Chin-Hsing Chen

Wireless Sensor Networks for Vital Signs Monitoring: Application in a Nursing Home

This study evaluated the application of a wireless sensor network (WSN) on a web-based vital signs monitoring system to nursing homes in Taiwan. The applicability assessment focused on the timely provision of information, information accuracy, system usability, and system accessibility of healthcare systems using a wireless sensor network. Experiments were performed under Internet-based network conditions to verify the timely information provision, especially for a web-based system, including Ajax technology. The accuracy of the information was verified from statistical analyses of the residents’ daily vital sign measurements. A comparison was performed between having and not having a healthcare monitoring system in nursing homes for system usability, system accessibility, and system efficacy. The results indicate that the successful application of a WSN healthcare monitoring system is feasible for use in nursing homes in Taiwan.

A compression layer for NAND type flash memory systems

Storage devices of embedded systems must have the characteristics of small size, great capacity, low-power consumption, lightweight, non-volatility, and vibration resistance. The NAND type flash memory, briefly denoted by NandFlash, is one of the more often-used storage devices. In terms of unit price, its cost is several dozen to hundred times more expensive than the traditional hard-disk (HD) since its storage space is limited. Therefore, to increase the storage space of NandFlash is great significance. In this paper, we improved the compression layer for NandFlash, which can be coordinated with the X-RL algorithm, to avoid overhead and reduce the degree of internal fragmentation in the compressed data pages. Hence, our proposed method can improve the compression rate. In the reading phase, we use the consecutive memory allocation method, which can reduce the superfluous time caused by non-consecutive access. Therefore, our architecture is meaningful and practical for embedded system applications.

Pancyclicity of Mobius cubes

The problem of containing pancyclic interconnection networks is an important research topic. An n-dimensional Mobius cube, MQ/sub n/, is a variant of hypercubes according to specific rules. In this paper, we prove that Mobius cubes are all pancyclic networks. Similarly, both an n-dimensional crossed cube, CQ/sub n/, and an n-dimensional twisted cube, TQ/sub n/, are also variants of hypercubes according to specific rules. Moreover although the pancyclic property of a crossed cube and a twisted cube had been proved, we propose an alternative proof of this property.

Development of Telemedicine and Telecare over Wireless Sensor Network

Telemedicine & Telecare aided by wireless sensor network (WSN) has recently become a health-caring trend in the future. However, the low data rate of WSN limited the acceptable quality of service. Researches [1-6] adopted ZigBee-based WSN to implement a platform and/or a telecare system. However, the capacity problem due to low data rate characteristic has not been addressed. Our research proposed an arrhythmia-aware telecare system and a new DSP-based WSN platform, enabling good digital signal processing performance in ZigBee-based WSN. Proved by simulations and several real tests, combination of the proposed platform and system can provide a more bandwidth-conserving and reliable telecare system, with lower wireless traffic jam and higher stability.

Using K-Nearest Neighbor Classification to Diagnose Abnormal Lung Sounds.

A reported 30% of people worldwide have abnormal lung sounds, including crackles, rhonchi, and wheezes. To date, the traditional stethoscope remains the most popular tool used by physicians to diagnose such abnormal lung sounds, however, many problems arise with the use of a stethoscope, including the effects of environmental noise, the inability to record and store lung sounds for follow-up or tracking, and the physician’s subjective diagnostic experience. This study has developed a digital stethoscope to help physicians overcome these problems when diagnosing abnormal lung sounds. In this digital system, mel-frequency cepstral coefficients (MFCCs) were used to extract the features of lung sounds, and then the K-means algorithm was used for feature clustering, to reduce the amount of data for computation. Finally, the K-nearest neighbor method was used to classify the lung sounds. The proposed system can also be used for home care: if the percentage of abnormal lung sound frames is > 30% of the whole test signal, the system can automatically warn the user to visit a physician for diagnosis. We also used bend sensors together with an amplification circuit, Bluetooth, and a microcontroller to implement a respiration detector. The respiratory signal extracted by the bend sensors can be transmitted to the computer via Bluetooth to calculate the respiratory cycle, for real-time assessment. If an abnormal status is detected, the device will warn the user automatically. Experimental results indicated that the error in respiratory cycles between measured and actual values was only 6.8%, illustrating the potential of our detector for home care applications.

The Real-Time Compression Layer for Flash Memory in Mobile Multimedia Devices

Flash memory is physically small, lightweight, nonvolatile, vibration resistant, and has high capacity and low power consumption. It has become an essential storage device in mobile multimedia products, such as mobile phones, digital cameras, and MP3 players. The compression technique can effectively increase capacity and reduce data transfer. Hence, we propose a mechanism that uses a packing agent and a ping-pong buffer to cooperate with the X-match and run-length compression/decompression algorithm to create a real-time compression layer. This mechanism does not create the internal fragmentation space that increases the compression ratio, which makes the reading response time stable, and it reduces the writing response time of the Yim et al method by 60%.

