JP7188755B2 - Doppler signal acquisition device, Doppler signal acquisition method, and program for automatic tracking of signal source - Google Patents

Description

The present invention relates to a Doppler signal acquisition device or the like that receives a signal source (reflection source) having a Doppler shift in a three-dimensional target area to be observed at a two-dimensional observation aperture and automatically tracks it. For example, the automatic tracking is performed synchronously with the heartbeat, and furthermore, for example, after the initial discovery identification, the automatic tracking process is performed iteratively (recursively) to save computational resources. Concerning those trying to make savings.

Conventionally, in order to appropriately monitor fetal hearts in the mother's body and blood vessels in the living body, etc., using Doppler signals, it is desired to maintain monitoring while tracking the positions of moving fetuses and blood vessels. There is a technical requirement.

As such a conventional reflected wave signal acquisition device having an automatic tracking function, there are several precedents, including those that simply measure the intensity of reflected waves and those that perform mechanical steering. Further, as a reflected wave signal sampling device specialized for Doppler components, for example, the device shown in Patent Document 1 has been known.

JP 2017-158622 A (page 1, FIG. 1, etc.)

However, in the above technology, it is said that information for tracking a target located inside the subject cannot be obtained easily and quickly by using the Doppler signal component of the wave reflected from the subject. I had a problem. For this reason, for example, it has not been possible to easily and quickly track a target within the subject.

For example, in techniques such as those described above, the signal returning from the target to be acquired is directed not only to the depth (distance) axis (i.e., the z-axis) of object space but also to the two orthogonal axes of azimuth (x, y or θ). , φ) are also approached with equal consideration and thought, and these three axes are not mutually prioritized in the course of the tracking work. For this reason, for example, in terms of procedure, first, the distance z of the signal source is obtained from the curved surface of the incoming wavefront by Fresnel transform (in other words, a suitable Fresnel transform template), and then the azimuth angles θ and φ of the signal source are obtained. A Fresnel transform template adapted to the distance thus obtained is applied to the process of sliding convolution. This procedure is mathematically scientifically correct and has no omissions, but the amount of calculation is a problem for performing moment-to-moment tracking. I had no choice but to make it my favorite to do collective post-processing, that is, a stored batch process.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is an object of the present invention to easily and quickly track a target located inside a subject using a Doppler signal component of a reflected wave from the subject. It is an object of the present invention to provide a Doppler signal acquisition device or the like capable of

The Doppler signal acquisition apparatus of the present invention includes a receiving unit that receives distribution information that is information indicating the distribution of Doppler signal components of reflected waves of ultrasonic waves irradiated to a subject; and an output unit for outputting information according to the target azimuth angle and distance acquired by the acquisition unit, wherein the acquisition unit acquires the target distance After that, the process of acquiring the target azimuth angle is repeated using the distribution information received by the reception unit, and the output unit outputs information according to the azimuth angle acquired by the acquisition unit after acquiring the target distance Doppler signal It is a sampling device.

With such a configuration, it is possible to easily and quickly track a target located inside the subject.

Further, the Doppler signal acquisition device of the present invention further includes a heartbeat acquisition unit that acquires the heartbeat of the subject in the Doppler signal acquisition device, and the acquisition unit acquires the distribution information received by the reception unit after acquiring the target distance. The Doppler signal acquisition device may perform a process of acquiring the target azimuth angle in synchronization with the heartbeat using the distribution information synchronized with the heartbeat of the subject acquired by the heartbeat acquisition unit.

With such a configuration, it is possible to accurately track a target located inside the subject in synchronization with the heartbeat.

Further, in the Doppler signal sampling apparatus of the present invention, the distribution information received by the receiving unit is obtained by multiplexing the signal obtained from the reflected wave with the reference local oscillation signal, and then selecting either the top or the bottom of the signal. It may be a Doppler signal acquisition device that is distribution information acquired using the sideband of .

With such a configuration, it is possible to easily and quickly track a target located inside the subject.

According to the Doppler signal acquisition device and the like according to the present invention, it is possible to easily and quickly track a target located inside the subject.

1 is a block diagram showing an example of a Doppler signal acquisition device according to an embodiment of the present invention; FIG. Flowchart for explaining the operation of the same Doppler signal acquisition device A diagram showing an example of a phase distribution of a reflected wave for explaining the same Doppler signal acquisition device. Cross-sectional view showing an example of a beam profile for explaining the same Doppler signal acquisition device A diagram showing the position of the focal point for explaining the same Doppler signal acquisition device. Schematic diagram showing the processing procedure of the same Doppler signal acquisition device on the time axis 1 is a diagram showing an example of the appearance of a computer system according to an embodiment of the present invention; FIG. Diagram showing an example of the configuration of the same computer system

Hereinafter, embodiments of a Doppler signal acquisition device and the like will be described with reference to the drawings. It should be noted that, since components denoted by the same reference numerals in the embodiments perform similar operations, repetitive description may be omitted.

(Embodiment)
In this embodiment, the dynamic relationship between the observation aperture (probe) and the target reflection source (blood circulation system, fetal heart, etc.) in the sound field to be observed is carefully considered, and the amount of calculation required is extremely reduced. real-time tracking operation. The tracking operation here is, for example, acquiring information necessary for tracking, such as information indicating the position of a target that can change over time, or using information necessary for tracking that can change over time. For example, one or more predetermined processes are performed in correspondence with the position of the target. It may be considered that the position of the target that can change over time also includes a state in which the position of the target does not change over time. As a result of intensive research by the present inventor, in Doppler signal acquisition devices, etc., the dynamic relationship between the observation aperture (probe) and the target reflection source (blood circulation system, fetal heart, etc.) in the sound field to be observed, that is, the target , among the three parameters that must be dynamically changed for tracking, the displacement angles θ, φ, and the distance z, the ones with the highest urgency (that is, change every moment) are θ, φ led me to the idea that z is relatively less urgent (i.e. it doesn't change often/faster). For example, to explain from a different perspective, the positional relationship between the probe and the target (for example, the target fetal heart) is likely to sway, and the fetus is likely to sway, for example, according to reasons such as the progress of maternal respiration and delivery. It has led to the idea that it is primarily azimuth, not distance, that "runs away". The situation is the same when attempting to automatically track a medium- or small-diameter blood vessel deep inside a living body. In addition, when a pulsed Doppler system is adopted as an observation system, information on the distance to the target reflection source can be roughly obtained directly as the depth of the range gate where the signal is observed, so it is necessary to obtain this from the curvature of the incoming wavefront is less. Also regarding the beam profile (or the spatial resolution of the Fresnel transform) in the sound field formed by the observation aperture in practical dimensions (ratio to wavelength), the azimuth resolution is much higher than the range resolution. The damage in case of deviation is also greater in the azimuth angle space.

