Hermida R C, Mojón A, Fernández J R, Ayala D E
Bioengineering and Chronobiology Laboratories, ETSI Telecomunicación, University of Vigo, Campus Universitario, Spain.
Biomed Instrum Technol. 1996 May-Jun;30(3):267-83.
A computer-based system for assessing hypertension was designed by combining hardware for automatic, long-term blood pressure (BP) measurement with a set of software modules for computing time-specified tolerance intervals and evaluating measures of BP excess. BP is so variable that the identification and proper definition of hypertension are highly ambiguous when based on single measurements. One first step in dealing with such variability is to replace the constant limits for BP frequently used in the assessment of hypertension by a time-specified reference interval. Once such a threshold is available, a hyperbaric index can be computed by numerical integration as the total area (within one cycle) of any given patient's BP above the threshold. In order to examine the extent of normal physiologic excess, a series of 266 systolic and diastolic BP and heart rate (HR) measurements were automatically monitored every 30 minutes for at least 48 hours from clinically healthy subjects, aged 19 to 25 years. Original data were used to obtain 90% tolerance intervals for each gender separately. The hyperbaric index was then computed for each individual BP profile. The distribution of the maximum hyperbaric index (maximum of the values computed for systolic, mean arterial, and diastolic BP levels shows a highest value of 14.839 mmHg x hr for the men and of 10.229 mmHg x hr for the women. These values represent a testable threshold for assessing hypertension based on the proposed approach. The tolerance intervals obtained from the reference population were also used to compute hyperbaric indices for a series of 175 BP measurements sampled from clinically healthy people, as well as a series of 60 measurements sampled from patients with mild hypertension. Sensitivity and specificity in the diagnosis of hypertension based on the hyperbaric index were both 100%, as opposed to values obtained from computing the BP load, the average of the BP series, or the circadian amplitude, all of which provided a much poorer diagnostic test. The software system developed for automatically establishing time-qualified tolerance limits from a reference population and assessing the extent and timing of BP elevation for a test subject may help to establish a prognosis and diagnosis, with a correspondingly better assessment of health status, to initiate treatment if needed, to time treatment when it is most desirable and least harmful in terms of undesired effects, and to gauge the patient's response to treatment.
通过将用于自动长期测量血压（BP）的硬件与一组用于计算特定时间的容忍区间和评估血压过高指标的软件模块相结合，设计了一种基于计算机的高血压评估系统。血压变化很大，以至于基于单次测量来识别和正确定义高血压非常模糊。处理这种变异性的第一步是用特定时间的参考区间取代高血压评估中常用的固定血压限值。一旦有了这样一个阈值，就可以通过数值积分计算出一个高压指数，即任何给定患者血压高于该阈值（在一个周期内）的总面积。为了研究正常生理过高的程度，对19至25岁临床健康受试者的一系列266次收缩压、舒张压和心率（HR）测量值每30分钟自动监测一次，至少持续48小时。原始数据用于分别获得每种性别的90%容忍区间。然后为每个个体的血压曲线计算高压指数。最大高压指数（为收缩压、平均动脉压和舒张压水平计算的值中的最大值）的分布显示，男性最高值为14.839 mmHg×小时，女性为10.229 mmHg×小时。这些值代表了基于所提出方法评估高血压的可测试阈值。从参考人群获得的容忍区间还用于为从临床健康人群中抽取的一系列175次血压测量值以及从轻度高血压患者中抽取的一系列60次测量值计算高压指数。基于高压指数诊断高血压的敏感性和特异性均为100%，这与通过计算血压负荷、血压系列平均值或昼夜振幅获得的值相反，所有这些值提供的诊断测试效果都差得多。为从参考人群自动建立时间限定的容忍限值以及评估测试对象血压升高的程度和时间而开发的软件系统，可能有助于建立预后和诊断，从而相应地更好地评估健康状况，在需要时启动治疗，在最理想且副作用最小的时候安排治疗时间，并衡量患者对治疗的反应。
