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1.
Healthc Technol Lett ; 6(4): 87-91, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31531221

RESUMO

Diabetes is a metabolic disorder that affects more than 400 million people worldwide. Most existing approaches for measuring fasting blood glucose levels (FBGLs) are invasive. This work presents a proof-of-concept study in which saliva is used as a proxy biofluid to estimate FBGL. Saliva collected from 175 volunteers was analysed using portable, handheld sensors to measure its electrochemical properties such as conductivity, redox potential, pH and K+, Na+ and Ca2+ ionic concentrations. These data, along with the person's gender and age, were trained and tested after casewise annotation with their true FBGL values using a set of mathematical algorithms. An accuracy of 87.4 ± 1.7% and a mean relative deviation of 14.1% (R 2 = 0.76) was achieved using a mathematical algorithm. All parameters except the gender were found to play a key role in the FBGL determination process. Finally, the individual electrochemical sensors were integrated into a single platform and interfaced with the authors' algorithm through a simple graphical user interface. The system was revalidated on 60 new saliva samples and gave an accuracy of 81.67 ± 2.53% (R 2 = 0.71). This study paves the way for rapid, efficient and painless FBGL estimation from saliva.

2.
IEEE Trans Neural Syst Rehabil Eng ; 27(12): 2369-2377, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31545737

RESUMO

Robots have the potential to help provide exercise therapy in a repeatable and reproducible manner for stroke survivors. To facilitate rehabilitation of the wrist and fingers joint, an electromechanical exoskeleton was developed that simultaneously moves the wrist and metacarpophalangeal joints. The device was designed for the ease of manufacturing and maintenance, with specific considerations for countries with limited resources. Active participation of the user is ensured by the implementation of electromyographic control and visual feedback of performance. Muscle activity requirements, movement parameters, range of motion and speed, of the device can all be customized to meet the needs of the user. Twelve stroke survivors, ranging from the subacute to chronic phases of recovery (mean 10.6 months post-stroke) participated in a pilot study with the device. Participants completed 20 sessions, each lasting 45 minutes. Overall, subjects exhibited statistically significant changes (p < 0.05) in clinical outcome measures following the treatment, with the Fugl-Meyer Stroke Assessment score for the upper extremity increasing from 36 to 50 and the Barthel Index increasing from 74 to 89. Active range of wrist motion increased by 19° while spasticity decreased from 1.75 to 1.29 on the Modified Ashworth Scale. Thus, this device shows promise for improving rehabilitation outcomes, especially for patients in countries with limited resources.


Assuntos
Exoesqueleto Energizado , Articulações dos Dedos/fisiologia , Robótica/métodos , Reabilitação do Acidente Vascular Cerebral/métodos , Punho/fisiologia , Adolescente , Adulto , Idoso , Países em Desenvolvimento , Retroalimentação Sensorial , Feminino , Análise de Elementos Finitos , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Projetos Piloto , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Resultado do Tratamento , Adulto Jovem
3.
J Med Eng Technol ; 43(4): 217-222, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31464536

RESUMO

The reported paper presents the development of a microwave sensor with a resonant frequency 2.4 GHz. The sensor is also demonstrated in vitro to investigate the variation in its response as a function of glucose concentration. The sensor could be used for the monitoring of blood glucose level in diabetics through non-invasive technology. The approach followed is based on the notion that, change in glucose concentration in the blood affects dielectric properties of blood which in turn produce an impact on reflection properties of the sensor. This effect on response of sensor will be ultimately used to estimate blood glucose concentration. The design specifications considered for the development of sensor are defined in the paper. The experimental setup for in vitro experiment and procedure employed for the investigation of the reflection properties of the sensor as a function of glucose concentration are also discussed in detail. The shift in resonance frequency and the change in the magnitude of the reflection coefficient of proposed sensor have been observed. The reported measurement results are the preliminary results in exploring the implementation of proposed sensor for non-invasive blood glucose monitoring.


