Biomedical Engineering: Applications, Basis and Communications

This paper presents a computer-assisted diagnostic system for mass detection and classification, which performs mass detection on regions of interest followed by the benign-malignant classification on detected masses. In order for mass detection to be effective, a sequence of preprocessing steps are designed to enhance the intensity of a region of interest, remove the noise effects and locate suspicious masses using five texture features generated from the spatial gray level difference matrix (SGLDM) and fractal dimension. Finally, a probabilistic neural network (PNN) coupled with entropic thresholding techniques is developed for mass extraction. Since the shapes of masses are crucial in classification between benignancy and malignancy, four shape features are further generated and joined with the five features previously used in mass detection to be implemented in another PNN for mass classification. To evaluate our designed system a data set collected in the Taichung Veteran General Hospital, Taiwan, R.O.C. was used for performance evaluation. The results are encouraging and have shown promise of our system.

A light and portable-type wireless physiological signal retrieving system has always been a medical personnel's dream. To fulfill this dream, this paper investigates a feasible method to create a wireless-type physiological signal measuring system using a PDA and the bluetooth technology. The proposed system will reduce the service costs and raise the service efficiency for current medical care systems. The waveforms and data of physiological signals, such as electrocardiograms (ECGs), phonocardiograms (PCGs), electroencephalograms (EEGs), body temperatures, and so forth, are always the vital references for medical doctors to diagnose the patients' body condition. The traditional physiological signal measuring instruments or devices possess some shortcomings, such as high prices, bulky dimensions, ill-portability and excessive connection cables. In contrast, the proposed wireless-type physiological signal measuring system, being able to get rid of said shortcomings, holds apparent advantages in service costs and service efficiency and, hence, shall be the trend for the future. This study has completed some tests in ECG, PCG, and body temperature measurements. The proposed prototype system has successfully using the bluetooth technology to invisibly transmit and receive physical signals through the air.

The purpose of this research was to evaluate the treatment effect of modulated-frequency mode of acupuncture-like transcutaneous electrical nerve stimulation (AL-TENS) on patients with tennis elbow pain. Twenty patients suffering from tennis elbow pain for at least three months were involved in the study from Chung Yuan Christian University. The subjects were randomly assigned to three treatment groups in different time slots as repeated measures design. Each group (n = 20) was respectively treated with either 5 KHz modulated by 2 Hz frequency mode (LF group), 5 KHz modulated by 100 Hz frequency mode of TENS (HF group) on acupuncture points (LI10 and LI11) located in the area of elbow, or sham TENS (control group). Two electrodes were placed on two right acupoints and two electrodes on the left. The intensity of stimulation was adjusted at a tolerable level for each subject. Patients were treated for twenty minutes per visit, three times a week for two weeks. Visual analog scale (VAS) was used to rank the degree of pain before and two weeks after the treatment. A device, the design of which is based on the Ryodoraku theorem, was used to measure the electrical conductance of 12 meridians and 2 acupoints (LI10 and LI11) on both sides of the subjects. The results showed that: (1) after the AL-TENS treatment in this study, the electrical conductances of either meridians or acupuncture points increased with the decrease of VAS of the patients; the correlation was higher in the acupoints than that in the meridians; (2) the effect of AL-TENS on the percentage change of VAS is more related to the percentage change of electrical conductances of acupoints than that of meridians; (3) 5 KHz modulated by 2 Hz or 100 Hz frequency mode of AL-TENS was effective in the treatment of the patients with tennis elbow pain.

Articular cartilage defects heal poorly and lead to consequences as osteoarthritis. Clinical experience has indicated that no existing medication would substantially promote the healing process, and the cartilage defect requires surgical replacement. Allograft decays quickly for multiple reasons including the preparation process and immune reaction, and the outcome is disappointing. The extreme shortage of sparing in articular cartilage has much discouraged the use of autograft, which requires modification. The concept that constructs a chondral or osteochondral construct for the replacement of injured native tissue introduces that of tissue engineering. Limited number of cells are expanded either in vitro or in vivo, and resided temporally on a scaffold of biomaterial, which also acts as a vehicle to transfer the cells to the recipient site. Three core elements constitute this technique: the cell, a biodegradable scaffold, and an environment suitable for cells to present their proposed activity. Modern researches have kept updating those elements for a better performance of such cultivation of living tissue.

The aim of this research is to design a simple three-dimensional aortic model to measure the relation of aortic pressure distributions and blood flow rate at the outlets of the aorta. The current experiment considers an area-varying curved tube with one branch to mimic an aortic arch. The measurement utilizes a water pump to substitute for the heart pumping task and collects data for the distributions of the pressure and flow rate relied on a PC-controlled pressure sensor. Various pressures as 160, 140, 110 and 90 mm Hg are chosen as aortic entrance blood pressure conditions for the test cases. The pressure distributions from the current measurement will be used for the numerical boundary condition which can not be obtained from the current image technology.

Sleep-related breathing disorders can cause heart rate changes known as cyclical variation. The heart rate variation of patients with obstructive sleep apnea syndrome (OSAS) is more prominent in sleep. For this reason, to analyze heart rate variability (HRV) of patients with sleep apnea is a very important issue that can assist physicians to diagnose and give suitable treatment for patients. In this paper, a novel QRS detection algorithm is developed and applied to the analysis for HRV of patients with sleep apnea. The advantageous of the proposed algorithm is the combination of digital filtering and reverse R wave detection techniques to enhance the accuracy of R wave detection and easily implement into portable ECG monitoring system with light complexities of computation. The proposed algorithm is verified by simulation and experimental results.

Owing to the improvement of computing power, computer-aided multi-unit acquisition and separation rapidly proliferated during the last two decades. To utilize this technology is, however, not easy since task-specific designs are usually mandatory. To overcome this obstacle, a commercial data acquisition system was used to evaluate whether it is possible to accomplish the task of multi-unit acquisition without the aid of these devices. As the results shown that the technique of spike-trigger acquisition can provide the capability to reduce the data amount to 2% while compared with that sampled by continuous acquisition. However, the interval between two consecutive spikes cannot be shorter than 5 ms. This suggests that special designed devices are still necessary.

Morse code, with its single switch operation, has been shown to be a valuable tool in assistive technology, augmentative and alternative communication, and rehabilitation for people with various neuromuscular diseases, such as amyotrophic lateral sclerosis, multiple sclerosis, and muscular dystrophy. A major hindrance is a stable typing rate, which is strictly required for the recognition of Morse code characters, especially for persons with severe disabilities. In this paper, a combination of two methods, support vector machines and the variable degree variable step least-mean-square algorithm was used to increase the prediction accuracy for Mandarin Morse code recognition. Experimental findings revealed that the proposed method results in a better recognition rate when compared to alternative methods from the literature.