Epileptic detection in single and multi-lead EEG signals using persistent homology based on bi-directional weighted visibility graphs.

Epilepsy is a widespread neurological disorder, and its recurrence and suddenness are making automatic detection of seizure an urgent necessity. For this purpose, this paper performs topological data analysis (TDA) of electroencephalographic (EEG) signals by the medium of graphs to explore the potential brain activity information they contain. Through our innovative method, we first map the time series of epileptic EEGs into bi-directional weighted visibility graphs (BWVGs), which give more comprehensive reflections of the signals compared to previous existing structures. Traditional graph-theoretic measurements are generally partial and mainly consider differences or correlations in vertices or edges, whereas persistent homology (PH), the essential part of TDA, provides an alternative way of thinking by quantifying the topology structure of the graphs and analyzing the evolution of these topological properties with scale changes. Therefore, we analyze the PH for BWVGs and then obtain the two indicators of persistence and birth-death for homology groups to reflect the topology of the mapping graphs of EEG signals and reveal the discrepancies in brain dynamics. Furthermore, we adopt neural networks (NNs) for the automatic detection of epileptic signals and successfully achieve a classification accuracy of 99.67% when distinguishing among three different sets of EEG signals from seizure, seizure-free, and healthy subjects. In addition, to accommodate multi-leads, we propose a classifier that incorporates graph structure to distinguish seizure and seizure-free EEG signals. The classification accuracies of the two subjects used in the classifier are as high as 99.23% and 94.76%, respectively, indicating that our proposed model is useful for the analysis of EEG signals.

Multivariate joint order recurrence networks for characterization of multi-lead ECG time series from healthy and pathological heartbeat dynamics.

Analysis of nonlinear dynamic characteristics of cardiac systems has been a hot topic of clinical research, and the recurrence plots have earned much attention as an effective tool for it. In this paper, we propose a novel method of multivariate joint order recurrence networks (MJORNs) to evaluate the multi-lead electrocardiography (ECG) time series with healthy and psychological heart states. The similarity between time series is studied by quantifying the structure in a joint order pattern recurrence plot. We take the time series that corresponds to each of the 12-lead ECG signals as a node in the network and use the entropy of diagonal line length that describes the complex structure of joint order pattern recurrence plot as the weight to construct MJORN. The analysis of network topology reveals differences in nonlinear complexity for healthy and heart diseased heartbeat systems. Experimental outcomes show that the values of average weighted path length are reduced in MJORN constructed from crowds with heart diseases, compared to those from healthy individuals, and the results of the average weighted clustering coefficient are the opposite. Due to the impaired cardiac fractal-like structures, the similarity between different leads of ECG is reduced, leading to a decrease in the nonlinear complexity of the cardiac system. The topological changes of MJORN reflect, to some extent, modifications in the nonlinear dynamics of the cardiac system from healthy to diseased conditions. Compared to multivariate cross recurrence networks and multivariate joint recurrence networks, our results suggest that MJORN performs better in discriminating healthy and pathological heartbeat dynamics.

Non-invasive manipulation scheme of spherical particle in viscous fluids in a tube based on acoustic radiation force.

A theoretical solution of the acoustic radiation force (ARF) on spherical particles by an arbitrary beam in viscous fluids in a tube is proposed. Based on the parametric design with the purpose of promoting calculi in the urinary system, theoretical solutions and finite element simulations are carried out, which mutually confirm the accuracy and feasibility of the scheme. The variation law of the ARF with adjustable parameters, such as incident angle, frequency spectrum, particle radius, tube radius, and viscosity, is studied, and the mechanism of the variation law is explained. This solution lays a foundation for the application of non-contact and non-invasive in-tube manipulation based on ARF in medicine and life sciences.

A method to locate spatial distribution of scattering centers from ultrasonic backscatter signal.

The purpose of this work is to find a method to locate the scattering centers in spatial domain; by using this information, the mean scatter spacing (MSS) can be estimated, and the spatial information is the one-dimensional imaging of scattering centers. This paper presents a method that can locate the scattering centers in spatial domain robustly and automatically. By incorporating it with fast Fourier transformation, the MSS can be estimated. The three foremost processes, matched filtering, envelope extraction, and peak reconstruction, are incorporated in the authors' algorithm. Monte Carlo simulations demonstrate that the proposed method is a robust one to locate scattering centers in spatial domain, and has a better performance than spectrum-based MSS estimation techniques. Especially exploited in estimating MSS which varies from 0.6 to 1.2 mm in the range of human mean trabecular bone spacing, the proposed method shows great potential in medical use. Simple but widely used phantom experiments demonstrate that the proposed algorithm has the capacity to locate scattering centers in spatial domain.

[Software Design for a Portable Ultrasound Bone Densitometer].

