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Most current Holter devices monitor the ECG for 24 to 72 hours. However, for the accurate diagnosis of many cardiac diseases, especially for the wide variety of asymptomatic cases, continuous ECG monitoring for weeks or even months may be required. In this paper, we focus on the issue of ECG compression during long-term monitoring of the patient. The patient may be at home, at work, or even on a trip...
Nowadays, circulatory support has become a common practice in medicine and a standard in the treatments of cardio vascular disease (CVD). A new pneumatic ventricular assist device (VAD) has been developed in Mexico City. This paper shows the first results of acute in-vivo trials, intended to verify the new system for providing physiological flows and pressures. Two VADs were implanted to as right...
Current implantable LVADs are bulky and expensive. They all require high-risk surgery for insertion including a need for a heart/lung machine and complex connection to the heart or major blood vessels. This paper presents a newly designed "plug and play" transventricle LVAD that can be plugged into the circulation easily and work instantly with no complicated surgical procedure, no prime,...
Continuous flow blood pumps, such as axial flow and centrifugal pumps, have been gaining interest as circulatory devices for total artificial hearts (TAHs) and a biventricular assist device (BVAD) because of their smaller size and simpler structure compared to pulsatile pumps. However, continuous flow pumps are more prone to suction of the left ventricle than pulsatile pumps are. Sudden increases...
The authors have been developing a newly-designed totally-implantable artificial myocardium using a covalent shape-memory alloy fibre (Biometalreg, Toki Corporation), which is attached onto the ventricular wall and is also capable of supporting the natural ventricular contraction. This mechanical system consists of a contraction assistive device, which is made of Ti-Ni alloy. And the phenomenon of...
In the development of left ventricular assist devices (LVADs), numerical simulations of the cardiovascular (CV) system have been widely used. Further, electrohydraulic simulations have been developed to evaluate the performance of a physical LVAD prototype against a numerical model of the CV system. The effects of dynamic cardiac compression (DCC) have been less well modeled. This paper considers...
The paper describes three types of artificial gas exchange techniques for respiratory failure; extracorporeal membrane oxygenation (ECMO) for acute respiratory failure address the problem of oxygenation and CO2 removal; arteriovenous carbon dioxide removal (AVCO 2) for acute and respiratory failure with residual function, achieve total CO2 removal supplement native lung apneic oxygenation; paracorporeal...
This article presents an analysis of the information rate of neural spike trains in an auditory nerve fiber (ANF) model stimulated extracellularly by sinusoidal electric stimuli under the case where a high-rate pulsatile waveform is presented as a conditioner for increasing the across-fiber-independency, i.e., desynchronization. In the computer simulation, stimulus current waveforms were presented...
Based on Poisson variability, the strength of cross-correlation of two spike trains was quantified by a cross-correlation index (CCI). Discriminant analysis with CCI was used to quantify the contribution of cross-correlation in stimulus feature discrimination in an ensemble of retinal ganglion cells. Compared with simulated Poisson cell pair, it was found that cross-correlation carried useful information...
The role of the lateral geniculate nucleus (LGN) of the thalamus in visual encoding remains an open question. Visual stimulation of the LGN produces two distinct types of responses: tonic and burst. It has been suggested that these two modes of response could serve to transmit high fidelity features of the visual world (tonic) or robustly detect salient features of the visual world (burst). Here,...
Brain machine interface development typically falls into two arenas, invasive extracellular recording and non-invasive electroencephalogram recording methods. The relationship between action potentials and field potentials is not well understood, and investigation of interrelationships may improve design of neuroprosthetic control systems. Rats were trained on a motor learning task whereby they had...
Features of epilepsy from human extracranial EEG recordings were obtained using the wavelet artificial neural network (WANN). The WANN is also a robust signal processing tool for the estimation of nonlinear time-frequency relation and it had previously been shown to be able to classify and predict state transitions in the in vitro hippocampal slice model exhibiting spontaneous epilepsy. The variations...
We developed a method for testing guide wires and catheters that realistically evaluates the forces applied to anatomical structures by these instruments during urological procedures. The placement of guide wires and catheters to gain access to the upper urinary tract can induce undesirable stresses on the tissues. Previous studies have characterized wire/catheter performances base on their physical...
Electrical safety is always an important item of medical equipment in hospital. With the development of clinical engineering, the electric safety testing has become a routine procedure for the unit of clinical engineering in hospital. Among the parameters of safety standard of medical equipment, the leakage currents are more important than others. This study is aimed in the measurement of different...
The study was to investigate thrombolysis in vivo with ultrasound, and to discuss effects of thrombolysis with ultrasound on the structure of erythrocyte and its safety threshold, under different ultrasound intensity and exposure time. The structure of erythrocyte in thrombus was evaluated under light microscope. The relationship between the structure of erythrocyte in thrombus and ultrasound intensity...
We tested the effects of some kinds of time-varying magnetic fields (0-1.2T) on neurotransmitter-induced transient increases in intracellular Ca2+ concentration ([Ca2+]) of cultured chromaffin and HeLa cells. After these cells were exposed for 2 hours to these magnetic fields, transient increases in [Ca2+]i by addition of acetylcholine or histamine were measured. In control cells, after addition of...
This paper starts with analyzing the development and history of clinical engineering in China, analyzing the macro-environment of clinical engineering and summarizing the practice experiences of Chinese and foreign CE department. It puts forward a new idea that clinical engineering working mode should be changed from "working around repairing" to "working around equipment quality control...
In clinical first-pass myocardial perfusion studies, physiological and patient motions are inevitable. Such motions impair the sensitivity and reliability in assessing myocardial perfusion abnormalities. The current study aims to correct the misregistration of myocardium during first-pass perfusion imaging by using a normalized mutual information approach. Multi-slice registrations were performed...
High-dimensional deformable registration of MRI brain images is presented here. The deformation is driven by local forces estimated from point similarities based on joint histogram and with the use of prior information obtained from tissue probability maps available in selected commonly used brain atlases. Three point similarity measures are tested in an experiment with data obtained from standard...
A semi-automatic multiple-stage segmentation scheme of brainstem and cerebellum is proposed in this paper. This proposed scheme contains a modified scale-based fuzzy connectedness (FC) algorithm, a morphology operator, Chain code, and active contour mode (ACM). A modified scale-based FC is utilized to delivery a rough segmentation, a morphology operator and Chain code are used to compensate the uncompleted...
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