Novel magnetomechanical MR compatible vibrational device for producing kinesthetic illusion during fMRI

Abstract

Purpose: Functional MRI (fMRI) can provide insights into the functioning of the sensorimotor system, which is of particular interest in studying people with movement disorders or chronic pain conditions. This creates a demand for manipulanda that can fit and operate within the environment of a MRI scanner. Here, the authors present a magnetomechanical device that delivers a vibrotactile sensation to the skin with a force of approximately 9 N. Methods: MRI compatibility of the device was tested in a 3 T scanner using a phantom to simulate the head. Preliminary investigation into the effectiveness of the device at producing cortical and subcortical activity was also conducted with a group of seven healthy subjects. The vibration was applied to the right extensor carpi ulnaris tendon to induce a kinesthetic illusion of flexion and extension of the wrist. Results: The MRI compatibility tests showed the device did not produce image artifacts and the generated electromagnetic field did not disrupt the static magnetic field of the scanner or its operation. The subject group results showed activity in the contralateral putamen, premotor cortex, and dorsal lateral prefrontal cortex. Ipsilaterally, there was increased activity in the superior and inferior parietal lobules. Areas that activated bilaterally included the thalamus, anterior cingulate, secondary somatosensory areas (S2), temporal lobes, and visual association areas. Conclusions: This device offers an effective tool with precise control over the vibratory stimulus, delivering higher forces than some other types of devices (e.g., piezoelectric actuators). It can be useful for investigating sensory systems and sensorimotor integration.

Assessing MR-compatibility of somatosensory stimulation devices: A systematic review on testing methodologies

“…The actuator was based on the coiling of the printed circuit board (PCB) (instead of the conventional winding of copper wire on a bobbin), enabling “excellent repeatability and thermal characteristics, durability, humidity resistance, ability to assume various shapes, and lightweight construction.” They also designed a filter trap to protect the drive unit of the system from induced currents (due to the RF pulses and switching gradients). The works of Gallasch et al (2006) and Carr et al (2013) were also based on this principle of actuation.…”

“…The majority of the records included in this review were intended for upper-limb somatosensory stimulation, mainly the fingers, which have a larger cortical representation in the primary somatosensory cortex (S1) ( Harrington et al, 2000 ; Gassert et al, 2006a ; Hartwig et al, 2006 ; Di Diodato et al, 2007 ; Montant et al, 2009 ; Yang et al, 2009 , 2011 ; Yu et al, 2011b ; Guo et al, 2012 ; Carr et al, 2013 ; Kim et al, 2013 ; Chen et al, 2014 ; Wang et al, 2015 ; Huang et al, 2017 ). Only one study was dedicated to the development of a computer-controlled MR-compatible stimulation device for punctate tactile stimuli of the face and hands ( Dresel et al, 2008 ).…”

“…They also designed a filter trap to protect the drive unit of the system from induced currents (due to the RF pulses and switching gradients). The works of Gallasch et al (2006) and Carr et al (2013) were also based on this principle of actuation.…”

“…The penetration panel, together with RF filters, was used by the following papers: (Harrington et al, 2000;Di Diodato et al, 2007;Dresel et al, 2008;Yang et al, 2011;Wang et al, 2015). On other hand, the following studies opted for the waveguide: (Gassert et al, 2006a;Hartwig et al, 2006;Carr et al, 2013;Hao et al, 2013;Kim et al, 2013;Huang et al, 2017). The remaining papers do not explicitly report this issue (Gallasch et al, 2006;Montant et al, 2009;Yang et al, 2009;Yu et al, 2011b;Guo et al, 2012;Chen et al, 2014;Goossens et al, 2016), excepting the work of Duenas et al (2011), where (according to our interpretation) both communication methods Communication methods between the scanner and the control rooms described in the records included in this review: a similar percentage of records opted for the waveguide and penetration panel and only one paper used both configurations; the remaining records did not specify the communication method (N.A.…”

MR-safe multisegmental vibration device for cortical mapping of paraspinal afferent input

“…Detailed cortical maps of paraspinal afferent input might be crucial to further explore their pathological meaning in persistent LBP, yet suitable stimulation methods are lacking. Although MR-compatible vibration devices exist 4,5 , none of them is capable of applying controlled vibrotactile stimulation at different thoracolumbar segments with appropriate amplitude in supine subjects. Vibration frequencies around 80Hz (and amplitudes between 0.5-1mm) have been shown to modulate the activity profile of muscle spindles and therefore proprioceptive information 6 .…”