Assuntos
Automonitorização da Glicemia , Glucose/análise , Micro-Ondas
4.
J Med Eng Technol ; 42(4): 274-289, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-30019971

RESUMO

Electrical impedance tomography (EIT) is an upcoming and capable imaging modality used for clinical imaging. It is non-invasive, non-ionising and an inexpensive technique. This paper explains the designing and the analysis of a low-cost multifrequency electrical impedance-based system (MFEIBS) having a flexible mechanism of interfacing up to 32 electrodes, suitable for 1 kHz-2 MHz. Various indicators to check the performance of the EIT system were evaluated and presented here. The performance of VCO and VCCS was measured up to 2 MHz. SNR was measured with saline phantom and its mean value is 74 dB for the complete bandwidth. Different combinations of resistors and capacitors were used to find the accuracy of the system, and relative error was less than 0.55% for the entire range. CMRR of the system was calculated and it was found to be maximum 85 dB at 1 kHz frequency. A 16-electrode circular plastic phantom having a diameter of 18 cm was established and connected with a simple MFEIBS. Obtained surface potential was applied to the computer used for image formation using NI USB-6259, 16-bit, 1.25 MS/s M Series High-speed DAQ. Images reconstructed using the system presented in this paper was generated from a 16-electrode plastic phantom filled with NaCl up to 1.2 cm height.


Assuntos
Impedância Elétrica , Tomografia/métodos , Desenho de Equipamento , Tomografia/instrumentação
5.
J Healthc Eng ; 2018: 9213707, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29808111

RESUMO

This paper presents a classification system to classify the cognitive load corresponding to targets and distractors present in opposite visual hemifields. The approach includes the study of EEG (electroencephalogram) signal features acquired in a spatial attention task. The process comprises of EEG feature selection based on the feature distribution, followed by the stepwise discriminant analysis- (SDA-) based channel selection. Repeated measure analysis of variance (rANOVA) is applied to test the statistical significance of the selected features. Classifiers are developed and compared using the selected features to classify the target and distractor present in visual hemifields. The results provide a maximum classification accuracy of 87.2% and 86.1% and an average classification accuracy of 76.5 ± 4% and 76.2 ± 5.3% over the thirteen subjects corresponding to the two task conditions. These correlates present a step towards building a feature-based neurofeedback system for visual attention.


Assuntos
Atenção , Eletroencefalografia , Neurorretroalimentação , Reabilitação/métodos , Campos Visuais , Adulto , Algoritmos , Análise de Variância , Interfaces Cérebro-Computador , Análise Discriminante , Eletrodos , Feminino , Humanos , Masculino , Redes Neurais de Computação , Neuroimagem , Curva ROC , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Máquina de Vetores de Suporte , Adulto Jovem
6.
J Med Eng Technol ; 42(2): 113-120, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29448856

RESUMO

Selective visual attention is the ability to selectively pay attention to the targets while inhibiting the distractors. This paper aims to study the targets and non-targets interplay in spatial attention task while subject attends to the target object present in one visual hemifield and ignores the distractor present in another visual hemifield. This paper performs the averaged evoked response potential (ERP) analysis and time-frequency analysis. ERP analysis agrees to the left hemisphere superiority over late potentials for the targets present in right visual hemifield. Time-frequency analysis performed suggests two parameters i.e. event-related spectral perturbation (ERSP) and inter-trial coherence (ITC). These parameters show the same properties for the target present in either of the visual hemifields but show the difference while comparing the activity corresponding to the targets and non-targets. In this way, this study helps to visualise the difference between targets present in the left and right visual hemifields and, also the targets and non-targets present in the left and right visual hemifields. These results could be utilised to monitor subjects' performance in brain-computer interface (BCI) and neurorehabilitation.


