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1.
Med J Malaysia ; 76(4): 594-596, 2021 07.
Article in English | MEDLINE | ID: mdl-34305128

ABSTRACT

Post Endoscopic Retrograde Cholangiopancreatography (ERCP) pneumoperitoneum is commonly associated with perforated viscus but is rarely associated with benign causes. We present a case of 29 years old lady who underwent ERCP, who was found to have benign pneumoperitoneum subsequently. She was treated conservatively and recovered without complication. Although rare, post ERCP pneumoperitoneum of benign causes should be investigated as the course of treatment and outcome differ largely.


Subject(s)
Cholangiopancreatography, Endoscopic Retrograde , Pneumoperitoneum , Adult , Cholangiopancreatography, Endoscopic Retrograde/adverse effects , Female , Humans , Pneumoperitoneum/diagnostic imaging , Pneumoperitoneum/etiology
2.
Food Chem ; 307: 125631, 2020 Mar 01.
Article in English | MEDLINE | ID: mdl-31634761

ABSTRACT

Lutein available in the current market is derived from marigold petals. However, extensive studies showed that microalgae are rich in lutein content and potentially exploitable for its dietary and other industrial applications. In this study, microwave assisted binary phase solvent extraction method (MABS) was the novel protocol being developed and optimized to achieve maximum lutein recovery from microalgae Scenedesmus sp. biomass. Results showed that 60% potassium hydroxide solution with acetone in the ratio of 0.1 (ml/ml) was the ideal binary phase solvent composition. Empirical model developed using response surface methodology revealed highest lutein content can be recovered through MABS extraction method at 55 °C treatment temperature, 36 min in extraction time, 0.7 (mg/ml) for biomass to solvent ratio, 250 Watt microwave power and 250 rpm stirring speed. This optimized novel protocol had increased the amount of lutein recovered by 130% and shorten the overall extraction time by 3-folds.


Subject(s)
Food Additives , Liquid-Liquid Extraction/methods , Lutein/isolation & purification , Scenedesmus/chemistry , Hot Temperature , Microalgae/chemistry , Solvents
3.
Clin Exp Dermatol ; 44(4): 411-413, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30239029

ABSTRACT

Allergic contact dermatitis (ACD) is an increasing problem in children. We sought to investigate the extent of haptens or contact allergens present in baby cosmetic products. Computer programming scripts were written to web-scrape UK supermarkets and pharmacies. In total, 438 unique 'baby products' were identified, and constituent ingredient information was extracted. Data were cross-referenced against 10 standardized patch test reference series. We found that 88% of products had at least one reference contact allergen. There was a mean of 2.21 (range 1-15) reference allergens per product. The most abundant compounds were parabens, fragrances, cetyl/steryl alcohol, methylisothiazolinone, sodium lauryl sulfate and lanolin alcohol. Branded products and those marketed as 'sensitive/gentle/organic/fragrance-free' appeared to contain a greater number of reference allergens than those not marketed as such. This study highlights the increasing number of cosmetic products targeted to children in the UK, and the extent of potential allergens present in these products.


Subject(s)
Allergens/immunology , Cosmetics/adverse effects , Dermatitis, Allergic Contact/epidemiology , Haptens/immunology , Dermatitis, Allergic Contact/immunology , Disinfectants/adverse effects , Humans , Infant , Parabens/adverse effects , Preservatives, Pharmaceutical/adverse effects , Prevalence , Thiazoles/adverse effects , United Kingdom/epidemiology
4.
Eur J Hum Genet ; 26(6): 796-807, 2018 06.
Article in English | MEDLINE | ID: mdl-29511323

