BACKGROUND: The blood oxygen saturation is an important physiological parameter of human hfe; it can be affected by multiple factors due to the imbalance of oxygen supply and consumption, and consequently, the normal physical metabolism is affected. The existing manufacturing techniques are complex and are used with higher demands. OBJECTIVE: To investigate the accuracy of the novel reflecting oximeter designed on the basis of reflecting principle in monitoring the variance of blood oxygen saturation with the change of its concentration. DESIGN: To introduce the structure, working principle and design of the reflecting oximeter and make comparative study with adult rabbits as the subjects. SETTING: Cardiopolmonary Bypass Department of Cardiovascular disease hospital of the Chinese Academy of MedicalSciences. MATERIALS: The study was performed at the Departments of Anesthesiology and Cardiopulmonary Bypass of the Cardiovascular Disease Hospital,Chinese Academy of Medical Sciences from August to October in 2001.Ten adult rabbits were selected. METHODS: The oximeter consists of a converter, a driver, a central processing mould and liquid-crystal monitor. It is characterized by the onethree optical cable connected with reflecting probe, postcentral management system and digital displayer. This oxmeter was developed basing on the basis of fixed relationship between blood oxygen saturation and radiant absorbency (or reflecting). In this study,cardiovascular-pulmonary bypass was established on rabbits that were then exposed to oxygen and NO mixture supply of different concentrations,and then the corresponding blood oxygen saturations were determined with the new oximeter and compared with series-wound Baite saturation meter and blood-gas analysis. MAIN OUTCOME MEASURES: The blood oxygen saturation at different concentrations determined with the reflecting oximeter and Baite saturation meter. RESULTS: At the same oxygen concentration, the blood oxygen saturation determined with the new measure was not significantly different from that determined with Baite blood oxygen saturation meter(P＞0.05 ). CONCLUSION: The variance of blood oxygen saturation with the change of oxygen concentration can be detected by the reflecting oximeter with the result similar to that by Baite blood oxygen saturation meter.

Objective:To analyze the clinical data of patients with end-stage ankle and hindfoot ar-thropathy who underwent tibiotalocalcaneal(TTC)arthrodesis by the same surgeon,explore the short-and mid-term clinical results,complications and functional improvement,and discuss the clinical progno-sis and precautions of TTC arthrodesis.Methods:Retrospective analysis was made on the clinical data of 40 patients who underwent TTC arthrodesis by the same surgeon from March 2011 to December 2020.In this study,23 males and 17 females were included,with an average age of(49.1±16.0)years.All the patients underwent unilateral surgery.The clinical characteristics,imaging manifestations,main diagno-sis and specific surgical techniques of the patients were recorded.The clinical outcomes were evaluated by comparison of the American Orthopaedic Foot and Ankle Society(AOFAS)ankle-hindfoot score and visual analogue scale(VAS)between pre-operation and at the last follow-up.The fusion healing time,symptom improvement(significant improvement,certain improvement,no improvement or deterioration)and postoperative complications were also recorded.Results:The median follow-up time was 38.0(26.3,58.8)months.The preoperative VAS score was 6.0(4.0,7.0),and the AOFAS score was 33.0(25.3,47.3).At the last follow-up,the median VAS score was 0(0,3.0),and the AOFAS score was 80.0(59.0,84.0).All the significantly improved compared with their preoperative corre-sponding values(P＜0.05).There was no wound necrosis or infection in the patients.One patient suf-fered from subtalar joint nonunion,which was syphilitic Charcot arthropathy.The median bony healing time of other patients was 15.0(12.0,20.0)weeks.Among the included patients,there were 25 cases with significant improvement in symptom compared with that preoperative,8 cases with certain improve-ment,4 cases with no improvement,and 3 cases with worse symptoms than that before operation.Con-clusion:TTC arthrodesis is a reliable method for the treatment of the end-stage ankle and hindfoot ar-thropathy.The function of most patients was improved postoperatively,with little impact on daily life.The causes of poor prognosis included toe stiffness,stress concentration in adjacent knee joints,nonunion and pain of unknown causes.