Based on this idea, the target is first found by acquiring the distance z to the target and the azimuth angles θ and φ. When tracking is performed only for the object, the process of obtaining the distance z can be eliminated at the stage of tracking, and the process can be greatly reduced compared to the conventional method, making it much easier to locate the target within the subject. The inventors have found that it is possible to provide a Doppler signal acquisition device capable of tracking the . This embodiment describes an embodiment of such a Doppler signal acquisition device.

Note that the azimuth angle here is two-dimensional, or is treated as two-dimensional. One of the azimuth angles θ and φ described here is usually called an elevation angle, but here both are called azimuth angles without distinguishing between them. Also, the azimuth angles θ and φ here may be considered, for example, as two declination angles θ and φ in a polar coordinate system. Also, the distance z here may be considered as the radius vector r in the polar coordinate system. This also applies to the following.

FIG. 1 is a block diagram of a Doppler signal acquisition device 1 according to this embodiment.
The Doppler signal acquisition device 1 includes an irradiation unit 101, a receiver array 102, a receiver array 103, a filter array 104, an A/D converter 105, a storage unit 106, a reception unit 107, a heartbeat acquisition unit 108, an acquisition unit 109, It has an output unit 110 and a template acquisition unit 111 . Here, as an example, a case where the irradiation unit 101 and the receiver array 102 are installed in the case 100 will be described. However, parts other than these may be further set in the case 100 .

The material, shape, etc. of the case 100 do not matter. The case 100 is composed of, for example, an isophonic foil wall. The case 100 is, for example, a liquid chamber structure filled with a sound-permeable liquid (eg, water, mineral oil, glycerin hydrate, etc.). However, the case 100 may also be a so-called solid structure with sound-permeable plastic inside.

The irradiation unit 101 irradiates the subject 10 with ultrasonic waves. The ultrasonic waves 1001 emitted by the irradiation unit 101 are plane waves, cylindrical waves, or spherical waves, for example. Ultrasonic waves 1001 are, for example, continuous waves. However, the ultrasonic waves 1001 may be pulses. The ultrasonic waves emitted by the irradiation unit 101 are, for example, ultrasonic waves at a predetermined level or ultrasonic waves at a level designated by the user. A level is, for example, intensity. ^A typical example of the Doppler signal acquisition device ¹ of the present embodiment will be described. is. However, the frequency of the ultrasonic waves emitted by the irradiation unit 101 does not matter. For example, the irradiating unit 101 irradiates ultrasonic waves having a frequency used for normal ultrasonic echoes. In FIG. 1, the arrow of the ultrasonic wave 1001 indicates the traveling direction of the ultrasonic wave.

The irradiation unit 101 has, for example, a wave transmitting transducer and an ultrasonic transmitter. A transmit transducer is also called an illumination transducer. Here, as an example, a case where the irradiation unit 101 includes an oscillator 1011, a power amplifier 1012, and an ultrasonic wave transmitter 1013 will be described.

Oscillator 1011 generates ultrasound at a predetermined frequency, eg, the observed ultrasound frequency as described above. For example, oscillator 1011 generates a continuous wave.

A power amplifier 1012 amplifies the ultrasonic waves generated by the oscillator 1011 .

The ultrasonic transmitter 1013 transmits ultrasonic waves amplified by the power amplifier 1012 . For example, the ultrasonic transmitter 1013 emits substantially non-directional ultrasonic waves. However, as the ultrasonic transmitter 1013, one that emits ultrasonic waves having directivity may be used.

A subject 10 is, for example, an object to be examined. The subject 10 is, for example, a living body such as a human body or an animal. For example, the irradiation unit 101 irradiates the target 9 in the subject 10 with ultrasonic waves. The target 9 may be considered an observation target site within the subject 10 . The target 9 is usually a site inside the living body, for example, a site that cannot be observed from the surface of the living body or is difficult to observe. The target is preferably one whose movement or movement can be detected, for example, by Doppler signals. The target 9 may be, for example, a blood circulation group with a medium or small diameter, a fetus, a fetal heart, or the like.

For example, in a state where the surface from which the ultrasonic waves 1001 emitted by the irradiation unit 101 of the case 100 shown in FIG. , a target 9 inside the subject 10 can be irradiated with ultrasound. It is preferable that at least the portion of the case 100 that is in contact with the subject 10 has a material or structure that is highly permeable to ultrasonic waves.

Although the case where the irradiation unit 101 of the Doppler signal acquisition device 1 has the oscillator 1011 and the power amplifier 1012 has been described here, the oscillator 1011 and the power amplifier 1012 are provided outside the Doppler signal acquisition device 1, and the oscillator 1011 is generated, and the ultrasonic waves amplified by the power amplifier 1012 are supplied to the ultrasonic wave transmitter 1013 of the irradiation unit 101, and the ultrasonic wave transmitter 1013 transmits the ultrasonic waves to the subject 10. may In this case, oscillator 1011 and power amplifier 1012 may be considered part of Doppler signal acquisition device 1 or not included in Doppler signal acquisition device 1 .

A reflected wave 1002 from the subject 10 of the ultrasonic waves irradiated by the irradiation unit 101 is incident on the wave receiver array 102 . The receiver array 102 converts the incident reflected wave 1002 into an electrical signal. A reflected wave 1002 from, for example, the target 9 in the subject 10 is incident on the wave receiver array 102 . The wave receiver array 102 has an incident surface on which reflected waves 1002 are incident. Since it can be said that the reflected wave 1002 is imaged on the plane of incidence of the wave receiver array 102, the plane of the wave receiver array 102 on which the reflected wave 1002 is incident may be considered as the focal plane. The Doppler signal acquisition device 1 may have an acoustic lens or the like for adjusting the focal length.

The wave receiver array 102 is usually arranged at a position where the reflected wave 1002 is incident. The reflected wave 1002 enters the case 100 from, for example, a portion of the case 100 that contacts the subject 10 and enters the wave receiver array 102 . In addition, in FIG. 1, the arrow of the reflected wave 1002 indicates the traveling direction of the reflected wave 1002 .

The wave receiver array 102 has a plurality of wave receivers 1021 . The plurality of wave receivers 1021 included in the wave receiver array 102 are arranged, for example, in a two-dimensional direction. On the surface of the wave receiver array 102 on which the reflected waves 1002 are incident, for example, the surfaces on which the reflected waves of a plurality of wave receivers 1021 are incident are arranged in a two-dimensional direction. A plurality of wave receivers 1021 constituting the wave receiver array 102 acquires, for example, received wave signals, which are electrical signals corresponding to the intensity of received reflected waves (ultrasonic waves). The intensity-dependent signal is, for example, an intensity-dependent current or voltage level signal. Receiver 1021 may be considered an element of receiver array 102 . Receiver array 102 may be, for example, a receiver transducer array, a focal plane array, a focal plane array, or the like. The receiver array 102 has, for example, a circle with a diameter of about 32 mm or a square with a diameter of about 32×32 mm. The dimensions are x2 mm. The wave receiver array 102 is composed of, for example, a total of 16×16=256 or 32×32=1024 wave receivers 1021 as a whole. Alternatively, if the ends are truncated to approximate a circle, the receiver array 102 is composed of π/4 times as many elements. However, this is only an example, and the shape and size of the wave receiver array 102, the number of wave receivers 1021 constituting the array, etc. are not limited.