ABSTRACT

CHN is genetically heterogeneous and its genetic basis is difficult to determine on features alone. CNTNAP1 encodes CASPR, integral in the paranodal junction high molecular mass complex. Nineteen individuals with biallelic variants have been described in association with severe congenital hypomyelinating neuropathy, respiratory compromise, profound intellectual disability and death within the first year. We report 7 additional patients ascertained through exome sequencing. We identified 9 novel CNTNAP1 variants in 6 families: three missense variants, four nonsense variants, one frameshift variant and one splice site variant. Significant polyhydramnios occurred in 6/7 pregnancies. Severe respiratory compromise was seen in 6/7 (tracheostomy in 5). A complex neurological phenotype was seen in all patients who had marked brain hypomyelination/demyelination and profound developmental delay. Additional neurological findings included cranial nerve compromise: orobulbar dysfunction in 5/7, facial nerve weakness in 4/7 and vocal cord paresis in 5/7. Dystonia occurred in 2/7 patients and limb contractures in 5/7. All had severe gastroesophageal reflux, and a gastrostomy was required in 5/7. In contrast to most previous reports, only one patient died in the first year of life. Protein modelling was performed for all detected CNTNAP1 variants. We propose a genotype-phenotype correlation, whereby hypomorphic missense variants partially ameliorate the phenotype, prolonging survival. This study suggests that biallelic variants in CNTNAP1 cause a distinct recognisable syndrome, which is not caused by other genes associated with CHN. Neonates presenting with this phenotype will benefit from early genetic definition to inform clinical management and enable essential genetic counselling for their families.


Subject(s)
Cell Adhesion Molecules, Neuronal/genetics , Charcot-Marie-Tooth Disease/genetics , Intellectual Disability/genetics , Adolescent , Charcot-Marie-Tooth Disease/epidemiology , Charcot-Marie-Tooth Disease/physiopathology , Child , Child, Preschool , Exome/genetics , Female , Frameshift Mutation , Genetic Association Studies , Humans , Infant , Infant, Newborn , Intellectual Disability/epidemiology , Intellectual Disability/physiopathology , Male , Phenotype , Survival
5.
Clin Exp Allergy ; 47(2): 200-207, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27664415

ABSTRACT

BACKGROUND: Abnormal vocal cord movements can cause laryngeal extrathoracic airway obstruction (often called vocal cord dysfunction - VCD) leading to asthma-like symptoms. These aberrant movements are characteristically present during inspiration and termed paradoxical vocal cord movement (PVCM). We have reported PVCM in up to 40% of severe asthmatics, but it is not known if PVCM is detectable in all patients with asthma-like symptoms and if the condition is more often associated with abnormal lung function. OBJECTIVE: We hypothesized that PVCM is frequently associated with asthma symptoms accompanied by airflow limitation. Studies examined whether PVCM is solely linked to experiencing asthma symptoms, or if PVCM is related to airflow limitation and/or other disease characteristics. METHODS: Patients with asthma symptoms were recruited from general practice and severe asthma clinics (n = 155). Pulmonary function measurements were conducted, asthma control and Nijmegen (dysfunctional breathing) questionnaires were administered and skin prick testing was carried out. PVCM was quantified using dynamic 320-slice computerized tomography of the larynx. Groups were divided into patients with FEV1 ≥ 80% predicted or FEV1 < 80% predicted and FEV1 /FVC < 0.7. ATS/ERS definitions of severity were also applied and evaluated. Detection of PVCM in the groups was compared and analyses performed to identify features associated with PVCM. RESULTS: Overall (n = 155), PVCM was detected in 42 cases (27.1%). Patients with FEV1 < 80% predicted had PVCM more often (25/68, 36.8%) than individuals with normal spirometry (17/87, 19.5%; P = 0.016). PVCM was associated with older age (P = 0.003) and with Nijmegen scores > 20 (P = 0.04). Patients with FEV1 < 80% predicted plus Nijmegen scores > 20 were more likely to have PVCM (OR = 9.3, P = 0.02). CONCLUSIONS AND CLINICAL RELEVANCE: Paradoxical vocal cord movement is more often associated with asthma symptoms accompanied by airflow limitation and dysfunctional breathing. Further studies are needed to determine whether PVCM is induced by dysfunctional breathing practices and/or airway obstruction. How PVCM links with symptomatic asthma and VCD also requires evaluation.


