The primary objective of this study is to explore the application of the Firefly® device for delivering NMES to anatomically defined regions of the upper limb and to observe associated physiological changes. Specifically, the study will assess alterations in arterial and venous blood flow, as well as local muscle oxygen saturation, as potential indicators of muscle perfusion during NMES.
Who can participate
Age range
18 Years – 45 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Aged 18 to 45 years (inclusive)
* No known history of vascular or neurological conditions affecting the upper extremities
* Able to read, understand, and communicate in English to ensure informed consent and safe participation in the study
Exclusion Criteria:
* Presence of any condition that contraindicates the use of neuromuscular electrical stimulation (e.g., implanted pacemaker, epilepsy)
* Current or recent injury to the upper limbs that may interfere with stimulation or measurement
* Anatomical variations in the brachial artery or axillary vein, specifically vascular branching outside expected anatomical locations, as identified by ultrasound, which may impair accurate blood flow measurement or device placement
* Currently participating in another interventional or physiological research study or having done so within the past 30 days.
* Currently pregnant
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Change in upper-limb blood flow volume during NMES (ON vs OFF)
Timeframe: During single study visit (approximately 2 hours), across repeated stimulation ON/OFF cycles
2
Change in upper-limb peak systolic velocity during NMES (ON vs OFF)
Timeframe: During a single study visit (approximately 2 hours), across repeated stimulation ON/OFF cycles.
3
Change in upper-limb end-diastolic velocity during NMES (ON vs OFF)
Timeframe: During a single study visit (approximately 2 hours), across repeated stimulation ON/OFF cycles.
4
Change in upper-limb resistive index during NMES (ON vs OFF)
Timeframe: During a single study visit (approximately 2 hours), across repeated stimulation ON/OFF cycles.
5
Change in upper-limb muscle oxygen saturation during NMES (ON vs OFF)
Timeframe: During a single study visit (approximately 2 hours), across repeated stimulation ON/OFF cycles.