The evaluation of blood compatibility of biomaterials is crucial for ensuring the clinical safety of implantable medical devices. To address the limitations of traditional testing methods in real-time monitoring and electrical property analysis, this study developed a portable electrical impedance tomography (EIT) system. The system uses a 16-electrode design, operates within a frequency range of 1 to 500 kHz, achieves a signal to noise ratio (SNR) of 69.54 dB at 50 kHz, and has a data collection speed of 20 frames per second. Experimental results show that the EIT system developed in this study is highly consistent with a microplate reader ( R ²=0.97) in detecting the hemolytic behavior of industrial-grade titanium (TA3) and titanium alloy-titanium 6 aluminum 4 vanadium (TC4) in anticoagulated bovine blood. Additionally, with the support of a multimodal image fusion Gauss-Newton one-step iterative algorithm, the system can accurately locate and monitor in real-time the dynamic changes in blood permeation and coagulation caused by TC4 in vivo. In conclusion, the EIT system developed in this study provides a new and effective method for evaluating the blood compatibility of biomaterials.
Electric Impedance ; Animals ; Tomography/instrumentation* ; Biocompatible Materials ; Materials Testing/instrumentation* ; Cattle ; Titanium ; Alloys ; Prostheses and Implants

Objective:To explore the current status and the influencing factors of protracted postpartum urinary retention(P-PUR) in women with labor analgesia, so as to provide evidences for early diagnosis and timely intervention for P-PUR.Methods:A total of 41 995 women who were given vaginal delivery under labor analgesia from January 2017 to October 2020 in Women′s Hospital of Nanjing Medical University were chosen as the research objects. A retrospective analysis was performed for the clinical data of 62 women with P-PUR, and a 1∶4 matching case control study was conducted. Logistic regression analysis was used to analyze the variables with statistical difference in univariate analysis, so as to explore the independent influencing factors of P-PUR in women with labor analgesia.Results:Among 41 995 women with labor analgesia, 62 women suffered from P-PUR, and the incidence was about 0.15% (62/41 995). The Logistic regression model showed that nulliparity ( OR=121.80, 95% CI 8.59-1 727.40, P<0.05), forceps delivery ( OR=13.41, 95% CI 2.21-81.58, P<0.05),Ⅱdegree porineal iaceration ( OR=0.04, 95% CI 0.01-0.11, P<0.05), episiotomy ( OR=0.13, 95% CI 0.04-0.47, P<0.05) and perineotomy with perineal laceration ( OR=0.20, 95% CI 0.06-0.63, P<0.05) were the independent risk factors. Conclusions:For primiparas with labor analgesia, interventions should be taken to reduce perineal injury, and indications of forceps delivery should be strictly controlled, so as to reduce P-PUR and adverse urinary tract complications.