Subject(s)
Airway Obstruction/complications , Airway Obstruction/physiopathology , Asthma/complications , Asthma/physiopathology , Vocal Cord Dysfunction/etiology , Adult , Aged , Airway Obstruction/diagnosis , Asthma/diagnosis , Female , Humans , Male , Middle Aged , Respiratory Function Tests , Skin Tests , Symptom Assessment , Tomography, X-Ray Computed
6.
Bioinspir Biomim ; 11(5): 056012, 2016 09 09.
Article in English | MEDLINE | ID: mdl-27609700

ABSTRACT

This paper describes the design, fabrication and locomotion of a starfish robot whose locomotion principle is derived from a starfish. The starfish robot has a number of tentacles or arms extending from its central body in the form of a disk, like the topology of a real starfish. The arm, which is a soft and composite structure (which we call the smart modular structure (SMS)) generating a planar reciprocal motion with a high speed of response upon the actuation provided by the shape memory alloy (SMA) wires, is fabricated from soft and smart materials. Based on the variation in the resistance of the SMA wires during their heating, an adaptive regulation (AR) heating strategy is proposed to (i) avoid overheating of the SMA wires, (ii) provide bending range control and (iii) achieve a high speed of response favorable to successfully propelling the starfish robot. Using a finite-segment method, a thermal dynamic model of the SMS is established to describe its thermal behavior under the AR and a constant heating strategy. A starfish robot with five SMS tentacles was tested with different control parameters to optimize its locomotion speed. As demonstrated in the accompanying video file, the robot successfully propelled in semi-submerged and underwater environments show its locomotion ability in the multi-media, like a real starfish. The propulsion speed of the starfish robot is at least an order of magnitude higher than that of those reported in the literature-thanks to the SMS controlled with the AR strategy.


Subject(s)
Biomimetic Materials , Locomotion/physiology , Robotics , Starfish/physiology , Alloys , Animals , Equipment Design , Gait/physiology , Models, Theoretical , Regeneration/physiology , Starfish/anatomy & histology , Thermodynamics
7.
Methods Mol Biol ; 1409: 95-123, 2016.
Article in English | MEDLINE | ID: mdl-26846806

ABSTRACT

Tumor-targeted Salmonella offers a promising approach to the delivery of therapeutics for the treatment of cancer. The Salmonella strains used, however, must be stably attenuated in order to provide sufficient safety for administration. Approaches to the generation of attenuated Salmonella strains have included deletion of the msbB gene that is responsible for addition of the terminal myristol group to lipid A. In the absence of myristoylation, lipid A is no longer capable of inducing septic shock, resulting in a significant enhancement in safety. However, msbB Salmonella strains also exhibit an unusual set of additional physiological characteristics, including sensitivities to NaCl, EGTA, deoxycholate, polymyxin, and CO2. Suppressor mutations that compensate for these sensitivities include somA, Suwwan, pmrA (C), and zwf. We describe here methods for isolation of strains with compensatory mutations that suppress these types of sensitivities and techniques for determining their underlying genetic changes and analysis of their effects in murine tumor models.


Subject(s)
Bacterial Proteins/genetics , Mutation , Salmonella typhimurium/genetics , Animals , Carbon Dioxide/metabolism , Chromosome Mapping , Cloning, Molecular , DNA Transposable Elements , Disease Models, Animal , Drug Delivery Systems , Humans , Mice , Neoplasms/genetics , Neoplasms/metabolism , Neoplasms/pathology , Neoplasms/therapy , Salmonella typhimurium/metabolism , Tumor Burden
8.
Trop Biomed ; 33(3): 469-475, 2016 Sep 01.
Article in English | MEDLINE | ID: mdl-33579118

