Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.
Objective To evaluate the utility of collagen-gel droplet embedded-culture drug sensitivity test (CD-DST) in pancreatic carcinoma cell by compared with WST-8. Methods The chemosensitivity to 5-fluorouracil (5-FU), gemzar (GEM) and oxaliplatin (OXA) of pancreatic adenocarcinoma cells SW1990, PCT-3 and ASPC-1 were tested by WST-8 and CD-DST respectively. Results In a certain living cell number range (500-10 000), there was a linear correlation (r=0.991 1, P＜0.05) between the integral optical density in CD-DST and the cell number. The inhibition ratios of three kinds of cell growth tested by CD-DST were higher than those tested by WST-8 (P＜0.05). The results of drug chemosensitivity to 5-FU， GEM and OXA detected by two methods were uniform. Conclusion The CD-DST can be used to assay the drug chemosensitivity in vitro for pancreatic carcinoma.
In order to solve the saturation distortion phenomenon of R component in fingertip video image, this paper proposes an iterative threshold segmentation algorithm, which adaptively generates the region to be detected for the R component, and extracts the human pulse signal by calculating the gray mean value of the region to be detected. The original pulse signal has baseline drift and high frequency noise. Combining with the characteristics of pulse signal, a zero phase digital filter is designed to filter out noise interference. Fingertip video images are collected on different smartphones, and the region to be detected is extracted by the algorithm proposed in this paper. Considering that the fingertip’s pressure will be different during each measurement, this paper makes a comparative analysis of pulse signals extracted under different pressures. In order to verify the accuracy of the algorithm proposed in this paper in heart rate detection, a comparative experiment of heart rate detection was conducted. The results show that the algorithm proposed in this paper can accurately extract human heart rate information and has certain portability, which provides certain theoretical help for further development of physiological monitoring application on smartphone platform.
In order to solve imperfection of heart rate extraction by method of traditional ballistocardiogram (BCG), this paper proposes an improved method for detecting heart rate by BCG. First, weak cardiac activity signals are acquired in real time by embedded sensors. Local BCG beats are obtained by signal filtering and signal conversion. Second, the heart rate is estimated directly from the BCG beat without the use of a heartbeat template. Compared with other methods, the proposed method has strong advantages in heart rate data accuracy and anti-interference, and it also realizes non-contact online detection. Finally, by analyzing the data of more than 20,000 heart rates of 13 subjects, the average beat error was 0.86% and the coverage was 96.71%. It provides a new way to estimate heart rate for hospital clinical and home care.
Lower limb amputation is a significant change in body structure. Loss of muscle, blood vessels, and blood leads to a redistribution of blood flow and changes in resistance at the end of blood vessels. In view of the significant increase in the prevalence of cardiovascular disease after lower limb amputation, the mechanism of which is still unclear, this study aims to establish an animal research model that can verify and explore the effects of amputation on cardiovascular system, and provide the experimental basis for subsequent animal experiments when exploring the effect of different amputation levels on the cardiovascular system. SPF New Zealand rabbits were divided into normal group (n = 6) and amputation group (n = 6). The amputation group was treated with above-knee amputation. The changes of low-density liptein cholesterol (LDL-C) and total cholesterol (TC) in serum of all the rabbits were monitored regularly after the surgery. The arterial pathological examination was conducted after the experimental rabbits were executed. The results showed that compared with the normal group, serum LDL-C content and TC content in the amputation group were significantly increased (P<0.05); The blood vessels of the amputated rabbits had pathological changes such as degeneration and necrosis of smooth muscle cells in the middle membrane layer and rupture of elastic fibers. At the abdominal aorta and aortic arch, the elastic fiber area expression percentage (EFEP) of the experimental group was significantly lower than that of the normal group. The results suggest that the cardiovascular system of rabbits has the tendency of decreased arterial elasticity and lipid deposition in blood after amputation, indicating that the animal research model on the effect of amputation on the cardiovascular system has been successfully established, and can provide an experimental platform for further study on the mechanism of the effect of amputation on the cardiovascular system.
