Patent Application
20140343427
The present invention relates to a diagnostic imaging apparatus and an image display method, and in particular to a technique for displaying an image of a site performing periodical movement such as a heart of an examinee.
A doctor examines whether a site performing periodical movement is normal or in a disease condition by observing images of the site performing periodical movement corresponding to a plurality of cycles, which are obtained from a diagnostic imaging apparatus in synchronization with a biological signal which periodically changes, such as an electrocardiographic waveform, pulsation, blood pressure and cardiac sound. Especially, if the site performing periodical movement is a heart, the doctor examines whether the movement of the heart is normal or in a disease condition (cardiac function).
Examples of cardiac function measurement using an ultrasound diagnostic apparatus are disclosed in Patent Literature 1 and Non-Patent Literature 1. In Patent Literature 1 and the like, among ultrasound image data collected in synchronization with heartbeats of successive three cycles, time between the most past heartbeat and the next-cycle heartbeat and time between the next-cycle heartbeat and the heartbeat of the next after the next cycle (the most recent) are measured first as a first heartbeat time and a second heartbeat time, respectively. Next, time difference between the first heartbeat time and the second heartbeat time is calculated. Next, ultrasound image data collected in synchronization with a heartbeat when the calculated time difference is equal to a setting value (threshold range) or below is stored into an image memory.
In Patent Literature 1 and the like, the configuration is such that, when the time difference is beyond the threshold range, the ultrasound image data is not stored into the image memory. Therefore, in order to continually perform collection of ultrasound image data using the ultrasound diagnostic apparatus of Patent Literature 1 and the like, an examiner is required to observe the time difference between the first heartbeat time and the second heartbeat time, which is different according to each examinee, and make adjustment manually so that the time difference is within the threshold range, for each examination. That is, in the prior-art technique in Patent Literature 1 and the like, an unsolved problem as described above is that ultrasound image data is not appropriately displayed for all examinees unless an examiner performs manual adjustment of a threshold range which is different according to each examinee.
Thus, the present invention has been made in view of the above problem, and its object is to provide a diagnostic imaging apparatus and an image display method which are capable of appropriately displaying ultrasound image data for all examinees without an examiner performing manual adjustment of a threshold range.
In order to achieve the above object, the present invention picks up an image of a site performing periodical movement (for example, a heart) of an examinee to generate image data, acquires biological signal data which periodically changes, such as heartbeats of the examinee, detects particular signal waveforms of the acquired biological signal data, stores the generated image data in synchronization with the biological signal data, calculates, on the basis of time difference or time ratio among a plurality of successive periods constituted by intervals among the detected particular signal waveforms, evaluation values indicating steadiness of the periodical movement among the respective periods, performs extraction from among the plurality of successive periods on the basis of the calculated evaluation values and a time difference or time ratio threshold range, reads out image data generated during an adaptive period extracted from the stored image data, and displays the read-out image data.
According to the present invention, it is possible to provide a diagnostic imaging apparatus and an image display method which are capable of appropriately displaying ultrasound image data for all examinees without an examiner performing manual adjustment of a threshold range.
Embodiments of the present invention will be described below with the use of drawings. Components having the same function and procedures having the same processing content are given the same reference numerals, and repetition of description thereof is omitted. In each embodiment described in this document, description will be made with the case of using an ultrasound diagnostic apparatus as a diagnostic imaging apparatus and performing diagnostic imaging of the cardiac function of an examinee. The diagnostic imaging apparatus, however, is not limited to an ultrasound diagnostic apparatus, and an MRI apparatus and an X-ray CT apparatus are also possible. That is, the diagnostic imaging apparatus only has to have an imaging section 20, a storage section 6, an input section 7, a display section 8, a biological signal acquisition section 9, a biological signal analysis section 10 and a control section 11 as shown in
In the ultrasound diagnostic apparatus, the imaging section 20 is formed with an ultrasound probe 3, an ultrasonic wave transmission/reception section 4, and an ultrasound image generation section 5. Description of detailed functions of each component will be made later. Others. In an MRI apparatus, a static magnetic field generator, a gradient magnetic field generator, a transmission pulse generator and a receiving coil correspond to the imaging section 20. In an X-ray CT apparatus, an X-ray scanner with an X-ray tube and an X-ray detector attached to a rotating disk corresponds to the imaging section 20. Though an electrocardiogram is used as a biological signal resulting from periodical movement of the heart (beats), the pulse, blood pressure, heart sound and the like are also possible.