ABSTRACT

Leptospirosis is under-reported and remarkably neglected in Malaysia, especially in companion animals. In recent years, dogs have become popular pets and potentially act as one of the risk factors for human leptospiral infection. The purpose of this study was to determine the serological and molecular status of leptospirosis in healthy and dogs with kidney disease in Klang Valley, Malaysia and to gain insight of the possible serovars involved in the dog population in Klang Valley, Malaysia. Blood samples were obtained from 57 dogs (19 kidney disease patient; 38 healthy dogs, respectively). Serum samples obtained from these animals were screened for leptospiral antibodies by the microscopic agglutination test (MAT). Polymerase chain reaction (PCR) assay was performed on plasma samples to detect leptospiral DNA. By MAT, three out of 19 (15.8%) dogs with kidney disease were positive for L. canicola. One out of 38 (2.6%) healthy dogs was positive for L. icterohemorrhagiae. The overall seroprevalence for leptospirosis in dogs in Klang Valley, Malaysia was 7.0% (n=4/57). Only one out of the 19 dogs (5.3%) with kidney disease was tested positive to pathogenic Leptospira by PCR assay. All the 38 healthy dogs were negative. Positive results in healthy dogs and dogs with kidney disease for leptospirosis warrant further investigation of leptospirosis in dog population in Malaysia. The prevalence and incidence of this disease in the dog population in this country need further investigation.

9.
Tropical Biomedicine ; : 469-475, 2016.
Article in English | WPRIM (Western Pacific) | ID: wpr-630835

ABSTRACT

Leptospirosis is under-reported and remarkably neglected in Malaysia, especially in companion animals. In recent years, dogs have become popular pets and potentially act as one of the risk factors for human leptospiral infection. The purpose of this study was to determine the serological and molecular status of leptospirosis in healthy and dogs with kidney disease in Klang Valley, Malaysia and to gain insight of the possible serovars involved in the dog population in Klang Valley, Malaysia. Blood samples were obtained from 57 dogs (19 kidney disease patient; 38 healthy dogs, respectively). Serum samples obtained from these animals were screened for leptospiral antibodies by the microscopic agglutination test (MAT). Polymerase chain reaction (PCR) assay was performed on plasma samples to detect leptospiral DNA. By MAT, three out of 19 (15.8%) dogs with kidney disease were positive for L. canicola. One out of 38 (2.6%) healthy dogs was positive for L. icterohemorrhagiae. The overall seroprevalence for leptospirosis in dogs in Klang Valley, Malaysia was 7.0% (n=4/57). Only one out of the 19 dogs (5.3%) with kidney disease was tested positive to pathogenic Leptospira by PCR assay. All the 38 healthy dogs were negative. Positive results in healthy dogs and dogs with kidney disease for leptospirosis warrant further investigation of leptospirosis in dog population in Malaysia. The prevalence and incidence of this disease in the dog population in this country need further investigation.

12.
Med Vet Entomol ; 28 Suppl 1: 104-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25171613

ABSTRACT

Rickettsioses are emerging zoonotic diseases reported worldwide. In spite of the serological evidence of spotted fever group rickettsioses in febrile patients in Malaysia, limited studies have been conducted to identify the animal reservoirs and vectors of rickettsioses. This study investigated the presence of rickettsiae in the tissue homogenates of 95 wild rats and 589 animal ectoparasites. Using PCR assays targeting the citrate synthase gene (gltA), rickettsial DNA was detected in the tissue homogenates of 13 (13.7%) wild rats. Sequence analysis of the gltA amplicons showed 98.6-100% similarity with those of Rickettsia honei/R. conorii/R. raoultii (Rickettsiales: Rickettsiaceae). Sequence analysis of outer membrane protein A gene (ompA) identified Rickettsia sp. TCM1 strain from two rats. No rickettsia was detected from Laelaps mites, Rhipicephalus sanguineus and Haemaphysalis bispinosa ticks, and Felicola subrostratus lice in this study. R. felis was identified from 32.2% of 177 Ctenocephalides felis fleas. Sequence analysis of the gltA amplicons revealed two genotypes of R. felis (Rf31 and RF2125) in the fleas. As wild rats and cat fleas play an important role in the enzoonotic maintenance of rickettsiae, control of rodent and flea populations may be able to reduce transmission of rickettsioses in the local setting.


