Development of a Two-Channel Simultaneous Photoplethysmography Recording System

Multi-site photoplethysmograph  (PPG) recording enables researchers to study the vascular and hemodynamic  properties of human subjects. Currently, there  is  no  commercial  system  available  in  the  market  to  perform  either  one channel or multi-channel PPG recording. PPG is an optoelectronic technique that measures  changes  in  blood  volume  associated  with  cardiac  contraction.  The measurements  can  be  obtained  from  fingertips,  ear  lobes  and toes  due  to  their low absorption and high degree of vasculature. The main objective of this project is to develop a two-channel simultaneous PPG recording system to acquire PPG signals  from  two  different  physiological  sites  using  a  Nellcor  equivalent  PPG probe.  MATLAB  software  was  used  during  the  development  phase  to  ensure rapid prototyping. The experiment results show that there was no inter -channel delay in the developed two-channel PPG system. Our preliminary results show that the delays between the left and the right arm were from 4 to 12 ms in three healthy random subjects. The system is portable, powered by universal serial bus (USB) and allows the user to do the PPG data acquisition in a clinical setting

A NOVEL WAVEFORM MIRRORING TECHNIQUE FOR SYSTOLIC BLOOD PRESSURE ESTIMATION FROM ANACROTIC PHOTOPLETHYSMOGRAM

Continuous cuffless Blood Pressure (BP) measurement is an important tool to monitor the health of individuals at risk. In this study, a new method is proposed for Systolic BP (SBP) estimation utilizing Photoplethysmograms (PPG). To this end, toe and carotid PPG were recorded from seventeen subjects aged 20-28 years, whereas their SBP were measured using a standard BP cuff monitor for validation purpose. The proposed method is based on a novel mirroring technique, which allows for an accurate estimation of the Pulse Transit Time (PTT) from the PPG’s rising part (anacrotic) waveform using an ARX System Identification approach. Based on the modified Moens-Korteweg equation, SBP was then calculated based on the estimated PTT values obtained from the ARX model. The estimated PTT was found to be highly correlated to the measured SBP (R2 = 0.98). Comparison of calculated SBP to the measured SBP obtained using standard BP cuff monitor results in a mean error of 3.4%. Given that 95% of the estimated SBP values are accurate in the +/- 8 mmHg range, this method seems promising for non-invasive, continuous BP monitorin

Electrocardiogram-based parameters for the prediction of sudden cardiac death: a review

There has recently been a resurgence of interest in electrocardiogram-based (ECG-based) parameters in predicting Sudden Cardiac Death (SCD) risk. Accurate and timely SCD predictions are essential clinical practice for physicians to provide effective prevention and treatment. An ECG is a non-invasive and inexpensive diagnostic test, and has been firmly established as a clinical tool for assessing the risk of cardiac disease. The electrocardiographic signal derived from the ECG recording consists of a distinctive waveform that depicts the electrical activity of the heart, which can be analyzed for the identification of abnormalities in the heart rhythm. The parameter or characteristic found in the ECG signal might be important for predicting the SCD. A number of systematic reports by expert meetings and review articles in indexed journals identified ECG-based parameters as QRS duration, QT interval, Signal Average ECG (SAECG), T-wave alternan (TWA), Heart Rate Variability (HRV), Heart Rate Turbulence (HRT), T-peak to T-end (Tpe), fragmented QRS complexes (fQRS), and Early Repolarization (ER). This article reviews the mechanism and morphology of these parameters, which may potentially have a role to play in a future algorithm designed to identify early signs of SCD. As of now, none of the ECG-based parameters have been found to be sufficiently stable to predict the SCD risk. Nevertheless, the combination of two or more of the parameters listed, as suggested in many studies, may become a useful component for predicting SCD in the future

Investigating the effect of total radiated power on fetus using optical simulation approach based on exposure safety limit for eye and tissue injury

This paper presents an analysis of the effect of the total radiated LED power on fetus in order to evaluate the exposure safety limit via optical simulation technique. The simulation results are then compared with the theoretical values calculated from the equations as defined by ICNIRP. The outcome from this study is beneficial in the future as it can be used to justify the safety issues on retinal injury and thermal heating concerning the application of low and high power LEDs specifically in the transabdominal fetal monitoring equipment which has been overlooked before

Development of graphical interface software for solar flare monitoring system

Solar activity such as solar flares causes increased X-ray and ultraviolet ray flux. This event will cause sudden ionospheric disturbances (SID) and disrupts the communication systems as well as the space-based equipment on Earth. Public awareness especially to school students on the effects of solar activities towards humans on Earth is very important as the dependency of human daily life on space technology is increasing. The awareness has been conducted by the Space Science Center, Institute of Climate Change, UKM using UKM-SID™ system. Based on the program, it was found that school student experienced constraints in the process of analyzing data due to the absence of computers in schools. Therefore, UKM-SID™ system, with portable kit equipped with an interactive software to produce an easy-to-understand figure, was proposed. An algorithm was also developed to transfer the observed data onto the server in near real time. The developed Graphical Interface software showed a visualized sunrise and sunset patterns which is in agreement with the previous study. A solar flare was detected on 1 December 2020. The observed data is also successfully uploaded onto the server in near real time. Result shows that this new UKM-SID™ system is able to capture the solar flare occurrence. This new system is also at an optimal and sophisticated level compared to the technology that has been used. Hence, the researchers believe the UKM-SID™ is able to help educators, students and the general public in the learning of space science more effectively

Comparing quality of life and treatment satisfaction between patients on warfarin and direct oral anticoagulants : a cross-sectional study

