Detection and monitoring of abdominal aortic aneurysm

• US 9,801,558 B2
• Filed: 07/14/2011
• Issued: 10/31/2017
• Est. Priority Date: 07/21/2010
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Morren, Geert Gui Georges
• Primary Examiner(s): Gillman, Amelie R
• Application Number:
  US13/811,297
• Publication Number:
  US 20130116576A1
• Time in Patent Office: 2,301 Days
• Field of Search: None
• CPC Class Codes: A61B 5/02014 Determining aneurysm
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence

Abstract

Ruptured Abdominal Aortic Aneurysms (AAA) cause a large number of deaths annually. Ruptures occur even in people who are already diagnosed with AAA and are being monitored. The reason is that the interval between tests is too long because of the need to visit a pathological facility with imaging equipment. It is preferable to estimate the progress of AAA frequently, once detected, in a non-invasive manner, preferably at the subject'"'"'s home, without the need for the subject to visit a pathological facility. A device is disclosed for detecting a state of a vascular pathology of a subject, comprising a sensor signal unit (103) for providing a signal representative of a blood volume in a body part of a subject, a comparator (107) for comparing the sensor signal with a reference signal, and a user interface (109) for conveying a result based on the comparison to a user of the device.

Claims

1. A device for testing a subject for estimating a progress of a state of an existing abdominal aorta aneurysm of the subject based on a determined change over time, the device comprising:

a sensor configured to sense a pulsation of blood volume in a body part of the subject;

a memory;

a processor configured to;

acquire from the sensor an amplified sensor signal representative of the blood volume in the body part of the subject;

acquire an electrocardiogram (ECG) signal of the subject via an ECG electrode, the ECG signal indicating an activity of the heart muscle of the subject;

analyze a time interval between a peak of the ECG signal and the sensor signal for a number of cycles so as to synchronize the acquisition of the sensor signal with the ECG signal;

increase the amplification of a DC component of the sensor signal to a higher amplification for the time period when the ECG signal indicates that the heart muscle of the subject is in a diastolic state, and reduce the amplification of the DC component of the sensor signal for the time period when the ECG signal indicates that the heart muscle of the subject is in a systolic state;

compare one or more characteristics of the sensor signal with corresponding one or more characteristics of a reference signal stored in the memory, wherein the reference signal is a corresponding sensor signal previously acquired from a test on the subject a time period ago, timing information of the ECG signal being used to compensate for a difference in heart rates of the subject between acquisitions of the sensor signal and the reference signal; and

determine a change in the one or more characteristics of the sensor signal over the time period; and

a user interface configured to display a result of the determination,

wherein the result provides an estimate of the progress of the state of the existing abdominal aorta aneurysm.

2. The device of claim 1, wherein the sensor is a photoplethysmogram sensor.

3. The device of claim 1, wherein the processor is further configured to:

determine a change in one or more relationships between the sensor signal and the ECG signal of the subject,

wherein the one or more relationships comprise the time interval between a peak of the ECG signal and the sensor signal,

and further wherein the result of the determination is based upon the determined change in the one or more relationships between the sensor signal and the ECG signal.

4. A method of testing a subject for estimating a progress of a state of an existing abdominal aorta aneurysm of the subject based on a determined change over time, the method comprising:

sensing a pulsation of blood volume in a body part of the subject with a sensor and acquiring an amplified sensor signal representative of the blood volume;

acquiring, by a processor, an electrocardiogram (ECG) signal of the subject via an ECG electrode, the ECG signal indicating an activity of the heart muscle of the subject;

analyzing, by the processor, a time interval between a peak of the ECG signal and the sensor signal for a number of cycles so as to synchronize, by the processor, the acquisition of the sensor signal with the ECG signal;

amplifying to a higher amplification, by the processor, a DC component of the sensor signal when the ECG signal indicates that the heart muscle of the subject is in a diastolic state, and reducing the amplification of the DC component of the sensor signal for the time period when the ECG signal indicates that the heart muscle of the subject is in a systolic state;

comparing, by the processor, one or more characteristics of the sensor signal with corresponding one or more characteristics of a reference signal stored in a memory, wherein the reference signal is a corresponding sensor signal previously acquired from a test on the subject a time period ago, timing information of the ECG signal being used to compensate for a difference in heart rates of the subject between acquisitions of the sensor signal and the reference signal;

determining, by the processor, a change in the one or more characteristics of the sensor signal over the time period; and

displaying a result of the determination, wherein the result provides an estimate of the progress of the state of the existing abdominal aorta aneurysm.

5. The method of claim 4, further comprising determining a change in one or more relationships between the sensor signal and the ECG signal,

wherein the one or more relationships comprise the time interval between a peak of the ECG signal and the sensor signal,

and further wherein the result of the determination is based upon the determined change in the one or more relationships between the sensor signal and the ECG signal.