First, the configuration of an ultrasound diagnostic apparatus according to each embodiment will be described on the basis of
As shown in
The ultrasound probe 3 is configured by arranging transducer elements represented by piezoelectric substances in an array shape. The ultrasound probe 3 is caused to be in contact with an examinee 2 to transmit ultrasonic wave and also to receive a reflected wave reflected in the examinee and generate a reflected echo signal. An ultrasound probe having a scanning method of the linear type, convex type, sector type or the like can be applied to the ultrasound probe 3.
The ultrasonic wave transmission/reception section 4 receives information from the control section 11 about the power and timing of an ultrasonic signal to be transmitted to or received, and it transmits a pulse signal for radiating ultrasonic waves to the ultrasound probe 3 and also performs control for causing the ultrasound probe 3 to acquire a predetermined reflected echo signal. Then, the ultrasonic wave transmission/reception section 4 outputs the reflected echo signal received by the ultrasound probe 3 to the ultrasound image generation section 5.
The ultrasound image generation section 5 causes the reflected echo signal inputted from the ultrasonic wave transmission/reception section 4 to pass into a phasing circuit and an amplification circuit and, furthermore, performs signal processing in accordance with setting of an image given from the control section 11. Then, the ultrasound image generation section 5 generates ultrasound image data, such as, for example, a tomographic image of the biotissue of the examinee 2, a blood flow image and blood flow speed image based on Doppler measurement and a tissue Doppler image, on the basis of the shaped reflected echo signal.
The ultrasound image data generated by the ultrasound image generation section 5 and biological signal data acquired by the biological signal acquisition section 9 are synchronization-processed by the control section 11 and stored into the storage section 6. A program realizing the function of each of the sections constituting the ultrasound diagnostic apparatus 1 is also stored in the storage section 6. For example, an arithmetic algorithm for biological signal analysis executed by the biological signal analysis section 10 is stored.
The input section 7 is an interface used by an examiner who performs various operations of the ultrasound diagnostic apparatus 1 and is provided with input equipment such as, for example, a keyboard, a trackball, switches and a dial. The input section 7 is used, for example, to make biotissue measurement settings on an ultrasound image displayed on a display screen of the display section 8 or to move the current time phase or period of a reproduced image.
The display section 8 displays a biological signal or an ultrasound image on a screen.
The biological signal acquisition section 9 acquires a biological signal of the examinee 2, converts it to biological signal data and stores it into the storage section 6. At the time of causing the biological signal acquisition section 9 to operate in real time, the biological signal acquisition section 9 outputs the biological signal data directly to the biological signal analysis section 10. In each embodiment, an electrocardiograph is configured independently from the ultrasound diagnostic apparatus 1, and the biological signal acquisition section 9 is electrically connected to the electrocardiograph and is configured as an interface of the ultrasound diagnostic apparatus 1 which receives electrocardiographic data from this electrocardiograph. The biological signal acquisition section 9, however, may be configured as an electrocardiograph electrically connected to the ultrasound diagnostic apparatus 1.
The biological signal analysis section 10 detects particular signal waveforms on the basis of the biological signal data read from the storage section 6 or biological signal data inputted from the biological signal acquisition section 9. In each embodiment, R-waves included in an electrocardiographic waveform are detected as the particular signal waveforms. Then, the biological signal analysis section 10 calculates time of an electrocardiographic waveform between adjoining R-waves (hereinafter referred to as an “R-R period” or simply a “period”).
Next, the biological signal analysis section 10 calculates the ratio or time difference between two successive periods preceding an evaluation target period and calculates an evaluation value using this time ratio or time difference. Though the evaluation value is also referred to as an index value using time ratio or time difference here, description will be made below with the use of the term “evaluation value”. Then, the biological signal analysis section 10 judges whether or not the evaluation target period is to be a period to be targeted by examination (hereinafter referred to as a “detection period”) using this evaluation value. The biological signal analysis section 10 also judges whether the R-R period or the detection period corresponds to any of tachycardia and bradycardia. The details of the detection period extraction process and tachycardia/bradycardia judgment process described above will be described later.
The control section 11 is configured being provided with an arithmetic/control device such as a CPU, and it controls the whole of the ultrasound diagnostic apparatus 1. In each embodiment, the control section 11 performs synchronization control of biological signal data and ultrasonic measurement data and performs control for synchronously storing these biological signal data and ultrasonic measurement data into the storage section 6. The control section 11 also controls synchronization of a series of processes related to the display section 8, the biological signal acquisition section 9 and the biological signal analysis section 10.
