ObjectiveA simulation study was used to generate the multivariate normal distribution data with a residual effect based on series of N-of-1 trials. The statistical performance of paired t-test, mixed effect model and Bayesian mixed effect model were compared.MethodsThree-cycles N-of-1 trials were set, and the participants were randomly assigned to 2 different treatments in each cycle. The simulation study included the following procedures: producing six-dimensional normal distribution data, randomly allocating intervention methods and patients, adding residual effects, constructing and evaluating 3 models, and setting the parameters. The sample sizes were set as 3, 5, 8 and 10, and the correlation coefficients among different times were set as 0.0, 0.5 and 0.8. Different proportions of residual effects for the 2 groups were set. Type I error, power, mean error (ME), and mean square error (MSE) were used to compare the 3 models.ResultsWhen there was no residual effect in the 2 groups, type I errors of 3 models were approximately 0.05, and their MEs were approximately 0. Paired t-test had the highest power and the lowest MSE. When the residual effect existed in the 2 groups, the type I error of paired t-test increased, and its estimated value deviated from the true value (ME≠0). Type I errors of the mixed effect model and Bayesian mixed-effect model were approximately 0.05, and they had the same power. The estimated values of the two models were close to the true value (ME was approximately 0).ConclusionsWhen there is no residual effect (0% vs. 0%), paired t-test is suitable for data analysis of N-of-1 trials. When there is a residual effect, the mixed effect model and Bayesian mixed-effect model are suitable for data analysis of N-of-1 trials.
Objective To evaluate the application value of infrared thermography in breast reconstruction, cosmetic surgery, and limb reconstruction. Methods A retrospective analysis of clinical data from 67 patients undergoing breast reconstruction and cosmetic procedures and 30 patients undergoing limb reconstruction between February 2022 and June 2025. The patients undergoing breast reconstruction and cosmetic surgery were all female, aged 25-60 years with a median age of 48 years. Procedures included breast reconstructions in 48 cases, breast reductions in 8, nipple reconstructions in 5, revision breast reconstructions in 2, revision nipple reconstruction in 1, and labia minora reductions in 3. Among the patients undergoing limb reconstruction, 18 were males and 12 were females, aged 29-62 years with a mean age of 43 years. Procedures included skin flap transplants for wound repair in 10 cases, fracture internal fixation in 17, and limb lengthening reconstructions in 3. An infrared thermography device was applied intraoperatively and within 48 hours postoperatively to monitor flap and distal limb temperature and vascular perfusion. Results Intra- and post-operative infrared thermography assessment indicated 2 positive cases (2.1%, 2/97), comprising 1 false positive. Among the 95 negative cases (97.9%, 95/97), 1 false negative was recorded. After operation, 1 case of immediate breast reconstruction exhibited localized vascular compromise at the edge of the local flap, though infrared detection showed no abnormally low skin temperature. The wound healed with delayed healing following dressing changes. One case of latissimus dorsi myocutaneous flap exhibited persistent infrared hypothermia during transfer. However, the flap demonstrated active dermal hemorrhage and a positive pinch test. Continuous monitoring revealed a subsequent rise in flap temperature, confirming adequate perfusion. The flap survived, with primary wound closure achieved. The postoperative infrared thermal imaging monitoring of the surgical site indicated adequate blood supply with no local ischemic necrosis in other patients. All patients were followed up. The patients undergoing breast reconstruction were followed up 1-30 months, with a median follow-up time of 15 months. The reconstructed breasts and nipples demonstrated good survival. The patients undergoing labia minora reduction were followed 3, 8, and 13 months, respectively. The surgical sites exhibited favorable appearance and blood supply. The patients undergoing limb reconstruction were followed 1-12 months (mean, 7 months). Transplanted flaps showed good survival, and patients with fractures or limb lengthening achieved favorable limb recovery. Conclusion Infrared thermography offers a convenient, non-invasive, and objective supplementary indicator for breast and limb reconstruction. This technology can be used intra- and post-operatively to assess blood supply, thereby aiding surgical decision-making and reducing the risk of postoperative complications. However, attention should be paid to the potential for false positives and false negatives.