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.
Objective To explore the anatomical parameters of the cervical uncinate process “inflection point” through cervical CT angiography (CTA) and MRI measurements, offering a reliable and safe anatomical landmark for anterior cervical decompression surgery. Methods A retrospective analysis was conducted on the cervical CTA and MRI imaging data of normal adults who met the selection criteria between January 2020 and January 2024. The CTA dataset included 326 cases, with 200 males and 126 females, aged 22-55 years (mean, 46.7 years). The MRI dataset included 300 cases, with 200 males and 100 females, aged 18-55 years (mean, 43.7 years). Based on the CTA data, three-dimensional models of C3-C7 were constructed, and the following measurements were obtained from the superior view: uncinate process “inflection point” to vertebral artery distance (UIVD), uncinate process tip to vertebral artery distance (UTVD), uncinate process “inflection point” to “inflection point” distance (UID), uncinate process long-axis to sagittal angle (ULSA), and uncinate process “inflection point” to transverse foramen-sagittal angle (UITSA). From the anterior view, the anterior uncinate process to sagittal angle (AUSA) was measured. From the posterior view, the posterior uncinate process to sagittal angle (PUSA) was measured. Based on the MRI data, uncinate process “inflection point” to dural sac distance (UIDD) and dural sac width (DSW) were measured. The trends in measurement parameters of C3-C7 were observed, and the differences in measurement parameters between genders and between the left and right sides of the same segment were compared, as well as the difference in UID and DSW within the same segment was compared. Results The measurement parameters from C3 to C7 in the CTA data showed a general increasing trend, with no significant difference between the left and right sides within the same segment (P>0.05). The UIVD, UTVD, and UID were greater in males than in females, with significant differences observed in the UIVD and UTVD at C3 and C6 and UID at C3, C6, and C7 (P<0.05). The MRI measured DSW showed a general increasing trend from C3 to C7, and the DSW at C6 was greater in females than in males, with a significant difference (P<0.05). The UIDD showed a gradual decreasing trend, with the smallest value at C6. There was no significant difference between males and females or between the left and right sides within the same segment (P>0.05). The UID was greater than the DSW at C3-C7, and the differences were significant (P<0.05). ConclusionThe uncinate process “inflection point” is a constant anatomical structure located at the anteromedial aspect of the uncinate process tip and laterally to the dural sac. It maintains a certain safe distance from the vertebral artery. As a decompression landmark in anterior cervical spine surgery, it not only ensures surgical safety but also guarantees complete decompression.
ObjectiveTo explore the anthropometric changes of the auricle after auricular cartilage unfolding in moderate concha-type microtia patients, so as to provide the basis to help evaluate surgical timing and prognostic.MethodsA total of 33 children with moderate concha-type microtia, who were treated with auricular cartilage unfolding between October 2016 and September 2018 and met the inclusive criteria, were included in the study. There were 24 boys and 9 girls with an average age of 1.4 years (range, 1-3 years). Sixteen cases were left ears and 17 cases were right ears. The follow-up time was 12-23 months (mean, 17.5 months). The affected auricular detailed structures were observed and quantitatively analyzed before operation and at immediate after operation. The width, length, and perimeter of auricle before operation and at immediate after operation and at last follow-up were noted with three dimensional-scanning technology. The normal auricle was noted as control.ResultsThere were (7.5±1.0) and (11.3±0.8) structures of the affected auricle at pre- and post-operation, respectively, showing significant difference between pre- and post-operation (t=23.279, P=0.000). The length, width, and perimeter of the affected auricle constantly increased after operation, and there were significant differences between pre-operation and immediately after operation and between immediately after operation and last follow-up (P<0.05). The differences of length, width, and perimeter of the affected auricle between immediately after operation and last follow-up were (3.13±1.44), (2.44±0.92), and (8.50±3.76) mm, respectively. And the differences of length, width, and perimeter of the normal auricle between pre-operation and last follow-up were (3.16±1.54), (2.35±0.86), and (9.79±4.60) mm, respectively. There was no significant difference in the differences of length, width, and perimeter between the affected auricle and the normal auricle (P>0.05).ConclusionThe auricular cartilage unfolding in treatment of the moderate concha-type microtia can receive more ear structures and increase auricle sizes, which make it possible for free composite tissue transplantation. In addition, the affected and the contralateral normal auricles have a very similar growth rate and it offers the theoretical foundation for the early treatment for moderate concha-type microtia.
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.
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.
