PhD Defense by Nicholas Bolus

Event Details
  • Date/Time:
    • Friday April 10, 2020 - Saturday April 11, 2020
      2:00 pm - 3:59 pm
  • Location: REMOTE: BLUE JEANS
  • Phone:
  • URL: BlueJeans
  • Email:
  • Fee(s):
  • Extras:
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Summary Sentence: Systems for Noninvasive Assessment of Biomechanical Load in the Lower Limb

Full Summary: No summary paragraph submitted.

Nicholas B. Bolus

BioE PhD Defense


Date: Friday, April 10, 2020

Time: 2:00 PM

Location: BlueJeans (link below)



Omer T. Inan, PhD (Georgia Institute of Technology)



Young-Hui Chang, PhD (Georgia Institute of Technology)

Geza Kogler, PhD, CPO (Kennesaw State University)

Gregory Sawicki, PhD (Georgia Institute of Technology)

Aaron Young, PhD (Georgia Institute of Technology)


Systems for Noninvasive Assessment of Biomechanical Load in the Lower Limb

            Every move you make—and, yes, every step you take—is the result of action at a joint, and so proper joint function is pivotal to the way we explore and interact with the world around us. Unfortunately, joint function is often disrupted by injuries, chronic disorders, or neurological deficits, which can, in turn, disrupt quality of life. Many forms of joint dysfunction derive from adverse biomechanical loading conditions—that is, the forces and torques to which our limbs are subjected—and, thus, techniques for monitoring these loads during daily life may improve our understanding of how injuries and disorders arise and progress—and, most importantly, how best to treat them.

            The standard methods for assessing these loading conditions, however, are almost all benchtop-bound and confined to laboratories or clinics, so their utility in at-home or ambulatory settings—where they may be most impactful—is limited. In an attempt to address this void, in this work, we present three novel techniques for extracting information related to joint loading using a synthesis of noninvasive / wearable sensing and machine learning. First, we detail the development of an adjustable-stiffness ankle exoskeleton with multimodal sensing capabilities and use it to explore how humans interact with external elastic loading of the ankle during walking. Then, in an attempt to peer “under the skin,” we develop a novel form-factor for capturing joint sounds—the skin-surface vibrations produced by articulating structures internal to the joint—and demonstrate that these noninvasive measurements can be used to discriminate levels of axial loading at the knee. Finally, taking the concept of joint acoustics one step further, we introduce a new, active acoustics-based technique whereby the tensile loading of a particular tissue—the Achilles tendon—can be estimated by measuring the tissue’s mechanical response to a burst vibration on the skin surface. Using this approach, we are able to assess this loading state (and, by association, the net moment at the ankle) reliably across several activities of daily life, and, through a proof-of-concept study, we demonstrate how the technique can effectively translate to a fully wearable device.

            Collectively, the efforts reported in this thesis represent a novel, multi-path approach to assessing biomechanical loading states in the lower limb and the effects thereof. These tools and insights may serve as a basis for future development of wearable, accessible technologies for monitoring joint load during daily life, thereby reducing injury risk, tracking disease progress, assessing the efficacy of treatment, and accelerating recovery. 

Meeting URL

Meeting ID: 148 758 727

Additional Information

In Campus Calendar

Graduate Studies

Invited Audience
Faculty/Staff, Public, Graduate students, Undergraduate students
Phd Defense
  • Created By: Tatianna Richardson
  • Workflow Status: Published
  • Created On: Mar 27, 2020 - 11:51am
  • Last Updated: Mar 27, 2020 - 11:51am