Objective To investigate the relationship between cerebrospinal fluid albumin/serum albumin(C-ALB/S-Alb)and the systemic immune inflammatory index(SII)and postoperative delirium(POD)in elderly patients with general anesthesia combined with epidural anesthesia.Methods Elderly patients who un-derwent elective hip replacement surgery and received general anesthesia combined with epidural anesthesia in this hospital from October 2023 to June 2024 were selected.According to the assessment results of the Chi-nese version of the 3-Minute Delirium Diagnostic Scale(3D-CAM),the patients were divided into the POD group(68 cases)and the non-POD group(76 cases).The general information of the patients was collected,the cerebrospinal fluid and venous blood specimens were detected.The levels of cerebrospinal fluid albumin(C-Alb),serum albumin(S-Alb),α-synuclein(α-syn),β-amyloid protein(Aβ)1-42,Aβ1-40,total Tau protein(t-Tau),phosphorylated Tau protein(p-Tau)were detected by enzyme-linked immunosorbent assay(ELISA).The neutrophil count,platelet count and lymphocyte count of the patients were detected by the fully automatic blood analyzer,and the SII was calculated.Results Compared with the non-POD group,the levels of C-Alb,α-syn,t-Tau,p-tau,SII and C-Alb/S-Alb in the POD group increased,while Aβ1-42 and Aβ1-40 were significantly decreased,and the differences were statistically significant(P＜0.05).C-Alb,t-Tau,SII and C-Alb/S-Alb were all independent risk factors for the occurrence of POD.The results of the receiver operating characteristic(ROC)curve analysis showed that the areas under the curve(AUC)of the ROC curves of SII,t-Tau,C-Alb,C-Alb/S-Alb and C-Alb/S-Alb combined with SII for predicting delirium were 0.824,0.818,0.723,0.862 and 0.926,respectively.The AUC predicted by C-Alb/S-Alb combined with SII was the highest(all P＜0.05).Conclusion High SII and C-Alb/S-Alb are independent risk factors for POD occurrence in eld-erly patients with general anesthesia combined with epidural anesthesia.Both have good predictive efficacy for POD,and the combined use has better predictive efficacy.

With the development of science and technology and the improvement of living standards, people's understanding of "health" has also changed. The patients with chronic diseases and the people who do not have obvious symptoms of disease all hope to further improve the quality of life as well as the sense of happiness, gain and security. Disabled people and the elderly people with degraded physical functions are in need of corresponding rehabilitation devices. These needs determine that the research scope of biomedical engineering should be expanded, so as to use modern scientific technology and medical methods to study related issues and improve the health of the people. As a result, the concept of "healthcare medical engineering" emerged. In this paper, the definition of healthcare medical engineering were proposed, its significance, characteristics, content, and outlook for the future were introduced. This paper is expected to broaden the horizons and inspire ideas of researchers engaged in biomedical engineering research for future research in finding solutions to many problems in the field of medical and health care, thereby improving the quality of medical services and management, and promoting the development of the national health industry.