Nur Azah Hamzaid

Nur Azah Hamzaid
University of Malaya | UM · Department of Biomedical Engineering

PhD

About

90
Publications
17,284
Reads
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677
Citations
Additional affiliations
March 2010 - present
University of Malaya
Position
  • Professor (Associate)
August 2005 - February 2010
The University of Sydney
Position
  • PhD Student

Publications

Publications (90)
Article
Background: Repetitive electrically-evoked muscle contractions lead to early onset of muscle fatigue. This study assessed the relationship between muscle mechanomyography (%RMS-MMG) and tissue oxygen saturation (%TSI) in extensor carpi radialis (ECR) during electrically-evoked fatiguing exercise in individuals with tetraplegia. Methods: Skin-sur...
Chapter
Biomechatronics is a field that integrates engineering principles into biological systems, symbolised by the shape of the letter ‘M.’ The vertical direction the ‘M’ represents specialisationSpecialisation in a specific domain of the biological system, while the horizontal direction represents the ability to appreciate and understand other areas of...
Article
Call bell systems play an essential role in patient and nurse interaction in hospitals and at homes. However, many hospitalized patients, especially patients with tetraplegia, cannot press a call bell button for assistance due to hand weakness or paralysis from the neck down. This problem has motivated developing a fabric-based multi-array pressure...
Article
Hearing loss is a common neurodegenerative disease that can start at any stage of life. Misalignment of the auditory neural impairment may impose challenges in processing incoming auditory stimulus that can be measured using electroencephalography (EEG). The electrophysiological behaviour response emanated from EEG auditory evoked potential (AEP) r...
Article
Individuals with paraplegia spend their time on the wheelchair for life. Adapting to prolonged wheelchair seating for almost all activities of daily living is challenging. The loss of abilities to sense any pain or excessive seating pressure cause them to remain seated on the wheelchair without any pressure relief activities. This situation leads t...
Book
Full-text available
The purpose of this Online Teaching and Learning Guideline is to assist academic staffs and all related stakeholders in implementing online teaching and learning effectively. The guideline has three (3) main sections: Online Teaching and Learning Design; Online Teaching and Learning Delivery; and Online Teaching and Learning Assessment. Each sectio...
Chapter
Full-text available
This chapter presents University Malaya’s early journey to prepare its academics for open access education. The chapter traces the university community’s early technophobic hesitations to UM’s eventual campus-wide adoption of e-learning via Moodle, and the university’s current efforts to offer MOOCs.
Article
Full-text available
Background Due to its clinically proven safety and health benefits, functional electrical stimulation (FES) cycling has become a popular exercise modality for individuals with spinal cord injury (SCI). Since its inception in 2013, the Cybathlon championship has been a platform for publicizing the potential of FES cycling in rehabilitation and exerc...
Article
A transfemoral prosthesis is required to assist amputees to perform the activity of daily living (ADL). The passive prosthesis has some drawbacks such as utilization of high metabolic energy. In contrast, the active prosthesis consumes less metabolic energy and offers better performance. However, the recent active prosthesis uses surface electromyo...
Article
Functional electrical stimulation (FES) has been used to produce force-related activities on the paralyzed muscle among spinal cord injury (SCI) individuals. Early muscle fatigue is an issue in all FES applications. If not properly monitored, overstimulation can occur, which can lead to muscle damage. A real-time mechanomyography (MMG)-based FES sy...
Article
Full-text available
Early Career Faculties (ECFs) are an important demographic of university faculty population shaping the future of the institution and higher education, despite the challenges they face as new academics. Analysis of scholarly output on ECFs offers useful data to inform and aid both national policy formulations and institutional planning decisions es...
Article
Background and objective: Using traditional regression modelling, we have previously demonstrated a positive and strong relationship between paralyzed knee extensors' mechanomyographic (MMG) signals and neuromuscular electrical stimulation (NMES)-assisted knee torque in persons with spinal cord injuries. In the present study, a method of estimatin...
Article
Full-text available
A paradigm shift in health system did intensify the need for research on wearable electronics. There are numerous reasons that could lead to skin ulcers. The most common are lesion due to constant pressure, incontinence control, excessive humidity and postural changes. Over the years, there have been numerous interventions ranging from specific ski...
Article
Micro-processor controlled prosthetic legs (MPCPL) offer better functionality than conventional prosthetic legs as they use actuators to replace missing joint function. This potentially reduces the user’s metabolic energy consumption and normal walking gait can be mimicked as closely as possible. However, MPCPL require a good control system to perf...
Article
Standing up and sitting down movements are important prerequisites to achieve functional independence in everyday life of spinal cord injury (SCI) patients. Thus, mechanomyography (MMG) was proposed as a safe monitoring tool to evaluate muscle function performance of these activities. Two incomplete SCI participants performed repetitive sit-to-stan...
