JP4527838B2 - Ultrasonic diagnostic equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic diagnostic apparatus, and more particularly to evaluation of cardiac function.
[0002]
[Prior art and problems]
As the heart (for example, the left ventricle) contracts or relaxes, the pressure in the left ventricle changes periodically. That is, the pressure increases during systole and decreases during diastole. On the other hand, the volume (volume) of the left ventricle also changes periodically, decreasing in the systole and increasing in the diastole. Here, the pressure and volume of the left ventricle do not change independently, but change in relation to each other.
[0003]
Conventionally, an ultrasonic diagnostic apparatus equipped with a function for calculating the volume of the left ventricular cavity has been put into practical use. On the other hand, the left ventricular pressure and the pressure correlated therewith can be measured, for example, by inserting a catheter having a pressure detecting function into the heart or a predetermined blood vessel.
[0004]
Therefore, conventionally, the volume value displayed on the ultrasonic diagnostic apparatus and the pressure measured separately from the volume value are manually plotted on a coordinate system, and thereby a cardiac function evaluation graph showing the relationship between pressure and volume is obtained. I was making it. In this method, pressure and volume cannot be measured at the same time. Therefore, there is a problem in the reliability of the graph, and there is a problem that it is complicated because many manual operations are required.
[0005]
The present invention has been made in view of the above-described conventional problems, and an object thereof is to realize reliable functional evaluation of a moving organ.
[0006]
[Means for Solving the Problems]
(1) In order to achieve the above object, the present invention calculates the volume of a lumen of a moving organ included in the ultrasonic image in an ultrasonic diagnostic apparatus that forms an ultrasonic image by transmitting and receiving ultrasonic waves. Volume calculation means, pressure measurement means for measuring pressure with respect to the moving organ, and creation of a graph for creating a function evaluation graph by plotting the relationship between volume and pressure at each time on a coordinate system having a volume axis and a pressure axis Means.
[0007]
According to the above configuration, the volume of the lumen of a moving organ (especially the left ventricle) is measured using ultrasonic diagnosis, and on the other hand, by a pressure measuring means such as a catheter with a pressure sensor or a pressure gauge attached to the body surface The pressure of the moving organ or the pressure correlated therewith is measured, and these two measured values are correlated to create a function evaluation graph. The function evaluation graph is displayed on the screen of the ultrasonic diagnostic apparatus, for example. In that case, it is desirable to display the function evaluation graph together with the tomographic image and other biological signal waveforms. According to such a configuration, it is possible to perform comprehensive diagnosis while observing the tomographic image of the measurement target. Become.
[0008]
The volume of the lumen can be calculated using various known methods (for example, see Japanese Patent Laid-Open No. 8-103442). For example, the contour of the lumen is detected using an edge detection method on a tomographic image. The volume can be estimated by obtaining the area of the lumen from the contour and performing an integration operation based on the area. This calculation can be performed in real time simultaneously with the acquisition of the ultrasound image.
[0009]
As pressure measurement means, a catheter can be inserted into a moving organ via a blood vessel and the pressure can be directly measured in real time. The pressure may be estimated. In addition, for a group medical examination or the like, it is possible to use a simplified method of indirectly detecting a pressure by winding a blood pressure monitor around an arm or the like. The ultrasonic diagnostic apparatus is provided with an input terminal for inputting a biological signal, and it is desirable to perform graph processing based on the pressure signal input to the input terminal and the volume value calculated by ultrasonic image processing.
[0010]
According to the above function evaluation graph, disease diagnosis and the like can be easily performed by comparing the size and form with the standard pattern. It is desirable that the function evaluation graph be captured and stored together with the ultrasonic image.
[0011]
Preferably, it includes means for calculating a predetermined evaluation index from the area of the loop drawn on the function evaluation graph. For example, in the case of the left ventricle, the loop area corresponds to the work amount, and the ejection function of the left ventricle can be evaluated from the area.
[0012]
Preferably, the volume calculation and the pressure measurement are performed simultaneously, and the function evaluation graph is displayed in real time according to the volume calculation and the pressure measurement. Such simultaneous measurement in real time can form a more reliable graph than the conventional method. Especially in the case of intermittent symptoms, simultaneous measurement is considered to be extremely meaningful.
[0013]
(2) In order to achieve the above object, according to the present invention, in an ultrasonic diagnostic apparatus that forms an ultrasonic image by transmitting and receiving ultrasonic waves, for each frame of the ultrasonic image, the left ventricular chamber of the heart Area calculating means for calculating the area, volume calculating means for calculating the volume of the left ventricular cavity from the area of the left ventricular cavity, pressure measuring means for measuring the pressure of the left ventricle of the heart or a pressure corresponding thereto, Graph creating means for creating a function evaluation graph by plotting a relationship between volume and pressure at each time concerning the left ventricular cavity on a coordinate system having a volume axis and a pressure axis.
