# A new method of spinal stimulation TO activate the diaphragm

> **NIH NIH F31** · UNIVERSITY OF FLORIDA · 2020 · $34,778

## Abstract

Project Summary/Abstract
A 3-yr fellowship project is proposed to develop a novel method to electrically stimulate the spinal cord. The
applicant has a unique and strong history in spinal cord electrical stimulation, and a PhD project and training
program has been designed to build upon his existing strengths while developing a new methodology. The
new method is called temporal interference (T-I) stimulation, and will be used to restore respiratory muscle
activation during acute or chronic hypoventilation following opioid overdose or neurotrauma. The premise is to
target the spinal cord with two, high frequency, but low amplitude electrical waveforms. The waveforms are
delivered at kilohertz frequencies that are well above values that directly stimulate neurons. The frequency of
the two waveforms is offset by a small amount (e.g. 1-5 Hz), and where the two electrical fields sum in the
tissue, neuronal populations are recruited in phase with the offset. In preliminary experiments, the applicant
delivered T-I stimulation using simple sub-cutaneous neck electrodes following acute opioid overdose in adult
rats. Remarkably, this approach was able to evoke diaphragm motor recruitment, and the discharge could be
regulated by varying the offset frequency between the two stimulus waveforms. Additional preliminary
experiments focused on epidural spinal cord stimulation. Electrodes on the mid-cervical dorsal epidural surface
were used to deliver two kilohertz waveforms, and this was remarkably effective at activating and regulating
diaphragm motor units. Compared to traditional single wave epidural stimulation, we predict that T-I will offer
advantages including 1) improved efficacy after incomplete and/or chronic lesions; 2) ability to produce
diaphragm motor unit recruitment with a more natural “burst” envelope, and 3) ability to more focally target the
stimulus to the ventral horn. The overall hypothesis guiding this proposal is that T-I stimulation can be used
to target energy to the ventral cervical spinal cord to regulate diaphragm activation with minimal off target
effects. This will be tested by evaluating and optimizing T-I stimulation delivered via subcutaneous (Aim 1) or
epidural electrodes (Aim 2). This PhD project is highly innovative since dual waveform T-I stimulation has not
previously been explored as a means of activating the respiratory muscles. Primary mentor Dr. Fuller has an
NIH-funded laboratory and an excellent track record of successfully mentoring PhD students. A carefully
developed training plan includes coursework in research design, statistics and ethics, participation in active
journal clubs and seminar series, attendance at national conferences, and training in new research techniques.
This fellowship targets development of novel strategies to restore ventilation in case of drug overdose and
spinal cord injury while helping to develop the career of a highly promising young scientist.

## Key facts

- **NIH application ID:** 9910066
- **Project number:** 5F31HL145831-02
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **Principal Investigator:** Michael Sunshine
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $34,778
- **Award type:** 5
- **Project period:** 2019-02-16 → 2021-01-01

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9910066

## Citation

> US National Institutes of Health, RePORTER application 9910066, A new method of spinal stimulation TO activate the diaphragm (5F31HL145831-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9910066. Licensed CC0.

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