The system bus 12 is a bus for exchanging data among the respective components.
A measurement arithmetic section which determines measurement data pertaining to the cardiac function, such as a blood flow state, blood flow speed, the speed of an annulus, the capacity of an atrium and movement of the wall of the heart, by arithmetic using a reflected echo signal outputted from the ultrasonic wave transmission/reception section 4 may be further provided though it is not shown in
A first embodiment is an example of so-called an off-line process in which electrocardiographic data to be an analysis target is stored in the storage section 6 in advance and then analysis-processed, and it is an embodiment in which one detection period optimal for diagnostic imaging for each examinee is displayed. That is, biological signal data and ultrasound image data are synchronously stored in the storage section 6, and the biological signal analysis section 10 extracts the detection period on the basis of the biological signal data read from the storage section 6.
The first embodiment will be described below on the basis of
The examiner fits an electrocardiograph (the biological signal acquisition section 9) to the examinee 2 to measure electrocardiographic data and causes the ultrasound probe 3 to be in contact with the chest of the examinee 2 to perform ultrasonic measurement by transmitting and receiving ultrasonic waves under predetermined imaging conditions. The ultrasound image generation section 5 generates ultrasonic measurement data which includes ultrasound image data and Doppler measurement data, on the basis of a reflected echo signal which the ultrasonic wave transmission/reception section 4 has outputted. The control section 11 synchronizes the electrocardiographic data and the ultrasonic measurement data with each other and stores them into the storage section 6 (S101). At this time, for example, an electrocardiographic waveform chart and a moving ultrasound image are displayed on the display screen of the display section 8.
Next, when the examiner performs a freeze operation from the input section 7, representation on the display screen of the display section 8 is stopped (S102). Since the first embodiment performs cardiac function analysis by an off-line process, the process for synchronizing and storing electrocardiographic data and ultrasonic measurement data by the storage section 6 ends at this step. Then, at and after step S103, cardiac function analysis is performed on the basis of the electrocardiographic data and ultrasonic measurement data stored in the storage section 6.
The biological signal analysis section 10 reads out the electrocardiographic data stored in the storage section 6 (S103).
The biological signal analysis section 10 starts electrocardiographic data analysis (S104). The R-waves of an electrocardiographic waveform as particular signal waveforms which the biological analysis section 10 detects are set as detection targets. Detection of R-wave is performed by a well-known method such as pattern matching of electrocardiographic waveform.
Next, the biological signal analysis section 10 calculates the evaluation value of each R-R period. In the first embodiment, the ratio of two successive periods adjoining a period to be an evaluation value calculation target is calculated as the evaluation value of each R-R period, and periods are extracted as detection periods in order from an evaluation value closest to 1. The evaluation value calculation process will be specifically described with the use of
Therefore, at this step, the biological signal analysis section 10 starts the process at the top of the cine-memory as in
Next, as in
The R-wave detection and evaluation value calculation/storage described above may be performed in order from the end to top of the cine-memory like in order of (c), (b) and (a) in
Evaluation value 1=|(preceding R-R)/(further-preceding R-R)−1|
Evaluation value 2=|(further-preceding R-R)/(still-further-preceding R-R)−1|
Evaluation value=evaluation value 1+evaluation value 2 Expression (1)
In the above case, 0 is the optimum evaluation value.
When
Evaluation value of R3-R2 period=|(R4-R3 period)/(R5-R4 period)−1|+|(R5-R4 period)/(R6-R5 period)−1|
As another evaluation value, difference between two successive periods adjoining a period to be an evaluation value calculation target may be calculated, and periods may be extracted as detection periods in order from such an evaluation value that the absolute value of the time difference is closest to 0. For example, in the case of calculating an evaluation value using time difference among three adjoining heartbeats, the evaluation value may be calculated by calculating evaluation values 1 and 2 using adjoining heartbeats among the three heartbeats and calculating a value of accumulation of the evaluation values as the evaluation value using the three heartbeats by Expression (2) below.
Evaluation value 1=|(preceding R-R)/(further-preceding R-R)|
Evaluation value 2=|(further-preceding R-R)/(still-further-preceding R-R)|
Evaluation value=evaluation value 1+evaluation value 2 Expression (2)
In the above case also, 0 is the optimum evaluation value.
