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EP-3761866-B1 - CARDIOVASCULAR HEALTH MONITORING

EP3761866B1EP 3761866 B1EP3761866 B1EP 3761866B1EP-3761866-B1

Inventors

  • GBATI, Israel Ninsaw

Dates

Publication Date
20260506
Application Date
20190308

Claims (14)

  1. A cardiovascular monitoring apparatus, the apparatus comprising: a photoplethysmography (PPG) sensor, having a plurality of light emitting elements (310) and a plurality of light sensing elements (320), for obtaining at least one PPG signal from a patient; a member (300) for supporting the plurality of light emitting elements (310) and the plurality of light sensing elements (320), wherein the light emitting elements (310) and light sensing elements (320) are arranged as respective arrays on the member (300), and wherein the arrays are arranged such that the array of light emitting elements (310) are interleaved with the array of light sensing elements (320); and a controller (530) comprising: a detection module for detecting objects proximate the plurality of light sensing elements (320) thereby to determine a subset of the plurality of light sensing elements (320), and, subsequently to detecting objects, obtaining signals using the subset of the plurality of light sensing elements (320); a determination module (550) for determining whether signals obtained by the subset of the plurality of light sensing elements (320) are each suitable for deriving information relevant to a patient's cardiovascular system; and a processing module (540) for processing a signal that is determined to be suitable for deriving information relevant to the patient's cardiovascular system to derive information relevant to the patient's cardiovascular system.
  2. An apparatus according to Claim 1, wherein, responsive to the determination module determining that a signal obtained by a particular light sensing element is not suitable for deriving information relevant to a patient's cardiovascular system, the determination module is arranged to determine whether a signal obtained by a different light sensing element is suitable for deriving information relevant to a patient's cardiovascular system.
  3. An apparatus according to any preceding claim, wherein determining whether a signal obtained by a particular light sensing element is suitable for deriving information relevant to a patient's cardiovascular system comprises comparing the obtained signal against one or more criteria, preferably wherein the one or more criteria comprises at least one criterion relating to the shape of the signal waveform, more preferably wherein the comparing to the at least one criterion relating to the shape of the signal waveform is performed using at least one of: Cross-Correlation, Sign Comparison, Sum of Absolute Difference, Interval Matching, Dynamic Time Warping (DTW), and machine learning, and/or wherein the one or more criteria comprises at least one criterion relating to the frequency of the signal, and/or wherein the comparing comprises comparing at least one period of the signal, preferably exactly one period of the signal, to the one or more criteria, and/or wherein the apparatus further comprises means for storing a sample of the signal for comparison with the one or more criteria.
  4. An apparatus according to Claim 3, wherein the controller further comprises a selection module for selecting at least one signal that is determined to be suitable for deriving information relevant to the patient's cardiovascular system for processing by the processing module; said selection being from a plurality of such signals, preferably wherein the selection is based on the comparison against the one or more criteria.
  5. An apparatus according to any preceding claim, wherein the controller further comprises a detection module for detecting objects proximate the at least one light sensing element, preferably wherein detecting objects comprises detecting a parameter related to the ambient light received by the at least one light sensing element; and comparing the detected parameter to a threshold value.
  6. An apparatus according to Claim 5, wherein the at least one light emitting element is adapted to emit light only when an object is detected proximate the at least one light sensing element and/or wherein the determination module is arranged to perform the determination on only those signals obtained by the at least one light sensing element in relation to which a proximate object is detected.
  7. An apparatus according to any preceding claim, wherein the processing module terminates processing of the signal when the signal ceases to be suitable for deriving cardiovascular parameters, and/or wherein the apparatus further comprises a conditioner circuit, wherein the processing module processes the signal digitally.
  8. An apparatus according to any preceding claim further comprising a module for determining (and optionally storing) at least one location within the array of the light sensing elements which obtains a signal that is determined to be suitable for deriving information relevant to a patient's cardiovascular system.
  9. An apparatus according to any preceding claim, further comprising a module for determining movement of at least one body part of the patient in relation to the array; optionally wherein the at least one body part is at least one finger; preferably wherein the processing module is arranged to process only those signals that correspond to light sensing elements in relation to which no movement of the at least one body part is detected (more preferably over a predetermined period of time).
  10. A cardiovascular monitoring apparatus according to any preceding claim, wherein at least one of the array of light emitting elements and the array of light sensing elements extend over an area of the member that is larger than 10 cm 2 ; preferably larger than 15 cm 2 ; and more preferably larger than 20 cm 2 .
  11. A cardiovascular monitoring apparatus according to any preceding claim, wherein the member is a flexible plastic substrate, and/or is curved.
  12. A cardiovascular monitoring apparatus according to any preceding claim, wherein the array of light emitting elements is arranged in or on a first layer of the member and the array of light sensing elements is arranged in or on a second layer of the member, preferably wherein at least one of the first layer and the second layer comprises one or more apertures to allow light to pass therethrough, more preferably wherein one of the array of light emitting elements and the array of light sensing elements are formed of a light emitter or light sensor and the one or more apertures in the first layer or the second layer, wherein, in use, the light emitter or light sensor is provided underneath the layer having the one or more apertures, and yet more preferably wherein the other of the array of light emitting elements and the array of light sensing elements is arranged in or on the layer having the one or more apertures.
  13. A consumer product incorporating the apparatus of any preceding claim, preferably wherein the at least one light sensing element is provided on a part of the product which is gripped by a user for using the product, more preferably wherein the plurality of light sensing elements are distributed across at least one surface of the product which is gripped by a user for using the product, still more preferably wherein the consumer product is: a trackpad for a computing device; or a computing device, such as a laptop computer, wherein the apparatus is provided on a user input device such as a trackpad.
  14. A system comprising two or more separate cardiovascular monitoring apparatuses according to any of Claims 1 to 12, preferably wherein each of the separate cardiovascular monitoring apparatuses is connected to a network, and more preferably wherein the system further comprises computing means connected to the network adapted to store information obtained by each apparatus.

