Department of Psychology, University of Southern California, Los Angeles, CA 90089-1061, USA.
Department of Mathematics, University of Southern California, Los Angeles, CA 90089-2532, USA.
Addict Behav. 2018 Aug;83:48-55. doi: 10.1016/j.addbeh.2017.11.038. Epub 2017 Dec 2.
Biosensors have been developed to measure transdermal alcohol concentration (TAC), but converting TAC into interpretable indices of blood/breath alcohol concentration (BAC/BrAC) is difficult because of variations that occur in TAC across individuals, drinking episodes, and devices. We have developed mathematical models and the BrAC Estimator software for calibrating and inverting TAC into quantifiable BrAC estimates (eBrAC). The calibration protocol to determine the individualized parameters for a specific individual wearing a specific device requires a drinking session in which BrAC and TAC measurements are obtained simultaneously. This calibration protocol was originally conducted in the laboratory with breath analyzers used to produce the BrAC data. Here we develop and test an alternative calibration protocol using drinking diary data collected in the field with the smartphone app Intellidrink to produce the BrAC calibration data. We compared BrAC Estimator software results for 11 drinking episodes collected by an expert user when using Intellidrink versus breath analyzer measurements as BrAC calibration data. Inversion phase results indicated the Intellidrink calibration protocol produced similar eBrAC curves and captured peak eBrAC to within 0.0003%, time of peak eBrAC to within 18min, and area under the eBrAC curve to within 0.025% alcohol-hours as the breath analyzer calibration protocol. This study provides evidence that drinking diary data can be used in place of breath analyzer data in the BrAC Estimator software calibration procedure, which can reduce participant and researcher burden and expand the potential software user pool beyond researchers studying participants who can drink in the laboratory.
生物传感器已被开发用于测量经皮酒精浓度（TAC），但由于个体之间、饮酒事件和设备之间 TAC 的变化，将 TAC 转换为可解释的血液/呼气酒精浓度（BAC/BrAC）指标较为困难。我们已经开发了数学模型和 BrAC 估算器软件，用于校准和反转 TAC 以获得可量化的 BrAC 估算值（eBrAC）。确定特定个体佩戴特定设备的个性化参数的校准协议需要在实验室中进行，其中同时获得 BrAC 和 TAC 测量值。该校准协议最初是使用用于产生 BrAC 数据的呼吸分析仪在实验室中进行的。在这里，我们开发并测试了一种替代校准协议，使用智能手机应用程序 Intellidrink 在现场收集的饮酒日记数据来生成 BrAC 校准数据。我们比较了使用 Intellidrink 时专家用户收集的 11 个饮酒事件的 BrAC 估算器软件结果与呼吸分析仪测量值作为 BrAC 校准数据。反转阶段的结果表明，Intellidrink 校准协议产生了相似的 eBrAC 曲线，并在 0.0003%以内捕获峰值 eBrAC、在 18 分钟以内捕获峰值 eBrAC 的时间以及在 0.025%酒精小时以内捕获 eBrAC 曲线下面积，与呼吸分析仪校准协议相同。这项研究提供了证据表明，在 BrAC 估算器软件校准过程中可以使用饮酒日记数据代替呼吸分析仪数据，这可以减轻参与者和研究人员的负担，并将潜在的软件用户群体扩展到研究实验室中能够饮酒的参与者之外的研究人员。