When
Evaluation value of R3-R2 period=|(R4-R3 period)−(R5-R4 period)|+|(R5-R4 period)−(R6-R5 period)|
If two adjoining periods are almost the same when compared, the pulse can be evaluated to be regular and steady. On the other hand, if the difference is large, the pulse can be evaluated to be irregular. Therefore, by analyzing all pairs of adjoining R-R periods, the best evaluation value in the cine-memory is identified.
The biological signal analysis section 10 searches for the best evaluation value (best value) among all the evaluation values calculated at step S104 and extracts only a period having the best value as a detection period (S105). The best value defined in this document refers to an evaluation value closest to “1” in the case of using time ratio (R-R ratio) as an evaluation value, and, in the case of using time difference as an evaluation value, for example, in the case of determining the evaluation value of the R4-R3 period by {(R5-R4 period)−(R6-R5 period)} in
There may be a case where a plurality of periods have the same evaluation value because of the reason of an evaluation value calculation method, rounding off of evaluation values and the like, In such a case, all periods having the best value may be displayed as a detection result, or only the latest period in the cine-memory may be regarded as a detection period. Furthermore, it is also possible to use a plurality of evaluation values of time ratio and time difference as evaluation values and leave only one period which comprehensively has the best value when the plurality of evaluation values are combined.
The display section 8 displays a screen showing a detection result (9106).
For example, in
The display section 8 displays, on the display screen 201, “BEST 1.10” 206 which is the most favorable evaluation value in the cine-memory (hereinafter referred to as “the best value”) and “number of detection periods: 2” 207 which is the number of periods having the best value, as detailed information. Thereby, if the value of the best value or the number of detection periods displayed is not favorable, it can be judged that a biological signal is to be taken again without confirming the values of the best values or the numbers of detection periods by tracing back the cine-memory, which contributes to procedure improvement.
On the display screen 201, an ultrasound image 202, which is a tomographic image of a heart, is also displayed. This ultrasound image 202 is a tomographic image of a heart at a position on the time axis of a time phase bar 203 displayed on the electrocardiographic waveform 204. That is, the time phase bar 203 shows the time phase on the electrocardiographic waveform of the currently reproduced ultrasound image 202. The time phase bar 203 may be positioned on the detection period 205 in the initial state of the display screen 201. Thereby, an ultrasound image of a detection period showing the best value can be initially displayed. This display control of the ultrasound image 202 is realized by the display section 8 reading out an ultrasound image at the time phase of the time phase bar 203 from the storage section 6 and displaying the ultrasound image.
As described above, since the diagnostic imaging apparatus according to the first embodiment is provided with the imaging section 20 picking up an image of a site of the examinee 2 to generate image data; the biological signal acquisition section 9 acquiring biological signal data which is periodical movement of the site of the examinee 2; the storage section 6 synchronously storing the generated image data and the acquired biological signal data; the biological signal analysis section 10 analyzing the biological signal data to detect particular signal waveforms; and the control section 11 calculating, on the basis of time difference or time ratio among a plurality of successive periods constituted by intervals among the detected particular signal waveforms, evaluation values indicating steadiness of the periodical movement among the respective periods, performing extraction from among the plurality of successive periods on the basis of the calculated evaluation values and a time difference or time ratio threshold range, and reading out image data generated during an extracted adaptive period, among the image data stored in the storage section 6, from the storage section 6; and the display section 8 displaying the read-out image data, it is possible to appropriately display ultrasound image data for all examinees without an examiner performing manual adjustment of a threshold range.
In the first embodiment, the biological signal analysis section extracts a period having the best evaluation value as a detection period. Thereby, the examiner can quickly find the best value and the detection period he is most interested in. Furthermore, since the best value is calculated on the basis of a biological signal of each examinee and is not extracted by comparison with a particular threshold range, it is possible to calculate and display the best value of each examinee irrespective of the condition of the examinee and avoid trouble in which the best value is not displayed at all.
The second embodiment is an example of the so-called off-line process similarly to the first embodiment. However, while the first embodiment is an embodiment in which only a period having the best value is displayed as a detection period, the second embodiment is characterized in that the number of detection periods to be left as a detection result is specified. The merits of the second embodiment are a point that, for example, in the case where, even though a best-value period is detected, an ultrasound image stored in the storage section 6 cannot be used for cardiac function measurement because of being disturbed by influence of an irregular pulse, the cardiac function measurement can be performed with the ultrasound image of another detection period, and a point that, from a viewpoint that it is generally recommended that measurement results with a plurality of numbers of heartbeats should be averaged in the case of an irregular pulse, the convenience of cardiac function measurement for an examinee with an irregular pulse is improved.
