Gelareh Hajian

University of Toronto | U of T

Background Driving cessation among people with cognitive impairments (e.g., Mild Cognitive Impairment; MCI) significantly impacts their independence and overall well‐being. Conditionally Automated Vehicles (CAVs) have emerged as a promising solution, potentially extending the safe driving years of at‐risk drivers. However, the safety of using CAVs...

In the field of EMG-based force modeling, the ability to generalize models across individuals could play a significant role in its adoption across a range of applications, including assistive devices, robotic and rehabilitation devices. However, current studies have predominately focused on intra-subject modeling, largely neglecting the burden of e...

This tutorial intends to provide insight, instructions and "best practices" for those who are novices-including clinicians, engineers and non-engineers-in extracting electromyogram (EMG) amplitude from the bipolar surface EMG (sEMG) signal of voluntary contractions. A brief discussion of sEMG amplitude extraction from high density sEMG (HDsEMG) arr...

EMG-based force estimation is crucial in applications, such as control of powered prosthetic and rehabilitation devices. Most previous studies focus on intra-subject force modelling. However, a generalized EMG-force estimation model, which is capable of estimating force across users, is needed for surgical and rehabilitation robotics. In this study...

Accurate force/torque estimation is essential for applications such as powered exoskeletons, robotics, and rehabilitation. However, force/torque estimation under dynamic conditions is a challenging due to changing joint angles, force levels, muscle lengths, and movement speeds. We propose a novel method to accurately model the generated force under...

EMG-based motion estimation is required for applications such as myoelectric control, where the simultaneous estimation of kinematic information, namely joint angle and velocity, is challenging and critical. We propose a novel method for accurately modelling the generated joint angle and velocity simultaneously under isotonic, isokinetic (quasi-dyn...

Accurate force/torque estimation is essential for applications such as powered exoskeletons, robotics, and rehabilitation. However, force/torque estimation under dynamic conditions is challenging due to changing joint angles, force levels, muscle lengths, and movement speeds. We propose a novel method to accurately model the generated force under i...

Accurate torque estimation during dynamic conditions is challenging, yet an important problem for many applications such as robotics, prosthesis control, and clinical diagnostics. Our objective is to accurately estimate the torque generated at the elbow during flexion and extension, under quasi-dynamic and dynamic conditions. High-density surface e...

EMG-based force estimation is generally done in a subject specific manner. In this paper, we explore force estimation in a manner generalizable across individuals, where the EMG signals are recorded from the long head and the short head of biceps brachii, and the brachioradialis, under isometric elbow flexion, while the contact force is measured at...

Accurate and real-time estimation of force from surface electromyogram (EMG) signals enables a variety of applications. We developed and validated new approaches for selecting subsets of high-density (HD) EMG channels for improved and lower-dimensionality force estimation. First, a large dataset was recorded from a number of participants performing...

In this paper, extracted features in time and frequency domain, from high-density surface electromyogram (HD-sEMG) signals acquired from the long head and short head of biceps brachii, and brachioradialis during isometric elbow flexion are used to estimate force induced at the wrist using an artificial neural network (ANN). Different hidden layer s...

In this paper, a method for selecting channels to improve estimated force using fast orthogonal search (FOS) has been proposed. Surface electromyogram (sEMG) signals acquired from linear surface electrode arrays, placed on the long head and short head of biceps brachii, and brachioradialis during isometric contractions are used to estimate force-in...

In this paper, the surface electromyogram (sEMG) signals acquired from linear surface electrode arrays, placed on the long head and short head of biceps brachii, and brachioradi-alis during isometric contractions are used to estimate force induced at the wrist using an artificial neural network (ANN). We extracted some features, in time and frequen...

In this paper, methods for selecting channels to improve estimated force using fast orthogonal search (FOS) have been investigated and a new method is proposed. The surface electromyogram (sEMG) signal acquired from linear surface electrode arrays, placed on the long head and short head of biceps brachii and brachioradialis during isometric contrac...

The effects of elbow joint angle, forearm posture and different force levels on the activation level of the long head and short head of biceps brachii, the brachioradialis, and the triceps brachii during isometric contractions were investigated. The muscle activation levels are simultaneously acquired by linear surface electrode arrays placed on th...

A linear electrode array was used to investigate the relationship between inter-electrode distance (IED) and frequency content of the surface EMG during isometric contraction of the elbow flexor muscles. It is shown that mean and median frequencies decrease as IED is increased from 5mm to 15mm. No effect of joint angle was observed, but it was note...

A high-active, high-quality, and high-yield hollow Pd–PVP–Fe (palladium–poly(N-vinylpyrrolidone)–iron) nano-sphere catalyst with cubic structure was synthesized via a cheap method without using any support. This catalyst exhibited excellent catalytic activity in the Mizoroki–Heck reactions of less reactive chlorobenzene and some aryl bromides with...

In the cold climate of Nordic countries (Sweden, Finland, Denmark and Norway) energy is vital for survival. The scarcity and uneven distribution of energy resources, rising energy prices and concern for climate change have all contributed to growing global need for energy efficiency and increased use of renewable energy resources. In this paper PV-...

A novel microstrip low-pass filter with good characteristics, such as sharp roll-off, wide stop-band, low insertion loss and good return loss is presented. The proposed filter with a 3 dB cut off frequency at 1.19 GHz, roll-off rate equal to 218 dB/GHz and a relative stop-band bandwidth of 163.5% (referred to a suppression level of -20 dB) is desig...

In this paper, a novel lowpass filter with ultra-wide stopband using the butterfly-shaped resonator is proposed. This filter with -3 dB cutoff frequency at 1.74 GHz is designed. Maximum insertion loss is less than 0.1 dB in the passband and the fabricated filter presents ultra-wide stopband from 2.1 GHz to 26.51 GHz with the attenuation level bette...