tFUS for Blind Spot

Overseen By Mark S George, MD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Medical University of South Carolina

Must not be taking: Psychoactive drugs

Disqualifiers: Depression, Anxiety, Schizophrenia, Bipolar, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 1 session

30 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores a new technique called transcranial Focused Ultrasound Stimulation (tFUS) to assess its effects on brain activity. Researchers aim to determine the amount of tFUS needed to alter how the brain processes visual information. They also seek to compare its effects on conscious visual detection versus sight-guided actions that occur without conscious thought. Individuals with normal vision and hearing, and without neurological or psychological illnesses, may be suitable for this study. As an unphased study, this trial offers a unique opportunity to contribute to groundbreaking research in brain stimulation techniques.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are using any non-prescribed psychoactive medications or drugs.

What prior data suggests that this technique is safe?

Research shows that transcranial Focused Ultrasound Stimulation (tFUS) at low levels is generally safe and well-tolerated. Studies have found that side effects are very rare. However, high levels of tFUS might cause issues such as bleeding or cell damage. These risks are mainly linked to higher power levels, which careful studies do not typically use. This trial uses low-intensity tFUS, tested in both humans and animals, and it has a strong safety record. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about tFUS (transcranial focused ultrasound) for treating vision-related issues because it offers a non-invasive approach that directly targets the brain's visual cortex, known as V1. Unlike traditional treatments that might involve medications or surgeries, tFUS uses sound waves to stimulate brain areas responsible for vision, potentially improving blind spots without physical intervention. This innovative method could offer quicker and more precise adjustments to vision impairments, making it a promising frontier in visual rehabilitation.

What evidence suggests that tFUS is effective for visual detection?

Research shows that transcranial Focused Ultrasound Stimulation (tFUS) can influence brain activity. Studies have found that tFUS can activate the visual cortex, the part of the brain responsible for sight. This effect has been observed in both normal and vision-impaired animals. tFUS changes how brain cells communicate by altering ion channels and the connections between nerve cells. These findings suggest that tFUS could affect visual information processing, which is why researchers are studying it in this trial for eye-related conditions. ^{6 7 8 9 10}

Are You a Good Fit for This Trial?

This trial is for healthy individuals who can safely undergo a procedure that temporarily affects their vision. Specific criteria for joining or reasons to be excluded aren't provided, but typically participants must meet certain health standards and not have conditions that could interfere with the study.

Inclusion Criteria

I am either male or female.

My vision and hearing are normal, or corrected to normal.

I do not have any neurological or psychological illnesses.

Exclusion Criteria

I have been diagnosed with depression or an anxiety disorder.

I have been diagnosed with schizophrenia or bipolar disorder.

Pregnancy (or suspected/possible pregnancy or plan to become pregnant in the short term)

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive transcranial Focused Ultrasound Stimulation (tFUS) to measure the threshold for effective tFUS and produce a transient scotoma

1 session

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

10 minutes

What Are the Treatments Tested in This Trial?

Interventions

• tFUS

Trial Overview The study is testing a technique using the Brainsonix Bx Pulsar machine to apply focused ultrasound (tFUS) to the brain. It aims to find out how much tFUS is needed to affect visual perception without causing harm.

How Is the Trial Designed?

Group I: tFUS over V1 Experimental Treatment 1 Intervention

All subjects will get tFUS, open label

Who Is Running the Clinical Trial?

Medical University of South Carolina

Lead Sponsor

Trials

994

Recruited

7,408,000+

Published Research Related to This Trial

Transcranial focused ultrasound (tFUS) is a promising non-surgical technique for neuromodulation that offers better spatial resolution compared to traditional electro and electromagnetic methods.

tFUS can effectively target sub-cortical brain structures non-invasively, and its combination with BOLD functional MRI allows for enhanced examination of brain activity in humans.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial focused ultrasound for BOLD fMRI signal modulation in humans. Leo Ai, ., Mueller, JK., Grant, A., et al.[2022]

Transcranial focused ultrasound (tFUS) can selectively target and modulate deep brain structures, such as the amygdala and entorhinal cortex, in healthy adults, leading to significant changes in brain perfusion and activity.

The study demonstrated that tFUS does not activate the auditory cortex, indicating that its effects are due to direct neuromodulation rather than an acoustic response, suggesting potential therapeutic applications for neurological and psychiatric disorders.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Transcranial focused ultrasound selectively increases perfusion and modulates functional connectivity of deep brain regions in humans. Kuhn, T., Spivak, NM., Dang, BH., et al.[2023]

A systematic review of 33 studies on low-intensity transcranial focused ultrasound stimulation (TFUS) indicates that adverse effects are very rare, with most studies showing no significant negative outcomes even when safety limits were exceeded.

