Smriti Bala

Novel Methods for Handwriting-based Automated Grading of Degree of Handedness

Muscle Synergy-Based Functional Electrical Stimulation Reduces Muscular Fatigue in Post-Stroke Patients: A Systematic Comparison

IEEE Transactions on Neural Systems and Rehabilitation Engineering

Muscle synergy-based functional electrical stimulation had improved movement kinematics instantly... more Muscle synergy-based functional electrical stimulation had improved movement kinematics instantly and in long-term use in post-stroke patients. However, the therapeutic benefits and efficacy of muscle synergy-based functional electrical stimulation patterns over traditional stimulation patterns need exploration. This paper presents the therapeutic benefits of muscle synergy-based functional electrical stimulation compared to traditional stimulation patterns from the perspective of muscular fatigue and kinematic performance produced. Three stimulation waveforms/envelopes: customized rectangular, trapezoidal, and muscle synergy-based FES patterns were administered on six healthy and six post-stroke patients to achieve full elbow flexion. The muscular fatigue was measured through evoked-electromyography, and the kinematic outcome was measured through angular displacement during elbow flexion. The time domain (peak-to-peak amplitude, mean absolute value, root-mean-square) and frequency domain (mean frequency, median frequency) myoelectric indices of fatigue were calculated from evoked-electromyography. Myoelectric indices of fatigue and peak angular displacements of elbow joint were compared across waveforms. The presented study found that the muscle synergy-based stimulation pattern sustained the kinematic output for longer durations and induced less muscular fatigue followed by trapezoidal and customized rectangular patterns in healthy and post-stroke participants. These findings imply that the therapeutic effect of muscle synergy-based functional electrical stimulation stems from not only being biomimetic but also due to it being efficient in inducing less fatigue. The slope of current injection was a crucial factor

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An Attention-based Deep CNN-BiLSTM Model for Forecasting of Fatigue-induced Surface Electromyography Signals During Isotonic Contractions

An accurate estimation of muscle fatigue is critical for adaptive control of existing assistive... more An accurate estimation of muscle fatigue is critical for adaptive control of existing assistive devices, such as an exoskeleton, prosthesis, and functional electrical stimulation (FES)-based neuroprostheses. However, the estimation of muscle fatigue using surface electromyography (sEMG) for a long duration of time becomes challenging due to loosening of sEMG sensors, sweating, and other accidental failures. These problems can be potentially solved by forecasting future sEMG signals using initially recorded high-quality data points. For the first time, we attempt to forecast the fatigue-induced electromyography signal using the initial sEMG recorded for a shorter interval of time, during biceps curl with weights of 1 kg, 2 kg, 3 kg, and 4 kg. An attention-based deep CNN-BiLSTM neural network model that captures input sEMG dynamics to forecast future sEMG signals corresponding to fatigue state was trained and tested. An average mean absolute percentage error (MAPE) of 2...

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Novel Methods for Handwriting-based Automated Grading of Degree of Handedness

Hand preference and degree of handedness are two different aspects of human behavior which are of... more Hand preference and degree of handedness are two different aspects of human behavior which are often confused to be one. While hand preference is affected by various natural, environmental, and socio-cultural causes, degree of handedness reflects the inherent capability of a human gained by nature which can be modified with training. In this paper, we present two novel methods to quantify the degree of handedness for the first time using handwriting features of dominant and non-dominant hand on three categories of subjects- “Unidextrous”, “Partially-Unidextrous”, and “Ambidextrous”. Methods: Time, static, and dynamic variables of handwriting signal were used as the features for quantification of degree of handedness. Davies Bouldin Score as a statistical method and Neural Network accuracy-based 4-point scale as an automated method for this quantification were presented and compared with the well-known degree of handedness assessment questionnaires from Edinburgh Inventory (EI). Resu...

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Functionalization, Immobilization and Stabilization of Biomolecules in Microfluidic Devices

Since the advent of biosensors for rapid analytical applications and use of micro fabrication tec... more Since the advent of biosensors for rapid analytical applications and use of micro fabrication technology for their miniaturization, science has come a long way in addressing the requirements for multiplexing, reusability and automation required for multianalyte biosensing. Though, microfluidic device fabrication has become more or less a standard technique nowadays, it is often tricky to immobilize the bio recognition element onto them after device assembly. For example glass-PDMS based microfluidic devices needs to be bonded using oxygen plasma or UV-ozone. Therefore, biomolecules, such as enzymes, antibodies etc. cannot be immobilized prior to device bonding. In this chapter, we shall put special emphasis on such critical immobilization procedures, while we shall also discuss the methods of their stabilization for the sake of enhanced shelf-life and reusability. Our discussions shall be based also on lateral flow immuno-devices and other paper microfluidic devices apart from glass...

Functionalization, Immobilization and Stabilization of Biomolecules in Microfluidic Devices

Immobilization Strategies, 2020

Since the advent of biosensors for rapid analytical applications and use of micro fabrication tec... more Since the advent of biosensors for rapid analytical applications and use of micro fabrication technology for their miniaturization, science has come a long way in addressing the requirements for multiplexing, reusability and automation required for multianalyte biosensing. Though, microfluidic device fabrication has become more or less a standard technique nowadays, it is often tricky to immobilize the bio recognition element onto them after device assembly. For example glass-PDMS based microfluidic devices needs to be bonded using oxygen plasma or UV-ozone. Therefore, biomolecules, such as enzymes, antibodies etc. cannot be immobilized prior to device bonding. In this chapter, we shall put special emphasis on such critical immobilization procedures, while we shall also discuss the methods of their stabilization for the sake of enhanced shelf-life and reusability. Our discussions shall be based also on lateral flow immuno-devices and other paper microfluidic devices apart from glass-glass, glass-PDMS, PMMA-PMMA, Si-wafers and other combinations.

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