The wave receiver array 102 may receive reflected waves 1002 that are incident at different times, and acquire received wave signals at different times. The wave receiver array 102 may, for example, receive continuously incident reflected waves 1002 and continuously acquire received wave signals.

Since the wave receiver array 102 and the wave receiver 1021 are well-known technologies, detailed description thereof is omitted here.

The receiver array 103 receives the received wave signal acquired by each wave receiver 1021 constituting the wave receiver array 102 . Receiver array 103 has a plurality of receivers 1031 . Each of the plurality of receivers 1031 of the receiver array 103 is connected to each of the wave receivers 1021 constituting the wave receiver array 102 by wiring or the like (not shown). 1021 receives the received wave signal. Here, each receiver 1031, for example, a low-noise amplifier 10311 that amplifies the received wave signal acquired by each wave receiver 1021 as an input, and the received wave signal amplified by the low-noise amplifier 10311 A case in which a quadrature detector 10312 for performing quadrature detection with the unified common transmission carrier 16 secondarily supplied from the oscillator 1011 is provided will be described as an example. However, the configuration of each receiver 1031 is not limited to this.

The filter array 104 acquires a Doppler signal from a received wave signal that is received by each receiver 1031 that constitutes the receiver array 103 and that has undergone amplification or the like. The Doppler signal here is the Doppler signal component of the reflected wave obtained from the subject 10 . A Doppler signal component is, for example, a Doppler shift component. Here, the filter array 104 includes a plurality of Doppler filters 1041 connected to the receivers 1031 of the receiver array 103 by wires (not shown). A case of obtaining a Doppler signal from a received wave signal that has undergone amplification or the like will be described. However, the configuration and the like of the filter array 104 are not limited to this. The output from the filter array 104 may be, for example, a pair of complex signals, in-phase (i) and quadrature (q), lending a certain Doppler-shifted frequency component of interest.

The reception of the above Doppler signal is single sideband (single sideband, SSB) reception. Extracted by filter array 104 . The Doppler signal output by the filter array 104 is, for example, distribution information acquired using either the upper or lower sideband after multiplexing the signal obtained from the reflected wave with the reference local oscillation signal. . The reason why SSB reception is used as the Doppler observation system here is that the phase distribution of the incoming wave at the aperture plane can be correctly observed according to that, and only by that.

A/D converter 105 A/D converts the output of filter array 104 . That is, the Doppler output, which is an analog signal output from the filter array 104, is converted into a digital signal. The A/D converter 105 acquires and outputs information indicating a two-dimensional distribution of Doppler signal components (hereinafter referred to as distribution information) using the Doppler signal converted as described above. The output here may be transmission or accumulation. The distribution information may be considered as distribution information of Doppler signal components on the receiving surface of the receiver array 102 described above, for example. The information obtained by distributing the information indicating the Doppler signal and the like in association with the two-dimensional arrangement is, for example, the information indicating the Doppler shift component acquired by each Doppler filter 1041 and the information indicating the Doppler shift component obtained by each Doppler filter 1041 . This information is associated with coordinates corresponding to the dimension arrangement, information indicating the order of arrangement, and the like. Alternatively, the information in which the information indicating the Doppler shift component and the like are distributed in association with the two-dimensional arrangement is, for example, the information indicating the Doppler shift component of the pixels corresponding to the two-dimensional arrangement of the receiver 1021 corresponding to the Doppler filter 1041. It may be two-dimensional image information having pixel values. Note that the A/D converter 105 may have means or the like for performing predetermined processing or the like on the Doppler signals or the like acquired by the plurality of Doppler filters 1041 other than the A/D conversion processing. good.

For example, the A/D converter 105 may acquire and output distribution information for each received wave signal acquired by the wave receiver array 102 at different times as described above. For example, the A/D converter 105 may acquire and output distribution information for each received wave signal continuously acquired by the wave receiver array 102 as described above. The A/D converter 105 sequentially obtains a plurality of pieces of distribution information by sequentially repeating the process of obtaining one piece of distribution information, for example, by appropriately using the received wave signals continuously obtained by the wave receiver array 102. Alternatively, a plurality of pieces of distribution information obtained in this manner may be considered as continuously obtained distribution information.

For example, the A/D converter 105 may associate the acquired distribution information with time information related to the distribution information, such as the time when the distribution information was acquired or the time when the reflected wave was received, and output the information. Information such as a serial number indicating the acquisition order of distribution information may be associated and output, or information such as file names and identifiers obtained according to predetermined rules may be associated and output. . The time information may be absolute time such as standard time, or relative time obtained by a timer, counter, or the like.

In the following description, the A/D converter 105 acquires distribution information and stores it in the storage unit 106 as an example. Accumulation here may be considered as temporary accumulation in a memory or the like, for example, temporary storage.

Although the case where the A/D converter 105 acquires and outputs the distribution information has been described here, it does not matter how the Doppler signal acquisition device 1 acquires and outputs the distribution information. For example, instead of the A/D converter 105 acquiring the distribution information, the distribution information is acquired using the Doppler signal output by the A/D converter 105 and stored in the storage unit 106; The Doppler signal acquisition device 1 may further have means for outputting to the .

Here, the receiver array 103 and filter array 104 quadrature-detect and filter the received wave signals obtained by the receiver array 102 for each element to drop them down to the baseband. (not shown) etc.) etc. sample or A/D convert the received ultrasonic wave signal (high frequency signal) as it is at a necessary and sufficient density and store it, and all necessary processing including some initial filter procedures is digital. It can also be realized by executing it in the form of sample point sequence signal processing.

From the viewpoint of the stored signal data, the baseband system (BB, baseband sampling system), the high frequency system (RF, RF sampling system), and the intermediate frequency system that is handled by heterodyne conversion into an intermediate frequency signal that is easy to handle once. (IF, IF sampling system), etc. is only a matter of definition or interpretation of the arrangement (arrangement) of sample point sequence data. Therefore, in the present application, the above description may be implemented with any hardware and with any sample point sequence signal processing. Further, it does not matter whether the Doppler signal acquisition device 1 of this embodiment is an RF system, an IF system, or a BB system.

The storage unit 106 stores one or more pieces of distribution information. The distribution information is, as described above, information indicating the two-dimensional distribution of the Doppler component of the reflected wave with respect to the ultrasonic wave irradiated to the subject 10 . For example, the distribution information stored in the storage unit 106 is the distribution information acquired by the A/D converter 105 . However, the process of accumulating the distribution information in the storage unit 106 does not matter. For example, the reception unit 107 may store the distribution information received from the A/D converter 105 or the like in the storage unit 106 .