The second embodiment will be described below on the basis of
From step S101 to step S104 in
Thus, at step S105, the biological signal analysis section 10 performs sort processing in ascending order of the second evaluation values of the respective periods, and extracts detection periods corresponding to the number of detection periods specified, in order from the highest position as a result of the sort processing (S105). Then, the display section 8 displays a detection result (S106).
In the second embodiment, a first specification section which specifies the number of periods to be extracted as detection periods is provided. The first specification section is configured so that, for example, an examiner presets the number of detection periods on a screen of the display section 8 in advance or specifies change in the number of detection periods by operating the input section 7 after displaying a detection result once. If the number of detection periods is reflected on the display screen immediately when an operation of specifying the number of detection periods is performed, the convenience is further enhanced. When the number of detection periods is set to 1, it is useful for the sort processing for detecting the best value in the first embodiment. The sort processing may be performed in descending order of second evaluation values, and detection periods corresponding to the specified number of detection periods are extracted in order from the lowest position as a result of the sort processing.
In the case of an examinee without an irregular pulse, the range of evaluation values of detection periods (“detected evaluation value” 209) and the range of evaluation values of all R-R periods (“evaluation values of all periods” 210) concentrate near 1.0 (for example, a result of 0.99 to 1.01 or the like is obtained). As the degree of serious condition of irregular pulse increases, the range gradually spreads. Therefore, there is a merit that, by displaying the range of evaluation values of detection periods (the “detected evaluation value” 209) and the range of evaluation values of all R-R periods (the “evaluation values of all periods” 210), the degree of serious condition of the irregular pulse of an examinee can be judged at a glance. Furthermore, the examiner can judge whether it is necessary or not to take electrocardiographic data again by referring to these values.
Next, another screen display example of the second embodiment will be described on the basis of
In
Furthermore, in a display screen 201b in
According to the image display example in
By this highlighting, it becomes possible for the examiner to make utilization such as performing cardiac function measurement with the detection results 205a and 205b within the evaluation value range he has specified, first, and, as for the period 212 which is detected but is outside the specified range, only referring to it, which further enhances usability. Though the examiner expresses the range of highlighting in the form of 1±x (x is an arbitrary numerical value) in the example in
Next, another screen display example of the second embodiment will be described on the basis of
In
When the examiner drags and drops the small-screen ultrasound image 212b or 212c into a display area of the enlarged ultrasound image 202 using the input section 6, the dropped ultrasound image in the small screen is updatedly displayed on the enlarged ultrasound image 202.
As described above, the diagnostic imaging apparatus according to the second embodiment has an advantage specific to the second embodiment in addition to the advantage of the first embodiment.
That is, in the example in
The specification of an evaluation value range to be highlighted in
A third embodiment is an embodiment in which tachycardia and bradycardia which are generally not used for cardiac function measurement are removed to extract detection periods. The third embodiment may be used together with the first and second embodiments.
Prior to the process, an R-R period (corresponding to a period of time (seconds) of one heartbeat) to be judged as tachycardia and an R-R period to be judged as bradycardia are preset for the biological signal analysis section 10.
The values may be set by an examiner. The tachycardia and bradycardia may be specified by the number of heartbeats in addition to the R-R period described above.
In the case of using the number of heartbeats for judging tachycardia and bradycardia, the number of heartbeats is converted to time per heartbeat for use. For example, if the case where the number of heartbeats per minute is 100 or larger is defined to be tachycardia, the number of heartbeats is converted to R-R time (one period) by calculation of Time per heartbeat: 60 (seconds)/100 (times)=0.6 (seconds), and a period with an R-R time of 0.6 (seconds) or fewer is judged to be tachycardia. If the case where the number of heartbeats per minute is 40 or smaller is defined to be bradycardia, the number of heartbeats is converted to R-R time by calculation of Time per heartbeat: 60 (seconds)/40 (times)=1.5 (seconds), and a period with an R-R time of 1.5 (seconds) or more is judged to be bradycardia.
In the third embodiment, there are two aspects: (1) an aspect of extracting detection periods and then removing detection periods of tachycardia and bradycardia, and (2) an aspect of removing tachycardia and bradycardia from electrocardiographic data and then extracting detection periods. The respective aspects will be described below in order.
