An interventional study of Sparrow Link in Mental Fatigue and Mental Stress, sponsored by Spark Biomedical, Inc.. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-06.
Sponsored by Spark Biomedical, Inc. · Not applicable, Interventional, and Treatment
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Among 56 studies in Mental Fatigue with a site in United States — 19 open to participants now, 23 under way, 1 of them phase 3. Mental Fatigue · United States.
Among the 56 studies in Mental Fatigue with a site in United States, this one is the 37th largest by enrollment of the 47 interventional ones that give a count, is one of 13 that started in 2025, is one of 36 with no phase, and was the 39th registered.
175 studies on the registry are indexed under Mental Fatigue; 54 are open to participants now.
Browse Mental Fatigue studies →19 of the 56 studies in Mental Fatigue with a site in United States are open now. Recruiting first, the newest first:
Florida Institute for Human and Machine Cognition · Sites in United States
Ages 18–39 · Healthy volunteers
St. Louis University · Sites in United States
Ages 18–50 · Healthy volunteers
University of Alabama at Birmingham · Sites in United States
Ages 18+
Samphire Group, Inc. · Sites in United States
Ages 18–65 · Women only · Healthy volunteers
Washington State University · Sites in United States
Ages 40–60 · Women only · Healthy volunteers
A study can be open while its sites in United States have not opened yet or have stopped. Only those recruiting at a site in United States →
Of the 29 Mental Fatigue studies recruiting now, 9 (31%) set no upper age limit and 19 (66%) stop at 75 or younger; 1 takes children under 18; 15 take healthy volunteers.
This study: 18 Years and older · all sexes · no healthy volunteers.
The full table on the hub →This tab as a report to print or save as PDF → With an account.
56 studies; the count open now beside each. This study's row is marked.
A study in two phases is counted once above. Listed by phase, each with its combined phases: Phase 1 3 · Phase 2 7 · Phase 3 1 · Phase 4 1
First in 2011; this study’s year is marked. 13 started in 2025.
By drug class, each counting the studies that test any of its medicines:
This study's enrollment of 23 is below the median of 45 across 143 interventional studies indexed under Mental Fatigue.
Median enrollment 35 across the 47 interventional studies, 55 across the 9 observational. Of the 32 that completed or were terminated, 4 (13%) have results posted.
This tab as a report to print or save as PDF → With an account.
13 of 56 have an industry lead sponsor. The 10 most frequent:
Spark Biomedical, Inc. is the lead sponsor of 13 studies on the registry; 3 are open to participants now.
Of its 8 completed or terminated interventional studies of FDA-regulated products, 1 (13%) have results posted.
Spark Biomedical, Inc. has 1 study filed under Mental Fatigue — fewer than ten, so there is no comparison to draw.
12 of the studies in Mental Fatigue with a site in United States that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT06095297University of Alabama at BirminghamLong COVID Brain Fog: Cognitive Rehabilitation Trial | 2026-12 |
| NCT07525063Duke UniversityPain & Reward Neuromodulation of CNS Circuits | 2026-12 |
| NCT06614309Mayo ClinicNon-invasive Treatment for Long COVID (Post COVID-19 Condition) Brain Fog | 2026-12 |
| NCT07892911Ancestral Supplements, LLCA Study to Evaluate the Effects of a Beef Liver Supplement on Energy, Mood, and Mental Clarity | 2026-12-01 |
| NCT06142253VA Office of Research and DevelopmentWater-based Activity to Enhance Recovery in Long COVID-19 | 2026-12-31 |
Add all 12 to your calendar (.ics) → With an account.
Among the 56 studies in Mental Fatigue with a site in United States, from their registry updates:
This tab as a report to print or save as PDF → With an account.
This study is designed as an open label, single arm, decentralized clinical study in which first responders will receive transcutaneous auricular neurostimulation (tAN), which targets the auricular branch of the vagus nerve (ABVN) via the mastoid and the auriculotemporal nerve (ATN) anterior to the tragus. Participants will be enrolled in the study over the course of eight weeks (56 days).
Participants will respond to daily and weekly questionnaires regarding mood, stress, sleep, energy/fatigue, and burnout. Each week, participants will complete consolidated online questionnaires (intended to last no longer than 15 minutes) comprised of the Perceived Stress Short-Form (PSS-4), Well-Being Index (WHO-5), Mini-Z Burnout (5-item), PROMS Sleep Disturbance (PROMIS-SD), GAD-7 (every 2 weeks), and Perceived Stress (PSS-10; monthly). The PSS-10 will replace the PSS-4 on Days 0, 28, and 56.