The storage unit 106 may store, for example, a plurality of pieces of distribution information corresponding to different times. The distribution information corresponding to different times is, for example, distribution information acquired at different times. The distribution information acquired at different times may be distribution information acquired at different times, or may be the time at which the reflected wave used to acquire the distribution information is received. For example, the plurality of pieces of distribution information stored in the storage unit 106 may be pieces of distribution information obtained for the same target 9 at different times. For example, the storage unit 106 may store continuously acquired distribution information. The continuously acquired distribution information is the distribution information for which the acquired times are continuous. However, it may be considered that the distribution information acquired at consecutive times includes, for example, distribution information acquired at predetermined time intervals or at time intervals within a predetermined time. Also, the distribution information obtained continuously may be distribution information obtained by sequentially repeating a process of obtaining one piece of distribution information by the receiver array 103 or the like. For example, the distribution information may be stored in the storage unit 106 in association with the acquisition time and the storage time by the A/D converter 105, the reception unit 107, or the like. The storage unit 106 is preferably a non-volatile recording medium, but can also be realized with a volatile recording medium.

In this embodiment, the case where one or more pieces of distribution information stored in storage unit 106 are distribution information acquired and accumulated by A/D converter 105 will be exemplified below. explain.

The receiving unit 107 receives distribution information indicating a distribution of Doppler signal components of reflected waves of ultrasonic waves irradiated to the subject. The reception here may be considered as reception of input, reception, reading of information accumulated in the storage unit, and the like. The receiving unit 107 receives, for example, distribution information output from the A/D converter 105 or the like. Further, the receiving unit 107 may receive distribution information by appropriately reading the distribution information stored in the storage unit 106 . For example, the receiving unit 107 reads out the distribution information stored in the storage unit 106 in order of acquisition or accumulation. However, the receiving unit 107 may read out distribution information separated by one or more pieces of distribution information in order of acquisition or accumulation, that is, read out by thinning out one or more pieces of distribution information. The distribution information received by the reception unit 107 is, for example, distribution information acquired using either the upper or lower sideband after multiplexing the signal obtained from the reflected wave with the reference local oscillation signal.

Note that the receiving unit 107 may receive, for example, the distribution information output from the A/D converter 105 or the like, and temporarily accumulate (for example, temporarily store) the information in the storage unit 106 .

Note that the irradiation unit 101, the receiver array 102, the receiver array 103, the filter array 104, and the A/D converter 105, which are the components for acquiring the distribution information of the Doppler signal components described above, It may be implemented by an external device different from the sampling device 1 . Then, the distribution information acquired by this device may be stored in the storage unit 106 or accepted by the reception unit 107 . Also, a device capable of acquiring distribution information having the same configuration as these may be used instead of these.

A heartbeat acquisition unit 108 acquires the heartbeat of the subject. For example, when the target 9 is a blood vessel or the like of the subject, the heartbeat acquisition unit 108 uses information acquired by a sensor (not shown) attached to the subject to acquire the heartbeat, and obtains the heartbeat. get. Acquiring the heartbeat may be acquiring information indicating the time or point in time when the heartbeat occurs. Acquisition of the heartbeat may be considered to be acquisition of information indicating the occurrence time and the occurrence point of the maximum heartbeat signal amplitude point. For example, the heartbeat acquiring unit 108 may be a heartbeat meter that acquires heartbeats using information acquired by a sensor or the like. The heartbeat acquiring unit 108 may acquire the heartbeat of the subject in any manner. For example, a heartbeat may be acquired from an electrical signal acquired by an electrode or the like, which is a sensor attached to the subject. Further, the heartbeat may be acquired using blood flow information or the like acquired by an infrared sensor or the like attached to the subject. The connection between the heart rate acquisition unit 108 and the sensors, heart rate monitor, etc. may be wired connection or wireless connection.

If the target 9 is the heart of a fetus or the like, the heartbeat acquisition unit 108 acquires the heartbeat of the fetus as the subject. The processing, configuration, etc. for detecting the signal amplitude, etc., having periodicity, which is considered to be the heartbeat signal of the fetus, are, for example, the technique disclosed in Japanese Patent Publication No. 56-7592, which is an invention by the inventor of the present application, Yasuhito Takeuchi. , are well known, and detailed description thereof is omitted here.

A part of the configuration of the Doppler signal acquisition device 1 of the present application may be used as appropriate in the process of acquiring the heartbeat. For example, the heartbeat acquisition unit 108 may acquire heartbeats using information received by the receiver array 103 or the like.

Note that the above-described configuration and processing for acquiring heartbeats by the heartbeat acquiring unit 108 are merely examples, and the present invention is not limited to any of these. Similarly, in the case of detection of periodicity considered to be the heartbeat of a fetus or the like, or detection of a signal amplitude having periodicity, it does not matter how the heartbeat is acquired.

The heartbeat acquisition unit 108 may also receive heartbeat signals such as electrocardiographic signals, heart sound signals, and pulse waves of a fetus or living body from another device (not shown) that acquires these signals. good. In this case, the acquisition of heartbeats by the heartbeat acquiring unit 108 may be considered as reception or reception of information indicating a signal indicating the timing at which heartbeats occur or time. Note that the heartbeat acquisition unit 108 may acquire heartbeats from any signal.

Note that the above-described A/D converter 105 and the like may acquire only the distribution information synchronized with the heartbeat and store this distribution information in the storage section 106 or output it to the reception section 107 .

The heartbeat acquisition unit 108 may have a sensor, for example. Also, the heartbeat acquiring unit 108 may be, for example, a heartbeat meter or the like connected to a sensor, or may be a receiving means or the like for receiving information from the heartbeat meter.

The acquisition unit 109 performs, for example, the following processes of target acquisition and tracking of the acquired target.
(1) In the initial stage, that is, the acquisition stage of the target 9, the target is found by searching for the three variables of distance and azimuth. In this case, priority is given to distance acquisition procedures and activities.
(2) In the stage of tracking after target acquisition, processing is performed for tracking only with respect to the two variables of the azimuth angle.

In particular, in the pulse Doppler system, it is more beneficial to find and identify the distance z at the initial stage at the position (distance) of the range gate rather than based on the Fresnel transform of the incoming wavefront. .

In addition, the discovery and identification of the azimuth angle in the tracking stage is performed in a beat-by-beat synchronous manner, and in particular, performed only once per beat at the maximum amplitude point of the heartbeat Doppler signal. A preferred embodiment may be to do it as an iterative operation to slightly modify the azimuth angle applied to the reception.