Article
This study investigates whether mechanomyography (MMG) produced from contracting muscles as a measure of their performance could be a proxy of muscle fatigue during a sustained functional electrical stimulation (FES)-supported standing-to-failure task. Bilateral FES-evoked contractions of quadriceps and glutei muscles, of four adults with motor-com...
Article
Gait detection is crucial especially in active prosthetic leg control mechanism. Vision system, floor sensors, and wearable sensors are the popular methods proposed to collect data for gait detection. However, in active prosthetic leg control, a tool that is practical in its implementation and is able to provide rich gait information is important f...
Article
Objectives The aim of this study was to investigate the performance of mechanomyography (MMG) and electromyography (EMG) in monitoring the sternocleidomastoid (SCM) as accessory respiratory muscles when breathing during singing. Methods MMG and EMG were used to record the activity of the SCM in 32 untrained singers reciting a monotonous text and a...
Article
Full-text available
Loss of sensory motor function is one of the main causes of physical and activity limitations among individual with spinal cord injury (SCI). SCI may lead to muscle paralysis, weakness and disused muscle atrophy. Evidences have shown electrical stimulation and strengthening exercise might improve lower limb muscle strength and size among individual...
Article
Patients with spinal cord injury (SCI) benefit from muscle training with functional electrical stimulation (FES). For safety reasons and to optimize training outcome, the fatigue state of the target muscle must be monitored. Detection of muscle fatigue from mel frequency cepstral coefficient (MFCC) feature of mechanomyographic (MMG) signal using su...
Article
An in-socket sensory system enables the monitoring of transfemoral amputee movement for a microprocessor-controlled prosthetic leg. User movement recognition from an in-socket sensor allows a powered prosthetic leg to actively mimic healthy ambulation, thereby reducing an amputee's metabolic energy consumption. This study established an adaptive ne...
Chapter
A smart fabric based multichannel pressure mapping Data Acquisition System (DAS) was specially designed to read and visualize real time pressure data from an array of piezoresistive fabric pressure sensor. This DAS is important to enable rapid monitoring of pressure distribution for biomedical engineering applications. A customized pressure mapping...
Chapter
Functional Electrical Stimulation (FES) has been widely used as part of physiotherapy for spinal cord injury (SCI) patients. The ability to do sit to stand (STS) manoeuvre is an important and practical indicator of functional independence in SCI individuals. One of the factors that contributes to STS movement is arm support. The objective of this s...
Chapter
Prosthetic leg is known as one of the solutions to help the amputee to regain back their ambulation ability. However, most of the current existing knee components still lacks in the ability to provide active body propulsion, which in turn. Thus, higher metabolic energy consumption is required by the amputee in doing locomotion movement. Hence, this...
Article
Full-text available
This study compared muscle oxygenation (StO2) during arm cranking (ACE), functional electrical stimulation-evoked leg cycling (FES-LCE), and hybrid (ACE+FES-LCE) exercise in spinal cord injury individuals. Eight subjects with C7-T12 lesions performed exercises at 3 submaximal intensities. StO2 was measured during rest and exercise at 40%, 60%, and...
Article
Repetitive electrically-evoked muscle contraction leads to accelerated muscle fatigue. This study assessed electrically-evoked fatiguing muscle with changes to mechanomyography root mean square percentage (%RMS-MMG) and tissue saturation index (%TSI) in extensor carpi radialis. Forty healthy volunteers (n=40) performed repetitive electrical-evoked...
Article
Full-text available
This study sought to design and deploy a torque monitoring system using an artificial neural network (ANN) with mechanomyography (MMG) for situations where muscle torque cannot be independently quantified. The MMG signals from the quadriceps were used to derive knee torque during prolonged functional electrical stimulation (FES)-assisted isometric...
Article
Background: Investigation of muscle fatigue during functional electrical stimulation (FES)-evoked exercise in individuals with spinal cord injury using dynamometry has limited capability to characterize the fatigue state of individual muscles. Mechanomyography has the potential to represent the state of muscle function at the muscle level. This st...
Article
Previous research investigated recumbent cycle power output (PO) from the perspective of knee and hip joint biomechanics. However, ankle-foot biomechanics and, in particular, the effect of ankle-foot orthosis (AFO)-constrained movements on cycle PO has not been widely explored. Therefore, the purpose of this study was to determine whether AFOs of a...
Article
Full-text available
A mechanomyography muscle contraction (MC) sensor, affixed to the skin surface, was used to quantify muscle tension during repetitive functional electrical stimulation (FES)-evoked isometric rectus femoris contractions to fatigue in individuals with spinal cord injury (SCI). Nine persons with motor complete SCI were seated on a commercial muscle dy...