Subject(s)
Bacterial Outer Membrane Proteins/genetics , Citrate (si)-Synthase/genetics , Ctenocephalides/microbiology , Rats , Rickettsia Infections/veterinary , Rickettsia/genetics , Rodent Diseases/epidemiology , Animals , Female , Malaysia , Male , Molecular Sequence Data , Polymerase Chain Reaction/veterinary , Rickettsia/classification , Rickettsia/isolation & purification , Rickettsia Infections/epidemiology , Rickettsia Infections/microbiology , Rodent Diseases/microbiology , Sequence Analysis, DNA/veterinary
13.
Pediatr Pulmonol ; 49(10): E140-3, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24799442

ABSTRACT

We describe a three generation family in whom multiple individuals are variably affected due to a PHOX2B non-polyalanine repeat mutation. This family demonstrates extreme phenotypic variability and autosomal dominant transmission over three generations not previously reported in the wider literature. Novel findings also inclue a history of recurrent second trimester miscarriage. Pediatr Pulmonol. 2014; 49:E140-E143. © 2014 Wiley Periodicals, Inc.


Subject(s)
Homeodomain Proteins/genetics , Hypoventilation/congenital , Mutation , Sleep Apnea, Central/genetics , Transcription Factors/genetics , Abortion, Habitual/genetics , Female , Humans , Hypoventilation/genetics , Infant , Male , Pedigree , Pregnancy
14.
Gait Posture ; 39(1): 443-8, 2014.
Article in English | MEDLINE | ID: mdl-24071020

ABSTRACT

Robotics is gaining its popularity in gait rehabilitation. Gait pattern planning is important to ensure that the gait patterns induced by robotic systems are tailored to each individual and varying walking speed. Most research groups planned gait patterns for their robotics systems based on Clinical Gait Analysis (CGA) data. The major problem with the method using the CGA data is that it cannot accommodate inter-subject differences. In addition, CGA data is limited to only one walking speed as per the published data. The objective of this work was to develop an individual-specific gait pattern prediction model for gait pattern planning in the robotic gait rehabilitation systems. The waveforms of lower limb joint angles in the sagittal plane during walking were obtained with a motion capture system. Each waveform was represented and reconstructed by a Fourier coefficient vector which consisted of eleven elements. Generalized regression neural networks (GRNNs) were designed to predict Fourier coefficient vectors from given gait parameters and lower limb anthropometric data. The generated waveforms from the predicted Fourier coefficient vectors were compared to the actual waveforms and CGA waveforms by using the assessment parameters of correlation coefficients, mean absolute deviation (MAD) and threshold absolute deviation (TAD). The results showed that lower limb joint angle waveforms generated by the gait pattern prediction model were closer to the actual waveforms compared to the CGA waveforms.


Subject(s)
Gait/physiology , Joints/physiology , Robotics/methods , Adolescent , Adult , Biomechanical Phenomena , Female , Gait Disorders, Neurologic/rehabilitation , Humans , Leg/physiology , Male , Models, Biological , Neural Networks, Computer , Regression Analysis , Young Adult
15.
Res Dev Disabil ; 34(4): 1226-35, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23396198

ABSTRACT

In order to identify optimal rehabilitation strategies for spinal cord injury (SCI) participants, assessment of impaired walking is required to detect, monitor and quantify movement disorders. In the proposed assessment, ten healthy and seven SCI participants were recruited to perform an over-ground walking test at slow walking speeds. SCI participants were given assistance from physiotherapists, if required, while they were walking. In agreement with other research, larger cadence and smaller step length and swing phase of SCI gait were observed as a result of muscle weakness and resultant gait instability. Muscle activation patterns of seven major leg muscles were collected. The EMG signal was processed by the RMS in frequency domain to represent the muscle activation power, and the distribution of muscle activation was compared between healthy and SCI participants. The alternations of muscle activation within the phases of the gait cycle are highlighted to facilitate our understanding of the underlying muscular activation following SCI. Key differences were observed (p-value=0.0006) in the reduced activation of tibialis anterior (TA) in single stance phase and rectus femoris (RF) in swing phase (p-value=0.0011). We can then conclude that the proposed assessment approach of gait provides valuable information that can be used to target and define therapeutic interventions and their evaluation; hence impacting the functional outcome of SCI individuals.