Assuntos
Potenciais Evocados/fisiologia , Feminino , Humanos , Masculino , Reabilitação Neurológica , Tempo de Reação/fisiologia , Percepção Visual/fisiologia
7.
Proc Inst Mech Eng H ; 230(8): 750-60, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27246916

RESUMO

Elastance is a distinguished marker in diagnosing various arterial diseases as studies have reported carotid artery-related diseases linked with stiffness index (ß) values greater than 5. This study was to estimate elasticity of common carotid artery by measuring the diameter during systolic and diastolic phases using pixel tracing of successive frames and blood pressure. The B-mode ultrasonography video containing arterial wall motion was captured and fragmented into image frames. Each pixel on the greyscale image was converted into RGB intensity values. The diameter of the artery as well as the thickness of the wall was measured by tracing the pixel displacements from successive frames during arterial pulsation. The study was conducted on 19 subjects aged 25-40 years. The systolic and diastolic carotid artery lumen diameters and carotid intima-media thickness were calculated as 7.1 ± 0.7, 6.3 ± 0.6 and 0.5 ± 0.05 mm (mean ± standard deviation), respectively. The mean stiffness index (ß), Peterson's modulus and Young's modulus of elasticity were 5.2 ± 1.1, 69 ± 15 kPa and 453 ± 99 kPa, respectively. The pixel displacements in tunica intima, tunica media and tunica adventitia were not homogeneous, due to varied macro-constituents such as endothelial tissues, smooth muscle cells, elastin lamina, fibrous tissue and micro-constituents such as collagen, fibroblast and elastin. We found that women have smaller arteries, and the stiffness increased during the systolic phase.


Assuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Adulto , Pressão Sanguínea/fisiologia , Artéria Carótida Primitiva/fisiopatologia , Espessura Intima-Media Carotídea , Módulo de Elasticidade/fisiologia , Técnicas de Imagem por Elasticidade , Feminino , Voluntários Saudáveis , Humanos , Masculino , Rigidez Vascular/fisiologia
8.
Surg Innov ; 23(6): 606-612, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27354550

RESUMO

With advancements in imaging techniques, neurosurgical procedures are becoming highly precise and minimally invasive, thus demanding development of new ergonomically aesthetic instruments. Conventionally, neurosurgical instruments are manufactured using subtractive manufacturing methods. Such a process is complex, time-consuming, and impractical for prototype development and validation of new designs. Therefore, an alternative design process has been used utilizing blue light scanning, computer-aided designing, and additive manufacturing direct metal laser sintering (DMLS) for microsurgical instrument prototype development. Deviations of DMLS-fabricated instrument were studied by superimposing scan data of fabricated instrument with the computer-aided designing model. Content and concurrent validity of the fabricated prototypes was done by a group of 15 neurosurgeons by performing sciatic nerve anastomosis in small laboratory animals. Comparative scoring was obtained for the control and study instrument. T test was applied to the individual parameters and P values for force (P < .0001) and surface roughness (P < .01) were found to be statistically significant. These 2 parameters were further analyzed using objective measures. Results depicts that additive manufacturing by DMLS provides an effective method for prototype development. However, direct application of these additive-manufactured instruments in the operating room requires further validation.


Assuntos
Desenho Assistido por Computador , Microcirurgia/instrumentação , Procedimentos Neurocirúrgicos/instrumentação , Instrumentos Cirúrgicos/tendências , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Segurança de Equipamentos , Humanos , Teste de Materiais , Procedimentos Neurocirúrgicos/métodos , Instrumentos Cirúrgicos/normas
9.
Springerplus ; 5(1): 701, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27350930

