Unconstrained Monitoring of Sleep Respiration Based on Detection of Pressure fluctuations on Mattress / 医用生物力学

Objective To develop a method for monitoring unconstrained sleep respiration suitable for daily use at home, so as to realize high precision screening of sleep apnea syndrome (SAS) or other respiratory diseases without affecting normal sleep. Methods A new unconstrained measurement method using sheet-type flexible pressure sensor was proposed. This method could obtain the information of respiratory motions of the chest and abdomen by measuring the pressure fluctuations of the chest and abdomen acting on the mattress. Experiments were conducted on ten healthy subjects to confirm effectiveness of the proposed method by comparing the result of the unconstrained measurement and those of respiratory inductance plethysmography (RIP) using band sensors, respectively. Results Sheet-type flexible pressure sensor could measure the pressure fluctuations of the chest and abdomen acting on the mattress during respiration and obtain respiratory waveform and respiratory rate. The respiratory rate measured with the sheet-type flexible pressure sensor agreed with those obtained by RIP. The gender and the lying position greatly affected whether the phases of the pressure fluctuations of the chest and abdomen measured with the flexible sensor differed from those obtained by RIP. The chest respiratory finite element model was established to analyze the phase difference of respiratory movement. Conclusions Sheet-type flexible pressure sensor is effective to monitor unconstrained sleep respiration, indicating the potential to identify the SAS types. But further researches of motion decoupling are required to identify the phase difference between the chest motion and the abdomen motion, which are coupled with each other.

Research progress in constructing animal models of staphylococcus aureus-associated osteomyelitis / 中国组织工程研究

BACKGROUND: Staphylococcus aureus has become the most important pathogen of osteomyelitis In the world. An excellent and standard homogenous animal model plays an Important role regarding the Infectious mechanism of osteomyelitis, the acquisition of new preventive and therapeutic measures, and the application of new technologies in clinical practice. OBJECTIVE: To review the research progress and problems in the construction of animal models of Staphylococcus aureus-associated osteomyelitis at home and abroad. METHODS: A computer-based search of CNKI, PubMed, MEDLINE, Embase, and Cochrane was performed for relevant articles concerning the experimental osteomyelitis model, including review, basic research and clinical research, published from January 2010 to June 2019. The keywords were "Staphylococcus aureus; bone Infection; osteomyelitis; Implant-associated osteomyelitis; bone defect osteomyelitis; fracture osteomyelitis; biofilm; experimental osteomyelitis model" in Chinese and English, respectively. After Initial screening of titles and abstracts and exclusion of irrelevant articles, 45 eligible articles were Included In final analysis. RESULTS AND CONCLUSION: Construction of an osteomyelitis animal model is related to many factors. Although researchers from various countries have continuously Improved and gradually quantified the Infection process In recent years, a unified standard has not yet been developed. To date, there is no single microbiology or Imaging method to determine bone Infection. In animal models of acute osteomyelitis, the use of microbiological tests such as nuc RTQ-PCR and bioluminescence tomography can dynamically monitor and quantify the bone Infection process at an early stage. In the animal model of chronic osteomyelitis, we can dynamically observe the process of osteolysis and bone remodeling based on the micro-CT and MRI images. Advanced Imaging technologies such as18F-FDG PET/CT can be used to confirm or exclude chronic osteomyelitis with high diagnostic accuracy. The use of animal models of osteomyelitis contributes to standardizing the number and activity of infected bacteria during early diagnosis and quantified treatment, which Is the direction for further research.

Ambient air pollution exposures and risk of drug-resistant tuberculosis.

BACKGROUND: Few epidemiological studies have explored the effects of air pollution on the risk of drug-resistant tuberculosis (DR-TB). OBJECTIVE: To investigate the short and long term residential concentrations of ambient air pollutants (particulate matter <10 µm in diameter (PM10) and particulate matter≤2.5 µm in diameter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO)) in relation to the risk of DR-TB in a typical air pollution city, Jinan city, China. METHODS: A total of 752 new culture-confirmed TB cases reported in TB prevention and control institutions of Jinan from January 1, 2014 to December 31, 2015 were included. Average individual-level concentrations of air pollution for 5 different exposure windows, vary from 90 days to 720 days to diagnosis were estimated using measurements from monitor closest to the patient home addresses. Logistic regression model adjusted for potential confounders was employed to evaluate correlation between air pollution and DR-TB risk at different five exposure windows individually. RESULTS: There were substantially increased mono-drug resistance and poly-drug resistance risks for ambient PM2.5, PM10, O3, and CO exposures. High exposure to PM2.5, PM10, and CO was also significantly associated with increased incidence of multi-drug resistance (MDR) both in the single- and multi-pollutants regression models. The dominant positive associations for PM2.5was observed at 540 days exposure, for O3 was observed at 180 days exposure, and for PM10 and CO was observed from 90 days to 540 days exposures. CONCLUSIONS: Our finding suggest that exposure to ambient air pollution (PM2.5, PM10, O3, and CO) are associated with increased risk of DR-TB. We provided epidemiological evidence of association between pollution exposure and mono-, poly- and multi-drug resistance.