Article
Full-text available
The walking mechanism of a prosthetic leg user is a tightly coordinated movement of several joints and limb segments. The interaction among the voluntary and mechanical joints and segments requires particular biomechanical insight. This study aims to analyze the inter-relationship between amputees' voluntary and mechanical coupled leg joints variab...
Conference Paper
Previous research has investigated functional electrical stimulation (FES) cycle force and power output (PO) from the perspective of knee and hip joint biomechanics. However, ankle-foot biomechanics and, in particular, the effect of releasing the ankle joint on cycle pedal force and PO during FES cycling in paraplegics has not been widely explored....
Conference Paper
Wearable pressure sensor is an important element in human gait and biomechanical investigations. Many studies have been carried out to ensure its reliability and comfort to the user even when the sensor has to be operated under extreme conditions such as uneven surface with high curvature area, high humidity environment, and wide range of dynamic p...
Conference Paper
Full-text available
Recent advances in digital and networked technologies coupled with an “open access” movement to provide free access to scientific research and educational resources, now includes "online distance education". This new movement extends higher educational opportunities and life-long learning possibilities to non-traditional students and life-long lear...
Conference Paper
The importance of communication in human daily lives is undeniable as it is a mean of expressing ideas, thoughts and most importantly the basic needs. Unfortunately, there are elderly patients with speech disabilities, commonly caused by aphasia. Aphasic patients can lose their ability to obtain basic needs and healthcare services as they are unabl...
Conference Paper
Stroke is one of the top five diseases in Malaysia contributing to major morbidity and mortality not only in Malaysia but in the whole world. Severe stroke can lead to death while the stroke survivors will face weakness (flaccid), spasticity and decrease in proprioceptive sensation depending on the affected part of the brain. The cost of rehabilita...
Article
This paper presents the design and evaluation of an in-socket sensory system for a transfemoral prosthetic leg using a set of piezoelectric sensors. The design process includes identifying the optimal mounting configuration of the sensors and determining their best placement. Two experiments were performed separately to address each objective. Resu...
Article
Full-text available
The difficulty of real-time muscle force or joint torque estimation during neuromuscular electrical stimulation (NMES) in physical therapy and exercise science has motivated recent research interest in torque estimation from other muscle characteristics. This study investigated the accuracy of a computational intelligence technique for estimating N...
Article
Full-text available
The interaction between muscle contractions and joint loading produces torques necessary for movements during activities of daily living. However, during neuromuscular electrical stimulation (NMES)-evoked contractions in persons with spinal cord injury (SCI), a simple and reliable proxy of torque at the muscle level has been minimally investigated....
Article
This pilot study reports the development of a novel closed-loop (CL) FES-gait control system, which employed a finite-state controller that processed kinematic feedback from four miniaturized motion sensors. This strategy automated the control of knee extension via quadriceps and gluteus stimulation during the stance phase of gait on the supporting...
Article
Full-text available
Background: Rapid muscle fatigue during functional electrical stimulation (FES)-evoked muscle contractions in individuals with spinal cord injury (SCI) is a significant limitation to attaining health benefits of FES-exercise. Delaying the onset of muscle fatigue is often cited as an important goal linked to FES clinical efficacy. Although the basi...
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Article
This is a case series study with the objective of comparing two motion sensor automated strategies to avert knee buckle during functional electrical stimulation (FES)—standing against a conventional hand-controlled (HC) FES approach. The research was conducted in a clinical exercise laboratory gymnasium at the University of Sydney, Australia. The a...
Article
This study describes the development of a basic computer-based play pedagogy intervention using a dyscalculia-remedy-oriented approach such as repetition and number orientation manipulation, and the investigation of its effect on children displaying dyscalculia characteristics. This computer play was evaluated in a group of 50 seven-year-old Malays...
Article
Full-text available
This paper presents an approach of identifying prosthetic knee movements through pattern recognition of mechanical responses at the internal socket’s wall. A quadrilateral double socket was custom made and instrumented with two force sensing resistors (FSR) attached to specific anterior and posterior sites of the socket’s wall. A second setup was e...
Article
Full-text available
Abstract In this paper, we presented the first stage of our closed loop functional electrical stimulator (FES) development work in reducing errors occurred at sensory feedback during FES-evoked contraction. This preliminary experimental study aims to verify that the measured voltage signal evoked by functional electrical stimulator across healthy h...
Article
Full-text available
The research conducted in the last three decades has collectively demonstrated that the skeletal muscle performance can be alternatively assessed by mechanomyographic signal (MMG) parameters. Indices of muscle performance, not limited to force, power, work, endurance and the related physiological processes underlying muscle activities during contra...
Article
Full-text available
This study investigated whether the relationship between muscle torque and m-waves remained constant after short recovery periods, between repeated intervals of isometric muscle contractions induced by functional electrical stimulation (FES). Eight subjects with spinal cord injury (SCI) were recruited for the study. All subjects had their quadricep...