RESUMO

Machine learning techniques such as logistic regression (LR), support vector machine (SVM) and artificial neural network (ANN) were used to detect fasting blood glucose levels (FBGL) in a mixed population of healthy and diseased individuals in an Indian population. The occurrence of elevated FBGL was estimated in a non-invasive manner from the status of an individual's salivary electrochemical parameters such as pH, redox potential, conductivity and concentration of sodium, potassium and calcium ions. The samples were obtained from 175 randomly selected volunteers comprising half healthy and half diabetic patients. The models were trained using 70 % of the total data, and tested upon the remaining set. For each algorithm, data points were cross-validated by randomly shuffling them three times prior to implementing the model. The performance of the machine learning technique was reported in terms of four statistically significant parameters-accuracy, precision, sensitivity and F1 score. SVM using RBF kernel showed the best performance for classifying high FBGLs with approximately 85 % accuracy, 84 % precision, 85 % sensitivity and 85 % F1 score. This study has been approved by the ethical committee of All India Institute of Medical Sciences, New Delhi, India with the reference number: IEC/NP-278/01-08-2014, RP-29/2014.

10.
World Neurosurg ; 86: 259-69, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26410199

RESUMO

BACKGROUND: Box trainers are ideal simulators, given they are inexpensive, accessible, and use appropriate fidelity. OBJECTIVE: The development and validation of an open-source, partial task simulator that teaches the fundamental skills necessary for endonasal skull-base neuro-endoscopic surgery. METHODS: We defined the Neuro-Endo-Trainer (NET) SkullBase-Task-GraspPickPlace with an activity area by analyzing the computed tomography scans of 15 adult patients with sellar suprasellar parasellar tumors. Four groups of participants (Group E, n = 4: expert neuroendoscopists; Group N, n =19: novice neurosurgeons; Group R, n = 11: neurosurgery residents with multiple iterations; and Group T, n = 27: neurosurgery residents with single iteration) performed grasp, pick, and place tasks using NET and were graded on task completion time and skills assessment scale score. RESULTS: Group E had lower task completion times and greater skills assessment scale scores than both Group N and R (P ≤ 0.03, 0.001). The performance of Groups N and R was found to be equivalent; in self-assessing neuro-endoscopic skill, the participants in these groups were found to have equally low pretraining scores (4/10) with significant improvement shown after NET simulation (6, 7 respectively). Angled scopes resulted in decreased scores with tilted plates compared with straight plates (30° P ≤ 0.04, 45° P ≤ 0.001). With tilted plates, decreased scores were observed when we compared the 0° with 45° endoscope (right, P ≤ 0.008; left, P ≤ 0.002). CONCLUSIONS: The NET, a face and construct valid open-source partial task neuroendoscopic trainer, was designed. Presimulation novice neurosurgeons and neurosurgical residents were described as having insufficient skills and preparation to practice neuro-endoscopy. Plate tilt and endoscope angle were shown to be important factors in participant performance. The NET was found to be a useful partial-task trainer for skill building in neuro-endoscopy.


Assuntos
Endoscopia/educação , Cavidade Nasal/cirurgia , Neuroendoscopia/educação , Neurocirurgia/educação , Adolescente , Adulto , Competência Clínica , Simulação por Computador , Avaliação Educacional , Feminino , Humanos , Índia , Internato e Residência , Masculino , Manequins , Pessoa de Meia-Idade , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/cirurgia , Reprodutibilidade dos Testes , Autoavaliação (Psicologia) , Base do Crânio/cirurgia , Cirurgiões , Tomografia Computadorizada por Raios X , Adulto Jovem
11.
Indian J Physiol Pharmacol ; 58(3): 211-21, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25906603

