[Ultra-fast response polymer optical fiber oxygen measurement device and its preliminary experimental report on continuous dynamic change of arterial oxygen partial pressure under mechanical ventilation in living animals].

Objective: We tried to implant the ultra-fast polymer optical fiber chemical oxygen sensor （POFCOS） into arterial blood vessel,connect with photoelectric conversion measurement system to record the continuous dynamic rapid changes of arterial PO2(PaO2) in whole living animals. It should be the experimental evidence for the new theory of holistic integrative physiology and medicine(HIPM) forexplain the mechanism of respiratory control and regulation in whole circusof respiration-circulation-metabolism. Methods: ①Fabrication of ultrafast POFCOS, calibration and its measuring system: The distal part of 2 m optical fiber was heated and pulled until it became a tapered tip. After cleaning and drying, the tip of 1 mm tapered optical fiber was dip-coated into the luminophore doped polymer solution, then was slowly pumped out while solvent was quickly evaporated to form an oxygen sensing tip, which was dried at room temperature for 24 hours. ②Animal experiments: Under general anesthesia and intubation, goatwas mechanically ventilated with 40%~60% oxygen. We exposed both right and left carotid arteries and the left femoral artery by skin cutting, and inserted the POFCOS directly into the arteries via indwelling catheter. The end of POFCOS were connected to the personal computer through optical fiber, excitation and detection Y-type optical fiber coupler through photoelectric conversion, so as we can realize the continuous dynamic response of living goat carotid PaO2 under mechanical ventilation. We mainly analyzed the intra-breath wave-form alternate increase and decrease of PaO2 and their time delay between lung and carotid arteries.We completes breathing control whole loop to explain the mechanism of mutual breathing and the switching of inspiration and exhalation. Results: The POFCOS has a very fast T90 response time was set 100 ms for liquid. When the heart rate of 40%~60% oxygen mechanical ventilated living goat was ~110 bpm, the PaO2 of left and right carotid artery showed a same wave-sizeup and down following with the inspiration and expiration of ventilator, with a range of up to 15 mmHg. There weresignificant noises of PaO2 change recorded in the left femoral artery. The lung-carotid artery time delay is 1.5~1.7 s after inhalation and exhalation, PaO2 at both left and right carotid arteries starts toincrease and decrease. After two-three heartbeats after the start of lung ventilation, thealternate up-down wave-form information of the arterialized pulmonary vein blood after pulmonary capillaries waspumpedby left ventricle to the position of peripheral chemoreceptors,thus realizing the whole cycle of inhalation and exhalation. It alternately interrupted inhalation, i.e. switching inhalation to exhalation, and then interrupted exhalation,i.e. switching exhalation to inhalation. Conclusion: The ultra-fast reactive implantableoxygen sensor and its measuring system can measure the physiological waveform changes of PaO2 in living animals, which can provide experimental evidence for explaining the mechanism of switching of inspiration-expiration in HIPM.