Sensing at least one biological parameter, E.G., heart rate or heart rate variability of a subject

Inventors

Shemesh, Eldad • Kouperman, Igor • Spektor, Boris

Assignees

Cardiacsense Ltd

Abstract

The present disclosure concerns a device for sensing at least one biological parameter (e.g., heart rate, heart rate variability) of a subject, the device comprising a contact surface configured for being brought into a contact with a skin surface of the subject. The device has at least one light source for illuminating the skin surface through the contact surface along an illumination source optical axis with illumination including at least one sensing wavelength, and at least one detector for detecting a response of said illumination at least at said wavelength, from the skin surface through the contact surface along a detector optical axis, and providing signals configured for determining said biological parameter based thereon, said illumination optical axis forming with said contact surface an acute included angle.

Core Innovation

The invention relates to a wearable skin-contact sensing device that senses at least one biological parameter of a subject using photoplethysmography (PPG) and optical illumination. The device includes a contact surface configured to be brought into contact with a skin surface, at least one light source element illuminating the skin surface through the contact surface along an illumination source optical axis with illumination including at least a first wavelength, and at least one detector element detecting a response of the illumination from the skin surface through the contact surface along a detector optical axis to provide signals indicative of the biological parameter.

A central structural feature places the light source element with respect to the detector sensing surface so that the geometric projection of the light source element on the plane defined by the detector element is entirely and continuously surrounded by the detector sensing surface, and in some embodiments borders with the detector sensing surface. This spatial and optical arrangement is described together with optical guiding elements and buffers that block non-reflected light to limit noise and improve what is detected from the skin.

The described wearable implementation integrates composite sensor assemblies in which optical PPG sensing is combined with electrical electrocardiogram (ECG) electrodes, optionally with a movement or pressure sensor to compensate PPG artifacts. The described architecture further derives Pulse Transmit Time (PTT) and blood pressure from signals associated with heart rate, heart rate variability (HRV), and related hemodynamic metrics, and includes a substrate coupled to a housing via flexible members to reduce pressure artifacts. In some configurations, the PPG is laterally confined between elevated ECG electrodes to enable simultaneous ECG and PPG from a small skin area.

Claims Coverage

The independent claims include 3 inventive claim sets, each requiring a skin-contact optical sensing device with at least one wavelength illumination and a detector that provides signals indicative of at least one biological parameter, together with a specific geometric placement relationship between the light source and the detector sensing surface.

Across the independent claims, the key claim coverage centers on skin-contact illumination at at least a first wavelength, optical detection providing signals indicative of the biological parameter, and a constrained geometric relationship in which the projection of the light source on the detector plane is entirely and continuously surrounded, with an additional borders limitation in one independent claim.

Stated Advantages

Documented Applications