Biomedical Engineering: Applications, Basis and Communications

A neuro-fuzzy inference system that recognizes the expression patterns of genes in microarray gene expression (MGE) data, called GeneCFE-ANFIS, is proposed to infer gene interactions. In this study, three primary features are utilized to extract genes' expression patterns and used as inputs to the neuro-fuzzy inference system. The proposed algorithm learns expression patterns from the known genetic interactions, such as the interactions confirmed by qRT-PCR experiments or collected through text-mining technique by surveying previously published literatures, and then predicts other gene interactions according to the learned patterns. The proposed neuro-fuzzy inference system was applied to a public yeast MGE dataset. Two simulations were conducted and checked against 112 pairs of qRT-PCR confirmed gene interactions and 77 TFs (Transcriptional Factors) pairs collected from literature respectively to evaluate the performance of the proposed algorithm.

The rehabilitation and exercise strategy for spondylolysis is controversial. Both lordotic and anti-lordotic braces, and both flexion and extension oriented motions were advised for spondylolysis rehabilitation. However, the biomechanical outcomes of the two strategies were less understood. The objective of current study is to evaluate the effect of postural sway on the strain of pars interarticularis, and to find the mechanical mechanism of lordotic and anti-lordotic rehabilitation strategies for spondylolysis.

Two-motion-segment porcine cervical spine model (C3-C5, C6-T1) was used to simulate human lumbar spine. The loadings induced by anterior, neutral, posterior, anterolateral, lateral and posterolateral sways were simulated by applying vertical eccentric pointed loadings. Two uni-axial strain gages were applied on the dorsal surface of bilateral pars interarticularis of middle vertebrae. It was revealed that the pars strains induced by posterior, lateral, posterolateral sways were significantly greater than those induced by anterior, neutral and anterolateral sways. The ipsilateral pars strains were higher than the contralateral pars strains during lateral and posterolateral sways. However, pars strains of ipsilateral and contralateral side were similar during anterolateral sway. These results proved that the postural sway affects the strain of pars interarticularis. The anti-lordotic braces and exercise are likely to reduce the strain of pars interarticularis.

In response to the home healthcare requirement of chronic patients, this paper proposes a mobile-care system integrated with a variety of vital-sign monitorings, where all the front-end vital-sign measuring devices are portable and have the ability of short-range wireless communication. In order to make the system suitable for home applications, wireless sensor network is introduced to transmit the captured vital signs to the residential gateway by means of multi-hop relay. Then the residential gateway uploads data to the care server via internet to carry out patient's condition monitoring and the management of pathological data. Furthermore, the system is equipped with the alarm mechanism, where the portable care device is able to immediately perceive the critical condition of the patient and send a warning message to medical and nursing personnels to achieve the goal of prompt rescue.

Polyhydroxyalkanoates (PHAs) is a newer family of biomaterials for tissue engineering applications. The objective of this study is to investigate the behaviors of human Schwann cells-like (hSCs-like) on various PHA films. The surface characteristics of PHA films were varied by the content of 3-hydroxyvalerate (HV) or 3-hydroxyhexanoate (HHx) and by the film preparation methods such as compression-molding and solvent-casting. Hyaluronic acid (HA) and poly(L-lysine) (PLL) were further applied on to improve the growth of hSCs-like on PHA membranes. The hSCs-like isolated from human body (MATERIALS AND METHODS) would have strong metabolic activities and produce many extracellular matrix (ECM). When HV content increased, there was a reduction in the crystallinity and the hydrophoicity of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) membranes. Despite that these different surface characteristics did not show significant effect on the metabolic activities of hSCs-like, these would affect adhering HA. Hyaluronic acid (HA)-coated PHA membranes could improve the metabolic activities and decrease the death ratio of hSCs-like. However, the condition of PLL coating has no obvious influence on the activities of hSCs.

The conventional apnea monitor adopts disposable electrodes as sensors for apnea detection and thus inducing the problems of skin irritation and other side effects. To tackle these shortcomings, we develop a non-attached type of apnea monitor. The device monitors the temperature of the breathing airflow by means of thermo sensors. These airflow frequencies linked with respiratory rates are indicated on the monitor. There is absolutely no contact with the patients' skin, avoiding the possibilities of any skin irritation. The system detects temperature changes induced by breathing and analyzes the breathing frequency changes displayed by both LED array and computer monitor. The data are collected and analyzed simultaneously by a personal computer, which can link to the central nursery room. The device provides a convenient way for family or nurses to detect abnormal respiratory rate in real time so they can handle any emergency and give the necessary treatment immediately for those patients in persistent vegetative state. Clinic application is presented and function validation of the device, on the other hand, is performed as well.

This paper is mainly to implement an active RFID system for 2-dimensional positioning service for home healthcare applications. It elaborates on the research processes including designing, planning and building of the system. The proposed system uses four active tags for the reference addresses and an object equipped with an active tag. It transmits the received signal strength indicator (RSSI) and the unique electronic product code (EPC) back to the tag reader through wireless transmission. Then the system employs the information, which is received from the tag reader via the monitor center, to compute the geometric relation between the reference tags and the object to determine the location of the object by the positioning algorithm. Because the radio signal is vulnerable to the interferences from the terrain and obstacles while propagating, the tag reader is likely to receive signals with bad quality thats result in errors. Therefore, this paper studies and sorts out several issues that could affect the positioning accuracy, and probes into the influence degree of distance errors by experiment. The experiment results show that the confidence rate of the distance error within 2.5 meters is as high as 95% of a 5 m × 5 m region where four coordinates references are arranged.

In this work, a preliminary numerical simulation of the lower urinary system using Computational Fluid Dynamics (CFD) is performed. Very few studies have been done on the simulation of three-dimensional urine through the lower urinary system. In this study, a simplified lower urinary model with rigid body assumption is proposed. The distributions of urine flow velocity, wall pressure and shear stress along the urethra are simulated based on MRI scanned uroflowmetry of a normal female. Numerical results show that violent secondary flows appear on the cross surface near the end of the urethra when the inflow rate is increased. The oscillative variation of pressure and shear stress distributions are found around the beginning section of the urethra when flow rate is at the peak value.

This paper concentrates on the effect of sewing ring geometry design on fluid flow past the prototype bi-leaflet aortic valve. To simulate the hemodynamic characteristics of the blood flow, CFX-4.3 software with finite volume method of analyzing the three-dimensional Reynolds-averaged Navier-Stokes equations is adopted. With the analysis model, we predict the blood velocity and the shear stress over the flow filed. The data provide information for the improvement of sewing ring geometry in order to minimize occurrence of hemolysis. An analysis of hemodynamic study for the St. Jude valve with various opening angles is present first and the geometry change is then recommended. After modifying the geometry of the sewing ring, the blood velocity slows down obviously. Maximum flow velocity reduces 54% compared to that of the original St. Jude model at peak systole. On the other hand, shear stress of aortic wall decreases accordingly. This would ease possible damage of endothelial cell of the aorta.