NCT07851727 · Evan (Huiliang) Wang
Gastric Focused Ultrasound Stimulation
What this study is about
This randomly assigned, sham-controlled crossover pilot study will evaluate whether noninvasive gastric focused ultrasound stimulation is associated with changes in postprandial gastric electrical activity and gastrointestinal symptoms in adults with gastroparesis or delayed gastric emptying.
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This randomized, sham-controlled crossover pilot study will evaluate whether noninvasive gastric focused ultrasound stimulation is associated with changes in postprandial gastric electrical activity and gastrointestinal symptoms in adults with gastroparesis or delayed gastric emptying. Participants will complete one active FUS visit and one sham-stimulation visit in randomized order, separated by at least 48 hours. At each visit, electrogastrography will be recorded before and after a standardized liquid nutritional drink, during active or sham stimulation, and during recovery. Gastrointestinal symptoms will be assessed at prespecified time points using the Total Symptom Score questionnaire.
Interventions
DEVICE
Gastric Focused Ultrasound Stimulation
Noninvasive focused ultrasound stimulation will be delivered through the abdominal skin over the stomach region using an ultrasound transducer and coupling gel. Active stimulation will use a center frequency of 650 kHz and a pulse repetition frequency of 1 kHz. Each pulse will consist of 200 microseconds on and 800 microseconds off, corresponding to a 20% pulse-level duty cycle. Pulsed ultrasound will be delivered in repeated blocks of 500 milliseconds on and 500 milliseconds off during a total FUS session of 600 seconds.
Primary outcome measures
Change in Gastrointestinal Symptom Severity Measured by Total Symptom Score
Time frame: Immediately before stimulation and 30 minutes after completion of active FUS or sham stimulation at each study visit.
The Total Symptom Score is the sum of participant-reported severity ratings for nausea, vomiting, early satiety, bloating, postprandial fullness, and abdominal pain. Each symptom is rated from 0 (absent) to 4 (extremely severe), yielding a total score ranging from 0 to 24; higher scores indicate greater symptom severity. Within-participant change in Total Symptom Score from immediately before stimulation to 30 minutes after completion of active FUS or sham stimulation will be compared between conditions.
Change in Gastric Dominant Frequency Measured by Electrogastrography
Time frame: At each study visit: 10-min fasting baseline; 10-min post-meal recording before active FUS or sham; 10-min recording during active FUS or sham; and 10-min recovery recording immediately after stimulation.
Gastric dominant frequency will be derived from electrogastrography (EGG) recordings and reported in cycles per minute (cpm). Within-participant values during active FUS and sham stimulation will be compared.
Change in Gastric EGG Signal Amplitude
Time frame: At each study visit: 10-min fasting baseline; 10-min post-meal recording before active FUS or sham; 10-min recording during active FUS or sham; and 10-min recovery recording immediately after stimulation.
Gastric EGG signal amplitude will be derived from EGG recordings and reported in microvolts (µV). Within-participant values during active FUS and sham stimulation will be compared.
Change in Percentage of Time in Normal Gastric Rhythm
Time frame: At each study visit: 10-min fasting baseline; 10-min post-meal recording before active FUS or sham; 10-min recording during active FUS or sham; and 10-min recovery recording immediately after stimulation.
The percentage of analyzable EGG recording time with gastric dominant frequency within the normogastric range of 2 to 4 cycles per minute will be calculated and reported as a percentage. Within-participant values during active FUS and sham stimulation will be compared.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age 18 to 70 years.
- Delayed gastric emptying or gastroparesis diagnosed by a clinician and confirmed by gastric emptying scintigraphy or a gastric emptying breath test.
- Ability to understand the study procedures, provide informed consent, and complete two study visits.
- Ability to consume the two bottles of Ensure or Glucerna nutritional drink used in the study.
Exclusion criteria
- Cardiac pacemaker or another implanted electronic medical device.
- Peritoneal dialysis.
- Daily use of narcotic or opioid medications.
- Abdominal wall ulcers, open wounds, active infection, or significant skin irritation in the area where the electrogastrography electrodes or focused ultrasound transducer will be placed.
- Known allergy or contraindication to the available Ensure or Glucerna nutritional drinks.
- Any other medical or safety condition that, in the judgment of the study team, would make participation unsafe. Medication Restrictions: Participants using medications that may significantly affect gastric motility or gastric emptying may be rescheduled if those medications were used within the study-defined restriction period. Relevant medications include opioid analgesics, prokinetic agents, anticholinergic or antispasmodic agents, GLP-1 receptor agonists or related medications, and anti-nausea or antiemetic medications that may affect gastrointestinal function. Participants should not discontinue any medically necessary medication without first consulting their treating physician.
Where
- Austin, Texas
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 1, 2026 · Source of record for eligibility and locations