Malarvili Balakrishnan | Universiti Teknologi Malaysia - UTM (original) (raw)

Papers by Malarvili Balakrishnan

License, which permits unrestricted use, distribution, and reproduction in any medium, provided t... more License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Saliva is increasingly recognised as an attractive diagnostic fluid. The presence of various disease signalling salivary biomarkers that accurately reflect normal and disease states in humans and the sampling benefits compared to blood sampling are some of the reasons for this recognition. This explains the burgeoning research field in assay developments and technological advancements for the detection of various salivary biomarkers to improve clinical diagnosis, management, and treatment. This paper reviews the significance of salivary biomarkers for clinical diagnosis and therapeutic applications, with focus on the technologies and biosensing platforms that have been reported for screening these biomarkers. 1.

2018 IEEE-EMBS Conference on Biomedical Engineering and Sciences (IECBES), 2018

Nowadays, many devices have been developed for muscle strength training, and most of it focus on ... more Nowadays, many devices have been developed for muscle strength training, and most of it focus on exercising without any sense of entertainment. To encounter this issue, hover board seems to be the best option since it already has been used for leisure outdoor activity. Recently, hover board showed similar effects on leg muscles caused by other rehabilitation tools like basu ball. Furthermore, the use of mobile application features for a simple health monitoring kit is a trend and seems to be useful. Therefore, the focus of this study is to develop a mobile muscle strength monitoring system for hover board. Gastrocnemius medialis (GM) and tibialis anterior (TA) muscle activation of six normal subjects were recorded using surface electromyography while using the hover board. Arduino Uno and accelerometer were used to record the peak of tilting angle of the hover board surface. Regression analysis were applied to determine the relationship between tilting angle and muscle activation. M...

Jurnal Mekanikal

Automotive turbochargers increase internal combustion engine power and efficiency in passenger an... more Automotive turbochargers increase internal combustion engine power and efficiency in passenger and commercial vehicles. The vibrational characteristics need to be closely monitored during testing as it indicates the state of the turbocharger and its components. For this purpose, an accurate accelerometer is a must. This paper presents the design of a drop impact test rig for accelerometer validation. The design is based on ASTM E1876 standard and able to cover a frequency range of 0-6000 Hz. This represents a typical turbocharger operating speed of up to 120,000 rpm, with four common types of vibrational mode expected – synchronous, sub-synchronous, harmonic, and non-synchronous. Three materials have been selected for the specimen plate, namely ABS, Copper and AISI 1050 steel. The abovementioned frequency range can be satisfied by varying the specimen thickness. The drop impact test rig allows four different drop heights. Further combined with four different steel ball sizes, the ma...

Automatic seizure detection based on the combination of newborn multi-channel EEG

Acupuncture treatment has been reported to reduce pain. It could inhibit sympathetic activation d... more Acupuncture treatment has been reported to reduce pain. It could inhibit sympathetic activation during mental stress which promotes relaxation and circulation of the functional state of the human body. However, the neurobiological basis of this effect is yet to be clearly stated. Thus, evaluation of electroacupuncture (EA) effects on heart rate variability (HRV) was conducted. Effect of EA was accessed by analyzing the HRV, which is a prominent non-invasive assessment method. The effect of HRV before and after EA and the relationship with acupoint stimulation based on extracted parameters from HRV was investigated. Electrocardiogram (ECG) signals of 29 healthy volunteers were acquired before and after EA stimulation at acupoint ST36 (Zu San Li). HRV is analyzed in both time-domain and frequency-domain to extract parameters such as heart rate (HR), SDNN, RMSSD, pNN50 and ratio of low frequency power over high frequency power (LF/HF). The result showed that EA stimulation has the effe...

Patient care is considered in top priority for all clinics and hospitals. Hence it is necessary t... more Patient care is considered in top priority for all clinics and hospitals. Hence it is necessary to provide a dedicated line of a mediator between nurse and patient to provide excellent patient safety and to minimize the medical errors. Till date, traditional nursing calling system was used for this purpose which limits the patient information until the nurse’s chamber and outcomes of the system depended on the nurse that sometimes fail due to unavailability or shortage of manpower. It may lead to patient death too. Therefore, this study presents a low cost and robust nursing calling system. The proposed system consists of five parts: 1) patient switch, 2) acknowledgment switch, 3) nurse center station board, 4) administrator board and 5) control board. Whenever a patient pressed the button, the signal enabled the patient’s room and bed number along with demographic details in nurse chamber for two minutes. If unattended by nurses, it passes the signal to the administrator or physici...

