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.
Crouzon s syndrome is one of the craniofacial dysostosis. It not only presents midface retrusion but also obstructs the air way. There were much more effective changes on speech and velopharyngeal function following LeFort Ⅲ maxillary advancement. In our study, 9 cases underwent maxillary advancement in the last seven years. All patients in this series underwent serial cephalometric study before and after maxillary advancement. The results showed that the distance from the posterior nasal spine to the posterior pharyngeal wall on the posterior pharyngeal wall on the lateral cephalograms reached 18.89mm which was 9.30mm more larger than that of the preoperative distance in average.The angle formed by the soft palate and the hard palate reached 159.4 degree which was 16 degree larger than the preopertive angle 144.6 degree. Clinically, improvement of phonation was very obvious.
In this paper, a new probe is proposed for the in vivo dielectric measurement of anisotropic tissue in radio frequency band, which could accomplish the dielectric measurement in perpendicular directions by one operation. The simulative studies are performed in the frequency range from 1–1 000 MHz in order to investigate the influence of probe dimension on the energy coupling and sensitivity of measurement. The suitable probe is designed and validated for the actual measurement in this frequency band. According to the simulation results, the energy coupling of the probe could be kept below –12 dB in the frequency range from 200–400 MHz with high sensitivity of measurement for the dielectric properties of anisotropic tissue. That indicates the new type of probe has the potential to achieve the dielectric measurement of anisotropic tissue in radio frequency band and could avoid the measurement error by multi-operations in the conventional method. This new type of probe could provide a new method for the in vivo dielectric measurement of anisotropic tissue in radio frequency band.
The velocity of blood in vessels is an important indicator that reflects the microcirculatory status. The core of the measurement technology, which is based on spatiotemporal (ST) image, is to map the cell motion trace to the two-dimensional ST image, and transfer the measurement of flow velocity to the detection of trace orientation in ST image. This paper proposes a trace orientation measurement algorithm is based on Randomized Hough Transformation and projection transformation, and it is able to estimate trace orientation and flow velocity in noisy ST images. Experiments showed that the agreement between the results by manual and by the proposed algorithm reached over 90%.
ObjectiveTo compare home blood pressure monitoring (HBPM) versus ambulatory blood pressure monitoring (ABPM) versus office blood pressure monitoring (OBPM) in diagnosis and management of hypertension, and to find the optimal blood pressure measurement and management.MethodsThe following were compared among three BP monitoring, such as cost-effectiveness, prognostic value of target organ damage (TOD), predictive value of the progress in chronic kidney disease (CKD) and blood pressure variety (BPV). ResultsCompared to OBPM, ABPM was the most cost-effective method in the primary diagnosis of hypertension, but HBPM was the optimal method in long-term and self-management in hypertension. In hypertensives, compared to OBPM, HBPM and ABPM, especially HBPM, had a stronger predictive value for cardiovascular events, stroke, end-stage renal dysfunction (ESRD) and all-cause mortality. In hypertensives with renal dysfunction, controlling HBPM and ABPM, especially controlling ABPM, was an effective way to slow the progress in renal dysfunction, to decrease cardiovascular events, and to decrease the need of dialysis. All BPV derived from OBPM, ABPM and HBPM had a predictive significance of cardiovascular events, and HBPM BPV performed the best.ConclusionCompared to OBPM, ABPM is the best method in primary diagnosis of hypertension and BP control in CKD patients, while HBPM is the best method in predicting and in evaluating BPV, as well as in long-term and self-management in hypertension.
Dyspnea is the most common symptom in patients with acute heart failure syndrome (AHFS), and relieving dyspnea is an important goal in clinical practice, clinical trials and new drug regulatory approval. However, in clinical and scientific research, there is still no consensus on how to evaluate dyspnea, and there is still a lack of unified measurement methods. This article introduces the pathophysiological mechanism of dyspnea in acute heart failure, the measuring time of dyspnea, the posture of patients during measurement, the measuring conditions, and the common measurement methods of dyspnea in clinical trials and their advantages and disadvantages, so as to provide references for the selection of measurement methods of dyspnea in clinical trials of acute heart failure.
Objective To recognize the different phases of Korotkoff sounds through deep learning technology, so as to improve the accuracy of blood pressure measurement in different populations. Methods A classification model of the Korotkoff sounds phases was designed, which fused attention mechanism (Attention), residual network (ResNet) and bidirectional long short-term memory (BiLSTM). First, a single Korotkoff sound signal was extracted from the whole Korotkoff sounds signals beat by beat, and each Korotkoff sound signal was converted into a Mel spectrogram. Then, the local feature extraction of Mel spectrogram was processed by using the Attention mechanism and ResNet network, and BiLSTM network was used to deal with the temporal relations between features, and full-connection layer network was applied in reducing the dimension of features. Finally, the classification was completed by SoftMax function. The dataset used in this study was collected from 44 volunteers (24 females, 20 males with an average age of 36 years), and the model performance was verified using 10-fold cross-validation. Results The classification accuracy of the established model for the 5 types of Korotkoff sounds phases was 93.4%, which was higher than that of other models. Conclusion This study proves that the deep learning method can accurately classify Korotkoff sounds phases, which lays a strong technical foundation for the subsequent design of automatic blood pressure measurement methods based on the classification of the Korotkoff sounds phases.
Patient-reported outcome measures (PROM) measure attribute studies refer to studies conducted by investigators to validate the measurement attributes of PROM. The consensus-based standards for the selection of health measurement instruments (COSMIN), an international consensus standard for the selection of health measurement instruments, divides this attribute into three aspects: reliability, validity and responsiveness, and adds interpretability as an additional important feature for evaluating PROM. The purpose of this paper is to introduce the verification methods and principles of the three major measurement attributes in the COSMIN consensus, as well as the significance and direction of interpretability evaluation, and to provide international methodological experience and reference for the development of high-quality PROM psychometric attribute verification in China.