Accurate measurements of voltage and current from electrosurgery are the basis of development of electrosurgery with feedback function. We, therefore, developed a parameter measurement system based on PC, with high voltage and current from electrosurgery being sensed with transformers, amplified, filtered, transformed into single-ended signals, and then into RMS signals. The root mean square (RMS) signals were transformed into digital signals through DAQ card and the data was processed in PC with Labview. The process included sampling, displaying and storage. The experiment results indicated that the measurement system could measure the output parameters from electrosurgery steadily and correctly so that the development of the system has been successful. It can be the basis of development of embedded parameters measurement system and can provide accurate feedback information for intellectual electrosurgery.
ObjectiveAntiviral treatments could benefit chronic hepatitis B (CHB) patients with the regression or improvement of liver fibrosis. However, the degree of dynamic change of liver fibrosis for patients who had not received antiviral treatment remained to be studied. The current study aimed to observe the long-term variation of liver stiffness measurement (LSM), virological and biochemical response on patients without standard antiviral therapy.MethodsA total of 220 patients who were diagnosed with chronic HBV infection, who had not reached the standard of antiviral therapy, and completed a follow-up date of over 2 years in the First Affiliated Hospital of Xi’an Jiaotong University from 2012 to 2018 were retrospectively enrolled. According to the changes of LSM in baseline and follow-up period, the patients were divided into regression group, non-progressive group, and progressive group. The virological and biochemical characteristics of each group were analyzed.ResultsAmong the 220 patients, 153 patients (69.5%) had no progress in LSM degree. Alanine aminotransferase (ALT), HBV DNA, and HBsAg in a few patients increased or slightly decreased, while the vast majority remained in a relatively stable state. 89.5% (137/153) of the non-progressive patients were in grade F0. In addition, 58 patients showed spontaneous improvement with a decreasing rate of 0.460 kPa per year. Patients with ALT of 1-2 ULN had a statistically significant decrease in LSM improvement compared to patients with normal ALT. 82.8% of the LSM-improving patients showed baseline LSM of F1-F3. Only 9 patients showed LSM deterioration, however, which could not be explained by virus replication or necroinflammatory activity. ConclusionsFor patients unsatisfying standard antiviral therapy, most patients with baseline LSM of F0 grade fail to progress, and patients with baseline LSM of F1-F3 show a decrease during follow-up, LSM progression occurs in 4.1% of patients.
Objective To propose a lightweight end-to-end neural network model for automated Korotkoff sound phase recognition and subsequent blood pressure (BP) measurement, aiming to improve measurement accuracy and population adaptability. Methods We developed a streamlined architecture integrating depthwise separable convolution (DSConv), multi-head attention (MHA), and bidirectional gated recurrent unit (BiGRU). The model directly processes Korotkoff sound time-series signals to identify auscultatory phases. Systolic BP (SBP) and diastolic BP (DBP) were determined using Phase Ⅰ and PhaseⅤdetections, respectively. Given the clinical relevance of phase Ⅳ for specific populations (e.g., children and pregnant women, denoted as DBPIV), BP values from this phase were also recorded. Results The study enrolled 106 volunteers with 70 males, 36 females at mean age of (40.0±12.0) years. The model achieved 94.25% phase recognition accuracy. Measurement errors were (0.1±2.5) mm Hg (SBP), (0.9±3.4) mm Hg (DBPIV), and (0.8±2.6) mm Hg (DBP). Conclusion Our method enables precise phase recognition and BP measurement, demonstrating potential for developing population-adaptive blood pressure monitoring systems.
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%.
Most of the existing near-infrared noninvasive blood glucose detection models focus on the relationship between near-infrared absorbance and blood glucose concentration, but do not consider the impact of human physiological state on blood glucose concentration. In order to improve the performance of prediction model, particle swarm optimization (PSO) algorithm was used to train the structure paramters of back propagation (BP) neural network. Moreover, systolic blood pressure, pulse rate, body temperature and 1 550 nm absorbance were introduced as input variables of blood glucose concentration prediction model, and BP neural network was used as prediction model. In order to solve the problem that traditional BP neural network is easy to fall into local optimization, a hybrid model based on PSO-BP was introduced in this paper. The results showed that the prediction effect of PSO-BP model was better than that of traditional BP neural network. The prediction root mean square error and correlation coefficient of ten-fold cross-validation were 0.95 mmol/L and 0.74, respectively. The Clarke error grid analysis results showed that the proportion of model prediction results falling into region A was 84.39%, and the proportion falling into region B was 15.61%, which met the clinical requirements. The model can quickly measure the blood glucose concentration of the subject, and has relatively high accuracy.