The acquisition unit 109 will be described below. The acquisition unit 109 acquires the distance z and the azimuth angles θ and φ of the target 9 positioned within the subject 10 using the distribution information received by the reception unit 107 . After obtaining the distance z, the process of obtaining the azimuth angles θ and φ is repeatedly performed using the distance z. Here, the distance z and the azimuth angles θ and φ acquired by the acquisition unit 109 are, for example, the position at which the wave receiver array 102 receives the reflected wave and the distance z and the azimuth angles θ and φ with respect to the receiving direction. be. The position where the reflected wave is received here is, for example, a reference point on the wave receiving surface of the wave receiver array 102, for example, a representative point such as the center. The azimuth angle here may be considered as an azimuth angle in a polar coordinate system when the distance between the target 9 and the reference point (for example, the center point) of the receiving surface of the receiver array 102 is r. . This azimuth angle is, for example, an azimuth angle when a direction perpendicular to the wave receiving surface is considered as a desired direction such as a depth direction.

The acquisition unit 109 acquires the distance z to the target 9 which is the signal source by performing Fresnel transform on the curvature of the incoming wavefront using the distribution information received by the reception unit 107 . The signal source here is for example a moving target 9 which is the source of the Doppler signal. The acquisition unit 109 acquires the distance z to the target 9 using, for example, a Fresnel transformation template provided by the template acquisition unit 111 . A template is, for example, phase distribution information corresponding to the receiver array 102 . For example, the template is information indicating the initial value of the phase distribution.

An example of processing for obtaining the distance z to the target 9 and the azimuth angles θ and φ using a template will be described below. Here, first, the acquisition unit 109 acquires the distance z. For example, the acquisition unit 109 performs Fresnel transform on the distribution information received by the reception unit 107 . Then, using a plurality of Fresnel transformation templates with different curvatures provided by the template acquisition unit 111, the curvature radius of the template that gives the highest correlation value (correlation peak stands) in the calculation region, that is, the distribution information is signaled. It is taken as the distance z to the target 9 which is the source. Templates with different curvatures are, for example, templates with slightly different curvatures. This template is, for example, a template with a predetermined curvature. Also, this template is a template corresponding to the wavelength of the ultrasonic wave 1001 used when acquiring the distribution information. The plurality of templates may be prepared in advance by the template acquisition unit 111 reading from a storage unit (not shown) or the like, or may be newly generated by the template acquisition unit 111 . For example, the Fresnel transformation template is a Newton ring template, and the template acquisition unit 111 may acquire a plurality of templates with different curvature radii by changing the curvature radii.

Next, the obtaining unit 109 obtains the azimuth angles θ and φ using the distance z. The acquisition unit 109 acquires from the template acquisition unit 111 a template for Fresnel transformation that is suitable for the acquired distance z and is specified by the wavelength of the ultrasonic wave 1001 used when acquiring the distribution information. Azimuth angles θ and φ (declination angles θ and φ) are obtained by applying the templates to the pixels of the data of the distribution information in the process of sliding convolution. Sliding convolution is to perform convolution by applying a template while sliding it to pixels of data of distribution information. A pixel of distribution information data is, for example, each pixel of distribution information data in which the value of each pixel is represented by the value of the Doppler shift component. Since the method for obtaining this azimuth angle is publicly known, detailed description thereof is omitted here.

Note that the acquisition unit 109 may collectively perform Fresnel transform instead of such processing for each pixel. Further, instead of performing Fresnel transform, Fourier transform may be performed to obtain the azimuth angle. When the distance of the signal source is infinite, or when it is in the Fraunhofer zone that can be approximated to it, it can be considered that a non-curved wavefront, i.e., a plane wave arrives. A Fourier transform can be applied. In this case, only two values are the answer: x, y or azimuth angles θ, φ, meaning the azimuth angle of the signal source (eg target 9). In principle, the Fresnel transform can be understood as a result of adding a phase-bent template (multiplication for each element) to the Fourier transform that is focused on the point at infinity, which becomes a close-up lens. It also holds true that one degenerate form is the Fourier transform.

Here, since the azimuth angles θ and φ are obtained using a template specified by the acquired distance z and wavelength, obtaining the distance z is the template for Fresnel transformation specified by this distance z , that is, obtaining a template for Fresnel transformation specified by the distance z and the wavelength.

Once the acquisition unit 109 acquires the target distance z, for example, after acquiring the target distance z and the azimuth angles θ and φ, the acquisition unit 109 does not perform the process of acquiring the distance z described above, and the reception unit Using the distribution information received by 107, the process of obtaining target azimuth angles θ and φ is repeated once or twice or more in the same manner as described above. This distribution information is, for example, distribution information acquired after the distribution information for acquiring the distance z. The obtaining unit 109 obtains the azimuth angles θ and φ sequentially obtained in this way as the azimuth angles θ and φ indicating the position of the target after obtaining the target distance z. The azimuth angles θ and φ may be considered as the azimuth angles θ and φ indicating the position of the target obtained from the distribution information obtained after the distribution information for obtaining the distance z of the target. Also, the distance z to the target 9 in this case is considered to be the latest distance z obtained immediately before. Note that this process may be considered as a process of obtaining the azimuth angles θ and φ using the Fresnel transform template specified by the distance z as described above.

Note that, as described above, the acquisition unit 109 uses the distribution information received by the reception unit 107 and synchronized with the heartbeat of the subject acquired by the heartbeat acquisition unit 108 to obtain the target in synchronization with the heartbeat. It is preferable to perform a process of obtaining the azimuth angle of . For example, when the acquisition unit 109 acquires the distance z and the azimuth angles θ and φ of the target 9, the distribution information received by the reception unit 107 is synchronized with the heartbeat of the subject acquired by the heartbeat acquisition unit 108. Using the distribution information, processing is performed to acquire the target distance z and the azimuth angles θ and φ in synchronism with the heartbeat. Synchronized with the heartbeat using the received distribution information synchronized with the heartbeat of the subject obtained by the heartbeat obtaining unit 108, which is received after the distribution information used when obtaining the distance z. Alternatively, the target azimuth angle may be acquired. For example, when the acquiring unit 109 acquires the azimuth angles θ and φ (including when acquiring the distance z), the A/D converter is synchronized with the heartbeat of the subject acquired by the heartbeat acquiring unit 108. The receiving unit 107 sequentially receives the distribution information output by the receiving unit 105, and the obtaining unit 109 uses the distribution information received by the receiving unit 107 to obtain the azimuth angles θ and φ as described above. Also good. Further, for example, when the acquisition unit 109 acquires the azimuth angles θ and φ (including when the distance z is acquired), the distribution information acquired by the A/D converter 105 and accumulated in the storage unit 106 The reception unit 107 sequentially reads and acquires the distribution information synchronized with the heartbeat of the subject acquired by the heartbeat acquisition unit 108 from among the distribution information, and the acquisition unit 109 uses the distribution information sequentially acquired by the reception unit 107. Therefore, the azimuth angles θ and φ may be obtained as described above.