2017 Asia-Pacific Signal and Information Processing Association Annual Summit and Conference (APSIPA ASC), 2017

The so-called DNA period-3 signals are significant indicators for exons locations in DNA sequence... more The so-called DNA period-3 signals are significant indicators for exons locations in DNA sequences. However, the sole dependence on one period-3 signal to identify exons locations in a DNA sequence provides limited performance. It has been recently shown that exons prediction performance can be improved by employing multiple different period-3 signals. In this paper, we aim to justify the reason of this improvement by investigating the correlation between different DNA period- 3 signals. For this purpose, we utilize Pearson's correlation coefficient. Moreover, we examine another configuration of employing multiple period-3 signals for exons prediction that is not handled in previous work. MATLAB simulation is conducted on the HMR195 genomic dataset utilizing the ROC curve as a performance evaluation tool. The results reveal an average weak correlation of 12% between period-3 signals obtained by using different numeric mapping schemes. Consequently, employing those period-3 signa...

In this study, the frequency contents of capnogram were investigated. Capnogram is the graphical ... more In this study, the frequency contents of capnogram were investigated. Capnogram is the graphical output of capnography that represents the different changes in expiratory volume. Capnography is generally used for the monitoring of carbon dioxide (CO2) level during respiration. This method is not only simple, non- invasive and relatively inexpensive, but also mandated or recommended for patient monitoring during clinical procedures by medical societies representing anaesthesiology, cardiology, critical care, paediatrics, respiratory care and emergency medicine. Hence, the signal processing and analysis of capnogram will help in understanding its nature for the diagnosis and prognosis of a variety of respiratory disorders. It should be noted that till now there is no attempt to investigate the frequency contents of capnogram. Therefore, we investigated the frequency properties of capnogram to lead towards better and more accurate diagnostic algorithms related to respiratory malady. Fa...

IFMBE Proceedings, 2007

In this paper, a new method for characterizing the newborn heart rate variability (HRV) is propos... more In this paper, a new method for characterizing the newborn heart rate variability (HRV) is proposed. The central of the method is the newly proposed technique for instantaneous frequency (IF) estimation specifically designed for nonstationary multicomponent signals such as HRV. The new method attempts to characterize the newborn HRV using features extracted from the time-frequency (TF) domain of the signal. These features comprise the IF, the instantaneous bandwidth (IB) and instantaneous energy (IE) of the different TF components of the HRV. Applied to the HRV of both normal and seizure-suffering newborns, this method clearly reveals the locations of the spectral peaks and their timevarying nature. The total energy of HRV components, ET and ratio of energy concentrated in the low-frequency (LF) to that in high-frequency (HF) components have been shown to be significant features in identifying the HRV of newborn with seizures.

2007 IEEE International Conference on Signal Processing and Communications, 2008

Abstract This work addresses the feature selection problem using a wrapper approach to select a f... more Abstract This work addresses the feature selection problem using a wrapper approach to select a feature subset to distinguish between the classes of newborn heart rate variability (HRV) corresponding to seizure and non-seizure. The method utilizes a filter as a pre-step to remove the irrelevant and redundant features from the original set of features to provide a starting feature subset for the wrapper. This reduces the computation load and the severity of the search operations involved in a wrapper approach. The goodness of the feature ...

Journal of Innovative Optical Health Sciences, 2021

The design of a handheld capnography device is in great demand because of its effective and pract... more The design of a handheld capnography device is in great demand because of its effective and practical uses in all cardiac arrest resuscitations, according to the recommendation of the American Heart Association. Herein, a handheld capnography device that can be used in clinical settings and the home environment is reported. The proposed device was developed by using an infrared CO2 sensor, Arduino Mega2560, and a high-resolution display (2.8”). Furthermore, two rechargeable batteries (7.6[Formula: see text]V, 0.99[Formula: see text]A) and a secure digital card with a capacity of 16[Formula: see text]GB were incorporated to increase the portability and usability of the device. Algorithms were implemented to measure standard features, namely, inspired CO2 (ICO2), end-tidal CO2 (EtCO2), and respiratory rate (RR). The features of 15 healthy subjects were recorded by using the developed prototype and the standard capnography device (CapnostreamTM20 Model CS08798). Validation was performe...

