INTRAPARTUM MEASUREMENT OF FETAL PH

在分娩过程中测量的胎儿头皮血液pH值是一个重要的变量 通过胎心率监测评估潜在的胎儿窘迫 和其他临床体征。新近开发的微型金属-金属氧化物 以及离子敏感场效应晶体管pH传感器 胎儿阴道内pH测定仪的研制 头皮血样与胎儿头皮组织的连续测量 PH值。在前一种情况下，微型pH传感器将放置在 与目前使用的采血管外形相似的探头 用于采集胎儿头皮血液样本，以便血液样本的pH值可以 在抽取样品后立即进行测量。这样做的好处是 技术是避免与转移到 移液器送到酸碱度测定仪。因此，建议的技术， 提供更快的PH值。组织酸碱度传感器将是 建造在外观上与目前使用的结构相似的结构 胎儿头皮心电图电极。这将应用于 与这些临床上可接受的传感器目前使用的方式相同 将提供连续的PH值读数。这两种类型的传感器都将 在实验室对无机缓冲液和眼压测量的血液进行了评估。这个 然后，头皮样本传感器将在来自 成人志愿者和婴儿，而组织传感器将在 狗。来自动物的样本将与中央动脉和 使用常规实验室技术分析的毛细样本。样本 将通过常规实验室方法进行测量，例如 以及新开发的传感器。两个传感器的最终评估将 对头皮采血并直接取胎儿的胎儿进行 心率监测有临床应用价值。这些临床研究将 在克利夫兰的围产期临床研究中心进行 大都会综合医院。这个中心由一位将军支持 临床研究中心获得美国国立卫生研究院研究资源部的资助。

Fetal scalp blood pH as measured during labor is an important variable in assessing potential fetal distress suggested by fetal heart rate monitoring and other clinical signs. Recently developed miniature metal-metal oxide and ion sensitive field effect transistor pH sensors will be incorporated into instrumentation for the intravaginal measurement of the pH of fetal scalp blood samples and the continuous measurement of fetal scalp tissue pH. In the former case, the miniature pH transducers will be placed on a probe similar in appearance to the blood collecting pipet currently used for taking fetal scalp blood samples, so that pH of the blood specimen can be measured immediately upon drawing the sample. The advantage of this technique is the avoidance of errors associated with samples transferred to pipets and transported to the pH instrument. The proposed technique, thus, provides a pH value more rapidly. The tissue pH sensors will be constructed in a structure similar in appearance to the presently used fetal scalp electrocardiographic electrodes. This will be applied in the same way that these clinically acceptable sensors are currently used and will provide continuous pH readings. Both types of sensors will be evaluated in the laboratory in inorganic buffer and tonometered blood. The scalp sample sensor will then be evaluated on capillary blood samples from adult volunteers and infants, while the tissue sensor will be evaluated on dogs. Samples from animals will be compared with central arterial and capillary samples analyzed using routine laboratory techniques. Samples from human subjects will be measured by conventionsl laboratory means as well as the newly developed sensors. Final evaluation of both sensors will be carried out on fetuses in whom scalp blood sampling and direct fetal heart rate monitoring is clinically indicated. These clinical studies will be carried out at the Perinatal Clinical Research Center at Cleveland Metropolitan General Hospital. This center is supported by a General Clinical Research Center grant from the NIH Division of Research Resources.