[0014]
Preferably, the pressure measuring means includes a catheter inserted into a blood vessel and a pressure detector provided on the catheter. Preferably, the function evaluation graph (loop) for each frame is displayed in multiple. For multiple display, the graph of each frame may be weighted equally, but the weight may be set smaller as time elapses.
[0015]
Preferably, the display of the function evaluation graph is controlled based on the heartbeat cycle of the heart. If a graph is formed in conjunction with the heartbeat cycle, it is possible to provide useful information in diagnosing diseases such as periodically representing only a predetermined time phase.
[0016]
Preferably, the left ventricular tomographic image as the ultrasonic image and the function evaluation graph are displayed simultaneously. According to this configuration, the function of the left ventricle can be evaluated numerically in comparison with the observed state of the left ventricle, and a comprehensive diagnosis is possible.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0018]
FIG. 1 shows a preferred embodiment of an ultrasonic diagnostic apparatus according to the present invention, and FIG. 1 is a block diagram showing the overall configuration thereof. This ultrasonic diagnostic apparatus measures the volume and pressure of the left ventricle of the heart in real time, and displays a graph showing the pressure-volume relationship together with an ultrasonic image.
[0019]
In FIG. 1, a probe 10 is a transducer that transmits and receives ultrasonic waves, and an array transducer is built in the probe 10. This array transducer is formed by linearly arranging a plurality of transducer elements, and an ultrasonic beam is scanned by electronic linear scanning, electronic sector scanning, or the like on the array transducer. As a result, the scanning surface 12 virtually shown in FIG. 1 is formed. In this embodiment, in order to calculate the volume of the left ventricle, the scanning plane 12 is appropriately adjusted with respect to the left ventricle by adjusting the contact position and the contact posture of the probe 10 while viewing the ultrasonic tomographic image. Is set. In FIG. 1, reference numeral 14 represents the lumen of the left ventricle.
[0020]
On the other hand, the pressure gauge 16 is comprised by the catheter 18 and the pressure sensor 20 provided in the front-end | tip in this embodiment. The catheter 18 is guided to, for example, a left ventricle or a predetermined site in the blood vessel via a blood vessel, and measures blood pressure in the left chamber or blood vessel. The pressure gauge 16 itself is known. Of course, a pressure gauge other than the pressure gauge 16 as shown in FIG. 1 may be used. In any case, it is desirable to measure pressure simultaneously with ultrasonic diagnosis.
[0021]
The transmission / reception unit 22 is a circuit that supplies a transmission signal to the probe 10 and performs predetermined processing on the reception signal output from the probe 10. The ultrasonic beam is scanned by the action of the transceiver 22. The image forming unit 24 is configured by, for example, a digital scan converter (DSC), and the tomographic image 101 is formed by the image forming unit 24. Of course, so-called two-dimensional Doppler images and other images may be formed. The tomographic image data 101 is output to the image composition unit 26. In addition, the tomographic image data 101 formed by the image forming unit 24 is output to the area calculating unit 28. The area calculating unit 28 extracts the left ventricular cavity using a known technique, and calculates the area of the lumen. Calculate. In this case, as described above, for example, the technique described in JP-A-8-103442 can be used. The volume calculation unit 30 is a circuit that estimates and calculates the volume of the left ventricle based on the area of the lumen of the left ventricle calculated by the area calculation unit 28. Data representing the volume is output to the graph creation unit 32.
[0022]
On the other hand, a pressure signal output from the pressure gauge 16 is input to the pressure signal input unit 34, and pressure value data is input to the graph creation unit 32 via the pressure signal input unit 34. An electrocardiogram signal output from the electrocardiograph 36 is input to the graph creation unit 32 via the electrocardiogram signal input unit 38. The graph creation unit 32 is a circuit that forms a pressure-volume graph, that is, a cardiac function evaluation graph, which will be described later. In that case, a graph is created in synchronization with the electrocardiogram signal as necessary. This will be described later.
[0023]
The cardiac function evaluation graph data 102 formed by the graph creation unit 32 is output to the image composition unit 26 and also to the work amount calculation unit 40. The work amount calculation unit is a circuit for calculating the work amount of the left ventricle from the closed loop area represented in the cardiac function evaluation graph. That is, it has been clarified from medical research that the area of the loop corresponds to the work volume of the left ventricle, and the work volume calculation unit 40 calculates the work volume of the left ventricle in real time. The work amount data 104 as the calculation result is output to the image composition unit 26.
[0024]
The image composition unit 26 performs image composition based on the tomographic image data 101, the cardiac function evaluation graph data 102, and the work amount data 104, and outputs the synthesized image to the display unit 42.