No tAN treatment will be delivered during the Baseline Period (days between Study Introduction and Day 0). Participants will complete the weekly set of questionnaires ("Weekly Questionnaires") on Day 0. Participants will be recommended to complete the daily set of questionnaires ("Daily Questionnaires ") on the other days of the Baseline Period.
On Days 1 - 28, participants will self-administer one session of one to two hours of tAN therapy each day. Participants will be recommended to complete the daily tAN session post-shift prior to sleep. Weekly Questionnaires will be completed by participants on Study Days 0, 7, 14, 21, 28, 35, 42, 49, and 56. Participants will be recommended to complete Daily Questionnaires on all other study days, up to Day 28. Daily Questionnaires will not be required to be completed by participants. Daily tAN sessions and Daily Questionnaires will cease after Day 28. Participants will complete a Study Satisfaction Questionnaire with the Weekly Questionnaires on Day 56.
Following Day 56, participants will schedule a Study Exit Interview with the Research Coordinator.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
First responders will self-administer once-daily active tAN sessions for 1-2 hours for 28 days. Participants will complete daily and weekly assessments to evaluate levels of stress, mood, energy/fatigue, sleep quality , and burnout. Daily assessments and tAN sessions will cease after Day 28. Participants will continue to complete weekly assessments until Day 56.
Device: Sparrow Link
Sparrow Link will be using the components of the Sparrow Ascent device: (FDA-cleared K230796) a wearable, battery-operated, neurostimulation system designed to transcutaneously stimulate nerves on and/or around the auricle. Participants will self-administer daily active tAN sessions on Days 1 - 28.
Also known as: Transcutaneous Auricular Neurostimulation
GAD-7
The GAD-7 is a valid and efficient tool for screening for GAD and assessing its severity in clinical practice and research. The questionnaire consists of 7 questions in which participants are asked to rate each item on a 0 (not at all) to 3 (nearly every day). GAD-7 total score for the seven items ranges from 0 to 21 where 0-4 represents minimal anxiety, 5-9 represents mild anxiety, 10-14 represents moderate anxiety and 15-21 represent severe anxiety.
Time frame: Screening, Day 0, Day 14, Day 28, Day 42, Day 56
Perceived Stress Scale (PSS-4, PSS-10)
The PSS-4 is a brief version of the Perceived Stress Scale used to assess the degree to which situations in one's life are appraised as stressful. The questionnaire consists of 4 items, with participants rating each on a 0 (never) to 4 (very often) scale. Scores range from 0 to 16, with higher scores indicating greater perceived stress. The PSS-10 consists of 10 items that assess how unpredictable, uncontrollable, and overloaded respondents find their lives. Each item is rated on a 0 (never) to 4 (very often) scale. Total scores range from 0 to 40, with higher scores indicating greater perceived stress. The PSS-10 will replace the PSS-4 on Days 0, 28, and 56.
Time frame: Weekly throughout enrollment beginning Day 0 through Day 56)
PROMIS Sleep Disturbance
The PROMIS Sleep Disturbance measure evaluates self-reported perceptions of sleep quality, sleep depth, and restoration associated with sleep. Participants respond to 8 items rated on a 1 (not at all) to 5 (very much) scale. Raw scores are converted to T-scores with a mean of 50 and a standard deviation of 10, where higher scores indicate greater sleep disturbance. The tool is suitable for use in clinical and research populations.
Time frame: Weekly throughout enrollment beginning Day 0 through Day 56)
WHO-5 Well-Being Index
The WHO-5 is a short, validated measure of current mental well-being. The questionnaire consists of 5 positively worded items rated on a 0 (at no time) to 5 (all of the time) scale. The raw score ranges from 0 to 25 and is multiplied by 4 to yield a final score from 0 to 100, with higher scores indicating greater well-being. A score below 50 suggests reduced well-being and may indicate the need for further assessment.
Time frame: Weekly throughout enrollment beginning Day 0 through Day 56)
Mini-Z Burnout Survey
The Mini-Z Burnout Survey is a brief tool for assessing burnout and job satisfaction. It includes 10 items covering emotional exhaustion, stress, satisfaction, and workload. Most items are rated on a 1 to 5 Likert scale. Higher scores on the burnout item (typically scored 1 to 5) reflect greater burnout, with a score of 3 or higher suggesting at least some level of burnout.
Time frame: Weekly throughout enrollment beginning Day 0 through Day 56)
Ran from Sep 2025 to primary completion in Aug 2026, 10 months.
Of 92 interventional studies with no phase under Mental Fatigue, half reached primary completion within 8 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 23. This study's 10 months is above that.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 6, 2026: primary completion Jul 2026 → Aug 2026 and completion Jul 2026 → Sep 2026.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Spark Biomedical, Inc.