In order to meet the requirements of ultrasound bone density measurement, we designed a sofware based on Visual Studio C+ + 2008. The software includes interface design, acquisition and control, data processing and parameter extraction, data storage and printing. Excellent human-computer interface (HCI) will give users a convenient experience. Auto gain control (AGC) and digital filter can improve the precision effectively. In addition, we can observe waveform clearly in real time. By using USB communication, we can send control commands to the acquisition and get data effectively, which can shorten the measuring time. Then we calculated the speed of sound (SOS) and broadband ultrasound attenuation (BUA). Patients' information can be accessed by using XML document. Finally, the software offers printing function.

[An improved software design of ultrasound bone densitometer].

In order to meet the requirements of ultrasound bone density measurement, we proposed a software solution to improve the accuracy and speed of measurement of bone mineral density of the ultrasound bone densitometer. We used a high-speed USB interface chip FT232H, along with a high-speed AD converter chip to calculate speed of sound (SOS), broadband ultrasound attenuation (BUA ) and other bone density parameters in the PC software. This solution improved the accuracy of the measurement data, reduced the measurement time and increased the quality of the displayed image. It is well concluded that the new software can greatly improve the accuracy and transmission speed of bone density measurement data through a high-speed USB interface and a software data processing technology.

Circ_0007351 Exerts an Oncogenic Role In Colorectal Cancer Depending on the Modulation of the miR-5195-3p/GPRC5A Cascade.

Circular RNAs (circRNAs) exert critical functions in colorectal cancer development. In this work, we wanted to elucidate the functional role and regulatory mechanism of circ_0007351 in colorectal cancer. For quantification of circ_0007351, microRNA (miR)-5195-3p and G Protein-coupled receptor class C group 5 member A (GPRC5A), a qRT-PCR, immunoblotting or immunohistochemistry assay was performed. Effects of circ_0007351/miR-5195-3p/GPRC5A cascade were evaluated by determining cell viability, proliferation, colony formation, motility, and invasion. Relationships among variables were assessed by dual-luciferase reporter assay. Animal studies were performed to evaluate circ_0007351's function in the growth of xenograft tumors. Circ_0007351 was markedly up-regulated in colorectal cancer tissues and cells. Down-regulation of circ_0007351 hindered cell growth, migration and invasiveness. Also, circ_0007351 depletion exerted a suppressive function in colorectal cell xenograft growth in vivo. Mechanistically, circ_0007351 sponged miR-5195-3p to sequester miR-5195-3p. Reduction of available miR-5195-3p neutralized the effects of circ_0007351 down-regulation on cell phenotypes. MiR-5195-3p directly targeted and inhibited GPRC5A. Circ_0007351 regulated GPRC5A expression by sponging miR-5195-3p. Moreover, the effects of circ_0007351 down-regulation on cell functional phenotypes were due to in part the reduction of GPRC5A expression. Our findings show that circ_0007351 down-regulation impedes proliferation, motility, and invasiveness in colorectal cancer cells at least in part via the regulation of the miR-5195-3p/GPRC5A cascade, highlighting that circ_0007351 inhibition may have a potential therapeutic value for colorectal cancer.

[Development of a multi-parameter and low-power monitor].

The development of a multi-parameter and low-power monitor is discussed in this paper. The monitor equips an AT91SAM9261 microprocessor as its main controller and contains multi-parameter signal collecting module, data storage module, human-computer interaction module, online communications module and printing module. The whole software system is based on the uC/OS-II equipped by uC/GUI, which is used to facilitate interface design. At the same time, for the convenience of data management, a YAFFS2 file system is transplanted. The monitor has the advantages of low consuming, low cost, real-time control and multi-functions.

Expression level of miRNA in the peripheral blood of patients with multiple myeloma and its clinical significance.

OBJECTIVE: To investigate the expression level of serum miRNA-192-5p and its clinical value in the diagnosis and care of patients with multiple myeloma (MM). METHODS: Eighty-eight patients with MM admitted to our hospital from June 2017 to April 2020 were selected as the observation group. In addition, 70 patients who received osteoporosis testing in our hospital in the corresponding period but were excluded from having MM and haematological malignancy were selected as the control group. The relative expression level of serum miRNA-192-5p was detected. The expression level of serum miRNA and its correlation with patient-related clinical parameters were compared and analyzed. The ROC curve was used to analyze its diagnostic efficacy for MM. RESULTS: The relative expression level of serum miRNA-192-5p in MM patients was remarkably lower than that in the control group (P < 0.05); the AUC area of serum miRNA-192-5p in patients with a diagnosis of MM was 0.853, with a cutoff value of 0.72, the sensitivity of 86.30%, and the specificity of 81.20%, P = 0.030. The relative expression level of miRNA-192-5p in the serum of patients with high ß2-MG and creatinine levels was markedly reduced compared to that in patients with low ß2-MG levels (P < 0.05); the relative expression level of miRNA-192-5p in the serum of patients with low hemoglobin and albumin levels was markedly reduced compared to that in patients with normal hemoglobin and albumin (P < 0.05); and there was significantly negative correlation between the relative expression level of miRNA-192-5p in the serum of MM patients and IgG and IgA levels, respectively (P < 0.05). CONCLUSION: miRNA-192-5p may serve as an auxiliary diagnostic tool in the diagnosis of MM. Furthermore, because there is certain correlation between serum miRNA-192-5p and MM progression and prognosis, it may be regarded as a novel marker for MM monitoring.

