[Negative Poisson's Ratio Material Structure Based on 3D Printing and Its Application in Medical Field].

First of all, the overall framework of 3D printing is briefly introduced, including the basic principles of the additive manufacturing process, the classification and summary of the seven processes. Secondly, the common negative Poisson's ratio structure is introduced. Compared with the conventional structure, the negative Poisson's ratio structure has stronger energy absorption capacity, better fracture resistance and better indentation resistance, which are its advantages in printing manufacturing. Finally, 3D printing, the application of negative Poisson's ratio structure and the combination of the two are introduced from the different perspective of medical field, for example, the application of cardiovascular stent, biomedical material structure preparation, and lumbar disc implants. This paper suggests that the structural design of negative Poisson's ratio in 3D printing guides the development of new application directions in the medical field. Negative Poisson's ratio materials have a wide range of applications, not only in the medical field but also in mechanical equipment, automotive manufacturing, aerospace, and other high-tech industries.

Myocardial infarction detection method based on the continuous T-wave area feature and multi-lead-fusion deep features.

Objective.Myocardial infarction (MI) is one of the most threatening cardiovascular diseases. This paper aims to explore a method for using an algorithm to autonomously classify MI based on the electrocardiogram (ECG).Approach.A detection method of MI that fuses continuous T-wave area (C_TWA) feature and ECG deep features is proposed. This method consists of three main parts: (1) The onset of MI is often accompanied by changes in the shape of the T-wave in the ECG, thus the area of the T-wave displayed on different heartbeats will be quite different. The adaptive sliding window method is used to detect the start and end of the T-wave, and calculate the C_TWA on the same ECG record. Additionally, the coefficient of variation of C_TWA is defined as the C_TWA feature of the ECG. (2) The multi lead fusion convolutional neural network was implemented to extract the deep features of the ECG. (3) The C_TWA feature and deep features of the ECG were fused by soft attention, and then inputted into the multi-layer perceptron to obtain the detection result.Main results.According to the inter-patient paradigm, the proposed method reached a 97.67% accuracy, 96.59% precision, and 98.96% recall on the PTB dataset, as well as reached 93.15% accuracy, 93.20% precision, and 95.14% recall on the clinical dataset.Significance.This method accurately extracts the feature of the C_TWA, and combines the deep features of the signal, thereby improving the detection accuracy and achieving favorable results on clinical datasets.

[Application Status and Prospect of Rehabilitation Assessment Technology].

Rehabilitation assessment is the basis and important part of rehabilitation diagnosis and treatment. At present, clinical evaluation is usually carried out by observation method and scale method. At the same time, researchers monitor patients' physical condition data through sensor system and other equipment as a supplement. The purpose of this study is to review the application and development of objective rehabilitation assessment technology in clinical practice, and to discuss its limitations and strategies to provide reference for related research.

Early diagnosis of coronary microvascular dysfunction by myocardial contrast stress echocardiography.

Coronary microvascular dysfunction (CMD) is one of the basic mechanisms of myocardial ischemia. Myocardial contrast echocardiography (MCE) is a bedside technique that utilises microbubbles which remain entirely within the intravascular space and denotes the status of microvascular perfusion within that region. Some pilot studies suggested that MCE may be used to diagnose CMD, but without further validation. This study is aimed to investigate the diagnostic performance of MCE for the evaluation of CMD. MCE was performed at rest and during adenosine triphosphate stress. ECG triggered real-time frames were acquired in the apical 4-chamber, 3-chamber, 2-chamber, and long-axis imaging planes. These images were imported into Narnar for further processing. Eighty-two participants with suspicion of coronary disease and absence of significant epicardial lesions were prospectively investigated. Thermodilution was used as the gold standard to diagnose CMD. CMD was present in 23 (28%) patients. Myocardial blood flow reserve (MBF) was assessed using MCE. CMD was defined as MBF reserve < 2. The MCE method had a high sensitivity (88.1%) and specificity (95.7%) in the diagnosis of CMD. There was strong agreement with thermodilution (Kappa coefficient was 0.727; 95% CI: 0.57-0.88, p < 0.001). However, the correlation coefficient (r = 0.376; p < 0.001) was not high.

[Research and Application of Smartphone-based Detection System to Immunoassay].

The emergence of smart phones has not only brought extensive changes to people's way of life, but also provided a new research platform for the expansion and application of science and technology. Technicians have combined immunoassay methods with smart phone sensing technology to develop a variety of smartphone-based biological sample analysis and detection sensing systems, promoting the application of immunoassay methods in POCT fields. In this review, we summarize the researches and applications of smart-phone in the field of immune analysis. According to the different sensors and detection objects, these applications can be divided into four aspects: camera-based spectrometer, camera-based enzyme reader, camera-based strip reader and spectrophotometer based on environmental light sensor. This study also briefly discusses some limitations of current smart phone application in immune analysis, and prospects the future applicability of smart phone sensing system.

Free PSA performs better than total PSA in predicting prostate volume in Chinese men with PSA levels of 2.5-9.9 ng ml-1.