RESUMO

OBJECTIVE: The objective of the study was to observe the effect of controlled breathing exercises including Sudarshan Kriya (SK) and Prana-Yoga (PY) on the psycho-physiological status. METHODS: The study group included 60 healthy volunteers (M:30, F:30) in the age group of 18 to 30 years (21.3 ± 3.2 yrs), randomly divided in to three groups of 20 subjects each--(1) The SK group (2) the PY group and the (3) Control group. The psycho-physiological data was collected at the following four time interventions: Baseline, 6th, 60th and the 150th day. Psychological assessment was done using questionnaires and for the autonomic tone quantification Heart Rate Variability (HRV) analysis was done using the standard lead II electrocardiogram recordings. In a post-hoc analysis each group was further sub divided in to the following two patterns, based on the baseline values of normalized Low Frequency (LF) power (cutoff 64 ms2): (i) Pattern A-Subjects with low level LF power, and (ii) Pattern B- subjects with high level LF power. RESULTS: The stress management skills have shown significant increase in SK group but not in PY and Control group. Subjects of SK, PY, and control group showed significant increase in LF value and LF:HF ratio for pattern A and significant decrease for pattern B. Plotted LF value for pattern A & B in SK and PY practitioners showed convergence, coming to a mean value over the period of 150 days. The LF:HF ratio curve plotted over time for pattern A & B showed convergence in SK group only. No such convergence in LF value & LF/HF ratio for pattern A & B was seen in control group. CONCLUSION: In conclusion, Sudarshan Kriya positively modifies stress coping behavior and initiates appropriate balance in cardiac autonomic tone.


Assuntos
Adaptação Psicológica , Exercícios Respiratórios , Frequência Cardíaca , Yoga , Adolescente , Adulto , Feminino , Humanos , Masculino
12.
Artigo em Inglês | MEDLINE | ID: mdl-24110253

RESUMO

This paper presents the study of bispectrum analysis methods of heart rate variability in normotensive pregnant and postpartum women. The self and cross spectral components are estimated from bispectrum of ECG of pregnant and postpartum women. It is observed that, very low frequency (VLF) and low frequency (LF) component coupling increases while the high frequency (HF) coupling and cross coupling between VLF-LF, VLF-HF and LF-HF decreases throughout the pregnancy. The power at very high frequencies decreases as gestation age progresses. Significant differences are found in similar and cross coupling frequency components in all three trimesters and postpartum. The results indicate that one possible discriminating dynamics for the pregnant women in all three trimesters is the absence of nonlinear interactions between the sympathetic and parasympathetic nervous systems.


Assuntos
Eletrocardiografia , Frequência Cardíaca/fisiologia , Período Pós-Parto/fisiologia , Feminino , Humanos , Gravidez , Trimestres da Gravidez/fisiologia , Adulto Jovem
13.
J Med Eng Technol ; 37(5): 342-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23795697

RESUMO

The aim of this study was to explore how foot type affects plantar pressure distribution during standing. In this study, 32 healthy subjects voluntarily participated and the subject feet were classified as: normal feet (n = 23), flat feet (n = 14) and high arch feet (n = 27) according to arch index (AI) values obtained from foot pressure intensity image analysis. Foot pressure intensity images were acquired by a pedopowergraph system to obtain a foot pressure distribution parameter-power ratio (PR) during standing in eight different regions of the foot. Contact area and mean PR were analysed in hind foot, mid-foot and fore foot regions. One-way analysis of variance was used to determine statistical differences between groups. The contact area and mean PR value beneath the mid-foot was significantly increased in the low arch foot when compared to the normal arch foot and high arch foot (p < 0.001) in both feet. However, subjects with low-arch feet had significantly higher body mass index (BMI) compared to subjects with high-arch feet (p < 0.05) and subjects with normal arch feet (p < 0.05) in both feet. In addition, subjects with low-arch feet had significant differences in arch index (AI) value as compared to subjects with high-arch feet (p < 0.001) and subjects with normal arch feet (p < 0.05) in both feet. Mean mid-foot PR value were positively (r = 0.54) correlated with increased arch index (AI) value. A significant (p < 0.05) change was obtained in PR value beneath the mid-foot of low arch feet when compared with other groups in both feet. The findings suggest that there is an increased mid-foot PR value in the low arch foot as compared to the normal arch foot and high arch foot during standing. Therefore, individuals with low arch feet could be at high risk for mid-foot collapse and Charcot foot problems, indicating that foot type should be assessed when determining an individual's risk for foot injury.