Subject(s)
Gait Disorders, Neurologic/physiopathology , Muscle, Skeletal/physiopathology , Spinal Cord Injuries/physiopathology , Adaptation, Physiological , Adult , Case-Control Studies , Cervical Vertebrae , Electromyography , Gait Disorders, Neurologic/diagnosis , Gait Disorders, Neurologic/etiology , Humans , Lower Extremity , Middle Aged , Quadriceps Muscle/physiopathology , Spinal Cord Injuries/complications , Spinal Cord Injuries/rehabilitation , Young Adult
16.
Int J Numer Method Biomed Eng ; 28(12): 1224-46, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23212798

ABSTRACT

In this study, an improved and robust one-dimensional human arterial network model is presented. The one-dimensional blood flow equations are solved using the Taylor-locally conservative Galerkin finite element method. The model improvements are carried out by adopting parts of the physical models from different authors to establish an accurate baseline model. The predicted pressure-flow waveforms at various monitoring positions are compared against in vivo measurements from published works. The results obtained show that wave shapes predicted are similar to that of the experimental data and exhibit a good overall agreement with measured waveforms. Finally, computational studies on the influence of an abdominal aortic aneurysm are presented. The presence of aneurysms results in a significant change in the waveforms throughout the network.


Subject(s)
Arteries/anatomy & histology , Arteries/physiology , Finite Element Analysis , Hemodynamics/physiology , Models, Cardiovascular , Adult , Aortic Aneurysm, Abdominal/pathology , Aortic Aneurysm, Abdominal/physiopathology , Humans
17.
Neurogastroenterol Motil ; 23(8): 739-e328, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21557790

ABSTRACT

BACKGROUND: Short bowel syndrome (SBS) is a serious clinical disorder characterized by diarrhea and nutritional deprivation. Glucagon-like peptide-1 (GLP-1) is a key hormone, produced by L-cells in the ileum, that regulates proximal gut transit. When extensive ileal resection occurs, as in SBS, GLP-1 levels may be deficient. In this study, we test whether the use of GLP-1 agonist exenatide can improve the nutritional state and intestinal symptoms of patients with SBS. METHODS: Five consecutive patients with SBS based on ≤90 cm of small bowel and clinical evidence of nutritional deprivation were selected. Baseline SBS symptoms, demographic and laboratory data were obtained. Antroduodenal manometry was performed on each subject. Each patient was then started on exenatide and over the following month, the baseline parameters were repeated. KEY RESULTS: The subjects consisted of four males and one female, aged 46-69 years. At baseline, all had severe diarrhea that ranged from 6 to 15 bowel movements per day, often occurring within minutes of eating. After exenatide, all five patients had immediate improvement in bowel frequency and form; bowel movements were no longer meal-related. Total parenteral nutrition was stopped successfully in three patients. Antroduodenal manometry revealed continuous low amplitude gastric contractions during fasting which completely normalized with exenatide. CONCLUSIONS & INFERENCES: Exenatide is a novel and safe treatment option for SBS. It produced substantial improvement in the bowel habits, nutritional status and quality of life of SBS patients. Successful treatment with exenatide may significantly reduce the need for parenteral nutrition and small bowel transplant.


Subject(s)
Glucagon-Like Peptide 1/agonists , Hypoglycemic Agents/therapeutic use , Peptides/therapeutic use , Short Bowel Syndrome/drug therapy , Venoms/therapeutic use , Aged , Exenatide , Female , Humans , Male , Manometry , Middle Aged , Nutritional Status , Parenteral Nutrition, Total , Retrospective Studies , Short Bowel Syndrome/diet therapy , Short Bowel Syndrome/etiology , Short Bowel Syndrome/physiopathology
18.
IEEE Int Conf Rehabil Robot ; 2011: 5975353, 2011.
Article in English | MEDLINE | ID: mdl-22275557