(1) Aspect of Extracting Detection Periods and then Removing Detection Periods of Tachycardia and Bradycardia
The aspect of (1) will be described on the basis of
In
The biological signal analysis section 10 selects detection periods corresponding to tachycardia and bradycardia from the detection periods detected at step S105. Then, by removing the selected detection periods, the biological signal analysis section 10 leaves only detection periods included in a range which is neither tachycardia nor bradycardia (S301). Then, the display section 8 displays only the remaining detection periods (S302).
A tachycardia/bradycardia judgment process will be described on the basis of
(1-1) First Detection Period Selection Method: A Method of Comparing Detection Periods with R-R Periods of Tachycardia and Bradycardia
The biological signal analysis section 10 compares a detection period with R-R periods at the time of tachycardia and bradycardia which are set in advance. Then, if the detection period is the R-R time specified as be tachycardia, 0.6 (seconds) or fewer in the above example, the biological signal analysis section 10 judges the detection period to be tachycardia. If the detection period is the R-R time specified as bradycardia, 1.5 (seconds) or more in the above example, the biological signal analysis section 10 judges the detection period to be bradycardia. Then, the biological signal analysis section 10 excludes the detection period judged to be tachycardia or bradycardia. In
As a result, at step S302, only R2-R1 is displayed as a detection period as shown in
(1-2) Second Detection Period Selection Method: A Method of Comparing R-R Periods Used for Calculation of the Evaluation Values of Detection Periods with R-R Periods of Tachycardia and Bradycardia
The biological signal analysis section 10 judges whether R-R periods used for calculation of the evaluation values of a detection period do not correspond to any of tachycardia and bradycardia, and, if any one of them corresponds to tachycardia or bradycardia, removes the detection period. Thereby, it is possible to remove a detection period detected as a result of performing biological analysis using R-R periods in which tachycardia and bradycardia are included. In
The biological signal analysis section 10 judges whether tachycardia or bradycardia is included in any of a detection period and an R-R period used for the calculation of the evaluation value of the detection period, and, if tachycardia or bradycardia is included in any of them, removes the detection period.
For example, in the case of
(2) Aspect of Removing Tachycardia and Bradycardia from Electrocardiographic Data and then Extracting Detection Periods
The aspect of (2) will be described on the basis of
In
The biological signal analysis section 10 extracts R-waves, which are particular waveform signals, from electrocardiographic data. Then, the biological signal analysis section 10 judges, for all the R-R periods of the electrocardiographic data, whether they do not correspond to tachycardia or bradycardia, and removes a period corresponding to tachycardia or bradycardia (S303).
For example, in the above example, an R-R period with 0.6 seconds or fewer, or 1.5 seconds or more is removed (is not targeted by the next electrocardiographic data analysis).
The biological signal analysis section 10 calculates the evaluation value of each of R-R periods remaining after the period corresponding to tachycardia or bradycardia is removed at step S303 (S304). Since the R-R period of tachycardia or bradycardia has been removed from the electrocardiographic data, the biological signal analysis section 10 determines the evaluation value of the last R-R period among successive three R-R periods using the ratio of preceding two R-R periods among the successive three R-R periods, among the remaining R-R periods.
The biological signal analysis section 10 detects a detection period on the basis of the evaluation values (S105) similarly to S105 in the first embodiment, and displays a result of the detection (S302) similarly to step S302 in
According to the aspect of (2), by comparing all periods of biological signal data (corresponding to the electrocardiographic data described above) with predetermined first set time and second set time, extracting only periods with time longer than the first set time and shorter than the second set time, and, on the basis of a period constituted by at least three or more successive such periods, extracting a detection period, periods of tachycardia and bradycardia are removed before analysis of electrocardiographic data. Therefore, the necessity of evaluation value calculation using tachycardia and bradycardia is eliminated, which leads to reduction of processing.
As described above, the diagnostic imaging apparatus according to the third embodiment has an advantage specific to the third embodiment in addition to the advantage of the first embodiment.
