Multi-task learning (MTL) has demonstrated significant advantages in the field of physiological signal measurement. This approach enhances the model's generalization ability by sharing parameters and features between similar tasks, even in data-scarce environments. However, traditional multi-task physiological signal measurement methods face challenges such as feature conflicts between tasks, task imbalance, and excessive model complexity, which limit their application in complex environments. To address these issues, this paper proposes an enhanced multi-scale spatiotemporal network (EMSTN) based on Eulerian video magnification (EVM), super-resolution reconstruction and convolutional multilayer perceptron. First, EVM is introduced in the input stage of the network to amplify subtle color and motion changes in the video, significantly improving the model's ability to capture pulse and respiratory signals. Additionally, a super-resolution reconstruction module is integrated into the network to enhance the image resolution, thereby improving detail capture and increasing the accuracy of facial action unit (AU) tasks. Then, convolutional multilayer perceptron is employed to replace traditional 2D convolutions, improving feature extraction efficiency and flexibility, which significantly boosts the performance of heart rate and respiratory rate measurements. Finally, comprehensive experiments on the Binghamton-Pittsburgh 4D Spontaneous Facial Expression Database (BP4D+) fully validate the effectiveness and superiority of the proposed method in multi-task physiological signal measurement.
The anterior cruciate ligament (ACL) reconstruction mostly relies on the experience of surgeons. To improve the effectiveness and adaptability of the tension after ACL reconstruction in knee joint rehabilitation, this paper establishes a lateral force measurement model with relaxation characteristics and designs an on-line stiffness measurement system of ACL. In this paper, we selected 20 sheep knee joints as experimental material for the knee joint stability test before the ACL reconstruction operation, which were divided into two groups for a comparative test of single-bundle ACL reconstruction through the anterolateral approach. The first group of surgeons carried out intraoperative detection with routine procedures. The second group used ACL on-line stiffness measurement system for intraoperative detection. After that, the above two groups were tested for postoperative stability. The study results show that the tension accuracy is (− 2.3 ± 0.04)%, and the displacement error is (1.5 ± 1.8)%. The forward stability, internal rotation stability, and external rotation stability of the two groups were better than those before operation (P < 0.05). But the data of the group using the system were closer to the preoperative knee joint measurement index, and there was no significant difference between them (P > 0.05). The system established in this paper is expected to help clinicians judge the ACL reconstruction tension in the operation process and effectively improve the surgical effect.
Retinal blood vessels are the only circulatory system that can be observed under non-invasive conditions. By observing the morphological changes of retinal blood vessels, the changes of blood circulation can be indirectly reflected. The occurrence, development and evolution of different diseases can be discovered. With the development of new detection technologies, especially the wide application of fundus photography and optical coherence tomography, a more intuitive and non-invasive quantitative index is provided for retinal vascular measurement. It is important for the diagnosis, guiding treatment and follow-up of related vascular diseases. This article reviews the development of retinal vessel diameter measurement methods and related applications in clinical diagnosis and treatment.
To address the challenges of capturing micro-strains in detecting esophageal motility disorders and the limitations of existing high-resolution manometry and functional intraluminal imaging probes in directly measuring esophageal tissue electrical impedance, this study proposes a novel flexible balloon sensor structure that integrates a piezoelectric film assembly with a distributed impedance electrode array. Using the electrical analysis module in the finite element analysis (FEA) software, simulations of the forward problem for esophageal impedance detection were conducted to optimize the excitation source parameters, and a physical prototype was fabricated. Under a relative excitation mode with a voltage sensitivity of 2.059%, the voltage output characteristics of the impedance electrode array were analyzed during linear changes in the balloon filling volume. Based on the performance variation of the piezoelectric film assembly, 80% was selected as the optimal filling volume. Force-electric coupling tests were conducted on the balloon sensor using a pressure testing platform, revealing that both the piezoelectric film assembly inside the balloon and the impedance electrodes outside the balloon exhibited significant load differentiation characteristics as the force application point shifted. In summary, this balloon sensor facilitates the localization of force application while simultaneously analyzing esophageal tissue properties, offering a novel diagnostic approach and objective tool for esophageal disease detection.
Based on the imaging photoplethysmography (iPPG) and blind source separation (BSS) theory the author put forward a method for non-contact heartbeat frequency estimation. Using the recorded video images of the human face in the ambient light with Webcam, we detected the human face through software, separated the detected facial image into three channels RGB components. And then preprocesses i.e. normalization, whitening, etc. were carried out to a certain number of RGB data. After the independent component analysis (ICA) theory and joint approximate diagonalization of eigenmatrices (JADE) algorithm were applied, we estimated the frequency of heart rate through spectrum analysis. Taking advantage of the consistency of Bland-Altman theory analysis and the commercial Pulse Oximetry Sensor test results, the root mean square error of the algorithm result was calculated as 2.06 beat/min. It indicated that the algorithm could realize the non-contact measurement of heart rate and lay the foundation for the remote and non-contact measurement of multi-parameter physiological measurements.