Antitumor activity and toxicological properties of doxorubicin conjugated to [alpha],[beta]-poly[(2-hydroxyethyl)-L-aspartamide] administered intraperitoneally in mice.

A polymer-drug conjugate was developed by conjugating doxorubicin (DOX) to [alpha],[beta]-poly[(2-hydroxyethyl)-L-aspartamide] (PHEA) with a succinic spacer. The suitability of PHEA-DOX in intraperitoneal chemotherapy was investigated both in vitro and in vivo. The results showed that the release rate of DOX from PHEA-DOX in S180 ascites was faster than that in mouse serum or in buffer solutions. An in-vivo antitumor study revealed that PHEA-DOX was more effective than DOX against solid S180 tumor after intraperitoneal injection at the same dose of 10 or 15 mg (DOX eq.)/kg, respectively. At a high dose of 28 mg (DOX eq.)/kg, which was lethal for free DOX to mice, PHEA-DOX could inhibit 61.5% of solid S180 tumor growth and markedly prolonged the survival time of ascetic S180-bearing mice. The toxicological effects of PHEA-DOX injected intraperitoneally in normal mice were assessed by using LD50, body weight increment, electrocardiography, blood biochemical indices, and myocardium histology, giving evidence that PHEA-DOX displayed considerably reduced systemic and cardiotoxicity compared with free DOX. All results suggest that PHEA-DOX has great potential for intraperitoneal chemotherapy because of its high therapeutic effects and few adverse side effects.

[Mosaicing for medical microscopic images based on estimation and compensation].

Image mosaicing can solve the problem that only very limited field of view is available when highly magnifying lens is used in microscope imaging. This paper puts forward an equation of the system's influence to the grayscale distribution of the medical microscopic images, based on the analysis of the influence. Then, by the system equation and the accurate registration equation, the least-squares optimization error function can be formulated. By these equations, a set of transcendental equations is formed. We can estimate the system's influence on the gray-level of the images by singular-value decomposition (SVD), based on the equations set, and compensating for it. This permits image mosaicing seamlessly, without lowering the speed.

[A wireless ECG monitor based on ARM].

This paper presents a novel monitor which uses ARM controller AT91SAM7S64 as its main processor, LCM (Liquid Crystal Display Module) for displaying ECG waves, SD (Secure Digital memory) card for data storage and RF module PTR8000 for radio data transmission. This portable monitor boasts alarm function for abnormality and can provide dynamic ECG monitoring for patients.

[A design of a portable acquistion system for autonomic nervous function data].

In this paper, a design of the portable acquisition system for autonomic nervous function data based on the microcontroller is introduced. The system contains an electrocardiogram amplifier and an AD convertor, using SD memory card as its storage device and thus it can record data for a longer time and exchange data with PC easily. The system with a simple structure realizes its miniaturization and low energy consumption.

[Dynamic three-dimensional reconstruction of tissue Doppler ultrasound heart images].

Traditional 3D ultrasound reconstruction system can just depict 3D anatomical structure, so it is very difficult to give an accurate assessment of the functionality of the heart. In this study, a dynamic 3D reconstruction method of tissue Doppler ultrasound heart images is set up based on the combination of 3D reconstruction and tissue Doppler imaging technique. Dynamic 3D acceleration field of heart movement is reconstructed to supply a new approach of accurate assessment of functionality of the heart. The key problem of vector interpolation and fusion imaging in the process of acceleration vector field reconstruction is solved. The 3D acceleration field of heart movement and anatomical structure is reconstructed separately from the original tissue Doppler acceleration images and showed in the same field. The experimental results testified that the 3D space relationship of acceleration and anatomical structure is correct and this method can supply more information for the assessment of heart functionality.

[A review of interpolation in multi-dimensional reconstruction of medical images].

Image interpolation techniques were widely applied in medical imaging for image generation and post processing. Firstly, traditional interpolation methods were listed out in the details of shape-based interpolation and dynamic elastic registration interpolation. Secondly, the characteristics, development and problems in interpolation of rotary scanning ultrasonic cardiac images were analyzed. The relation between interpolation and registration was stated. The analysis indicated that excellent methods in rotary scanning interpolation should be registration-based methods. At last, several evaluation methods about images interpolation were discussed.