Description

Field of Invention The present invention relates to cardiovascular health monitoring. More specifically, the invention relates to a photoplethysmographic cardiovascular monitoring apparatus. The invention further relates to a surface for monitoring cardiovascular health of humans and other animals. The invention further relates to a trackpad device for monitoring cardiovascular health of users. Background Cardiovascular illnesses are the number one cause of death worldwide. This is primarily because early symptoms of cardiovascular conditions are hard to detect by human sensory means. Because of this, people more prone to having cardiovascular conditions are required to visit the hospital regularly for checkups and are also required to actively monitor their cardiovascular health at home using some form of portable handheld devices. However, there is a problem with compliance. For instance, in the United States, less than 20% of all people required by their doctors to check their blood pressure daily, check only twice a week. Owing to this and other problems relating to convenience of time and avenue for continuous cardiovascular health monitoring, there is the need to be able to monitor cardiovascular health of patients or people in general completely non-invasively without the patient or person wearing a device, initiating the process or even thinking about it. Trackpads are also sometimes called touchpads. Trackpads are mostly used with computing devices to enable interaction with the computing device. They often include a touch sensing surface mostly capacitive and or resistive where the trackpad is configured to detect the position and motion of a user's finger or fingers that are in contact with the touch sensing surface. The prior art relevant to the present invention includes several disclosures in the field of cardiovascular monitoring using photoplethysmography (PPG) sensors. US20160278646A1 describes an opto-physiological sensor with a single light source and photodetector, focusing on optimal emitter-detector separation for PPG signal acquisition. US20170209055A1 discloses a wearable biometric monitor that employs multiple PPG sensors to measure arterial stiffness, utilizing inertial sensors for signal quality assessment. US20140081153A1 details a pulse data detecting apparatus with interleaved arrays of light-emitting and light-receiving elements, analyzing all sensor pairs to select optimal signals for pulse rate calculation. US20150374245A1 presents a PPG device with interleaved arrays and proximity detection to initiate operation, analyzing all emitter-detector pairs for cardiovascular information. US20160157781A1 describes a computing device with an electrode-based contact detection system and optional PPG sensors that are activated uniformly. Summary of the Invention Aspects and embodiments of the present invention are set out in the appended claims. These and other aspects and embodiments of the invention are also described herein. According to at least one aspect described herein, there is provided a cardiovascular monitoring apparatus, the apparatus comprising: a photoplethysmography (PPG) sensor, having a plurality of light emitting elements and a plurality of light sensing elements, for obtaining at least one PPG signal from a patient; a member for supporting the plurality of light emitting elements and the plurality of light sensing elements, wherein the light emitting elements and light sensing elements are arranged as respective arrays on the member, and wherein the arrays are arranged such that the array of light emitting elements are interleaved with the array of light sensing elements; and a controller comprising: a detection module for detecting objects proximate the plurality of light sensing elements thereby to determine a subset of the plurality of light sensing elements, and, subsequently to detecting objects, obtaining signals using the subset of the plurality of light sensing elements; a determination module for determining whether signals obtained by the subset of the plurality of light sensing elements are each suitable for deriving information relevant to a patient's cardiovascular system; and a processing module for processing a signal that is determined to be suitable for deriving information relevant to the patient's cardiovascular system to derive information relevant to the patient's cardiovascular system (preferably wherein the information is relevant to the patient's cardiovascular health). This may provide improved processing efficiency, in that an initial test of the usefulness of a particular signal is provided prior to full processing. This may be particularly useful where it is desired to pick from a plurality of possible signals (optionally from a plurality of possible sensors). The PPG sensor may further comprise a plurality of light sensing elements. Preferably, the determination module is arranged to determine whether signals obtained by at least a subs