Transit time flow measurement (TTFM),which is independent of vessel size and shape, has been considered to be an easy, reproducible and non-invasive method to assess the hemodynamic characteristics. Moreover, current studies have shown that TTFM has clinical application in identifying the function of grafted vessel and prognosis. Researchers have proved some reliable indicators for the function of grafted vessel as follows: mean graft flow (MGF) > 15 ml/min, diastolic flow (DF) >50% and pulsatility index (PI)<3 or 5. This article focuses on the review of clinical application and research progress of TTFM in CABG.
This paper presents the preliminary design of data acquisition system of a portable uroflowmeter. The system uses double-hole cantilever pressure sensor. The signal is transferred to ATmega644PA microprogrammed control unit (MCU), converted by A/D (analog to digital) convertor. Then the further data are processed and get the corresponding relationship of weight-time and two curves of urine flow and urinary flow rate. In the measurement accuracy of the device about urine flow, two factors about the placement and height of the data acquisition are analyzed to show the accuracy of the equipment through the Origin 8.0 data analysis software. The design is characterized by low cost and high speed of data collection, real-time, high accuracy.
In order to quantitatively evaluate the performance of dry electrode for fabric surface bioelectricity, a set of active measuring devices that can simulate electrocardiosignal has been developed on the basis of passive system by our group. Five Ag/AgCl fabric dry electrodes were selected to test and evaluate the devices. The results show that the deviation ratios of peak time interval of the five electrodes are all less than 1%. The maximum voltage amplitude decay rate is 7.2%, and the noise amplitudes are lower than 0.004 mV. The variable coefficient of peak time offset is less than 8%. The variable coefficient of voltage amplitude is less than 2%. The variable coefficient of noise amplitude is less than 10%. Research shows the devices has good repeatability and stability in measuring the simulated electrocardiosignal. The active measuring devices proposed in this paper can provide a new method for performance evaluation and standard formulation of surface bioelectricity dry electrode.
ObjectiveThrough the analysis on outcome measurements in domestic and overseas randomized controlled trials (RCTs) of smoking cessation, this study aimed to provide references for clinical trial design in the future. MethodsWe searched CNKI, WanFang Data, VIP, PubMed, EMbase, ScienceDirect and SpringLink databases to collect RCTs regarding smoking cessation from January 1998 to December 2013. Two reviewers screened literature according to the inclusive and exclusive criteria, extracted the data, and analyzed the outcome measurements of included RCTs. ResultsA total of 68 RCTs regarding smoking cessation were included. As for the baseline measurements, the frequency from high to low were age, sex, daily cigarette, smoking duration, Fagerstrom Test For Nicotine Dependence (FTND), race and education, etc.; there were significant differences of race, education level, smoking duration, smoking, starting age of smoking, attempts of trying to stop smoking, the presence of other basic disease, FTND and quit date between English and Chinese RCTs (all P<0.05). As for efficacy measurements, the continuous abstinence rate (77.8%) was mainly adopted in Chinese RCTs, while point abstinence rate (95.1%) and continuous abstinence rate (82.9%) was selected in English RCTs. As for the follow-up measurements, 22.1% of the included RCTs did not report it, 70.6% of the RCTs reported abstinence rate, and the follow-up time in Chinese RCTs was shorter than that in the English RCTs (P<0.05). ConclusionThe selection of outcome measurements is significantly different among RCTs regarding smoking cessation, the Chinese RCTs are inferior to English RCTs, and these are needed to be improved in the future clinical trials.
Objective To summarize the clinical application of esophagogastrostomy with layered anastomosis and to observe the healing quality of anastomotic stoma in animal experiments. Methods One thousand and twenty-four patients suffered from carcinoma of esophagus or carcinoma of gastric cardia had undergone esophagogastrostomy by layered anastomosis with absorbable suture. Twenty-four experimental dogs (adult male healthy hybrid dogs) were divided into two groups: the experimental group and the control group. The former (experimental group) underwent the layered anastomosis, the diameter of esophagogastric stoma and the length and depth of stomal scar were measured under anesthesia in both groups on 5th,8th,14th,and 42th postoperative day, respectively. So were done the histological measurement, such as the count infiltrating inflammatory cells, the proliferation of blood capillary and other cells. And the cytokines related to wound healing (LsAB technique) such as epidermal growth factor(EGF), transforming growth factor-beta 1 (TGF-beta 1) were detected, either. Results One thousand and twenty-four patients had no anastomotic leakage. There were only 6 patients suffered from mild anastomotic stricture, and they got well after one dilatation. The results of the measurement of 24 experimental dogs revealed that, in the experimental group, the mucosa was in good connecting condition, had a soften anastomotic stoma and a thin scar. The counts of inflammatory cells and fibroblast showed more in number at the early time after operation (Plt;0.05), while showed less in number at the advanced time of operation (Plt;0.05). In the control group, however, the mucosa were in a bad connecting condition, the scar was thicker, and the muscle layer was frequently exposed. The counts of inflammatory cells and fibroblast were fewer at the early time after operation, however, they had a clearly tendency of increasing at the anaphase after the operation. On the cytokines related to the healing of wound in the experimental group, there was a high expression and activity at the early period. There were a little expression up to postoperative 42 d. Whereas, in the control group, there had a low expression level,increased clearly on postoperative 8 d, and still a higher expression up to postoperative 42 d. Conclusions The esophagogastrostomy by layered anastomosis has a high healing quality with a thin scar. The proliferation of cells and the expression of growth factors benefits the normal healing of wound by first intention.