[Dynamic 3D reconstruction of Doppler flow ultrasound medical images].

OBJECTIVE: To implement dynamic 3D reconstruction of ultrasonic flow images by the technique of 3D reconstruction of ultrasonic medical images combined with Doppler flow imaging method. METHOD: Through analyzing the color-coded mode of Doppler flow images and utilizing the Color Bar in DFI provided by ultrasound system, the information of anatomical structure and blood flow velocity were separated from original DFI images. Then 3D reconstruction of blood velocity and its fusion display with 3D anatomical structure was implemented. RESULT: Clinical experiments showed that in vivo blood flow in heart cavity could be shown in 3D space simultaneously with anatomical structure of the heart, and the relationship between them was consistent with cardiology. The images rendered in such a way could show more medical information than that in traditional methods. CONCLUSION: The combination of 3D reconstruction of ultrasonic medical images and Doppler imaging technique could realize functional 3D reconstruction of ultrasonic medical images so as to give more medical information. It would have great potential application and present a new future for ultrasonic medical imaging.

Complexity and characteristic frequency studies in ECG signals of mice based on multiple scale factors.

Existing methods of physiological signal analysis based on nonlinear dynamic theories only examine the complexity difference of the signals under a single sampling frequency. We developed a technique to measure the multifractal characteristic parameter intimately associated with physiological activities through a frequency scale factor. This parameter is highly sensitive to physiological and pathological status. Mice received various drugs to imitate different physiological and pathological conditions, and the distributions of mass exponent spectrum curvature with scale factors from the electrocardiogram (ECG) signals of healthy and drug injected mice were determined. Next, we determined the characteristic frequency scope in which the signal was of the highest complexity and most sensitive to impaired cardiac function, and examined the relationships between heart rate, heartbeat dynamic complexity, and sensitive frequency scope of the ECG signal. We found that all animals exhibited a scale factor range in which the absolute magnitudes of ECG mass exponent spectrum curvature achieve the maximum, and this range (or frequency scope) is not changed with calculated data points or maximal coarse-grained scale factor. Further, the heart rate of mice was not necessarily associated with the nonlinear complexity of cardiac dynamics, but closely related to the most sensitive ECG frequency scope determined by characterization of this complex dynamic features for certain heartbeat conditions. Finally, we found that the health status of the hearts of mice was directly related to the heartbeat dynamic complexity, both of which were positively correlated within the scale factor around the extremum region of the multifractal parameter. With increasing heart rate, the sensitive frequency scope increased to a relatively high location. In conclusion, these data provide important theoretical and practical data for the early diagnosis of cardiac disorders.

Single-lead fetal electrocardiogram estimation by means of combining R-peak detection, resampling and comb filter.

Minimal detecting electrodes are preferred to miniaturise fetal electrocardiogram (fECG) monitoring devices for application in non-clinical environments. In this paper, a new method to estimate the fECG using a single-lead abdominal signal is introduced. In this method, for a preprocessed abdominal ECG recording, we follow a multi-step procedure to estimate the fECG signal. First, the locations of the maternal R-peaks are detected. Each R-R interval in the abdominal signal is resampled to have the same number of samples by changing its corresponding sampling frequency. A comb filter, which has teeth that coincide with the harmonics of the maternal electrocardiogram (mECG), is applied to the resampled signal. Each R-R interval in the filtered signal is resampled again to recover its original sampling frequency, and the mECG signal is obtained. This mECG signal is subtracted from the abdominal signal, and the residual signal is considered to be a primary estimate of the fECG signal. The same procedure can be applied to the residual signal to enhance the fECG signal. Compared to two other single-lead-based methods, singular value decomposition and nonlinear state-space projection, the proposed method has shown improved robustness and fidelity in restoration of the fECG during testing with synthetic ECG signals and a real fetal ECG database from MIT-BIH PhysioBank.

Vector Interpolation Method in Three-dimensional Reconstruction of Tissue Doppler Echocardiography.

A new method of vector interpolation in three-dimensional reconstruction of tissue Doppler echocardiography is developed and applied to the clinical research. Both the amplitude and direction information of functional parameters, such as velocity or acceleration, in tissue Doppler images is utilized to reconstruct dynamic three-dimensional vector field of myocardial tissue motion. The reconstructed three-dimensional field tissue motion can be visualized simultaneously with the three-dimensional anatomical structure to express the correlation between them. Clinical human experiments show that reconstructed results are consistent with the physiological characteristics of the heart. This method may have potential application in the study of cardiac electrophysiology.