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 optical sensing device for sensing at least one biological parameter of a subject by illuminating a skin surface through a contact surface and detecting a response of the illumination through the contact surface along a detector optical axis. A housing is coupled to a substrate by at least one flexible member distinct from the housing and the substrate so that the substrate and the contact surface move with respect to the housing at least in a direction perpendicular to the contact surface, while the contact surface is rigidly integrated with the substrate such that there is a full correlation between the movement of the contact surface and the substrate.

The invention further defines optical and spectral features for detecting a response to determine the biological parameter, including illuminating along an illumination source optical axis through the contact surface and using illumination including at least a first wavelength. The illumination optical axis forms an acute included angle with the contact surface, and the illumination can include different wavelengths, including at least a first wavelength within a green spectrum and a second wavelength within a violet spectrum.

Additional refinements include disposing at least two identical light sources symmetrically with respect to the detector and illuminating using light sources positioned at different distances from the detector. A barrier member confines at least one light source and at least one detector, and a buffer around the detector blocks light that is not reflected from the skin.

A movement and/or pressure sensor is disposed on the substrate to sense movement of and/or pressure applied on the contact surface, providing signals indicative of the biological parameter based on the detected response. Composite sensor assemblies are described to combine PPG with ECG and to derive parameters including Pulse Transmit Time (PTT), Pulse Transmit Velocity (PTV), and blood pressure, and the device is also described as supporting diagnostics and wearer authentication.

Claims Coverage

The independent claims cover multiple inventive aspects of the skin-contact optical sensing device, including optical illumination/detection via a rigidly integrated contact surface and substrate, mechanical coupling with full correlation of movement, optical geometry and multi-wavelength illumination refinements, detector light blocking via a buffer, and movement and/or pressure sensing disposed on the substrate. The claim coverage includes 10 inventive features.

Across the independent claims, the core claim coverage is the combination of optical sensing through a rigidly integrated contact surface and substrate, mechanical coupling that permits relative motion perpendicular to the contact surface while maintaining full movement correlation, and optical refinements and sensing refinements including multi-wavelength illumination, optical geometry, detector light blocking via a buffer, and movement/pressure sensing on the substrate to support signals indicative of the biological parameter.

Stated Advantages

Documented Applications