CMOS Magnetic Sensors for Wearable Magnetomyography

Abstract

Magnetomyography utilizes magnetic sensors to record small magnetic fields produced by the electrical activity of muscles, which also gives rise to the electromyogram (EMG) signal typically recorded with surface electrodes. Detection and recording of these small fields requires sensitive magnetic sensors possibly equipped with a CMOS readout system. This paper presents a highly sensitive Hall sensor fabricated in a standard 0.18 µm CMOS technology for future low-field MMG applications. Our experimental results show the proposed Hall sensor achieves a high current mode sensitivity of approximately 2400 V/A/mT. Further refinement is required to enable measurement of MMG signals from muscles.

Control Methods for Transradial Prostheses Based on Remnant Muscle Activity and Its Relationship with Proprioceptive Feedback

“…However, the high cost of the devices and the complexity of the setup (requiring a temperature-controlled environment with the removal of the environment noise) limit the spread of this sensing technique. Multiple biomagnetic sensing techniques offer more straightforward implementation when compared with SQUIDs, such as highly sensitive Hall-sensors [ 132 , 135 , 136 ], Optically Pumped Magnetometers [ 137 ] (OPM) and other [ 132 ]. Heidari et al [ 135 ] implemented a compact CMOS Hall-sensor, potentially making MMG more affordable for use in wearable devices and prosthetics.…”

Ultrasensitive Magnetic Field Sensors for Biomedical Applications

“…Magnetoneurography allows clinicians to achieve not just a three-dimensional signal of the neuronal impulse propagation in a particular part of a nerve but also provide information about the spread of abnormalities in the nervous systems of patients [5]. Magnetoencephalography provides information about time-varying brain activity [6] and neurophysiological patterns of mild cognitive impairment during neurodegenerative disorders [7], and magnetomyography provides vector information about the movement of skeletal muscles [8].…”

Integrated Pico-Tesla Resolution Magnetoresistive Sensors for Miniaturised Magnetomyography

“…Detecting weak biomagnetic fields, Magnetomyography (MMG), first formally proposed in 1972 by Cohen and Gilver [1]. With the development of efficient magnetic technologies, this non-invasive technique becomes more attractive because it has great potential to improve medical diagnosis and health monitoring, and to develop rehabilitation robotics where the human-machine interface can assist the disabled with limb difference to perform essential activities of daily living [2]. The MMG signals are recorded as components of the magnetic field vector versus time, which is generated the action potential from electric currents travelling along with skeletal muscle fibres.…”