CARDIAC MUSCLE EXCITATION WAVEFORM DETECTOR

• US 20130245476A1
• Filed: 03/05/2013
• Published: 09/19/2013
• Est. Priority Date: 03/15/2012
• Status: Active Grant

• Current Assignee: Nihon Kohden Corporation
• Original Assignee: Nihon Kohden Corporation
• Inventors: SUZUKI, Satoshi, TAKIZAWA, Koji, NISHIHARA, Tatsuo, IWANAGA, Yuuho, HATTORI, Naoki, YUZE, Hiroki
• Granted Patent: US 8,825,147 B2
• Time in Patent Office: Days
• US Class Current: 600/518
• CPC Class Codes: A61B 5/361 Detecting fibrillation
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence

Abstract

A cardiac muscle excitation waveform detector including: a waveform acquisition section that acquires, in a preset period, a waveform from an intracardiac electrocardiogram measured in middle of occurrence of atrial fibrillation; a waveform detection condition setting section that sets conditions for detecting a waveform of cardiac muscle excitation; and an excitation waveform detection section that detects a waveform of cardiac muscle excitation from the waveforms based on the conditions, wherein the waveform detection condition setting section includes a section that sets conditions based on a contour of a waveform to detect candidates for the waveform of cardiac muscle excitation, a section that sets a search period for searching for a waveform of cardiac muscle excitation; and a section that sets a preset period subsequent to detection as a detection exclusion period during which the candidate waveforms are not detected when the waveform of cardiac muscle excitation is detected.

Claims

1. A cardiac muscle excitation waveform detector comprising:

a waveform acquisition section configured to acquire, in a preset waveform analysis period, a waveform from an intracardiac electrocardiogram measured in middle of occurrence of atrial fibrillation;

a waveform detection condition setting section configured to set conditions for detecting a waveform of cardiac muscle excitation, which shows occurrence of excitation in cardiac muscle, from among waveforms that are acquired by the waveform acquisition section in the waveform analysis period; and

an excitation waveform detection section configured to detect a waveform of cardiac muscle excitation from the waveforms belonging to the waveform analysis period on the basis of the conditions set by the waveform detection condition setting section, wherein

the waveform detection condition setting section includes

a candidate waveform detection condition setting section configured to set conditions based on a contour of a waveform in order to detect candidates for the waveform of cardiac muscle excitation,

a search period setting section configured to set a search period for searching for a waveform of cardiac muscle excitation from among the candidate waveforms detected according to the conditions based on the contour of the waveform; and

a detection exclusion period setting section configured to set a preset period subsequent to detection as a detection exclusion period during which the candidate waveforms are not detected as a waveform of cardiac muscle excitation when the waveform of cardiac muscle excitation is detected from the candidate waveforms.

2. The cardiac muscle excitation waveform detector according to claim 1, wherein the conditions for searching for the waveform of cardiac muscle excitation in the search period set by the search period setting section are based on a maximum P-P value of the candidate waveform belonging to the search period.

3. The cardiac muscle excitation waveform detector according to claim 1, wherein the search period setting section sets the search period so as to become shorter than the detection exclusion period.

4. The cardiac muscle excitation waveform detector according to claim 1, further comprising a mean conduction time calculation section configured to calculate a mean conduction time during which cardiac muscle excitation is conducted, from the plurality of waveforms of cardiac muscle excitation detected by the excitation waveform detection section.

5. A cardiac muscle excitation waveform detection program for causing a computer to execute processing pertinent to:

a waveform acquisition procedure for measuring a size of a waveform which occurs in a preset waveform analysis period of an intracardiac electrocardiogram measured in middle of occurrence of atrial fibrillation, thereby acquiring a waveform meeting predetermined conditions as a candidate for a waveform of cardiac muscle excitation;

a cardiac muscle excitation detection procedure for taking as a cardiac muscle excitation search period a preset period that continues from occurrence of the waveform first acquired as the candidate waveform and detecting a candidate waveform which has the maximum P-P value in the cardiac muscle excitation search period as a waveform of cardiac muscle excitation; and

a cardiac muscle excitation exclusion procedure for taking as a waveform detection exclusion period a preset period that continues from occurrence of the waveform detected as a candidate for a waveform of cardiac muscle excitation and detecting the candidate waveform belonging to the waveform detection exclusion period as a waveform of cardiac muscle excitation.

6. The cardiac muscle excitation waveform detection program for causing a computer to perform processing according to claim 5, further comprising:

processing pertinent to a procedure for iterating processing pertinent to the cardiac muscle excitation detection procedure and the cardiac muscle excitation exclusion procedure after elapse of the waveform detection exclusion period; and

processing pertinent to a mean conduction time calculation procedure for calculating a mean conduction time during which cardiac muscle excitation is conducted, from a plurality of detected waveforms of cardiac muscle excitation.