For example, since the signal source moves moment by moment, but relatively slowly, without jumping, the distance and azimuth angle data of the signal source obtained at the maximum point of the heartbeat signal amplitude in the most recent past beat may be used as initial values. This makes it possible to significantly shorten and speed up the procedure for adaptively discovering and identifying new data on the distance and azimuth angle of the signal source at the heartbeat signal amplitude maximum point of the immediately following beat.

Note that if the azimuth angles θ and φ obtained by the obtaining unit 109 from the distribution information received by the receiving unit 107 after obtaining the distance z of the target 9 are inappropriate data (for example, the azimuth angles obtained immediately before Therefore, when the difference is greater than the threshold value, or when the value is an impossible number, etc.), the obtaining unit 109 may perform the process of obtaining the distance z again. Further, the acquisition unit 109 may periodically or irregularly acquire the distance z.

Acquisition unit 109 can usually be implemented by an MPU, a memory, or the like. The processing procedure of the acquisition unit 109 is normally realized by software, and the software is recorded in a recording medium such as a ROM. However, it may be realized by hardware (dedicated circuit).

The output unit 110 outputs information according to the distance z and the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109 . Further, the output unit 110 outputs information corresponding to the azimuth angles θ and φ acquired by the acquisition unit 109 after the distance z of the target 9 is acquired. For example, the output of information according to the distance z and the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109 is at least part of the distance z and the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109. (for example, the output of the distance z and the azimuth angles θ and φ, or the output of the azimuth angles θ and φ), and obtained using at least part of the distance z and the azimuth angles θ and φ It may be the output of the information obtained. Further, the output of information according to the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109 after acquiring the distance z of the target 9 is at least part of the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109. (for example, the output of the azimuth angles θ and φ, or the output of the azimuth angles θ and φ), and the output of information obtained using at least part of the azimuth angles θ and φ good too. The output of the information acquired using at least part of the azimuth angles θ and φ may be, for example, information indicating the amount of displacement from the previous values of the azimuth angles θ and φ. Further, the output of the information acquired using at least part of the azimuth angles θ and φ is an output such as a warning that is performed when at least one of the azimuth angles θ and φ becomes equal to or greater than a predetermined threshold value. Alternatively, an output such as a warning may be output when the amount of displacement of at least one of the azimuth angles θ and φ from the previous value exceeds a predetermined threshold value. The warning here is, for example, that the target 9 is about to deviate from an area observable by the Doppler signal acquisition device 1 (for example, an area in which ultrasonic waves can be irradiated or a Doppler signal can be received). Alternatively, it may be information warning that there is a possibility that it may come off, or information warning that it has come off. This warning may be a warning that tracking is about to break or has broken. The warning output here may be the output of a warning screen, the output of a warning sound, or the lighting of a warning light. The output of information obtained using the distance z and the azimuth angles θ and φ is obtained using the distance z and the azimuth angles θ and φ with respect to a device (not shown) that processes the target 9. Alternatively, a device (not shown) for automatically controlling the direction in which the Doppler signal acquisition device 1 emits ultrasonic waves and the direction in which Doppler signals are received may be set to the target 9 after movement. may be a control signal or the like for moving to enter the observable region. The distance z and the azimuth angles θ and φ in this case may be a combination of the distance z and the azimuth angles θ and φ obtained after obtaining the distance z. After obtaining the distance z of the target 9, the output unit 110 may output the distance z and the azimuth angles θ and φ obtained by the obtaining unit 109 after the distance z. Information corresponding to the azimuth angles θ and φ acquired by the acquisition unit 109 after the distance z may be output.

Note that the output unit 110 outputs information according to the distance z and the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109, and information according to the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109. , the information obtained from the target 9 may be acquired and output by specifying and tracking the target 9 using these pieces of information.

The output here is, for example, display on a display, projection using a projector, printing on a printer, sound output, transmission to an external device, storage on a recording medium, other processing device or other program, etc. It is a concept that includes delivery of processing results of

The output unit 110 may or may not include output devices such as a display and speakers. The output unit 110 can be realized by output device driver software, or by output device driver software and an output device.

Template acquisition unit 111 acquires one or more templates. The template acquired by the template acquisition unit 111 is a template for Fresnel transformation. Templates for Fresnel transforms are typically Newton ring templates. For example, the template acquisition unit 111 may acquire a template by reading a template stored in a storage unit (not shown), may acquire a template by generating a template, or may acquire a new template using one or more templates. template can be generated. For example, the template acquisition unit 111 uses a Newton ring template having a scale factor meaning a curvature radius stored in a storage unit (not shown) as a changeable parameter, and changes the scale factor to obtain a curvature radius may generate one or more templates with different . Such templates may be considered variable templates, for example. Further, when the acquisition unit 109 acquires the distance z to the target 9, the template acquisition unit 111 acquires the azimuth angles θ and φ using this distance z and the wavelength of the ultrasonic wave to be irradiated to the target. You may obtain the template used for In addition, when the acquired template includes non-ideal components such as redundancy, noise, and shape distortion, the template acquisition unit 111 may perform correction or the like to abstract them.

Note that the process by which the template acquisition unit 111 acquires a template is not limited to the above.

Next, an example of the operation of the Doppler signal acquisition device 1 will be described using the flowchart of FIG.

(Step S101) The irradiation unit 101 starts irradiation of ultrasonic waves. For example, the irradiation unit 101 starts irradiating an area including the target 9 of the subject 10 with ultrasonic waves. For example, a continuous wave transmission carrier output by the oscillator 1011 is appropriately energized by the power amplifier 1012 and is irradiated substantially omnidirectionally to the area including the target 9 by the ultrasonic wave transmitter 1013 .

(Step S102) The wave receiver array 102 receives reflected waves of the ultrasonic waves emitted in step S101. For example, the wave receiver array 102 sequentially receives reflected waves. For example, the receiver array 102 receives the reflected waves returned by the target 9 and converts them into multiple electrical signals.

(Step S<b>103 ) The receiver array 103 receives the signal output by the wave receiver array 102 . For example, the receiver array 103 sequentially receives signals output by the wave receiver array 102 . For example, each receiver 1031 forming the receiver array 103 receives a signal output by each wave receiver 1021 forming the wave receiver array 102 according to the received reflected wave.

(Step S<b>104 ) Filter array 104 selectively acquires only Doppler shift components from the signal received by receiver array 103 .

(Step S105) The A/D converter 105 converts the Doppler signal output by the Doppler filter 1041 forming the filter array 104 into a digital signal to obtain Doppler signal distribution information. The A/D converter 105 sequentially acquires distribution information from the Doppler signal output by the Doppler filter 1041, for example. The acquired distribution information is stored in the storage unit 106 in association with the acquisition time acquired from a clock (not shown) or the like.

(Step S106) The heartbeat acquisition unit 108 acquires heartbeats. For example, the maximum value time of the heartbeat signal is acquired sequentially.

(Step S107) The reception unit 107 substitutes 1 as the value of the counter k.

