背景电流为零的情况具有更高的准确性。我们还测试了增加传感器校准频率是否会提高传感器的准确性。
本报告包括对 7 名 1 型糖尿病患者的 20 个传感器数据集的分析。数据分为算法开发的训练集和对算法进行测试的验证集。测试了一系列潜在的背景电流。
使用 4nA 的背景电流修正，准确性有了显著提高（绝对相对差或绝对差提高了 3.5-5.5 个单位）。校准频率的增加导致准确性略有提高，最佳频率为每 4 小时一次。
与不进行修正相比，对商业可用葡萄糖传感器的估算背景电流进行修正可提高准确性，并更好地检测低血糖和高血糖。这里提出的优化方案可以实时实施。