Asthma is a chronic inflammatory disease of the bro nchial tubes that occurs in about 3 to 5% of ... more Asthma is a chronic inflammatory disease of the bro nchial tubes that occurs in about 3 to 5% of all pe ople and continues to be a significant cause of morbidity an d mortality. Traditionally, peak flow meter and spi rometer is used to monitor the asthmatic patients which have l ots of limitation. Nowadays, capnography is a new method used to monitor the asthmatic condition. It is able to show the different respiratory situation of pat ient including asthma. Unlike traditional methods, it is taken while the patient is breathing as comfortabl e as possible. Previous studies have shown significant c orrelation between the capnogram and asthmatic pati ent. However, all of them are just manual studies conduc ted through the conventional method. Manual analysis of capnogram is, however, time-consuming and led to erroneous due to human factor such as tiredness and l ack of proficiency. Therefore, it is proposed here to d evelop a computerized system to detect the severity of airway obstru...

Tropical Animal Health and Production

Advances in Science, Technology and Engineering Systems Journal

Stress occurring in the early days of an individual was often assumed to cause several health con... more Stress occurring in the early days of an individual was often assumed to cause several health consequences. A number of reports indicated that having to deal with unfavourable events or distress situation at a young age could tweak stress responses leading to a broad spectrum of poor mental and physical health condition. Therefore, changes identified within stress response were recommended to be taken as a measure in regulating and managing such health situation. This study combines the biomarker that represents both autonomic nervous system (ANS) and hypothalamic-pituitary-adrenocorticol (HPA) as a single measure to classify the stress response based on traumatic childhood experience and propose a stress response index as a future health indicator. Electrocardiograph (ECG), blood pressure, pulse rate and salivary cortisol (SCort) were collected from 12 participants who had traumatic childhood experience while the remaining 11 acted as the control group. The recording session was done during a Paced Auditory Serial Addition Test (PASAT). HRV was then computed from the ECG and the HRV features were extracted. Next, the best HRV features were selected using Genetic Algorithm (GA). Biomarkers such as BP, PR and SCort were then integrated with 12 HRV features picked from GA. The integrations were conducted using two fusion methods which are Euclidean distance and serial fusion. The differences in reaction of the fused features were then identified. Based on the result, the Euclidean distance (ed) which is the fused feature by the parallel fusion, displayed the most efficient reaction with accuracy, sensitivity, and specificity at 80.0%, 83.3% and 78.3%, respectively. Support Vector Machine (SVM) was utilized to attain such result. The fused feature performance was then fed into SVM which produced indexes on stress responses. The result retrieved from these indexes acts as a measure in handling future health deliverability and perhaps could eventually enhance the health care platform for midlife individuals.

TELKOMNIKA (Telecommunication Computing Electronics and Control)

Procedia Computer Science

Malaysian Journal of Fundamental and Applied Sciences

Balance training devices such as wobble board, basu ball and balance cushion are the tool use in ... more Balance training devices such as wobble board, basu ball and balance cushion are the tool use in balance training exercise programme in order to improve muscle strength and restore posture balance due degeneration of body function or injury. Recently, self-balancing scooter such as Segway and hover board showed a positive effects on rehabilitation. However, it is less known how these devices affect muscle physiological properties. This study aims to to measure ankle muscles activation on difference balance training devices and hover board. Besides, a comparison between these device will be done in order to identify if hover board has a promising feature to be an alternative balance training device. In this research, surface EMG (sEMG) was used to record tibialis anterior and gastrocnemius muscle activities. Seventeen healthy subjects were required to stand on three different types of balance training device such as wobble board, balance cushion, bosu ball and a hover board. They we...