(Step S<b>108 ) The receiving unit 107 receives distribution information at the occurrence of the k-th heartbeat from the distribution information stored in the storage unit 106 . For example, the reception unit 107 reads from the storage unit 106 the distribution information associated with the acquisition time that is the same as the k-th maximum value time of the heartbeat signal, which is the time of the k-th heartbeat acquired in step S106.

(Step S<b>109 ) The template acquisition unit 111 acquires a plurality of templates for Fresnel transformation with different curvature radii corresponding to the wavelengths of the ultrasonic waves output from the oscillator 1011 .

(Step S110) The acquisition unit 109 acquires the distance z to the target 9 by performing Fresnel transform on the k-th distribution information received immediately before by the reception unit 107 . For example, the acquisition unit 109 performs Fresnel transform on the distribution information received immediately before by the reception unit 107, and detects a template with a high correlation value from the plurality of different templates acquired in step S108. Then, the radius of curvature of the Newton ring shape corresponding to this template is acquired as the distance z to the target 9 . Note that the template acquisition unit 111 may acquire the distribution information obtained at this time by performing the Fresnel transform or a template having a shape similar thereto as a template for acquiring the azimuth angles θ and φ thereafter. good. At this time, the template may be subjected to correction processing for removing non-ideal components such as redundancy and noise. It should be noted that the acquisition of such a template may be considered to substantially correspond to the acquisition of the distance z.

(Step S111) For the k-th distribution information, the acquisition unit 109 acquires the azimuth angles θ and φ of the target 9 using a Newton ring-shaped template having a radius of curvature corresponding to the distance z acquired in step S110. . For example, the above template is applied to the process of sliding convolution to obtain the azimuth angles θ and φ.

(Step S112) The acquisition unit 109 determines whether or not the distance z has been acquired. If it has been acquired, the process proceeds to step S113, and if it has not been acquired, the process proceeds to step S114.

(Step S<b>113 ) The output unit 111 outputs information about the distance z to the target 9 and the azimuth angles θ and φ of the target 9 acquired by the acquisition unit 109 . For example, the output unit 111 outputs values of the distance z and the azimuth angles θ and φ. Then, the process proceeds to step S115.

(Step S114) The output unit 111 outputs the azimuth angles θ and φ obtained from the k-th distribution information. For example, the output unit 111 calculates the amount of displacement between the azimuth angles θ and φ obtained from the k-th distribution information and the azimuth angles θ and φ obtained from the (k−1)-th distribution information. Output a warning if the threshold is exceeded. If it does not exceed the limit, no warning is output. Then, the process proceeds to step S115.

(Step S115) The reception unit 107 increments the value of the counter k by one.

(Step S116) The reception unit 107 receives (reads) the distribution information at the occurrence of the k-th heartbeat from the distribution information stored in the storage unit 106, as in step S108. Then, the process proceeds to step S111.

In addition, in the flowchart of FIG. 2, for example, the processing from step S101 to step S105 shall be performed continuously and repeatedly.

Further, in step S114 or the like, if the displacement amount of the azimuth angle exceeds the threshold value, the value of the counter k may be incremented by 1 and the process may return to step S108.
In the flowchart of FIG. 2, instead of acquiring and accumulating Doppler signal distribution information in step S105, the A/D converter 105 acquires Doppler signal distribution information at timing synchronized with the heartbeat acquired in step S106. The distribution information may be obtained and the receiving unit 107 may receive this distribution information.

Note that in the flowchart of FIG. 2, the process ends when the power is turned off or when the process ends.

In the following, as a description related to the Doppler signal acquisition device 1 according to the present embodiment, it is assumed that the azimuth angles .theta. An example of base trial calculation is presented.

The setting conditions are 32×32 element arrangement on the aperture plane and 1024 total number of elements. At this time, when the ultrasonic frequency is 2 MHz, an aperture size of at least 15 mm square is required to avoid ambiguity in all azimuth angle spaces. or 30 degrees, the detection sensitivity can be enhanced by doubling or tripling this value.

FIG. 3 shows, with gradation, the phase distribution on the aperture plane of reflected waves arriving from a reflection source slightly displaced from the central axis, showing a typical Newton ring pattern.

FIG. 4 shows the level of the signal received according to the azimuth angle set on the receiving side when the reflected wave is received with the phase adjusted by Fresnel transformation, with the eccentric distance at the corresponding distance as the horizontal axis (that is, the beam profile ), from which it can be seen that the half power width of the sensitivity distribution is about 3 mm. Although the azimuth angle or eccentricity axis is two-dimensional, only one axis is shown because the receiving aperture is set equally for both axes.

FIG. 5 shows the focal position changed in the depth direction by changing the curvature of the wavefront of the Fresnel transform in the distance direction of the reflected wave from the same reflection source in the same setting. , the power half width before and after the focal point is about 13 mm.

From the above, it is proved that the deviation in the azimuth direction has a much greater influence than the deviation in the distance direction, and the extent to which it must be managed (tracked) is large.

In this embodiment, for example, using a variable template or the like, the process of changing and correcting the curvature radius and frequently using the Fresnel transform to know the distance of the signal reduction is performed only once at the time of initial setting, and thereafter During driving, the distance data is used as an abbreviated system to perform tracking by adaptively correcting the azimuth angle. For example, only one two-dimensional Fourier transform is required for this recursive tracking with one trial for each beat.

FIG. 6 expresses the processing procedure of the present invention on the time axis of the heartbeat signal. In the figure, the process of finding the distance to the signal source by frequently using Fresnel transform while correcting the variable template is performed only once at the time of initial setting. The task of tracking is done incrementally by essentially doing it only once in each heartbeat. This operation, which is essentially performed only once in each heartbeat, is selectively performed in small time intervals before and after the peak value time of the heartbeat signal. Means and methods for determining the maximum value time of the heartbeat signal are well-known and widely used, and therefore the description thereof is omitted here.

As described above, according to the present embodiment, in constructing a system for automatically discovering a target having a Doppler shift derived from heartbeat activity and automatically tracking the target after the discovery, the required amount of calculation can be greatly reduced. This makes it possible to easily and quickly track a target located inside the subject. In addition, due to such action and effect, it is beneficial because it greatly contributes to making the device lighter, thinner, shorter and smaller, and power saving.

In each of the above embodiments, each process (each function) may be implemented by centralized processing by a single device (system), or may be implemented by distributed processing by a plurality of devices. may be

Further, in each of the above embodiments, the case where the Doppler signal acquisition device is stand-alone has been described, but the Doppler signal acquisition device may be a stand-alone device mounted close to the sensor side, and short-distance transmission may be performed. It may also be implemented by a server-client system that takes the form of edge computing with centralized resources in the vicinity via the network. Furthermore, it is not prohibited to implement the computing and storage resources for these distributed processing in the form of cloud computing distributed in a virtual space on the network. In the case of distributed processing or distributed implementation, the output unit and reception unit receive input and output screens via communication lines.

