Browsing by Subject "Spinal cord stimulation"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Characterization of Biomimetic Spinal Cord Stimulations for Restoration of Sensory Feedback
    (2024-05) Zeiser, Sidnee L.; Yadav, Amol; Yoshida, Ken; Berbari, Edward; Sangha, Susan; Surowiec, Rachel
    Sensory feedback is a critical component for controlling neuroprosthetic devices and brain-machine interfaces (BMIs). A lack of sensory pathways can result in slow, coarse movements when using either of these technologies and, in addition, the user is unable to fully interact with the environment around them. Spinal cord stimulation (SCS) has shown potential for restoring these pathways, but traditional stimulation patterns with constant parameters fail to reproduce the complex neural firing necessary for conveying sensory information. Recent studies have proposed various biomimetic stimulation patterns as a more effective means of evoking naturalistic neural activity and, in turn, communicating meaningful sensory information to the brain. Unlike conventional patterns, biomimetic waveforms vary in frequency, amplitude, or pulse-width over the duration of the stimulation. To better understand the role of these parameters in sensory perception, this thesis worked to investigate the effects of SCS patterns utilizing stochastic frequency modulation, linear frequency modulation, and linear amplitude modulation. By calculating sensory detection thresholds and just-noticeable differences, the null hypothesis for stochastically-varied frequency and linear amplitude modulation techniques was rejected.
  • Thumbnail Image
    Item
    Generating Artificial Sensations with Spinal Cord Stimulation in Primates and Rodents
    (Elsevier, 2021) Yadav, Amol P.; Li, Shuangyan; Krucoff, Max O.; Lebedev, Mikhail A.; Abd-El-Barr, Muhammad M.; Nicolelis, Miguel A.L.; Neurological Surgery, School of Medicine
    For patients who have lost sensory function due to a neurological injury such as spinal cord injury (SCI), stroke, or amputation, spinal cord stimulation (SCS) may provide a mechanism for restoring somatic sensations via an intuitive, non-visual pathway. Inspired by this vision, here we trained rhesus monkeys and rats to detect and discriminate patterns of epidural SCS. Thereafter, we constructed psychometric curves describing the relationship between different SCS parameters and the animal's ability to detect SCS and/or changes in its characteristics. We found that the stimulus detection threshold decreased with higher frequency, longer pulse-width, and increasing duration of SCS. Moreover, we found that monkeys were able to discriminate temporally- and spatially-varying patterns (i.e. variations in frequency and location) of SCS delivered through multiple electrodes. Additionally, sensory discrimination of SCS-induced sensations in rats obeyed Weber's law of just-noticeable differences. These findings suggest that by varying SCS intensity, temporal pattern, and location different sensory experiences can be evoked. As such, we posit that SCS can provide intuitive sensory feedback in neuroprosthetic devices.