However, at high stimulation intensities, TFUS can potentially cause serious issues like hemorrhage, cell death, and unintended blood-brain barrier opening, highlighting the need for further research to establish clear safety guidelines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of transcranial focused ultrasound stimulation: A systematic review of the state of knowledge from both human and animal studies. Pasquinelli, C., Hanson, LG., Siebner, HR., et al.[2020]

Transcranial focused ultrasound (tFUS) can reversibly suppress neuronal activity in the thalamus, as demonstrated by its effects on somatosensory evoked potentials (SSEP) in a rodent model, indicating its potential as a non-invasive neuromodulation technique.

The primary mechanism of this suppression appears to be thermal effects caused by the focused ultrasound, as the suppression correlated with temperature changes without causing any pathological damage to the tissue.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Reversible neuroinhibition by focused ultrasound is mediated by a thermal mechanism. Darrow, DP., O'Brien, P., Richner, TJ., et al.[2020]

Transcranial focused ultrasound (FUS) can effectively stimulate the motor area of the brain in rats using lower acoustic intensities (4.9-5.6 W/cm²) with specific pulsing parameters, indicating its potential for safe brain stimulation.

The study found that pulsed sonication is more effective than continuous sonication for eliciting motor responses, suggesting that this method could be optimized for therapeutic applications while adhering to safety limits for biological tissue.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Focused ultrasound-mediated non-invasive brain stimulation: examination of sonication parameters. Kim, H., Chiu, A., Lee, SD., et al.[2022]

Transcranial focus ultrasound stimulation (tFUS) can significantly modulate excitability in the human motor cortex, with different parameters leading to either increased or decreased excitability, as shown in a study involving 10 subjects.

The study revealed that tFUS affects neurotransmitter levels, decreasing GABA and increasing glutamate concentrations, which suggests it alters the balance of excitatory and inhibitory signals in the brain, potentially impacting motor function and plasticity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Excitatory-inhibitory modulation of transcranial focus ultrasound stimulation on human motor cortex. Zhang, T., Guo, B., Zuo, Z., et al.[2023]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8153235/

Transcranial Focused Ultrasound for Non-invasive ... tFUS was used to successfully evoke neural activities in the visual cortex (VC) of both normal and retinal degenerate (RD) blind rats. Our results showed that ...

2. jneuroengrehab.biomedcentral.com jneuroengrehab.biomedcentral.com/articles/10.1186/s12984-025-01753-2

A panoramic review of transcranial focused ultrasound ... Numerous animal and human studies have shown that tFUS affects brain function through multi-level mechanisms involving ion channels, synaptic ...

3. nature.com nature.com/articles/s41467-024-48576-8

Transcranial focused ultrasound to V5 enhances human ... This study examines whether tFUS neuromodulation can improve BCI outcomes, and explores the underlying mechanism of action using high-density ...

4. sciencedirect.com sciencedirect.com/science/article/pii/S2772528625000196

Optimizing transcranial focused ultrasound parameters: A ... This paper presents a novel computational-experimental technique to improve tFUS parameters, addressing significant constraints in accuracy, efficacy, and ...

5. tandfonline.com tandfonline.com/doi/full/10.1080/02656736.2025.2539986

Strengths and weaknesses of transcranial ultrasound ... Abstract. This article reviews early studies that have demonstrated the ability of low intensity ultrasound waves to modulate brain activity.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9879416/

Safety Review and Perspectives of Transcranial Focused ... This review aims to provide safety information and perspectives of tFUS brain stimulation. First, the acoustic parameters most relevant to ...

7. sciencedirect.com sciencedirect.com/science/article/pii/S1935861X19303389

Safety of transcranial focused ultrasound stimulation Adverse effects of TFUS were very rare. At high stimulation intensity and/or rate, TFUS may cause haemorrhage, cell death or damage, and unintentional blood- ...

8. e-bnr.org e-bnr.org/Synapse/Data/PDFData/0176BN/bn-14-e4.pdf

Safety Review and Perspectives of Transcranial Focused ... This review aims to provide safety information and perspectives of tFUS brain stimulation. First, the acoustic parameters most relevant to ...

9. nature.com nature.com/articles/s41380-025-03033-w

Low-intensity transcranial focused ultrasound amygdala ... Safety of transcranial focused ultrasound stimulation: a systematic review of the state of knowledge from both human and animal studies.

10. clinicaltrials.gov clinicaltrials.gov/study/NCT05792020

Study Details | NCT05792020 | Safety, Parameterization ... All participants will receive three sessions of Focused Ultrasound Stimulation to their motor hotspot. This stimulation cycle will operate at a 50% duty cycle.