van der Bel René, Sliggers Bart C, van Houwelingen Marc J, van Lieshout Johannes J, Halliwill John R, van Hulst Robert A, Krediet C T Paul
Department of Internal Medicine, Academic Medical Center, University of Amsterdam, The Netherlands.
Department of Medical Technology, Academic Medical Center, University of Amsterdam, The Netherlands.
Diving Hyperb Med. 2016 Mar;46(1):38-42.
It would be desirable to safely and continuously measure blood pressure noninvasively under hyperbaric and/or hyperoxic conditions, in order to explore haemodynamic responses in humans under these conditions.
A systematic analysis according to 'failure mode and effects analysis' principles of a commercially available beat-by-beat non-invasive blood pressure monitoring device was performed using specifications provided by the manufacturer. Possible failure modes related to pressure resistance and fire hazard in hyperbaric and oxygen-enriched environments were identified and the device modified accordingly to mitigate these risks. The modified device was compared to an unaltered device in five healthy volunteers under normobaric conditions. Measurements were then performed under hyperbaric conditions (243 kPa) in five healthy subjects.
Modifications required included: 1) replacement of the carbon brush motorized pump by pressurized air connected through a balanced pressure valve; 2) modification of the 12V power supply connection in the multiplace hyperbaric chamber, and 3) replacement of gas-filled electrolytic capacitors by solid equivalents. There was concurrence between measurements under normobaric conditions, with no significant differences in blood pressure. Measurements under pressure were achieved without problems and matched intermittent measurement of brachial arterial pressure.
The modified system provides safe, stable, continuous non-invasive blood pressure trends under both normobaric and hyperbaric conditions.
为了探究人体在高压和/或高氧条件下的血流动力学反应，期望能在这些条件下安全、连续地进行无创血压测量。
根据“失效模式与效应分析”原则，利用制造商提供的规格对一款市售的逐搏无创血压监测设备进行系统分析。识别出在高压和富氧环境中与耐压性和火灾隐患相关的可能失效模式，并对设备进行相应修改以降低这些风险。在常压条件下，将修改后的设备与未改动的设备在五名健康志愿者身上进行比较。然后在五名健康受试者身上于高压条件（243 kPa）下进行测量。
所需的修改包括：1）用通过平衡压力阀连接的压缩空气替换碳刷电动泵；2）修改多人高压舱内的12V电源连接，以及3）用固态等效物替换充气电解电容器。常压条件下的测量结果一致，血压无显著差异。在压力条件下的测量顺利完成，且与肱动脉压力的间歇测量结果相符。
改进后的系统在常压和高压条件下均能提供安全、稳定、连续的无创血压趋势。
