Adoniram Johnson

Adoniram Johnson

Biography

Adoniram Johnson is a rising senior mechanical engineering major at the University of
Maryland, Baltimore County. He is translating his mechanical engineering background into
biomedical research and plans to pursue a Ph.D. in mechanical engineering upon graduation.
Previously, Adoniram explored biomedical research at the University of Nebraska-Lincoln,
where he fabricated elastomer composite matching layers for a wearable ultrasound patch.
In addition, he sought to improve magnetic particle imaging (MPI) by assisting with the
development of an AI-based model capable of quantifying iron oxide in MPI at Michigan State
University. This summer at MIT, Adoniram developed an ultrasound phantom of the lumbar
spine capable of depicting injuries associated with persistent pain syndromes, such as herniated
discs and nerve damage. Outside of research, Adoniram is a member of the Meyerhoff
Scholars Program and seeks to be involved in efforts to increase minority representation and
leadership in STEM.

Fabrication Of A Lumbar Phantom Able To Depict The Dorsal Root
Ganglion In Ultrasound
Adoniram Johnson1, Sarah Barreto Ornellas2, and Canan Dağdeviren2
1Department of Mechanical Engineering, University of Maryland, Baltimore County
2Media Lab, Massachusetts Institute of Technology

Ultrasound is widely recognized as an imaging modality that provides instantaneous images
of internal structures. Recently, research has shown that acoustic waves can also be used
therapeutically for pain relief when administered at low intensities, with evidence coming from
in vivo rodent studies stimulating the Dorsal Root Ganglion (DRG). Ultrasound phantoms are
tools designed to model various aspects of human tissue structural and material properties;
however, commercial phantoms are expensive and cannot be customized. This work details
the development of phantoms that depict the DRG using backscattering materials. Tissue
Mimicking Materials (TMM) modeled human anatomy around the lumbar spine, utilizing gel
wax and paraffin wax mixtures to depict different soft tissues. In addition, Polylactic Acid
(PLA) was used to 3D-print the bone structure. Backscattering was induced through aluminum
sheets and talc powder embedded at the surface of the lumbar vertebrae. The materials
accurately depicted lumbar anatomy and can be used to simulate the relevant structures during
ultrasound imaging. Ultimately, a low-intensity focused ultrasound device will be developed
to administer a non-invasive, physical stimulus capable of replacing prescription pain relief
medicine. To evaluate device performance, ultrasonic sensors will be included in the TMM to
monitor the acoustic pressure on the DRG.