Assuntos
Pé/anatomia & histologia , Pé/fisiologia , Postura , Adulto , Fenômenos Biomecânicos , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Adulto Jovem
14.
Foot (Edinb) ; 22(4): 276-82, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23102906

RESUMO

BACKGROUND: To investigate foot pressure distribution parameter-power ratio (PR) difference between pre-obese and non-obese adults subjects during standing and show the correlation between body mass index (BMI) and PR value. METHODS: We examined 22 healthy adult subjects aged from 20 to 45 years were classified into two groups according to their BMI values, as 11 non-obese and 11 pre-obese subjects. Foot pressure distribution image during standing was obtained using PedoPowerGraph system. Pedopowergraphic parameters such as percentage medial impulse, forefoot to hind foot pressure distribution ratio and PR were evaluated and compared between the groups. Correlation between BMI value and PR value was assessed. RESULTS: Our result shows significant change in contact area between the groups in mid foot regions. Also we found significant differences in mid foot PR values (p<0.05) between the groups, but no significant differences in hind foot and forefoot PR values. In addition BMI value was found to have positive correlation with right and left mid foot PR value (r=0.60 & 0.61) for all the subjects. CONCLUSION: This study provides for the first time new insights into foot pressure distribution difference in mid foot among pre-obese subjects as compared to non-obese adult subject while standing. Hence knowledge of high mid foot PR value among pre-obese subjects can provide suitable guidelines for designing orthotic devices.


Assuntos
Pé/fisiologia , Sobrepeso/fisiopatologia , Postura/fisiologia , Adulto , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Adulto Jovem
15.
Proc Inst Mech Eng H ; 226(4): 305-11, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22611870

RESUMO

The aim of this article is to investigate the association of limited joint mobility and foot sole hardness in north Asian Indian type 2 diabetic patients. Limited joint mobility and hardness of the foot sole were measured for 39 subjects attending the AIIMS Endocrinology & Metabolism Clinic. The total subject divided into three groups: 13 control subjects (nondiabetic), 13 diabetic patients without neuropathy and 13 diabetic neuropathy patients. Neuropathy status was assessed using 10 gm Semen's Weinstein monofilament. Joint mobility parameters, such as ankle dorsiflexion/plantar flexion and metatarsophalangeal-1 dorsiflexion/plantar flexion, are measured using a goniometer. Foot sole hardness was measured using a durometer or shore meter. We found that diabetic patients with a neuropathic foot had significantly reduced joint mobility and increased foot sole hardness, placing them at risk for subsequent ulceration. Metatarsophalangeal-1 dorsiflexion/plantar flexion of both feet of diabetic patients had significant correlation (at p < 0.05, p < 0.001, p < 0.001 level) over age and body mass index. Also ankle plantar flexion/dorsiflexion and metatarsophalangeal-1 dorsiflexion/plantar flexion has a significant correlations (at p < 0.01, p < 0.05, p < 0.001, p < 0.001 level) with foot sole hardness in both feet of diabetic neuropathy subjects. Also linear regression analysis showed that duration of diabetes was significantly associated with the joint mobility parameters. In this study we conclude that joint mobility had reduced further if neuropathy and increased foot sole hardness coexisted owing to high plantar pressures. Hence, both limited joint mobility and increased foot sole hardness appears to be important determinants of foot sole ulceration in diabetic neuropathic subject.


Assuntos
Articulação do Tornozelo/fisiopatologia , Pé Diabético/fisiopatologia , Instabilidade Articular/fisiopatologia , Amplitude de Movimento Articular , Pé Diabético/complicações , Feminino , Dureza , Humanos , Instabilidade Articular/etiologia , Masculino , Pessoa de Meia-Idade
16.
Foot (Edinb) ; 22(2): 95-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22386216