Mental fatigue is an important factor of human health and safety. It is important to achieve dynamic mental fatigue detection by using electroencephalogram (EEG) signals for fatigue prevention and job performance improvement. We in our study induced subjects' mental fatigue with 30 h sleep deprivation (SD) in the experiment. We extracted EEG features, including relative power, power ratio, center of gravity frequency (CGF), and basic relative power ratio. Then we built mental fatigue prediction model by using regression analysis. And we conducted lead optimization for prediction model. Result showed that R2 of prediction model could reach to 0.932. After lead optimization, 4 leads were used to build prediction model, in which R2 could reach to 0.811. It can meet the daily application accuracy of mental fatigue prediction.
Human immunodeficiency virus (HIV)-1 p24 antigen is one of the earliest proteins appearing after HIV infection. It can be used as a diagnostic marker to shorten the detection “window period” to about 14 days. It is of vital importance in the process of early diagnosis and antiviral therapy monitoring. This review briefly describes the basic structure and clinical significance of detection of HIV-1 p24 antigen, focusing on the current domestic and foreign researches on the biosensors of HIV-1 p24 antigen based on new nanomaterials, in order to provide a reference for developing novel detection technology.
Based on the capacitance coupling principle, we studied a capacitive way of non-contact electrocardiogram (ECG) monitoring, making it possible to obtain ECG on the condition that a patient is habilimented. Conductive fabric with a good electrical conductivity was used as electrodes. The electrodes fixed on a bed sheet is presented in this paper. A capacitance comes into being as long as the body gets close to the surface of electrode, sandwiching the cotton cushion, which acts as dielectric. The surface potential generated by heart is coupled to electrodes through the capacitance. After being processed, the signal is suitable for monitoring. The test results show that 93.5% of R wave could be detected for 9 volunteers and ECG with good signal quality could be acquired for 2 burnt patients. Non-contact ECG is harmless to skin, and it has advantages for those patients to whom stickup electrodes are not suitable. On the other hand, it is convenient to use and good for permanent monitoring.
【摘要】 目的 探讨全自动尿沉渣分析仪在尿管型检测中的应用。 方法 收集尿管型患者晨尿标本836份。所有标本均经尿干化学分析仪检测Pro≥1+或尿沉渣分析仪提示有管型。采用UF100全自动尿沉渣分析仪和显微镜检测管型，对比分析两者的检测结果。 结果 836份标本中，UF100全自动尿沉渣分析仪检测阳性者320例，占38.28%；显微镜检测阳性者195例，占23.33%。其中UF100全自动尿沉渣分析仪的假阳性率为26.52%，假阴性率为23.08%。UF100尿沉渣分析仪与显微镜检测管型的阳性结果比较，差异有统计学意义（Plt;0.01）。 结论 UF100全自动尿沉渣仪能快速筛检尿沉渣，但存在一定的假阴性，必须同时将其检测结果与尿干化学结果结合考虑以决定是否再进行显微镜检测，减少假阴性以防止漏检。【Abstract】 Objective To investigate the application of UF-100 full-auto urine sediment analyzer in detecting cylindruia. Methods 836 specimens with cylindruia were selected. All the specimens with Pro≥1+ were dectected by chemical dipstick or cylindruia by urine sediment analyzer. The cast were detected by urine sediment analyzer and microscope, and the results were compared. Results Of 836 specimens, 320 positive samples(38.28%) were found by UF-100 while 195 (23.33%) were found by microscope. False positive rate and false negative rate of UF100 were 26.52% and 23.08%. Compared the results of urine sediment analyzer with microscope, the difference was statistically significant (Plt;0.01). Conclusions UF100 can detect urinary cast quickly, but there is a little high false negative rate. So we should consider urine sample whether to be detected by microscope compared with results of UF100 and chemical dipstick.