Overview
- Temple published a small preprint, shared publicly on Monday, reporting that its forehead-worn optical metric called Brain Flow had a median within-subject correlation of about 0.8 with middle cerebral artery velocity during two tests: stationary cycling and a standing-to‑supine postural shift.
- The paper analysed data from 23 enrolled healthy adults with roughly 20 participants per protocol and is not peer reviewed, so its findings are preliminary and limited in statistical power and generalisability.
- The device uses an optical sensor at the temple to infer directional changes in cerebral blood‑flow signals and was compared with transcranial Doppler (TCD), an ultrasound method that measures blood‑flow velocity in major brain arteries rather than total or absolute cerebral blood flow.
- Temple says it is offering devices to qualified researchers, is running more validation studies of Brain Flow and another metric called Entropy, has reduced the device size, and acquired Longevous to add clinical expertise as it prepares limited preorders and a late‑2026 shipping target.
- What to watch next: independent peer review, larger and more diverse clinical studies, and regulatory or clinical proof are needed before the metric can be used for diagnosis or routine health guidance, though the tech could change how consumers and clinicians monitor brain blood‑flow if validated.