Single or multi-mode cardiac activity data collection, processing and display obtained in a non-invasive manner

• US 20030236466A1
• Filed: 06/21/2002
• Published: 12/25/2003
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Chih-Cheng Lu, Peter P. Tarjan, Walter G. Besio
• Original Assignee: Chih-Cheng Lu, Peter P. Tarjan, Walter G. Besio
• Inventors: Besio, Walter G., Lu, Chih-Cheng, Tarjan, Peter P.
• Granted Patent: US 7,043,292 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/28 for electrocardiography [ECG]
• CPC Class Codes: A61B 5/745 using a holographic display
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/488 involving Doppler signals

Abstract

The method for collecting cardiac activity data non-invasively from the chest or thorax of a patient comprises the steps of:

placing at least three active Laplacian ECG sensors at locations on the chest or thorax of the patient;

placing at least one ultrasonic sensor on the thorax where there is no underlying bone structure, only tissue, and where the ultrasonic sensor can transduce signals directly from the heart for measuring the time a burst of sound travels to and from the moving surface of the heart;

assuming the velocity of ultrasound propagation to be constant in the tissues involved;

making direct measurements of the exact sites of the sensors on the chest surface to determine the position and distance from the center of the sensor to the heart along a line orthogonal to the plane of the sensor to create a virtual heart surface;

updating the measurements at a reasonable rate to show the movement of the heart'"'"'s surface;

monitoring at each ultrasonic sensor site and each Laplacian ECG sensor site the position and movement of the heart and the depolarization wave-fronts in their vicinity;

treating those depolarization wave-fronts as moving dipoles at those sites to mimic time dependent charges or dipoles at those sites, equivalent to moving charges or dipoles on the heart; and,

displaying the heart activity like a moving picture which is equivalent to an approximation of the activation sequence on the virtual surface of the heart,

thereby to create chest surface maps of isochrones and the projections of those of isochrones onto a virtual surface that represents the heart, which can indicate the simultaneously depolarized zones for detecting zones of delayed depolarization, such as areas which have suffered infarctions and correlating those delayed zones with the movement and shape of the heart,

or thereby to create Laplacian isopotential maps either on the chest surface or their projection onto a virtual heart surface.

Claims

2-1. The method of claim 1 wherein said steps (a) to (g) are repeated for sequential time epochs.

9. An apparatus for measuring, analyzing and visualizing electrical and mechanical activities in a biological system, comprising a plurality of Laplacian ECG sensors and ultrasound transducers for detecting signals over part of a surface of a biological system, means for collecting the detected signals, means for determining positions of the sensors, means for determining the Moments of Activation (MOA'"'"'s) of the collected signals, means for determining the surface of interest in the ultrasound image, means for reducing measurement noise by applying digital filtering algorithms, and means for displaying simultaneously still images of the processed signals in both the time and space domains, together with the virtual image of the object of signal origination.

10. The apparatus of claim 9 further including means for analyzing the electrical and mechanical activities for sequential time epochs.

11. The apparatus of claim 9 further including means for analyzing the electrical and mechanical activities sequentially, using a stationary image of the heart during the display of the electrical activity, followed by the display of the contracting and relaxing surface of the object of signal origination.

12. The apparatus of claim 9 wherein the means for collecting the signals and the means for determining the MOAs and the means for determining the surface of interest include, respectively, an array of Laplacian ECG sensors and ultrasound transducers.

13. The apparatus of claim 9 wherein the plurality of sensors includes an array of magnetic sensors.

14. The apparatus of claim 9 wherein the plurality of sensors includes an array of magnetic sensors and an array of Laplacian ECG sensors.

15. The apparatus of claim 9 wherein the plurality of sensors includes an array of magnetic sensors and an array of Laplacian sensors and an array of ultrasound transducers.

16. A method for processing ultrasonic data from multiple sensors arranged to sense movements of a heart including the steps of:

combining time of flight information of the ultrasonic data to detect the distance between the sensor and its target, as well as the Doppler shift at the instant to be used for predicting the corresponding position of the reflecting surface for a next pulse of ultrasonic data to determine the actual position of the reflector; and

further combining an image of the heart'"'"'s surface with a Laplacian potential or isochronal maps.