Medical & Biological Engineering & Computing

AbstractAdverse childhood experiences have been suggested to cause changes in physiological proce... more AbstractAdverse childhood experiences have been suggested to cause changes in physiological processes and can determine the magnitude of the stress response which might have a significant impact on health later in life. To detect the stress response, biomarkers that represent both the Autonomic Nervous System (ANS) and Hypothalamic-Pituitary-Adrenal (HPA) axis are proposed. Among the available biomarkers, Heart Rate Variability (HRV) has been proven as a powerful biomarker that represents ANS. Meanwhile, salivary cortisol has been suggested as a biomarker that reflects the HPA axis. Even though many studies used multiple biomarkers to measure the stress response, the results for each biomarker were analyzed separately. Therefore, the objective of this study is to propose a fusion of ANS and HPA axis biomarkers in order to classify the stress response based on adverse childhood experience. Electrocardiograph, blood pressure (BP), pulse rate (PR), and salivary cortisol (SCort) measures were collected from 23 healthy participants; 11 participants had adverse childhood experience while the remaining 12 acted as the no adversity control group. HRV was then computed from the ECG and the HRV features were extracted. Next, the selected HRV features were combined with the other biomarkers using Euclidean distance (ed) and serial fusion, and the performance of the fused features was compared using Support Vector Machine. From the result, HRV-SCort using Euclidean distance achieved the most satisfactory performance with 80.0% accuracy, 83.3% sensitivity, and 78.3% specificity. Furthermore, the performance of the stress response classification of the fused biomarker, HRV-SCort, outperformed that of the single biomarkers: HRV (61% Accuracy), Cort (59.4% Accuracy), BP (78.3% accuracy), and PR (53.3% accuracy). From this study, it was proven that the fused biomarkers that represent both ANS and HPA (HRV-SCort) able to demonstrate a better classification performance in discriminating the stress response. Furthermore, a new approach for classification of stress response using Euclidean distance and SVM named as ed-SVM was proven to be an effective method for the HRV-SCort in classifying the stress response from PASAT. The robustness of this method is crucial in contributing to the effectiveness of the stress response measures and could further be used as an indicator for future health. Graphical abstractᅟ

Technology and health care : official journal of the European Society for Engineering and Medicine, Jan 27, 2018

Fetal heart rate (FHR) monitoring device is highly demanded to assess the fetus health condition ... more Fetal heart rate (FHR) monitoring device is highly demanded to assess the fetus health condition in home environments. Conventional standard devices such as ultrasonography and cardiotocography are expensive, bulky and uncomfortable and consequently not suitable for long-term monitoring. Herein, we report a device that can be used to measure fetal heart rate in clinical and home environments. The proposed device measures and displays the FHR on a screen liquid crystal display (LCD). The device consists of hardware that comprises condenser microphone sensor, signal conditioning, microcontroller and LCD, and software that involves the algorithm used for processing the conditioned fetal heart signal prior to FHR display. The device's performance is validated based on analysis of variance (ANOVA) test. FHR data was recorded from 22 pregnant women during the 17th to 37th week of gestation using the developed device and two standard devices; AngelSounds and Electronic Stethoscope. The...

Journal of Breath Research

Development of a human respiration carbon dioxide (CO2) measurement device remains a demanding re... more Development of a human respiration carbon dioxide (CO2) measurement device remains a demanding research to evaluate the cardio-respiratory status of human beings since last decades in and out of hospital. Hence, we report a real time, user operable CO2 measurement device using infrared CO2 sensor, Arduino Mega2560, and thin film transistor (TFT, 3.5"), incorporated with low pass (cut-off frequency,10Hz) and moving average (span,8) filters. The proposed device measures features such as partial end-tidal carbon dioxide (EtCO2), respiratory rate (RR), inspired carbon dioxide (ICO2) and newly proposed feature, Hjorth Activity that annotated with a date and time received from real-time clock and stores into the secure digital (SD) card. Further, it was tested on 22 healthy subjects and performance (reliability, validity and relationship) of each feature was established using, (1) intraclass correlation coefficient (ICC), (2) standard error measurement (SEM), (3) smallest detectable difference (SDD), (4) Bland and Altman plot and (5) Pearson's correlation (r). The SEM, SDD, and ICC values for interand intra-rater reliability were less than 5% and more than 0.8, respectively. Besides, Bland and Altman plot shows that mean differences + standard deviations for set limit were 0.30 + 0.77 mm Hg,-0.34 + 1.41 mm Hg and 0.21 + 0.64 breath per minute (bpm) for CO2, EtCO2 and RR. Findings revealed that developed device is highly reliable and valid measure for CO2, EtCO2, ICO2 and RR and can be used in clinical settings for cardiorespiratory assessment. This research also demonstrates that EtCO2 and RR (r,-0.696) is negatively correlated while EtCO2 and activity (r, 0.846) is positively correlated. Thus simultaneous measurement of these features may possibly assist physicians in understanding the subject's cardiopulmonary status. In future, the proposed device will be tested with asthmatic patient in order to use as an early screening tool outside of hospital.