Applied Mechanics and Materials Vol. 573

Abstract: Reliable detection of abnormal vessels in color fundus image is still a great issue in medical image processing. An Efficient and robust approach for automatic detection of abnormal blood vessels in digital color fundus images is presented in this paper. First, the fundus images are preprocessed by applying a 3x3 median filter. Then, the images are segmented using a novel morphological operation. To classify these segmented image into normal and abnormal, seven features based on shape, contrast, position and density are extracted. Finally, these features are classified using a non-linear Support Vector Machine (SVM) Classifier. The average computation time for blood vessel detection was less than 2.4sec with a success rate of 99%. The performance of our proposed method is measured on publically available DRIVE and STARE database.

Abstract: Functional near infrared spectroscopy is a noninvasive, non harmful, low cost and safe optical technique that can be used to study the functional activities in the human brain. This paper describes the development of two channel Near InfraRed Spectroscopy (NIRS) system and the results of the cerebral oxygenation changes during the different cognitive tasks. The objective of the study is to design, develop a portable non-invasive continuous wave NIRS system with dual wave length for determining the hemoglobin content of the blood chromophores during different activities of the prefrontal cortex of the brain. The two channel NIRS system designed and it was tested with 20 healthy, ie.,15 males and 5 females with an average age group of 21±2.25, they were given a 2 different mental tasks such as sequential subtraction (mathematical task) and spot the difference (Visuo-spatial task) and their Oxy & de-Oxy hemoglobin concentration was measured which showed more changes during the task period when compared to relaxation in both left and right part of pre-frontal cortex.

Abstract: According to current status Diabetes is the third leading cause of death after cancer and heart diseases. The serious complications of uncontrolled diabetes include kidney damage, eye damage, nerve disease and stroke. Diabetic retinopathy (DR) is a common retinal problem associated with diabetes. This paper focuses on Diabetic Retinopathy and finds the exudates parts in the eye by implementing combinations of global optimization techniques such as Particle Swarm Optimization (PSO) based on feature extraction. It can also be helpful in improving the performance by accuracy, sensitivity and specificity for detecting the Diabetic Retinopathy when compare to other traditional methods.

Abstract: Wireless Body Sensor Network (WBSN) is an emerging technology in the area of telemedicine. It helps doctors to remotely monitor the health condition of patients. The success of usage of WBSNs for health care monitoring relies mainly on the security provided to the medical information. In this paper, a fuzzy based key agreement scheme that uses ECG signal to protect the symmetric key to be exchanged is introduced. The effectiveness of the proposed scheme is evaluated using False Acceptance Rate (FAR) and our proposed system shows minimum FAR.

Abstract: Walking is an important tool for assessing individual’s health condition. Gait Pattern acquisition and analysis have been carried out using motion capture systems. The limitations of these systems include high cost, indoor monitoring and time consuming setup. Advent of MEMS sensors have overcome the above mentioned limitations. In this work, Wearable Wireless Sensor system has been developed. This system allows acquisition of gait data without intervention for subjects’ natural walking. The Spatio-Temporal parameters were determined for normal and pathological subjects. Results show existence of significant differences in critical phases of pathological gait. Overall degree of flexion / extension is reduced to half in polio gait. The data obtained from this work can be used for the development of subject specific therapeutic methods.

Abstract: The primary goal of this study is to expound the Artificial Intelligence schemes utilized in developing an automated sleep staging sytem. Sleep stages, broadly classified as REM and Non-REM (Rapid Eye Movement) are recognized during sleep studies. Electrocardiogram signal is one among the multiple signals recorded during a sleep study. An effort to bring out the correlation between Electrocardiogram and sleep stages would facilitate in developing an automated screening system for identifying sleep disorders. This study assimilates such researches and their outcomes conducted during the last two decades. It is also emphasized that due to liberal availability of Electrocardiogram data in hospitals, using it to distinguish sleep stages would aid in developing better healthcare. The prime methods identified from the literature are the statistical classifiers and neural network based classifiers.The reports discussed are typical of single night polysomnographic recordings. The collective results are then compared with manually scored sleep stages. Out of the various methods, Support Vector Machines and Detrended Fluctuation analysis are the popular methods owing to their nature of analyzing non stationary signals.

Abstract: The work describes the constructions of optical fiber based minimal invasive sensing system to measure pH and dissolved oxygen using sol-gel membranes which are attached internally in any transparent container. The disposable sensing membranes are very thin size and prepared as fluorescent dye doped in silica film using simple procedures. The sensor characteristics such as response time, linearity, repeatability and reversibility are evaluated and the performance of the sensor also compared with commercial meters. The experiments such as, chemical stability and photo stability are also carried out. The detection limit of pH sensor is found between 3 pH and 10 pH, however good sensitivity is obtained for the ranges from 4 pH and 9 pH with the response time of 7 seconds. Non-linear response is obtained for dissolved oxygen sensor and it is made linear by applying Stern-Volmer equation. The oxygen sensor shows good sensitivity in the ranges from 2 mg/L to 8 mg/L.

Abstract: ^{. The nasal cycle is referred to a cyclic fluctuation in congestion of the nasal mucosa that results in rhythmic and bilateral reciprocal alteration of nasal airway patency. The purpose of this study is to deal with statistical and power spectral analysis of nasal cycle by measuring the temperature difference between the airflow of both left and right nostrils. Five adult voluntary healthy subjects are enrolled for the study. Nasal temperature probe combined with amplifier are used for recording nasal airflow temperature on both nostrils. The highest nasal airflow temperature values are detected at the end of expiration and the lowest values are detected at the end of inspiration. Nasal cycle found in all the subjects and lasted to the minimum of 30 minutes to maximum of 6 hours. The difference in temperature of both nostrils is statistically significant (p<0.05) and spectral estimation is made using autoregressive modeling. The method is used to quantify nasal obstruction in pathological condition and also to correlate the related physiological phenomenon.}

Abstract: This paper describes the construction of low cost optical fiber sensor for the measurement of free chlorine and also residuals. The granules of poly (norborene) s bound with Cyanuric acid are synthesized as polymer film and applied on glass surface, which is used as sensing membrane. The prepared sensor membrane has a good photochemical stability and it would not leach out by continuous exposure to sample solution. The film is used to measure the changes in the absorbance intensity as a result of reaction between Cyanuric acid and free chlorine. The chlorine is used for the destruction of microbiological pathogens to protect the public health from water-borne diseases. This experiment was conducted for various chlorine samples. The sensor possess good repeatability with the range from 1.0 mg/l to 9.0 mg/l with minimal response time and also shows the characteristics such as reproducibility and stable results for more than 70 samples with a period of 5 days.