Inventors:
- Cupertino CA, US
Wren Nancy Dougherty - San Francisco CA, US
Richard C. Kimoto - Cupertino CA, US
Ravi K. Narasimhan - Sunnyvale CA, US
Thomas J. Sullivan - Cupertino CA, US
Stephen J. Waydo - Cupertino CA, US
Todd K. Whitehurst - Cupertino CA, US
Santiago Quijano - Cupertino CA, US
Derek Park-Shing Young - Cupertino CA, US
Zijing Zeng - Cupertino CA, US
International Classification:
A61B 5/021
A61B 5/00
A61B 5/11
Abstract:
Methods and devices for obtaining a blood pressure measurement of a subject measure a transit time of a blood pulse of the subject. A method includes sensing, with a pulse ejection sensor of a wrist-worn device, ejection of blood from the left ventricle. Arrival of a resulting blood pressure pulse at the wrist is sensed via a pulse arrival sensor of the wrist-worn device. A transit time of the blood pressure pulse from the left ventricle to the wrist is determined. A relative blood pressure value of the subject is determined based on the transit time. A reference absolute blood pressure value associated with the relative blood pressure value is received. An absolute blood pressure value for the relative blood pressure value is determined based on the reference absolute blood pressure value and the relative blood pressure value.