ABSTRACT

Due to the labor-intensiveness and the shortage of therapists in the application of most forms of manually assisted gait training in neuro-rehabilitation, robotics rehabilitation gait systems have been developed to contribute in such fields of neuro-rehabilitation. This paper presents an overground gait rehabilitation robot, which consists of a pair of robotic orthosis (RO) connected to pelvic arm (PA) and mounted on a mobile platform (MP). As the robotic orthosis (RO) is connected to pelvic arm (PA), the compensation between the two modules should be considered. Possible problems that may surface during overground walking include: 1. Ground impact problem. 2. Poor coordination to mobile platform (MP) which would cause foot drag. To reduce, if not to avoid, the ground impact and dragging of the footpad occurring during the course of overground walking with help of the device, a gait motion generation is developed and specified to adjust the gait patterns for an impactless and smooth footpad contact. The initial tests demonstrate the effectiveness and smoothness of the overground walking on the system.


Subject(s)
Gait/physiology , Robotics/instrumentation , Robotics/methods , Equipment Design , Humans , Spinal Cord Injuries/rehabilitation , Stroke Rehabilitation
19.
IEEE Int Conf Rehabil Robot ; 2011: 5975354, 2011.
Article in English | MEDLINE | ID: mdl-22275558

ABSTRACT

With the evolution of robotic systems to facilitate overground walking rehabilitation, it is important to understand the effect of robotic-aided body-weight supported loading on lower limb muscle activity, if we are to optimize neuromotor recovery. To achieve this objective, we have collected and studied electromyography (EMG) data from key muscles in the lower extremity from healthy subjects walking over a wide range of body-weight off-loading levels as provided by a bespoke gait robot. By examining the impact of body-weight off-loading, it was found that muscle activation patterns were sensitive to the level of off-loading. In addition, a large off-loading might introduce disturbance of muscle activation pattern, led to a wider range of motion in terms of dorsiflexion/plantarflexion. Therefore, any future overground training machine should be enhanced to exclude unnecessary effect of body off-loading in securing the sustaining upright posture and providing assist-as-needed BWS over gait rehabilitation.


Subject(s)
Exercise Therapy/instrumentation , Exercise Therapy/methods , Locomotion/physiology , Robotics/instrumentation , Robotics/methods , Adult , Body Weight/physiology , Electromyography , Female , Gait/physiology , Humans , Male , Spinal Cord Injuries , Stroke Rehabilitation , Weight-Bearing/physiology , Young Adult
20.
IEEE Int Conf Rehabil Robot ; 2011: 5975491, 2011.
Article in English | MEDLINE | ID: mdl-22275688

ABSTRACT

Robotic is gaining its popularity in gait rehabilitation. Gait pattern planning is important, in order to ensure the gait patterns induced by robotic systems on the patient are natural and smooth. It is known that the gait parameters (stride length, cadence) are the key factors, which affect gait pattern. However, a systematic methodology for gait pattern planning is missing. Therefore, a gait pattern generation methodology, GaitGen, was proposed in our previous work. In this paper, we introduce a new model to enhance the proposed methodology for generating the joint angle waveforms of the lower limb during walking, with the gait parameters and the lower limb anthropometric data as input. The walking motion was captured with a motion capture system using passive markers. The waveforms of lower limb joint angles were calculated from the experimental data and the waveforms were then decomposed into Fourier coefficients. Therefore, each joint angle waveform can be represented by a Fourier coefficient vector containing eleven elements to facilitate the waveform analysis. Multi-layer perceptron neural networks (MLPNNs) were designed to predict the Fourier coefficient vectors for specific subject and desired gait parameters. Assessment parameters such as correlation coefficient, mean absolute deviation (MAD) and threshold absolute deviation (TAD) were calculated to examine the quality of MLPNNs' prediction. The constructed waveforms from predicted Fourier coefficient vectors were compared with the actual waveforms calculated from experimental data by using the above-mentioned assessment parameters. The results show that the constructed waveforms closely match the experimental waveforms based on the assessment parameter outcomes.


Subject(s)
Lower Extremity/physiology , Neural Networks, Computer , Robotics/instrumentation , Robotics/methods , Adolescent , Adult , Gait/physiology , Humans , Male , Walking/physiology , Young Adult
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