RESUMO

BACKGROUND: Foot problems are common in older people and altered biomechanical parameters under the foot sole has been proposed as a key risk factor for foot lesions. Therefore the aim of this study was to investigate the age-related differences in the hardness of foot sole skin. METHODS: Twenty-six healthy volunteers without foot problems, aged from 26 to 65 years, were examined using shore meter. The hardness of the foot sole under the big toe (area 8), 1st metatarsal head (area 5), 3rd metatarsal head (area 6), 5th metatarsal head (area 7), mid foot (area 3, 4) and hind foot (area 1, 2) were measured. The correlation between age and hardness of foot sole was examined and comparisons were made between two age groups. RESULTS: From the result we observe statistical significant (p<0.05; p<0.01; p<0.005) differences in hardness between age groups in hind foot, metatarsal heads (1st, 3rd & 5th) and big toe. Strong positive correlations between age and hardness of the foot sole were found at the big toe (r=0.57; p<0.005), 1st metatarsal head (r=0.567; p<0.00001), 3rd metatarsal head (r=0.565; p<0.00001), 5th metatarsal head (r=0.55; p<0.00001), and heel (r=0.59; p<0.0001). CONCLUSION: The loss of compliance in the foot sole may be one of the factors responsible for the higher incidence of foot problems in aged people. Routine foot examination and appropriate therapeutic intervention including the use of foot orthoses and optimal hardness of foot wear insole may help to prevent the serious foot injuries.


Assuntos
Pé/anatomia & histologia , Envelhecimento da Pele/fisiologia , Pele/anatomia & histologia , Caminhada , Adulto , Idoso , Fenômenos Biomecânicos , Feminino , Seguimentos , Pé/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Valores de Referência
17.
Artigo em Inglês | MEDLINE | ID: mdl-21978095

RESUMO

A probabilistic modelling is presented to detect mental activity from gait signature recorded from healthy subjects. The proposed scheme is based on principal component analysis with reduced feature dimension followed by a naïve Gaussian Bayes classifier. The leave-one-out cross-validation shows the detection accuracy of 94% with specificity and sensitivity of 96% and 98.3%, respectively. The research has a potential application in the prevention of elderly risk falls, lie detection and rehabilitation among Parkinson's patients.


Assuntos
Cognição/fisiologia , Marcha/fisiologia , Modelos Biológicos , Adolescente , Adulto , Teorema de Bayes , Engenharia Biomédica , Simulação por Computador , Humanos , Funções Verossimilhança , Masculino , Modelos Psicológicos , Modelos Estatísticos , Análise de Componente Principal , Análise e Desempenho de Tarefas , Adulto Jovem
18.
Foot (Edinb) ; 21(3): 142-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21478010

RESUMO

BACKGROUND: Women and men are anatomically and physiologically different in a number of ways. They differ in both shape and size. These differences could potentially mean foot pressure distribution variation in men and women. The purpose of this study was to analyze standing foot pressure image to obtain the foot pressure distribution parameter - power ratio variation between men and women using image processing in frequency domain. METHODS: We examined 28 healthy adult subjects (14 men and 14 women) aged between 20 and 45 years was recruited for our study. Foot pressure distribution patterns while standing are obtained by using a PedoPowerGraph plantar pressure measurement system for foot image formation, a digital camera for image capturing, a TV tuner PC-add on card, a WinDvr software for still capture and Matlab software with dedicated image processing algorithms have been developed. Various PedoPowerGraphic parameters such as percentage medial impulse (PMI), fore foot to hind foot pressure distribution ratio (F/H), big toe to fore foot pressure distribution ratio (B/F) and power ratio (PR) were evaluated. RESULTS: In men, contact area was significantly larger in all regions of the foot compared with women. There were significant differences in plantar pressure distribution but there was no significant difference in F/H and B/F ratio. Mean PR value was significantly greater in men than women under the hind foot and fore foot. PMI value was greater in women than men. As compared to men, women have maximum PR variations in the mid foot. Hence there is significant difference at level p<0.05 in medial mid foot and mid foot PR of women as compared to men. CONCLUSION: There was variation in plantar pressure distribution because the contact area of the men foot was larger than that of women foot. Hence knowledge of pressure distributions variation of both feet can provide suitable guidelines to biomedical engineers and doctor for designing orthotic devices for reliving the area of excessively high pressure.


