Prediction of breathing signal and determining non-periodicity of breathing using signal-phase histogram

• US 9,392,962 B2
• Filed: 04/01/2011
• Issued: 07/19/2016
• Est. Priority Date: 04/01/2011
• Status: Active Grant

• Current Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Mostafavi, Hassan
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): WEARE, MEREDITH H
• Application Number:
  US13/078,903
• Publication Number:
  US 20120253217A1
• Time in Patent Office: 1,936 Days
• Field of Search: 600529-543
• US Class Current: 1/1
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/0823 Detecting or evaluating cough events
• CPC Class Codes: A61B 5/1128 using image analysis A61B5/1127 takes precedence
• CPC Class Codes: A61B 5/1135 by monitoring thoracic expansion
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7292 Prospective gating, i.e. predicting the occurrence of a physiological event for use as a synchronisation signal
• CPC Class Codes: A61B 6/022 Stereoscopic imaging
• CPC Class Codes: A61B 6/032 Transmission computed tomography [CT]
• CPC Class Codes: A61B 6/5288 involving retrospective matching to a physiological signal
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61N 2005/1059 using cameras imaging the patient
• CPC Class Codes: A61N 5/1067 in real time, i.e. during treatment
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A method of processing breathing signals of a subject includes obtaining breathing signals of a subject, obtaining a signal-phase histogram using the breathing signals, wherein the signal-phase histogram comprises a plurality of data points, each of the data points having at least a phase value and a signal value, determining a reference value using at least some of the plurality of data points from the signal-phase histogram, determining whether a difference between the reference value and a signal value that is associated with a current respiratory cycle exceeds a threshold, and generating an output when the difference exceeds the threshold. A method of predicting breathing signal is also provided.

Claims

1. A method of processing breathing signals of a subject, comprising:

obtaining breathing signals of a subject using a breathing monitoring device;

obtaining a signal-phase histogram using the breathing signals, wherein the signal-phase histogram comprises a plurality of data points, each of the data points having at least a phase value and a signal value;

determining, by a processing unit, a first reference value using at least some of the plurality of data points from the signal-phase histogram;

determining, by the processing unit, a difference between the first reference value and a signal value that is associated with a current respiratory cycle;

predicting, by the processing unit, a future signal value by;

determining, by the processing unit, a second reference value using at least some of the data points in the histogram corresponding with a future phase value, and adding the difference and the second reference value to predict the future signal value; and

providing, by the processing unit,

a control signal to a controller for controlling a component of a radiation system based at least in part on the future signal value that is predicted by the processing unit.

2. The method of claim 1, wherein at least one of the first reference value and the second reference value comprises an average value.

3. The method of claim 1, wherein at least one of the first reference value and the second reference value comprises a median value.

4. The method of claim 1, wherein the output is generated for indicating non-periodicity of a breathing of the subject.

5. The method of claim 1, wherein the signal value that is associated with a current respiratory cycle comprises a current signal value.

6. The method of claim 1, further comprising updating the signal-phase histogram by disregarding one or more of the signal values that are older than a prescribed period.

7. A method of processing breathing signals of a subject, comprising:

obtaining breathing signals of a subject using a breathing monitoring device;

determining a signal-phase histogram using the breathing signals, wherein the signal-phase histogram comprises a plurality of data points, each of the data points having at least a phase value and a signal value;

obtaining, by a processing unit, a current signal value that is associated with a current time instant in a respiratory cycle;

obtaining, by the processing unit, a future phase value;

predicting, by the processing unit, a future signal value, wherein the act of predicting the future signal value comprises determining a delta value representing a difference between the current signal value and a reference signal associated with the signal-phase histogram, and applying the delta value for the future phase value to predict the future signal value; and

providing a control signal to a controller for controlling a component of a radiation system based at least in part on the future signal value that is predicted by the processing unit.

8. The method of claim 7, further comprising updating the signal-phase histogram by disregarding one or more of the signal values that are older than a prescribed period.

9. The method of claim 7, wherein the component of the radiation system is controlled by using the predicted future signal value to control a delivery of treatment radiation.

10. The method of claim 7, wherein the component of the radiation system is controlled by using the predicted future signal value to control an imaging process.

11. A method of processing breathing signals of a subject, comprising:

obtaining breathing signals of a subject using a breathing monitoring device;

determining a signal-phase histogram using the breathing signals, wherein the signal-phase histogram comprises a plurality of data points, each of the data points having at least a phase value and a signal value;

obtaining a current signal value that is associated with a current time instant in a respiratory cycle;

obtaining a future phase value; and

predicting a future signal value using the current signal value, the future phase value, and the signal-phase histogram;

wherein the act of predicting the future signal value comprises;

determining, by a processing unit, a first reference value using at least some of the data points in the histogram that correspond with a current phase value;

determining, by the processing unit, a difference between the current signal value and the first reference value;

determining, by the processing unit, a second reference value using at least some of the data points in the histogram that correspond with the future phase value; and

adding, by the processing unit, the difference and the second reference value to determine the future signal value; and

providing, by the processing unit, a control signal to a controller to control a component of a radiation system based at least in part on the future signal value that is determined by the processing unit.

12. The method of claim 11, wherein at least one of the first reference value and the second reference value is determined by determining an average value using at least some of the data points in the signal-phase histogram.

13. The method of claim 11, wherein at least one of the first reference value and the second reference value is determined by determining a median value using at least some of the data points in the signal-phase histogram.

14. A system for processing breathing signals of a subject, comprising:

a processor configured for

obtaining breathing signals of a subject;

determining a signal-phase histogram using the breathing signals, wherein the signal-phase histogram comprises a plurality of data points, each of the data points having at least a phase value and a signal value;

obtaining a current signal value that is associated with a current time instant in a respiratory cycle; and

obtaining a future phase value; and

predicting a future signal value, wherein the processor is configured to predict the future signal value by determining a delta value representing a difference between the current signal value and a reference signal associated with the signal-phase histogram, and applying the delta value for the future phase value to predict the future signal value; and

providing a control signal to a controller to control a component of a radiation system based at least in part on the future signal value that is predicted by the processor.

15. A computer product having a set of instructions stored in a non-transitory medium, wherein an execution of the instructions causes a process to be performed, the process comprising:

obtaining breathing signals of a subject;

determining a signal-phase histogram using the breathing signals, wherein the signal-phase histogram comprises a plurality of data points, each of the data points having at least a phase value and a signal value;

obtaining, by a processing unit, a current signal value that is associated with a current time instant in a respiratory cycle;

obtaining, by the processing unit, a future phase value; and

predicting, by the processing unit, a future signal value, wherein the act of predicting the future signal value comprises determining a delta value representing a difference between the current signal value and a reference signal associated with the signal-phase histogram, and applying the delta value for the future phase value to predict the future signal value; and

providing, by the processing unit, a control signal to a controller to control a component of a radiation system based at least in part on the future signal value that is predicted by the processing unit.