Though description has been made with evaluation value calculation using time ratio or time difference as an example in the third embodiment, the present invention can be also applied in the case of extracting detection periods using another evaluation value calculation algorithm. For example, shape matching of successive electrocardiographic waveforms may be used as the evaluation value calculation algorithm. In this case, the shape matching of electrocardiographic waveforms tends to require longer processing time in comparison with the method of calculating an evaluation value using time difference or time ratio. Therefore, by removing periods of tachycardia and bradycardia and then extracting detection periods like the third embodiment, periods targeted by calculation are reduced, and it is more effective against reduction (speed-up) of processing time.
A fourth embodiment is an embodiment in which analysis processing is performed at the same time when electrocardiographic data targeted by analysis is successively stored into the storage section 6. That is, the fourth embodiment is an example of a so-called real-time process. More specifically, in the fourth embodiment, the biological signal analysis section 10 acquires biological signal data from the biological signal acquisition section 9 in real time to extract detection periods, and the display section 8 performs updated display of an image picked up during a new detection period.
The fourth embodiment will be described below on the basis of
An examiner fits an electrocardiograph to an examinee 2 to measure electrocardiographic data and causes the ultrasound probe 3 to be in contact with the chest of the examinee 2 to perform ultrasonic measurement by transmitting and receiving ultrasonic waves under predetermined imaging conditions. The ultrasound image generation section 5 generates ultrasonic measurement data which includes ultrasound image data and Doppler measurement data, on the basis of a reflected echo signal which the ultrasonic wave transmission/reception section 4 has received. The storage section 6 synchronously stores the electrocardiographic data and the ultrasonic measurement data (S401). An electrocardiographic waveform chart and a moving ultrasound image are displayed on the display screen of the display section 8 (S401).
The biological signal analysis section 10 performs analysis of the electrocardiographic data successively inputted (S402). That is, the biological signal analysis section 10 calculates an evaluation value using the latest two R-R periods stored in the storage section 6 (S402).
The biological signal analysis section 10 judges whether or not the best value is to be updated with the evaluation value calculated at step S402 (S403). If “Yes”, the biological signal analysis section 10 proceeds to step S404. If “No”, the biological signal analysis section 10 returns to step S401 and continues acquisition of electrocardiographic data. Since the evaluation value determined first becomes the best value, the biological signal analysis section 10 proceeds to “Yes” in the initial loop from S401 to S403. From the next loop, the biological signal analysis section 10 compares the best value stored and an evaluation value determined at the immediately previous step S402.
Similarly to the first embodiment, the display section 8 displays information about electrocardiographic data such as the best value 206 and the detected number of periods 207 on the display screen 201 as in
It is judged whether a freeze command from the input section 7 exists or not. If “Yes”, the biological signal analysis section 10 proceeds to step S406. If “No”, the biological signal analysis section 10 returns to step S401 and continues acquisition of electrocardiographic data.
Storage of new electrocardiographic data into the storage section 6 is stopped, and the process of the biological signal analysis section 10 ends (S406).
Display during the process of the fourth embodiment will be described on the basis of
b) is an example in which R1, which will have a better evaluation value, is inputted after
c) is an example in which R1, which will have the same evaluation value as the best value 1.20, is inputted after
d) is an example in which R1, which will have an evaluation value worse than the best value, is inputted after
As described above, the diagnostic imaging apparatus according to the fourth embodiment has an advantage specific to the fourth embodiment in addition to the advantage of the first embodiment.
According to the fourth embodiment, since it is possible to confirm the best value stored in the cine-memory (storage section 6) in real time, it becomes easier to determine the timing of stopping storage of electrocardiographic data.
When an evaluation value is displayed being attached to each R-R period, the evaluation value immediately goes out of the screen and disappears because, in real time, the waveform of an electrocardiogram constantly flows in a horizontal direction of the screen. Even if an evaluation value is displayed being fixed at one position on the screen, it is difficult to follow the evaluation value with eyes because a new heartbeat is inputted in less than one second and the evaluation value is updated. However, by updating only information about the best value as appropriate like the fourth embodiment, information to which the examiner pays attention is limited, which leads improvement of usability.
By making it possible to set an evaluation value threshold range and the number of times of the evaluation value exceeding the threshold range in advance, and providing a mechanism for automatically performing freeze at the time point when the evaluation value exceeding the threshold range is detected the set number of times or more, usability is improved more.
Though description has been made above with the update of the “best value” and the number of periods corresponding to the “best value” in real time as an example, a range of evaluation values corresponding to the “number of detection periods” may be updatedly displayed in real time. That is, at step S403 in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-003991 | Jan 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2013/050166 | 1/9/2013 | WO | 00 | 7/2/2014 |