This study investigated whether free prostate-specific antigen (fPSA) performs better than total PSA (tPSA) in predicting prostate volume (PV) in Chinese men with different PSA levels. A total of 5463 men with PSA levels of <10 ng ml-1 and without prostate cancer diagnosis were included in this study. Patients were classified into four groups: PSA <2.5 ng ml-1, 2.5-3.9 ng ml-1, 4.0-9.9 ng ml-1, and 2.5-9.9 ng ml-1. Pearson/Spearman's correlation coefficient (r) and receiver operating characteristic (ROC) curves were used to evaluate the ability of tPSA and fPSA to predict PV. The correlation coefficient between tPSA and PV in the PSA <2.5 ng ml-1 cohort (r = 0.422; P < 0.001) was markedly higher than those of the cohorts with PSA levels of 2.5-3.9 ng ml-1, 4.0-9.9 ng ml-1, and 2.5-9.9 ng ml-1 (r = 0.114, 0.167, and 0.264, respectively; all P ≤ 0.001), while fPSA levels did not differ significantly among different PSA groups. Area under ROC curve (AUC) analyses revealed that the performance of fPSA in predicting PV ≥40 ml (AUC: 0.694, 0.714, and 0.727) was better than that of tPSA (AUC = 0.545, 0.561, and 0.611) in men with PSA levels of 2.5-3.9 ng ml-1, 4.0-9.9 ng ml-1, and 2.5-9.9 ng ml-1, respectively, but not at PSA levels of <2.5 ng ml-1 (AUC: 0.713 vs 0.720). These findings suggest that the relationship between tPSA and PV may vary with PSA level and that fPSA is more powerful at predicting PV only in the ''gray zone'' (PSA levels of 2.5-9.9 ng ml-1), but its performance was similar to that of tPSA at PSA levels of <2.5 ng ml-1.

Intravesical injection of botulinum toxin type a may be an effective treatment option for autonomic dysreflexia in patients with high-level spinal cord injury.

OBJECTIVE: To evaluate the efficacy of intravesical injection of botulinum toxin type A (BTX-A) for neurogenic detrusor overactivity (DO) in reducing the frequency and severity of autonomic dysreflexia (AD). DESIGN: A cross-sectional nonrandomized trial with before (baseline) and after (follow-up) assessments. SETTING: A single spinal cord injury (SCI) rehabilitation center in China. PARTICIPANTS: Twenty-five patients with SCI at or above T6 and a history of AD who underwent urodynamic studies (UDS) before and 3 months after BTX-A injection. INTERVENTIONS: Received bladder injection treatment wtih 200 U BTX-A. OUTCOME MEASURES: The maximum detrusor pressure(Pdetmax) and voume at first DO(VFIDC), baseline and overall maximum systolic blood pressure (SBP) during UDS, and scores of Incontinence Specific Quality of Life Instrument (IQoL) were recorded before and 3 months after the injection. The change in SBP (ΔSBP) from baseline to maximum SBP during UDS was calculated to assess the severity. The frequency of AD was recorded using ambulatory blood pressure monitoring during a 24 h period before and 3 months after the injection. RESULTS: BTX-A injection decreased the Pdetmax and increased the VFIDC and mean urine volume per catheterization increased. The maximum SBP and the ΔSBP during UDS decreased significantly decreased after the injection (151.44 ± 13.92 vs 133.32 ± 9.20 mmHg and 49.44 ± 12.81 vs 33.08 ± 9.11 mmHg respectively, P < 0.05). The frequency of bladder-related ADs (i.e. performed a clean intermittent catheterization or leakage) during a 24-h period significantly decreased from 11.04 ± 1.81-7.88 ± 2.15 (P < 0.001). CONCLUSIONS: BTX-A decreases the severity of SBP increase and the number of AD episodes 3 months after intravesical injection.

[Research Progress of 3D Printing Technology in Medical Field].

3D printing technology is a kind of manufacturing technology for increasing materials. Based on its advantages of rapid prototyping, digitalization and customization, it can effectively meet the needs of personalized and accurate medical treatment, and has been widely studied and applied in the medical field. This paper introduces the principle, technology and materials of 3D printing technology, and describes the research and application status of the technology in medical field. Meanwhile, some problems of 3D printing technology existing in the current development and its future application prospects also will be discussed.

Effects of botulinum toxin A injections in spinal cord injury patients with detrusor overactivity and detrusor sphincter dyssynergia.

OBJECTIVE: To evaluate the safety and effect of botulinum toxin A injection in the detrusor and external urethral sphincter in male patients with detrusor overactivity (DO) and detrusor external sphincter dyssynergia (DESD) secondary to spinal cord injury. METHODS: A multicentre trial was conducted from June 2012 to August 2015. A total of 65 spinal cord injury patients with DO and DESD participated in the study. Of these, 59 received 200 U botulinum toxin Aintradetrusor and 100 U external urethral sphincter injections. The effective outcomes included maximum detrusor pressure at first DO and DESD, VDO-DESD, maximum urethral closure pressure, duration of first DO and DESD, Incontinence-Specific Quality-of-Life Instrument, voiding volume, urinary incontinence episodes and complete dryness. Adverse events were recorded. RESULTS: All patients experienced a significant mean reduction in PdetmaxDO -DESD (46.60%), maximum urethral closure pressure (29.61%), duration of first DO and DESD (42.93%) and a significant mean increase in VDO-DESD (38.11%) 12-weeks post-injection. Significant (p < 0.001) improvement in mean Incontinence-Specific Quality-of-Life Instrument, voiding volume, urinary incontinence episodes and complete dryness were found in all patients at 2 weeks and were sustained at 8 weeks and 16 weeks. CONCLUSION: Botulinum toxin A injection in the detrusor and external urethral sphincter is an effective treatment to protect the upper urinary tract and improve quality of life for patients with DO and DESD secondary to spinal cord injury.