ECG waveform detecting apparatus and imaging apparatus
According to one embodiment, an ECG waveform detecting apparatus includes an input circuit and processing circuitry. The input circuit receives an ECG signal. The processing circuitry performs first detection of a specific waveform included in the ECG signal, performs update processing of a detection parameter for detecting the specific waveform based on a part of the specific waveform or result of the first detection, performs second detection of the specific waveform from the ECG signal by using the detection parameter after the update processing, and generates a synchronization signal based on information on the second detection.
1. An ECG waveform detecting apparatus comprising:
an input circuit configured to receive at least one first ECG signal acquired from an object; and
processing circuitry configured to
(a) generate a second ECG signal by enhancing a high-frequency band of the first ECG signal,
(b) generating a template corresponding to a specific target waveform based on the second ECG signal,
(c) calculating an evaluation value by matching the template with the second ECG signal, and
(d) detecting the specific target waveform based on the evaluation value.
2. The ECG waveform detecting apparatus according to claim 1 ,
wherein the processing circuitry is configured to
(a) acquire information on operation state of an MRI apparatus, to which the ECG waveform detecting apparatus is connected, as a judging criterion for determination processing as to whether the template should be generated or not;
(b) determine that the template should not be generated in a period during which the MRI apparatus is acquiring magnetic resonance signals from the object; and
(c) determine that the template should be generated in a period during which the MRI apparatus is not acquiring magnetic resonance signals from the object.
3. The ECG waveform detecting apparatus according to claim 1 ,
wherein the processing circuitry is configured to extract a signal of a predetermined period from the first ECG signal based on a pulse wave signal or cardiac sound of the object, and to generate the template based on the signal of a predetermined period.
4. The ECG waveform detecting apparatus according to claim 1 ,
wherein the input circuit is configured to receive a plurality of first ECG signals simultaneously acquired from the object; and
the processing circuitry is configured to
(a) generate a plurality of second ECG signals by enhancing respective high-frequency bands of the plurality of first ECG signals,
(b) calculate a plurality of evaluation values respectively corresponding to the plurality of second ECG signals,
(c) calculate a synthetic evaluation value by adding the plurality of evaluation values or calculating a weighted sum of the plurality of evaluation values; and
(d) detect the specific target waveform based on the synthetic evaluation value.
5. The ECG waveform detecting apparatus according to claim 4 ,
wherein the plurality of first ECG signals are signals of generating a vectorcardiogram.
6. The ECG waveform detecting apparatus according to claim 4 ,
wherein the processing circuitry is configured to
(a) calculate principal component vectors by performing principal component analysis on the first ECG signals, which are N-dimensional time-series signals, and whose number is originally N, and
(b) reduce the number of the first ECG signals to the number smaller than N before enhancing respective high-frequency bands of the first ECG signals to generate the second ECG signals, by projecting the N-dimensional time-series signals onto a partial space generated from the principal component vectors each of which has a contribution rate larger than a predetermined value.
7. An imaging apparatus comprising the ECG waveform detecting apparatus according to claim 1 .