Article
Full-text available
Alternative sensory systems for the development of prosthetic knees are being increasingly highlighted nowadays, due to the rapid advancements in the field of lower limb prosthetics. This study presents the use of piezoelectric bimorphs as in-socket sensors for transfemoral amputees. An Instron machine was used in the calibration procedure and the...
Article
Study design: Prospective study of two cases. Objectives: To describe the effects of electrical stimulation (ES) therapy in the 4-week management of two sub-acute spinal cord-injured (SCI) individuals (C7 American Spinal Injury Association Impairment Scale (AIS) B and T9 AIS (B)). Setting: University Malaya Medical Centre, Kuala Lumpur, Malays...
Conference Paper
FES rowing is a complete whole body exercise that has potential to provide aerobic and muscle training benefits for individuals with SCI. Current FES rowing systems comprise `fixed' stretcher designs whereby the disabled rower moves their seated body mass over a sliding bar while the foot stretcher remains fixed. The present work describes the deve...
Conference Paper
The experiment is to investigate the reliability of two different mechanomyogram (MMG) sensors recording during functional electrical stimulation (FES)-evoked contraction. The MMG based sensors used in this study are vibromyography (VMG) and muscle contraction (MC) sensor. One spinal cord injured (SCI) patient was requested to perform knee extensio...
Conference Paper
The present work shows a preliminary study conducted using Vibromyography (VMG) sensor and Electromyography (EMG) sensor with the help of Biodex system on evaluating muscle performances. Surface EMG and Biodex torque are set as reference signal to be compared with VMG signal obtained from the experiment. A total of 5 healthy subjects performed isok...
Conference Paper
A pilot investigation was conducted on the measurement of muscle performance during voluntary exercise using a novel mechanomyogram muscle contraction sensor quantifying muscle tension - the MC-Sensor (TMG-BMC Ltd. Ljubljana, Slovenia). Surface electromyography (sEMG) and the torque output from an isokinetic dynamometer were used as reference for c...
Conference Paper
This paper presents a study protocol for comparing the effectiveness of two different configurations of multi-pad electrode array (MEA) in functional electrical stimulation (FES)-evoked cycling. In this study protocol, muscular force produced by quadriceps and the duration of achieving muscular fatigue would be compared between two different stimul...
Conference Paper
The purpose of this paper is to understand the importance of considering the same or similar parameters in terms of functional electric stimulation-leg ergometry (FES-LE) study designing to formulate careful systematic comparisons between studies to provide spinal cord injury (SCI) patients with the best beneficial usages of FES-LE by developing in...
Conference Paper
FES leg cycling exercise is a physical activity that has potential to provide aerobic fitness and cardiovascular health benefits for individuals with SCI. However, there are few high-quality studies or systematic reviews for sufficient Level I or Level II evidence supporting the putative benefits of FES-evoked exercise after SCL to make sound deter...
Conference Paper
FES-rowing has been developed as an alternative ‘hybrid’ exercise modality that has the capacity to increase exercise training intensity, and thus elicit greater cardiorespiratory and health responses. A novel manual controlled sliding stretcher FES rowing system has been recently developed, but it requires the rower with paralyzed lower limbs to m...
Conference Paper
Central nervous system (CNS) is composed of the brain and the spinal cord. Any impairment in the functionality of these parts can cause serious disabilities such as movement impairment and urinary incontinence. Spinal cord injury (SCI) and stroke are two conditions affected by injury of the CNS. This article presents a systematic review of the effi...
Article
Full-text available
Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees' gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gai...
Article
Full-text available
The evoked electromyographic signal (eEMG) potential is the standard index used to monitor both electrical changes within the motor unit during muscular activity and the electrical patterns during evoked contraction. However, technical and physiological limitations often preclude the acquisition and analysis of the signal especially during function...
Article
Full-text available
Sequel to spinal cord injury (SCI), functional impairment is sustained and the SCI individuals are often confined to wheelchair usage. Current trends of walking rehabilitation adopted is functional electrical stimulation (FES) assisted gait with partial body weight support. However, lack of lower limb proprioception, inability to control complex jo...
Article
Full-text available
Significant number of research attempts are noticed lately on validation of efficacy of alternative paradigm for muscle function assessment such as MMG after exhaustive trials on voluntary and evoked EMG with limited clinical and experimental impacts. Enhanced performance of conventional FES application for the SCI patients remains elusive partly d...
Conference Paper
To date, human walking behavior is typically characterized by plotting single kinematics and kinetics curves as a function of time or percentage of gait cycle. These kinematics and kinetics curves became the "textbook" to design prosthesis control that mimicks the normal gait by analyzing the prosthesis performance as close as the normal single-var...