A new fibre optic intravascular oxygen sensor for measuring fast and dynamic arterial blood oxygen tension changes online

我们已经证明，在患病的肺中，使用血管内电化学氧传感器的原型，肺泡单位在呼气时开始塌陷，在吸气时重新打开，这个过程（称为周期性不弛缓）导致动脉血中的氧分压（PaO2）在每次呼吸的基础上广泛振荡。这些结果已得到国际调查人员的独立证实。然而，我们和其他人使用的原型氧传感器无法准确测量流动血液中PaO2的快速振荡，特别是当氧合血红蛋白（血液中的红色色素）饱和度发生变化时。我们现在需要适应并进一步开发一种全新的血管内传感器，使用新技术来测量这些独立于氧血红蛋白饱和度的快速血氧振荡。此外，在重症监护病房对住院患者应用机械通气也会加剧这种重复性肺不张过程，并可能导致进一步的机械肺损伤，即呼吸机诱发的肺损伤（VILI）。有一个国际探索了解潜在的机制VILI和减少其发病率，并减少肺不动的有害影响。我们相信，与其他工作人员一起，动脉血中PaO2振荡的存在可以用于(a)检测肺部周期性不张的发作；(b)指导临床医生调整呼吸机的设置，以减少振荡的幅度，从而减少或消除不脱动过程本身。因此，临床需要一种快速反应的血管内氧传感器来在线和实时测量这些呼吸内PaO2振荡。目前可用的临床血管内氧传感器太慢（60-90秒的反应时间），无法用于这种逐呼吸的临床测量。因此，必须开发一种新的快速响应氧传感器，这就是本生物医学工程拨款申请的原因。这项工作将集中在开发这种新的传感器并在实验室进行测试，然后在生理条件下（体内）进行最终测试。这种基于光纤技术的新型传感器将能够在重症监护病房的危重病人中进行测量，以缓和VILI的发病率和严重程度。

We have demonstrated, in the diseased lung, using a prototype intravascular electrochemical oxygen sensor, that lung alveolar units begin to collapse in expiration and re-open in inspiration, and that process ( known as cyclical atelactasis) causes the oxygen partial pressure in the arterial blood (PaO2) to oscillate widely on a breath-by-breath basis. These results have been confirmed independently by international investigators. However, the prototype oxygen sensors used by ourselves and others were unable to measure rapid PaO2 oscillations in flowing blood accurately, especially when the oxyhaemoglobin (the red pigmant in blood) saturation was changing. We now need to adapt and further develop a brand new intravascular sensor, using new technology, to measure these fast blood oxygen oscillations independent of oxyhaemoglobin saturation.It is also well established that the application of mechanical ventilation to hospital patients in Intensive Care Units exacerbates this repetitive atelactasis process and can cause further mechanical lung damage, known as Ventilator Induced Lung Injury (VILI). There is an international quest to understand the mechanisms underlying VILI and to reduce its incidence, and to reduce the deleterious effects of atelactasis on the lung.We believe, along with other workers, that the presence of PaO2 oscillations in arterial blood can be used (a) to detect the onset of cyclical atelactasis in the lung; and (b) also to direct the clinician to adjust the ventilator settings to reduce the amplitude of the oscillations / and thus reduce or else eliminate the atelactasis process itself.A clinical need therefore exists for a rapid-response intravascular oxygen sensor to measure these intrabreath PaO2 oscillations on-line and in real time. Currently available clinical intravascular oxygen sensors are, far too slow (60-90 sec time response) to be used for this breath-by-breath clinical measurement. Therefore a new fast response oxygen sensor must be developed, and that is the reason for this biomedical engineering grant application. The work will concentrate on developing this new sensor and testing it in the laboratory, before it is ultimately tested in physiological conditions (in vivo). The new sensor, based on a fibre optic technique, will enable measurements to be made in critically-ill patients in the Intensive Care Unit, in order to moderate the incidence and severity of VILI.