Unconstrained detection of ballistocardiogram and heart rate based on vibration acceleration / 生物医学工程学杂志

The requirement for unconstrained monitoring of heartbeat during sleep is increasing, but the current detection devices can not meet the requirements of convenience and accuracy. This study designed an unconstrained ballistocardiogram (BCG) detection system using acceleration sensor and developed a heart rate extraction algorithm. BCG is a directional signal which is stronger and less affected by respiratory movements along spine direction than in other directions. In order to measure the BCG signal along spine direction during sleep, a 3-axis acceleration sensor was fixed on the bed to collect the vibration signals caused by heartbeat. An approximate frequency range was firstly assumed by frequency analysis to the BCG signals and segmental filtering was conducted to the original vibration signals within the frequency range. Secondly, to identify the true BCG waveform, the accurate frequency band was obtained by comparison with the theoretical waveform. The J waves were detected by BCG energy waveform and an adaptive threshold method was proposed to extract heart rates by using the information of both amplitude and period. The accuracy and robustness of the BCG detection system proposed and the algorithm developed in this study were confirmed by comparison with electrocardiogram (ECG). The test results of 30 subjects showed a high average accuracy of 99.21% to demonstrate the feasibility of the unconstrained BCG detection method based on vibration acceleration.

Postoperative complications following open reduction and internal fixation combined with vascularized bone flap graft versus only reduction and internal fixation for femoral neck fractures: a systematic review / 中华创伤骨科杂志

Objective To systematically evaluate the postoperative complications following open reduction and internal fixation combined with vascularized bone flap graft versus only reduction and internal fixation for femoral neck fractures.Methods CNKI,Wan Fang Chinese database,Pubmed,EMBASE and Google Scholar English database were searched for the randomized controlled trials from January 1,2000 through October 31,2017 which compared open reduction and internal fixation combined with vascularized bone flap graft (combined surgery group) with only reduction and internal fixation (simple surgery group) for femoral neck fractures.The data concerning postoperative nonunion and avascular necrosis of the femoral head were extracted.The 2 surgical treatments of the patients with femoral neck fracture were compared in terms of the 2 complications.Statistical analyses were conducted using software Stata 12 by relative risk (RR) and corresponding 95％ confidence intervals (95％ CI).Results According to our inclusion and exclusion criteria,a total of 23 studies were included,involving 2,162 cases (1,048 cases receiving combined surgery and 1,114 cases simple surgery).The Meta analyses showed that the fracture nonunion rate for the combined surgery group was significantly lower than that for the simple surgery group [RR =0.27,95％ CI(0.19,0.38),P ＜ 0.001] and the rate of avascular necrosis was also significantly lower for the former than for the latter [RR =0.31,95 ％ CI(0.24,0.42),P ＜ 0.001].Conclusion In the treatment of femoral neck fractures,open reduction and internal fixation combined with vascularied bone graft may lead to lower rates of nonunion and avascular necrosis of the femoral head than simple open reduction and internal fixation.

Efficacy of calf self-weight traction reduction combined with locking plate for treatment of intertrochanteric fractures in the elderly / 中华创伤杂志

Objective To investigate the efficacy of calf self weight traction reduction combined with locking plate fixation for the treatment of intertrochanteric fractures in the elderly.Methods A retrospective case series study was conducted on the clinical records of 174 elderly patients with the modified Evans Ⅰ-Ⅲ types of fresh intertrochanteric fractures treated with locking plate from January 2012 to December 2015.According to treatment method,the patients were assigned to traction bed reduction with locking plate fixation (Group A,62 patients) and calf self weight traction reduction with locking plate fixation (Group B,112 patients).Group A comprised 32 males and 30 females,with age range of 65-91 years [(72.47 ± 6.35) years].Group B comprised 68 males and 44 females,with age range of 65-95 years [(73.23 ± 6.05) years].The time of reduction,operation time,incision length,intraoperative blood loss,frequency of fluoroscopy,postoperative drainage volume,hospital stay,postoperative weightbearing standing time or walking time (ambulation time),surgical complications,and fracture healing were recorded.Harris and modified Barthel index score in Chinese (MBI-C) were used to evaluate the functional recovery of hip joint.Results All patients were followed up for 5-61 months (mean,15 months),and noted with fracture healing.The time of reduction in Group A was (13.27 ± 3.03) minutes,longer than that in Group B (0 minute) (P ＜0.05).The operation time in Group A was (63.63 ± 13.90)minutes,longer than that in Group B [(59.62 ± 8.38) minutes] (P ＜ 0.05).Fluoroscopy in Group A was (5.35 ± 2.36) times,more than (4.28 ± 3.11) times in Group B (P ＜ 0.05).There were no significant differences in the incision length,intraoperative blood loss,postoperative drainage volume,ambulation time,fracture healing time,Harris score,and MBI-C index between the two groups (P ＞0.05).There were no significant differences in the postoperative complications such as deep venous thrombosis,pulmonary infection,incisional infection,urinary tract infection,delirium,bed sores,cardiac insufficiency,electrolyte disturbance,and postoperative plate rupture between the two groups (P＞0.05).The incidence of deep vein thrombosis was 9.7％ (6/62) in Group A,and 4.5％ (5/112) in Group B (P ＞0.05).No screw fracture,nail and plate combination failure,bone nonunion,or screw cut out of the femoral head were observed in both groups.Conclusions For the modified Evans Ⅰ-Ⅲ types of intertrochanteric fractures,both traction bed reduction and calf weight reduction with locking plate have equivalent efficacy.However,the latter method has advantages of shorter reduction and operation time and less intraoperative X-ray exposure,and hence is worthy of clinical application.