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1.
J Theor Biol ; 452: 1-9, 2018 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-29727634

RESUMO

This study examines accurate and efficient computational method for identification of 5-methylcytosine sites in RNA modification. The occurrence of 5-methylcytosine (m5C) plays a vital role in a number of biological processes. For better comprehension of the biological functions and mechanism it is necessary to recognize m5C sites in RNA precisely. The laboratory techniques and procedures are available to identify m5C sites in RNA, but these procedures require a lot of time and resources. This study develops a new computational method for extracting the features of RNA sequence. In this method, first the RNA sequence is encoded via composite feature vector, then, for the selection of discriminate features, the minimum-redundancy-maximum-relevance algorithm was used. Secondly, the classification method used has been based on a support vector machine by using jackknife cross validation test. The suggested method efficiently identifies m5C sites from non- m5C sites and the outcome of the suggested algorithm is 93.33% with sensitivity of 90.0 and specificity of 96.66 on bench mark datasets. The result exhibits that proposed algorithm shown significant identification performance compared to the existing computational techniques. This study extends the knowledge about the occurrence sites of RNA modification which paves the way for better comprehension of the biological uses and mechanism.


Assuntos
5-Metilcitosina/metabolismo , Algoritmos , RNA/metabolismo , Máquina de Vetores de Suporte , 5-Metilcitosina/química , Sequência de Aminoácidos , Aminoácidos/genética , Sequência de Bases , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Modelos Teóricos , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , RNA/química , RNA/genética
2.
IEEE Int Conf Rehabil Robot ; 2017: 1562-1566, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28814042

RESUMO

Loss of joints and severed sensory pathway cause reduced mobility capabilities in lower limb amputees. Although prosthetic devices attempt to restore normal mobility functions, lack of awareness and control of limb placement increase the risk of falling and causing amputee to have high level of visual dependency. Haptic feedback can serve as a cue for gait events during ambulation thus providing sense of awareness of the limb position. This paper presents a wireless wearable skin stretch haptic device to be fitted around the thigh region. The movement profile of the device was characterized and a preliminary work with able-bodied participants and an above-knee amputee to assess the ability of users to perceive the delivered stimuli during static and dynamic mode is reported. Perceptibility was found to be increasing with stretch magnitude. It was observed that a higher magnitude of stretch was needed for the stimuli to be accurately perceived during walking in comparison to static standing, most likely due to the intense movement of the muscle and increased motor skills demand during walking activity.


Assuntos
Amputados/reabilitação , Membros Artificiais , Retroalimentação , Marcha/fisiologia , Extremidade Inferior/fisiopatologia , Tato/fisiologia , Adulto , Fenômenos Biomecânicos , Desenho de Equipamento , Humanos , Masculino , Fenômenos Fisiológicos da Pele , Adulto Jovem
3.
IEEE Trans Neural Syst Rehabil Eng ; 25(9): 1500-1509, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28114026

RESUMO

Lower extremity amputees suffer from mobility limitations which will result in a degradation of their quality of life. Wearable sensors are frequently used to assess spatio-temporal, kinematic and kinetic parameters providing the means to establish an interactive control of the amputee-prosthesis-environment system. Gait events and the gait phase detection of an amputee's locomotion are vital for controlling lower limb prosthetic devices. The paper presents an approach to real-time gait event detection for lower limb amputees using a wireless gyroscope attached to the shank when performing level ground and ramp activities. The results were validated using both healthy and amputee subjects and showed that the time differences in identifying Initial Contact (IC) and Toe Off (TO) events were larger in a transfemoral amputee when compared to the control subjects and a transtibial amputee (TTA). Overall, the time difference latency lies within a range of ±50 ms while the detection rate was 100% for all activities. Based on the validated results, the IC and TO events can be accurately detected using the proposed system in both control subjects and amputees when performing activities of daily living and can also be utilized in the clinical setup for rehabilitation and assessing the performance of lower limb prosthesis users.


Assuntos
Acelerometria/instrumentação , Membros Artificiais , Biorretroalimentação Psicológica/métodos , Transtornos Neurológicos da Marcha/reabilitação , Transtornos Neurológicos da Marcha/radioterapia , Marcha , Monitorização Ambulatorial/instrumentação , Adulto , Amputados/reabilitação , Biorretroalimentação Psicológica/instrumentação , Sistemas Computacionais , Desenho de Equipamento , Análise de Falha de Equipamento/instrumentação , Análise de Falha de Equipamento/métodos , Feminino , Humanos , Masculino , Desempenho Psicomotor , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Resultado do Tratamento
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 5067-5070, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28269407