Introduction and aim: Patient quality of life (QOL) while on long-term oral anticoagulant therapy has been receiving greater attention in recent years due to the increase in life expectancy brought about by advances in medical care. This study aimed to compare the QOL, treatment satisfaction, hospitalization and bleeding rate in patients on long-term warfarin versus direct oral anticoagulants (DOAC). Methods: This was a cross-sectional study of patients with non-valvular atrial fibrillation (NVAF) or venous thromboembolism (VTE) on long-term anticoagulant therapy attending the cardiology clinic and anticoagulation clinic of the University Malaya Medical Centre from July 1, 2016, to June 30, 2018. Patient QOL was assessed by using the Short Form 12 Health Survey (SF12), while treatment satisfaction was assessed by using the Perception of Anticoagulation Treatment Questionnaire 2 (PACT-Q2). Results: A total of 208 patients were recruited; 52.4% received warfarin and 47.6% received DOAC. There was no significant difference in QOL between warfarin and DOAC based on SF12 (physical QOL, P=0.083; mental QOL, P=0.665). Nevertheless, patients in the DOAC group were significantly more satisfied with their treatment compared to the warfarin group based on PACT-Q2 (P=0.004). The hospitalisation rate was significantly higher in the warfarin group than the DOAC group (15.6% versus 3.0%, P=0.002). Clinically relevant minor bleeds and severe bleeding events were non-significantly higher in the warfarin group than the DOAC group (66.7% versus 40.0%, P=0.069). Conclusion: Compared to warfarin, treatment of NVAF and VTE with DOAC showed comparable QOL, higher treatment satisfaction, lesser hospitalization, and a non-significant trend toward fewer bleeding episodes

Microwave brain imaging system to detect brain tumor using metamaterial loaded stacked antenna array

In this paper, proposes a microwave brain imaging system to detect brain tumors using a metamaterial (MTM) loaded three-dimensional (3D) stacked wideband antenna array. The antenna is comprised of metamaterial-loaded with three substrate layers, including two air gaps. One 1 x 4 MTM array element is used in the top layer and middle layer, and one 3 x 2 MTM array element is used in the bottom layer. The MTM array elements in layers are utilized to enhance the performance concerning antenna's efficiency, bandwidth, realized gain, radiation directionality in free space and near the head model. The antenna is fabricated on cost-effective Rogers RT5880 and RO4350B substrate, and the optimized dimension of the antenna is 50 x 40 x 8.66 mm3. The measured results show that the antenna has a fractional bandwidth of 79.20% (1.37-3.16 GHz), 93% radiation efficiency, 98% high fidelity factor, 6.67 dBi gain, and adequate field penetration in the head tissue with a maximum of 0.0018 W/kg specific absorption rate. In addition, a 3D realistic tissue-mimicking head phantom is fabricated and measured to verify the performance of the antenna. Later, a nine-antenna array-based microwave brain imaging (MBI) system is implemented and investigated by using phantom model. After that, the scattering parameters are collected, analyzed, and then processed by the Iteratively Corrected delay-multiply-and-sum algorithm to detect and reconstruct the brain tumor images. The imaging results demonstrated that the implemented MBI system can successfully detect the target benign and malignant tumors with their locations inside the brain. 2022, The Author(s).This research work is supported by the Universiti Kebangsaan Malaysia (UKM) research Grant DIP-2020-009.Scopu

FACE SHIELD@UKM: An Initiative by UKM To Protect Our Frontliner During Covid-19 Pandemic

COVID-19 is a threatening pandemic to human being worldwide. Many of frontliner being infected in many ways. Private protective equipment (PPE) is a must to wear by all the medical personal when handling the COVID or treating the contagious patients. In normal circumstances, PPEs are easily available from medical suppliers. However, it there is disease outbreak like this COVID-19 and worldwide are affected, face shields are in high demand. Traditional process may not be able to cope with the sudden surge of the demand as well as the raw material. Manpower and factory accessibility are other factors as most of the country practise social distance through restriction movement order or completely lock down the town. To overcome this problem, rapid prototyping tools such as 3D printing and laser cutting methods are the promising method in producing the medical shields for our medical frontliner in battling the Covid-19 outbreak in Malaysia. To keep this in mind that this effort should be an alternative or interim method while waiting for actual PPE to arrive. With this grant and contribution from various parties (NCWO/Faculty member), we have produced a total of 1834 pieces of 3D printed face shield. The location of the face shield recipients are from a total of 18 hospital and health clinics

A Novel Photoplethysmograph Sensor Probe Design For Motion Artifact Detection: A Comparison Study With Three Axis Accelerometer

Photoplethysmography (PPG) sensors have become widespread in most of the healthcare categories; its drawback is unreliable during non-stationary states. Adaptive noise cancellation is one of the several techniques have existed to address this issue. The problem of implementing this method still lacks for total detection of induced noise due to the motion. In this work, a new method was introduced for noise detection based on novel PPG sensor probe design by adding a covered photodetector (CPD) as a motion artifact reflector, in addition to the main photodetector (MPD). Experiments of several motion kinds were executed to the tied (CPD) with the accelerometer. Data analysis for the collected signals showed a lengthy convergence between the amplitude fluctuations in the time domain. The CPD precisely indicated all the fundamental frequencies of various induced noise, unlike the accelerometer. Using these photodetectors, the CPD as noise reflector and the MPD to track the contaminated PPG signal is more reliability than other approaches. Implementing this method ensures a high-level accuracy and reducing the cost of repeated false examinations. Furthermore, simple software computation and low power consumption. Practical application of this study will be presented in our next work