Further, in each of the above embodiments, each component may be configured by dedicated hardware, or components that can be realized by software may be realized by executing a program. For example, each component can be realized by reading and executing a software program recorded in a recording medium such as a hard disk or a semiconductor memory by a program execution unit such as a CPU. During execution, the program execution unit may execute the program while accessing a storage unit (for example, a recording medium such as a hard disk or memory). It also does not preclude equivalent functionality being implemented in cloud computing form via network commands for distributed execution.

The software that implements the Doppler signal acquisition device in each of the above embodiments is the following program, including the case where equivalent functions are constructed in the virtual space on the cloud via network commands. That is, this program comprises a computer, a receiving unit that receives distribution information that is information indicating the distribution of Doppler signal components of reflected waves with respect to ultrasonic waves irradiated to a subject, and a position in the subject using the distribution information. and an output unit for outputting information according to the target azimuth and distance obtained by the obtaining unit, and the obtaining unit obtains the target distance. After that, the process of acquiring the azimuth angle of the target is repeated using the distribution information received by the reception unit, and the output unit outputs information according to the azimuth angle acquired by the acquisition unit after acquiring the distance of the target. be.

In the above program, the transmission step for transmitting information and the reception step for receiving information are performed by hardware. not included).

In the program, the functions realized by the program do not include functions that can be realized only by hardware. For example, functions that can be realized only by hardware such as modems and interface cards, such as an acquisition unit that acquires information and an output unit that outputs information, are not included in the functions realized by the above program.

Also, the number of computers executing this program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

FIG. 7 is a schematic diagram showing an example of the appearance of a computer that executes the above program and realizes the Doppler signal acquisition device according to the above embodiment. The above embodiments can be implemented by computer hardware and computer programs executed thereon.

In FIG. 7, a computer system 900 comprises a computer 901 including a CD-ROM (Compact Disk Read Only Memory) drive 905 , a keyboard 902 , a mouse 903 and a monitor 904 .

FIG. 8 is a diagram showing the internal configuration of the computer system 900. As shown in FIG. In FIG. 8, a computer 901 includes a CD-ROM drive 905, an MPU (Micro Processing Unit) 911, a ROM 912 for storing programs such as a boot-up program, and a ROM 912 for storing programs such as a boot-up program. A RAM (Random Access Memory) 913 for temporarily storing and providing a temporary storage space, a hard disk 914 for storing application programs, system programs, and data, and a bus 915 for interconnecting the MPU 911, ROM 912, etc. Prepare. Note that computer 901 may include a network card (not shown) that provides connection to a LAN.

A program that causes the computer system 900 to perform the functions of the Doppler signal acquisition device according to the above embodiments may be stored in the CD-ROM 921 , inserted into the CD-ROM drive 905 , and transferred to the hard disk 914 . Alternatively, the program may be transmitted to computer 901 via a network (not shown) and stored in hard disk 914 . Programs are loaded into RAM 913 during execution. The program may be loaded directly from the CD-ROM 921 or network.

The program does not necessarily include an operating system (OS) or a third party program that causes the computer 901 to perform the functions of the Doppler signal acquisition device according to the above embodiments. A program may contain only those portions of instructions that call the appropriate functions (modules) in a controlled manner to produce the desired result. How the computer system 900 operates is well known and will not be described in detail.

It goes without saying that the present invention is not limited to the above-described embodiments, and that various modifications are possible and are also included within the scope of the present invention.

As described above, the Doppler signal acquisition device or the like according to the present invention is suitable as a device or the like for acquiring Doppler signals, and in particular, as a device or the like for acquiring target information in a subject using Doppler signals or the like. Useful.

1 Doppler signal acquisition device 9 target 10 subject 16 transmission carrier 100 case 101 irradiation unit 102 receiver array 103 receiver array 104 filter array 105 A/D converter 106 storage unit 107 reception unit 108 heartbeat acquisition unit 109 acquisition unit 110 output unit 111 template acquisition unit 1001 ultrasonic wave 1002 reflected wave 1011 oscillator 1012 power amplifier 1013 ultrasonic wave transmitter 1021 wave receiver 1021 each wave receiver 1031 receiver 1041 Doppler filter 10311 low noise amplifier 10312 quadrature detector

Claims (5)

a reception unit that receives distribution information, which is information indicating the distribution of the Doppler signal component of the reflected wave of the ultrasonic wave irradiated to the subject;
an acquisition unit that acquires the azimuth angle and distance of a target located within the subject using the distribution information;
an output unit that outputs information according to the target azimuth angle and distance acquired by the acquisition unit;
The acquisition unit, after acquiring the target distance, repeats a process of acquiring the target azimuth angle using the distribution information received by the reception unit,
The Doppler signal acquisition device, wherein the output unit outputs information corresponding to the azimuth angle acquired by the acquisition unit after acquiring the target distance. further comprising a heartbeat acquisition unit that acquires the heartbeat of the subject;
After acquiring the target distance, the acquisition unit uses the distribution information received by the reception unit and synchronized with the heartbeat of the subject acquired by the heartbeat acquisition unit to obtain the target distance in synchronization with the heartbeat. 2. The Doppler signal acquisition device according to claim 1, wherein a process of acquiring the azimuth angle of the target is performed by performing a process of acquiring the azimuth angle of the target. The distribution information received by the reception unit is distribution information acquired by using either the upper or lower sideband after multiplexing the signal obtained from the reflected wave with the reference local oscillation signal. 3. The Doppler signal acquisition device according to claim 1 or 2. A Doppler signal acquisition method performed using a reception unit, an acquisition unit, and an output unit,
a receiving step in which the receiving unit receives distribution information, which is information indicating a distribution of a Doppler signal component of a reflected wave of an ultrasonic wave irradiated to a subject;
an acquisition step in which the acquisition unit acquires the azimuth angle and distance of a target located within the subject using the distribution information;
an output step in which the output unit outputs information according to the target azimuth angle and distance obtained in the obtaining step;
The obtaining step repeats a process of obtaining the azimuth angle of the target using the distribution information received in the receiving step after obtaining the distance of the target,
The Doppler signal acquisition method in which the output step outputs information corresponding to the azimuth angle acquired in the acquisition step after acquisition of the target distance. the computer,
a reception unit that receives distribution information, which is information indicating the distribution of the Doppler signal component of the reflected wave of the ultrasonic wave irradiated to the subject;
an acquisition unit that acquires the azimuth angle and distance of a target located within the subject using the distribution information;
functioning as an output unit for outputting information according to the target azimuth angle and distance acquired by the acquisition unit;
The acquisition unit, after acquiring the target distance, repeats a process of acquiring the target azimuth angle using the distribution information received by the reception unit,
A program in which the output unit outputs information according to the azimuth angle acquired by the acquisition unit after acquiring the target distance.

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