Development of a New Ambulatory Monitoring System for Indirect Beat-to-Beat Arterial Blood Pressure Using the Volume-compensation Method

在项目首年研制出了一种采用容积补偿法动态监测瞬时动脉血压的便携式仪器。选择颞浅动脉作为测量点是为了尽量减少受试者的束缚，并避免在长期监测期间静脉充血。使用皮带将带有用于血容量检测的反射式光传感器的圆盘式袖带牢固地固定在受试者的头部，受试者携带一个袖带压力（Pc）控制（CPC）单元（32x65x110mm, 210g）和一个基于微处理器的中央处理和记录（MCPR）单元（85x185x200mm, 800g）。本年度亦开发了一套互动软件，以便在监测过程中以自动方式进行顺序测量控制和数据存储。CPC装置主要由一个用于压缩空气供应的微型气泵和一个用于Pc控制的微型压电阀（PVAA8000120H, JUPITOR Co.）组成。MCPR可自动设定伺服参考值，控制伺服增益，处理和存储搏动间间接收缩压（Pcs）、平均血压（Pcm）、舒张压（Pcd）和瞬时心率（HR）。每个数据总共可以在一个存储IC单元中存储60000次。监测结束后，使用传统的个人计算机或专门订购的数据分析设备（ECM-1DS, ESCOM CO.）对存储的数据进行再现和分析，得到pc、Pcm、Pcd和HR的趋势图和直方图。在项目第二年，对仪器进行了进一步改进，并通过临床和实地实验对其在一次手术中的性能进行了评价。设计了一种用于Pc控制的喷嘴-挡板式微型电-气转换器，该转换器与用于Pc测量的微型压力传感器一起安装在圆盘式袖带中。通过这些改进，Pc伺服控制系统的频率响应高，并且仅携带带有微型气泵的改进后的MCPR单元。为了评估该仪器测量血压的准确性，我们同时测量了导管患者的直接肱动脉和间接颞浅动脉压力，结果表明这两个值和压力波形吻合较好。在野外工作、高速公路驾驶、物理治疗等过程中，成功地进行了动态监测，表明该仪器具有良好的操作性能，是监测不受限制受试者瞬时血压变化的有效手段。由于采用颞浅动脉作为测量部位，可以在受试者不受不适影响的情况下进行长期监测。本研究项目的所有项目均在项目期限内完成，并取得如上所述的令人满意的结果。少

A new portable instrument for the ambulatory monitoring of instantaneous arterial blood pressure using the volume-compensation method previously proposed by us has been developed in the first project year. The superficial temporal artery was chosen as a measuring site order to minimize restraint for a subject and to avoid venous congestion during the long-term monitoring. A disc-type cuff with a reflectance-type photo-sensor for blood volume detection was firmly placed to the subject's head using a belt and the subject carried a cuff-pressure (Pc) control (CPC) unit (32x65x110mm, 210g) and a microprocessor-based central processing & recording (MCPR) unit (85x185x200mm, 800g). An interactive software was also developed in this year for sequential measurement control and data storage in an automatic manner during the monitoring. The CPC unit consisted mainly of a micro air pump for compressed air supply and a miniature piezo-electric valve (PVAA8000120H, JUPITOR Co.) for Pc control. The … More MCPR unit performs the automatic setting of the servo-reference value and control of the servo-gain, processing and storing of beat-to-beat indirect systolic (Pcs), mean (Pcm) and diastolic blood pressure (Pcd) and instantaneous heart rate (HR). Altogether 60,000 beats of each data can be stored in a memory IC unit. After the monitoring, the stored data are reproduced and analyzed using a conventional personal computer or a specially ordered equipment for data analysis (ECM-1DS, ESCOM CO.) to obtain trend charts and histograms of Pcs, Pcm, Pcd and HR.In the second project year, the instrument was further improved as follows and the performance in an operation was evaluated through the clinical and dieldwork experiments. A nozzle-flapper type miniature electro-pneumatic converter for Pc control was newly designed, which was installed in the disc-type cuff together with a miniature pressure toansducer for Pc measurement. Through these modification, the frequency response of the Pc servocontrol system was highly and only the improved MCPR unit including a micro-air pump was carried by a subject. In order to evaluate the accuracy for blood pressure measurement by this instrument, simultaneous measurements of direct brachial and indirect superficial temporal arterial pressure were made in catheterised patients, showing fairly good agreements between these two values and pressure wave forms. With this instrument, ambulatory monitorings during fieldwork, highway driving, physicotherapeutics and so on, were successfully carried out, revealing that the instrument seems to have good operating performances and to be an useful means to monitor instantaneous variations of blood pressure in unrestricted subjects. Because the superficial temporal artery was adopted as a measuring site, the long-term monitoring could be made in the subjects being little affected by discomfort.The whole programs of this research project were completed within the project term with satisfactory results as described above. Less