for people ages 18 years and up (full criteria)
at San Francisco, California
study started
estimated completion
Principal Investigator
Wade Smith
Photo of Wade Smith
Wade Smith



Accurate diagnosis of stroke due to large vessel occlusion (LVO) is an essential step in providing acute stroke care to a community. The gold-standard for diagnosis LVO is brain imaging, which is impractical in the pre-hospital setting. A non-invasive method to detect LVO is needed. Using highly sensitive accelerometers, one can measure the "HeadPulse"- tiny forces exerted on the skull from the cardiac contraction. This study tests the hypothesis that LVO alters the HeadPulse characteristically. Analysis of these data along with the subjects vascular status (LVO vs. non-LVO as measured by CT angiography) will be used to create a model that can predict LVO status in suspect stroke subjects.

Official Title

Measuring Cardiac Head Impulse to Detect Acute Large Vessel Ischemic Stroke


Large vessel occlusion (LVO) ischemic stroke is a treatable disease at specialized centers. Clinical outcomes of patients with LVO is time-dependent. To maximize clinical benefit of thrombectomy, stroke systems of care need accurate methods to triage patients with LVO to comprehensive stroke centers or thrombectomy ready centers rather than closer primary stroke centers.

EPISODE will evaluate whether measurements of the HeadPulse can predict the presence or absence of LVO based on recordings from a consecutive series of patients undergoing CTA for suspected stroke. Recordings from patients pre- and post-thrombectomy will also be compared to investigate whether a systematic change in cranial forces exists during LVO.


Acute Ischemic Stroke Stroke Cerebral Infarction Ischemia Cranial Accelerometry Measurement Suspected acute stroke


You can join if…

Open to people ages 18 years and up

  • Suspected acute stroke
  • CTA or MRA performed

You CAN'T join if...

  • Any patient in whom obtaining a non-invasive recording is judged by the treating team to interfere with clinical assessment or treatment of the patient.


  • UCSF accepting new patients
    San Francisco California 94143 United States

Lead Scientist at UCSF

  • Wade Smith
    Dr. Smith is a neurologist with training in Neurocritical Care and Vascular Neurology. He cares for patients with acute stroke and subarachnoid hemorrhage among all neurovascular conditions. His research interests are in developing methods to rapidly triage stroke patients to appropriate immediate care using biometrics, endovascular stroke therapy and cerebral concussion.


accepting new patients
Start Date
Completion Date
University of California, San Francisco
Study Type
Last Updated