Assuntos
Pé/fisiologia , Postura/fisiologia , Pressão , Adulto , Feminino , Análise de Fourier , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Software , Adulto Jovem
19.
Int J Pharm Investig ; 1(4): 234-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23071949

RESUMO

INTRODUCTION: The effect of DC iontophoresis using low (0.2 mA/cm(2)) and high current density (0.5 mA/cm(2)) on transdermal permeation of methotrexate loaded into polyacrylamide hydrogel patch was investigated. RESULTS: Flux of 20.57 ± 1.02 µg/cm(2)/h and 36.8 ± 2.21 µg/cm(2)/h was achieved with low and high current density DC iontophoresis, respectively. Attenuated total reflectance-Fourier Transform infrared (ATR-FTIR) spectra and microscopic studies of the treated skin samples supported the permeation results. A greater decrease in the peak height of asymmetric, symmetric C-H stretching vibration and ester peak was noticed with 0.5 mA/cm(2) current density as compared to 0.2 mA/cm(2) current density samples. Furthermore, an increase in the ratio of amide I and amide II bands from 2.6 to 11 with increase in current density was noticed, thus indicating that hydration levels are associated with iontophoresis and play an important role in increasing the drug permeation. Scanning electron microscopy revealed increase in pore size of the hair follicles. Light microscopy studies of the skin samples treated with low current density DC iontophoresis demonstrated epidermal thinning and focal disruptions, spongiosis and appendageal dilatations. With higher current density, disruption of epidermis in almost half of the sectioned area, loss of appendages and fractured collagen in the dermis was noticed. Moreover, the reversibility studies conducted in vivo on mice revealed that the recovery process had started within 24 h and is complete in 48 h for lower current density treated animals. However, the histological changes associated with 0.5 mA/cm(2) current density were not reversible in 48 h and edema, appendageal dilatations along with focal disruption of epidermis persisted. CONCLUSION: Hence our study suggests that high density current is not well-tolerated by the skin.

20.
Drug Dev Ind Pharm ; 36(11): 1303-11, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20849347

RESUMO

PURPOSE: The aim was to study transdermal electroporation of insulin-loaded nanocarriers as a methodology for delivering macromolecules. METHODS: The efficacy of electroporation of insulin as solution and nanoparticles was compared in vitro and in vivo. Histology and confocal laser scanning microscopy were used to assess the effects of electroporation on skin structure, whereas the latter also demonstrated the depth of permeation of the nanoparticles. In vivo studies were performed on streptozotocin-diabetic male Wistar rats and compared with subcutaneous administration. RESULTS: A linear increase in insulin flux was noted on increasing the applied voltage (R(2) = 0.9514), the number of pulses (R(2) = 0.8515), and the pulse length (R(2) = 0.9937). Electroporation of nanoparticles resulted in fourfold enhancement in insulin deposition in rat skin in contrast to solution. In vivo studies showed maximum reduction of 77 ± 5% (87.2 ± 6.4 mIU/mL, t = 2 hours) and 85 ± 8% (37.8 ± 10.2 mIU/mL, t = 4 hours) in blood glucose levels for solution and nanoparticles, respectively, with therapeutic levels maintained for 24 and 36 hours. CONCLUSION: Overall, electroporation of polymeric nanosystems proved to be an ideal alternative to injectable administration.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Insulina/administração & dosagem , Absorção Cutânea , Administração Cutânea , Animais , Glicemia/efeitos dos fármacos , Portadores de Fármacos/química , Eletroporação/métodos , Hipoglicemiantes/farmacocinética , Hipoglicemiantes/farmacologia , Insulina/farmacocinética , Insulina/farmacologia , Masculino , Microscopia Confocal , Nanopartículas , Polímeros/química , Ratos , Ratos Wistar , Estreptozocina
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