Signal processing apparatus, imaging apparatus, and signal processing method

Patent metadata

Field	Value
Publication number	US-2016128643-A1
Application number	US-201514929527-A
Country	US
Kind code	A1
Filing date	Nov 2, 2015
Priority date	Nov 6, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

In one embodiment, a signal processing apparatus includes a storage circuit and processing circuitry configured to (a) generate detection parameters for detecting a specific signal included in a biosignal relevant to a heartbeat, based on a waveform of the biosignal, (b) store the detection parameters in the storage circuit, (c) detect the specific signal by using the detection parameters, and (d) generate a synchronization signal for performing heartbeat synchronization imaging based on the specific signal.

First claim

What is claimed is:

1 . A signal processing apparatus comprising:
a storage circuit; and processing circuitry configured to (a) generate two or more detection parameters for detecting a specific signal included in a biosignal relevant to a heartbeat, based on a waveform of the biosignal, (b) store the two or more detection parameters in the storage circuit, (c) detect the specific signal by using the two or more detection parameters, and (d) generate a synchronization signal for performing heartbeat synchronization imaging based on the specific signal.

2 . The signal processing apparatus according to claim 1 ,
wherein the biosignal is an ECG signal, the specific waveform is an R-wave, and the detection parameters are waveform templates each of which corresponds to a part of a waveform of the R-wave.

3 . The signal processing apparatus according to claim 2 ,
wherein the processing circuitry is configured to (a) generate two or more waveform templates by extracting a part of each of two or more R-waves included in the ECG signal, (b) store the two or more waveform templates in the storage circuit, and (c) detect the R-wave by performing matching processing between a waveform of the ECG signal inputted time-sequentially and each of the two or more waveform templates.

4 . The signal processing apparatus according to claim 3 ,
wherein the processing circuitry is configured to (a) calculate two or more evaluation values respectively corresponding to the two or more waveform templates, by performing matching processing between the waveform of the ECG signal and the two or more waveform templates, and (b) detect the R-wave by comparing an integrated evaluation value obtained from the calculated two or more evaluation values with a predetermined threshold value.

5 . The signal processing apparatus according to claim 4 ,
wherein the two or more evaluation values are respective two or more difference evaluation values based on differences between the waveform of the ECG signal and the two or more waveform templates, and the integrated value is a smallest value among the two or more difference evaluation values.

6 . The signal processing apparatus according to claim 2 ,
wherein the processing circuitry is configured to (a) sequentially generate a new waveform template, by extracting a part of the waveform of the ECG signal inputted time-sequentially, and (b) update the waveform templates stored in the storage circuit by using the new waveform template.

7 . The signal processing apparatus according to claim 6 ,
wherein the processing circuitry is configured to (a) calculate a similarity value between the new waveform template and each of the waveform templates stored in the storage circuit, and (b) store the new waveform template when the similarity value is smaller than a predetermined value.

8 . The signal processing apparatus according to claim 6 ,
wherein the processing circuitry is configured to (a) monitor an operating state of an external imaging apparatus connected to the signal processing apparatus, and (b) determine whether the processing circuitry generates the new waveform template or not, depending on the operating state of the external imaging apparatus.

9 . The signal processing apparatus according to claim 8 ,
wherein the external imaging apparatus is an MRI apparatus, and wherein the processing circuitry is configured to (a) monitor an operating state of the MRI apparatus, (b) update the waveform templates in a period during which the MRI apparatus does not perform imaging, and (c) hold the waveform templates, which are stored in the storage circuit immediately before start of imaging performed by the MRI apparatus, without updating the waveform templates, during imaging performed by the MRI apparatus.

10 . The signal processing apparatus according to claim 2 ,
wherein the processing circuitry is configured to (a) enhance the R-wave in the ECG signal by performing filter processing, and (b) generate the waveform templates from the ECG signal in which the R-wave is enhanced by the filter processing.

11 . The signal processing apparatus according to claim 10 ,
wherein the processing circuitry is configured to (a) generate a high-frequency enhanced ECG signal by performing a first filter processing for enhancing a high-frequency band on the ECG signal, (b) generate a band-enhanced ECG signal by performing a second filter processing for enhancing a specific frequency band on the ECG signal, (c) generate two or more first waveform templates from the high-frequency enhanced ECG signal, (d) generate two or more second waveform templates from the band-enhanced ECG signal, (e) store the first waveform templates and the second waveform templates in the storage circuit, (f) calculate a first evaluation value by performing matching processing between a waveform of the high-frequency enhanced ECG signal and each of the first waveform templates, (g) calculate a second evaluation value by performing matching processing between a waveform of the band-enhanced ECG signal and each of the second waveform templates, and (h) detect the R-wave based on the first evaluation value and the second evaluation value.

12 . The signal processing apparatus according to claim 10 , further comprising a second storage circuit configured to store at least one fixed template which is preliminarily generated,
wherein the processing circuitry is configured to detect the R-wave based on (a) a fixed template evaluation value calculated by performing matching processing between the waveform of the inputted ECG signal and the at least one fixed template stored in the second storage circuit and (b) an evaluation value calculated by performing matching processing between the waveform of the inputted ECG signal and each of the waveform templates stored in the storage circuit.

13 . The signal processing apparatus according to claim 1 ,
wherein the biosignal includes at least one of an ECG signal, a pulse wave signal, and a cardiac sound signal.

14 . The signal processing apparatus according to claim 1 ,
wherein the biosignal is a vectorcardiogram which includes two or more ECG signals; and the processing circuitry is configured to perform coordinate conversion on the vectorcardiogram and to generate the synchronization signal from at least one of the ECG signals included in the vectorcardiogram subjected to the coordinate conversion.

15 . An imaging apparatus comprising:
a storage circuit; processing circuitry configured to
(a) generate two or more detection parameters for detecting a specific signal included in a biosignal relevant to a heartbeat, based on a waveform of the biosignal,
(b) store the two or more detection parameters in the storage circuit,
(c) detect the specific signal by using the two or more detection parameters, and
(d) generate a synchronization signal for performing heartbeat synchronization imaging based on the specific signal;
a data acquisition circuit configured to acquire imaging data from an object in synchronization with the synchronization signal; and an image generation circuit configured to generate an image of the object based on the imaging data.

16 . The imaging apparatus according to claim 15 , wherein the imaging apparatus is an MRI apparatus.

17 . The imaging apparatus according to claim 15 ,
wherein the biosignal includes at least one of an ECG signal, a pulse wave signal, and a cardiac sound signal.

18 . The imaging apparatus

Assignees

• Toshiba Kk
• Toshiba Medical Sys Corp

Inventors

• Yoshida Takami

Classifications

• A61B6/541

  involving acquisition triggered by a physiological signal · CPC title

• A61B5/0245

  by using sensing means generating electric signals, {i.e. ECG signals} · CPC title

• A61B5/7285 Primary

  for synchronizing or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal · CPC title

• A61B5/7289

  Retrospective gating, i.e. associating measured signals or images with a physiological event after the actual measurement or image acquisition, e.g. by simultaneously recording an additional physiological signal during the measurement or image acquisition · CPC title

• A61B5/0456

  Human Necessities · mapped topic