RESUMO

This paper presents a rule-based real-time gait event/phase detection system (R-GEDS) using a shank mounted inertial measurement unit (IMU) for lower limb amputees during the level ground walking. Development of the algorithm is based on the shank angular velocity in the sagittal plane and linear acceleration signal in the shank longitudinal direction. System performance was evaluated with four control subjects (CS) and one transfemoral amputee (TFA) and the results were validated with four FlexiForce footswitches (FSW). The results showed a data latency for initial contact (IC) and toe off (TO) within a range of ± 40 ms for both CS and TFA. A delay of about 3.7 ± 62 ms for a foot-flat start (FFS) and an early detection of -9.4 ± 66 ms for heel-off (HO) was found for CS. Prosthetic side showed an early detection of -105 ± 95 ms for FFS whereas intact side showed a delay of 141 ±73 ms for HO. The difference in the kinematics of the TFA and CS is one of the potential reasons for high variations in the time difference. Overall, detection accuracy was 99.78% for all the events in both groups. Based on the validated results, the proposed system can be used to accurately detect the temporal gait events in real-time that leads to the detection of gait phase system and therefore, can be utilized in gait analysis applications and the control of lower limb prostheses.


Assuntos
Amputados , Membros Artificiais , Marcha/fisiologia , Extremidade Inferior/fisiopatologia , Aceleração , Adulto , Algoritmos , Fenômenos Biomecânicos , Pé/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Processamento de Sinais Assistido por Computador , Fatores de Tempo , Caminhada
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 1676-1679, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28324949

RESUMO

In developed countries, the highest number of amputees are elderly with transtibial amputation. Walking on inclined surfaces is difficult for amputees due to loss of muscle volume and strength thereby transtibial amputees (TA) rely on the intact limb to maintain stability. The aim of this study was to use the concatenated non-negative matrix factorization (CNMF) technique to calculate muscle synergy components and compare the difference in muscle synergies and their associated activation profiles in the healthy and amputee groups during ramp ascending (RA) activity. Healthy subjects' dominant leg and amputee's intact leg (IL) were considered for recording surface electromyography (sEMG). The muscle synergies comparison showed a reasonable correlation between the healthy and amputee groups. This suggests the central nervous system (CNS) activates the same group of muscles synergistically. However, the activation coefficient profile (C) results indicated statistically significant difference (p <; 0.05) in some parts of the gait cycle (GC) in healthy and amputee groups. The difference exhibited in activation profiles of amputee's IL could be due to the instability of the prosthetic leg during the GC which resulted in alteration of the IL muscles activations. This information will be useful in rehabilitation and in the future development of prosthetic devices by using the IL muscles information to control the prostheses.


Assuntos
Amputados , Marcha , Perna (Membro)/fisiologia , Músculo Esquelético/fisiologia , Fenômenos Biomecânicos , Eletromiografia , Humanos
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 2120-2123, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28268750

RESUMO

Haptic feedback to lower limb amputees is essential to maximize the functionality of a prosthetic device by providing information to the user about the interaction with the environment and the position of the prostheses in space. Severed sensory pathway and the absence of connection between the prosthesis and the Central Nervous System (CNS) after lower limb amputation reduces balance control, increases visual dependency and increases risk of falls among amputees. This work describes the design of a wearable haptic feedback device for lower limb amputees using lateral skin-stretch modality intended to serve as a feedback cue during ambulation. A feedback scheme was proposed based on gait event detection for possible real-time postural adjustment. Preliminary perceptual test with healthy subjects in static condition was carried out and the results indicated over 98% accuracy in determining stimuli location around the upper leg region, suggesting good perceptibility of the delivered stimuli.


Assuntos
Amputados/reabilitação , Membros Artificiais , Vestuário , Retroalimentação , Tato , Humanos , Fenômenos Fisiológicos da Pele , Caminhada/fisiologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-26737364

RESUMO

Events and phases detection of the human gait are vital for controlling prosthesis, orthosis and functional electrical stimulation (FES) systems. Wearable sensors are inexpensive, portable and have fast processing capability. They are frequently used to assess spatio-temporal, kinematic and kinetic parameters of the human gait which in turn provide more details about the human voluntary control and ampute-eprosthesis interaction. This paper presents a reliable real-time gait event detection algorithm based on simple heuristics approach, applicable to signals from tri-axial gyroscope for lower limb amputees during ramp ascending and descending. Experimental validation is done by comparing the results of gyroscope signal with footswitches. For healthy subjects, the mean difference between events detected by gyroscope and footswitches is 14 ms and 10.5 ms for initial contact (IC) whereas for toe off (TO) it is -5 ms and -25 ms for ramp up and down respectively. For transfemoral amputee, the error is slightly higher either due to the placement of footswitches underneath the foot or the lack of proper knee flexion and ankle plantarflexion/dorsiflexion during ramp up and down. Finally, repeatability tests showed promising results.


Assuntos
Marcha/fisiologia , Adulto , Algoritmos , Amputados , Fenômenos Biomecânicos , Humanos , Extremidade Inferior/fisiologia , Masculino , Pessoa de Meia-Idade
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