Bidirectional and Multi-User Telerehabilitation System: Clinical Effect on Balance, Functional Activity, and Satisfaction in Patients with Chronic Stroke Living in Long-Term Care Facilities

Background The application of internet technology for telerehabilitation in patients with stroke has developed rapidly. Objective The current study aimed to evaluate the effect of a bidirectional and multi-user telerehabilitation system on balance and satisfaction in patients with chronic stroke living in long-term care facilities (LTCFs). Method This pilot study used a multi-site, blocked randomization design. Twenty-four participants from three LTCFs were recruited, and the participants were randomly assigned into the telerehabilitation (Tele) and conventional therapy (Conv) groups within each LTCF. Tele group received telerehabilitation but the Conv group received conventional therapy with two persons in each group for three sessions per week and for four weeks. The outcome measures included Berg Balance Scale (BBS), Barthel Index (BI), and the telerehabilitation satisfaction of the participants. Setting A telerehabilitation system included “therapist end” in a laboratory, and the “client end” in LTCFs. The conventional therapy was conducted in LTCFs. Results Training programs conducted for both the Tele and Conv groups showed significant effects within groups on the participant BBS as well as the total and self-care scores of BI. No significant difference between groups could be demonstrated. The satisfaction of participants between the Tele and the Conv groups also did not show significant difference. Conclusions This pilot study indicated that the multi-user telerehabilitation program is feasible for improving the balance and functional activity similar to conventional therapy in patients with chronic stroke living in LTCFs.

On the fault-tolerant pancyclicity of crossed cubes

A graph is pancyclic if it contains all cycles from lengths 4 to |V(G)|. An n-dimensional crossed cube, an important variation of hypercube denoted as CQ/sub n/, has been proved to be pancyclic because it contains all cycles whose lengths range from 4 to |V(CQ/sub n/)|. Since vertex and edge faults may occur when a network is used, it is practical and meaningful to evaluate the performance of a faulty network. Moreover the vertex fault-tolerant Hamiltonicity and the edge fault-tolerant Hamiltonicity measure the performances of the Hamiltonian properties in the faulty networks. From this fault-tolerant concept, we propose using the fault-tolerant pancyclicity of networks to measure the performance of faulty networks. In this paper we consider a faulty crossed n-cube with vertex and/or edge faults here. Let the faulty set F be a subset of V(CQ/sub n/)/spl cup/E(CQ/sub n/). We prove that any cycle of length l(4/spl les/l/spl les/|V(CQ/sub n/)|-f/sub /spl nu//) can be embedded into a faulty crossed n-cube CQ/sub n/-F with dilation 1, where |F|=f/sub /spl nu//+f/sub e/ is less than n-2, f/sub /spl nu// is the number of faulty vertices of F, f/sub e/ is the number of faulty edges of F, and n is greater than 2. The results can readily be used in the optimum embedding of a ring of the specified length in a faulty crossed cube.

A vision-based regression model to evaluate Parkinsonian gait from monocular image sequences

Parkinsons Disease (PD) is a common neurodegenerative disorder with progressive loss of dopaminergic and other sub-cortical neurons. Among various approaches, gait analysis is commonly used to help identify the biometric features of PD. There have been some studies to date on both the classification of PD and estimation of gait parameters. However, it is also important to construct a regression system that can evaluate the degree of abnormality in PD patients. In this paper, we intended to develop a PD gait regression model that is capable of predicting the severity of motor dysfunction from given gait image sequences. We used a model-free strategy and thus avoided the critical demands of segmentation and parameter estimation. Furthermore, we used linear discriminant analysis (LDA) to increase the feature efficiency by maximizing and minimizing the between- and within-group variations. Regression was also achieved by assessing the spatial and temporal information through classification and finally by using these two new indices for linear regression. According to the experiments, the outcomes significantly correlated with the sum of sub-scores from the Unified Parkinsons Disease Rating Scale (UPDRS): motor examination section with r=0.92 and 0.85 for training and testing, respectively, with p<0.0001. Compared with conventional methods, our system provided a better evaluation of PD abnormality.

Development of a Novel Bidirectional Control Telecare System over a Wireless Sensor Network and the Internet

The telecare system has become usable and accessible nowadays due to the development of information and communication technology. Its daily use has been made possible in long-term care through the use of wireless sensor networks. Unfortunately, the person in need of care may not be able to operate this sensor by him/herself. He/she is only able to turn this sensor on and off. Furthermore, he/she may be unconscious when an alert message is transferred. Against this backdrop, this paper therefore focuses on how the sensor can be automatically turned on to begin measuring physiological signals. In this research, a bidirectional sensor controlling design for a wireless sensor network with a Web-based interface using the Internet was proposed. Rich Internet application (RIA) technology was used to make a Web client-side user interface (UI) easier to use. Scalable vector graphics (SVG) technology, recommended by World Wide Web Consortium (W3C), was adopted to achieve dynamic charting of the browser. The combination of Ajax and SVG technology provides real-time interactivity and improves user experience on the use of the healthcare system. A complete system which includes the sensors, the wireless physiological detection network, the Web and database server, and the client side user interface was developed. To prove system reliability and accessibility, experiment and performance test of a real case were conducted.