检测临床前认知变化

时钟绘图测试 - 一种简单的铅笔和纸张测试 - 已被用于50多年的筛选工具，以区分具有认知障碍的人的健康个体，并证明有助于帮助诊断与神经系统疾病相关的认知功能障碍Alzheimer’s disease, Parkinson’s disease, and other dementias and conditions. For nearly a decade we have been administering the test using a digitizing ballpoint pen that reports its position with considerable spatial and temporal precision. We developed a methodology that analyzes the pen stroke data from these drawings and computed a large collection of features (statistics) of the drawings. We applied a variety of machine learning techniques to the data, producing interpretable predictive and prescriptive models. The resulting scoring systems were designed to be as easy to use as scoring systems currently used by clinicians, but more accurate. These new tests do not rely on doctors’ subjective judgment, unlike the current (non-digitized) clock drawing test. We evaluated our new models with a variety of techniques, including operationalizing a number of widely used manual scoring systems so that we could use them as benchmarks. We explored the tradeoffs in performance and interpretability in classifiers built using a number of different subsets of these features and a variety of different machine learning techniques. While more work is required for FDA approval, the work we have done offers the possibility of substantial improvement in detecting cognitive impairment earlier than currently possible. Given that the costs incurred for just a single form of dementia — Alzheimer’s Disease — are currently $200 billion per year, and are projected to reach one trillion dollars annually by 2050, early detection of impairment will have considerable medical, sociological, and economic impact.