[0025]
FIG. 2 is a graph showing the relationship between the left ventricular pressure and volume. First, (A) shows time changes of the left atrial pressure, the left ventricular pressure, and the aortic pressure on the time axis. Further, (B) shows the time change of the left ventricular volume on the time axis. (C) shows a plot of left ventricular pressure against left ventricular volume, and a closed loop is recursively formed according to the heartbeat of the heart as shown. Here, A, B, C, and D respectively correspond to the time phases shown in (A), and the loop is continuously formed in the counterclockwise direction. Incidentally, the correlation shown in FIG. 2 is known. However, in the past, it has been known to draw such a loop as a graph itself, but it has not been realized at all to form such a graph on an ultrasonic diagnostic apparatus. An apparatus that measures the volume and graphs them in real time has not been realized.
[0026]
Therefore, in the present embodiment, the image 100 shown in FIG. 3 can be formed by the configuration shown in FIG. In the image 100, reference numeral 101A represents a tomographic image similar to the conventional one. This tomographic image 101A is displayed in real time. Reference numeral 102A represents a cardiac function evaluation graph, which is the same as that shown in FIG. Reference numeral 104 </ b> A indicates the work calculated by the work calculation unit 40 as a numerical value.
[0027]
According to the image as shown in FIG. 3, the left ventricular function can be evaluated on the graph while observing the tomographic image of the left ventricle, and as a result, the cardiac function can be comprehensively diagnosed. It becomes. As a result, there is an advantage that disease diagnosis can be performed more accurately.
[0028]
With regard to the cardiac function evaluation graph 102A shown in FIG. 3, the loop image may be reset every time a loop is formed, or the loop image may be displayed in a multiple manner over a plurality of heartbeats. Good. According to such multiple expressions, it is possible to observe the movement of the left ventricle over a certain time range, and it is possible to capture abnormal movements that occur suddenly. As shown in FIG. 1, since an electrocardiogram signal is input to the ultrasonic diagnostic apparatus, a graph may be drawn only for a predetermined period specified based on the electrocardiogram signal. For example, only the diastole or systole is graphed. In addition, in the case of performing the above-described multiple display, the so-called afterimage expression can be realized by increasing the weighting such as luminance with respect to the latest loop image and decreasing the weighting step by step as going back in the past. It is possible to evaluate the current cardiac function in comparison with the past.
[0029]
【The invention's effect】
As described above, according to the present invention, since a function evaluation graph can be displayed, there is an advantage that disease diagnosis of a motor organ can be performed more accurately.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the overall configuration of an ultrasonic diagnostic apparatus according to the present invention.
FIG. 2 is a diagram for explaining the relationship between the volume of the left ventricle and the pressure.
FIG. 3 is a diagram illustrating an example of an image displayed on a display unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Probe, 12 Scan plane, 14 Left ventricle lumen, 16 Pressure gauge, 18 Catheter, 20 Pressure sensor, 22 Transmission / reception part, 24 Image formation part, 26 Image composition part, 28 Area calculation part, 30 Volume calculation part , 32 Graph creation unit, 34 Pressure signal input unit, 36 ECG, 38 ECG signal input unit, 40 Work calculation unit, 42 display unit.

Claims (4)

In an ultrasonic diagnostic apparatus that forms an ultrasonic image by transmitting and receiving ultrasonic waves,
For each frame of the ultrasound image, an area calculating means for calculating the area of the left ventricular cavity of the heart,
Volume calculating means for calculating the volume of the left ventricle from the area of the left ventricle,
Pressure measuring means for measuring the pressure of the left ventricle of the heart or a pressure corresponding thereto simultaneously with the volume calculation based on the transmission and reception of the ultrasonic wave ;
An electrocardiograph that generates an electrocardiogram signal;
Coordinates having a volume axis and a pressure axis in synchronization with the heartbeat cycle represented by the electrocardiogram signal based on the volume calculated by the transmission / reception of the ultrasonic wave and the pressure measured by the pressure measuring means On the system, a graph creating means for plotting a relationship between volume and pressure at each time concerning the left ventricular cavity to create a function evaluation graph;
Means for calculating a predetermined evaluation index corresponding to the work volume of the left ventricle from the area of the loop drawn on the function evaluation graph;
Means for simultaneously displaying the ultrasonic image, the function evaluation graph and the predetermined evaluation index in real time;
An ultrasonic diagnostic apparatus comprising: The apparatus of claim 1 .
The ultrasonic diagnostic apparatus, wherein the pressure measuring means includes a catheter inserted into a blood vessel and a pressure detector provided on the catheter. The apparatus of claim 1 .
An ultrasonic diagnostic apparatus, wherein the function evaluation graph for each frame is displayed in multiple. The apparatus of claim 1 .
In the functional evaluation graph, the ultrasonic diagnostic apparatus is characterized in that a loop is reset every time a loop is formed .

Images