Ultrasound diagnostic equipment

Abstract

To achieve both reduced degradation of ultrasound probes and improved examination efficiency. [Solution] The ultrasound diagnostic apparatus according to the embodiment comprises at least two detection units, a setting unit, and a determination unit. The at least two detection units each detect the airborne state of the ultrasound probe based on different detection criteria. The setting unit sets the scan conditions for the ultrasound scan using the ultrasound probe. The determination unit determines the degree of airborne state, which indicates the likelihood of the airborne state, based on the detection results of the detection units and the scan conditions set by the setting unit.

Description

【Technical Field】 【0001】 The embodiments disclosed in this specification and the drawings relate to an ultrasonic diagnostic apparatus. 【Background Art】 【0002】 Conventionally, in an ultrasonic diagnostic apparatus, there has been a problem that when an ultrasonic probe is left in the air (i.e., in a non-biological contact state) for a long time and transmits and receives ultrasonic waves, the temperature of the ultrasonic probe rises and the ultrasonic probe deteriorates. Therefore, in order to suppress the temperature rise of the ultrasonic probe, there is a technique for detecting the state of being left in the air and automatically controlling the ultrasonic scan according to the detected state of being left in the air. Specifically, as the control of the ultrasonic scan, suppression of the frame rate, suppression of the acoustic output, etc. are performed. For the detection of the state of being left in the air, detection of the movement amount of pixels between frames, analysis of the luminance difference between frames, analysis of the luminance histogram, etc. are used. 【0003】 However, in the conventional method for detecting the state of being left in the air, since the detection results are not uniform according to differences in scan conditions such as frequency and scan depth, it has been difficult to improve the detection accuracy of the state of being left in the air. Due to the difficulty of improving the detection accuracy of the state of being left in the air, there is a possibility that the frame rate may be suppressed by erroneously determining that it is in the state of being left in the air even during normal scanning. When the frame rate is suppressed, the inspection efficiency decreases. Therefore, it is required to achieve both suppression of the deterioration of the ultrasonic probe and improvement of the inspection efficiency. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2004-159770 [[ID=ISSN]]【Patent Document 2】 Japanese Patent Application Laid-Open No. 2005-58285 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 One of the problems that the embodiments disclosed in this specification and drawings aim to solve is to achieve both suppression of ultrasonic probe degradation and improvement of inspection efficiency. However, the problems that the embodiments disclosed in this specification and drawings aim to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described later can also be positioned as other problems. [Means for solving the problem] 【0006】 The ultrasound diagnostic apparatus according to this embodiment comprises at least two detection units, a setting unit, and a determination unit. The at least two detection units each detect the state of the ultrasound probe being left in the air based on different detection criteria. The setting unit sets the scan conditions for the ultrasound scan using the ultrasound probe. The determination unit determines the degree of air exposure, which indicates the likelihood of the probe being left in the air, based on the detection results of the detection units and the scan conditions set by the setting unit. [Brief explanation of the drawing] 【0007】 [Figure 1] Figure 1 is a block diagram showing an example configuration of an ultrasound diagnostic apparatus according to the first embodiment. [Figure 2] Figure 2 is a flowchart showing an example of operation of the ultrasound diagnostic device according to the first embodiment. [Figure 3] Figure 3 is a flowchart showing the process for determining whether the device is left in the air, in an example of operation of an ultrasonic diagnostic device according to the first embodiment. [Figure 4] Figure 4 is a flowchart showing the detection process for an airborne state based on a first detection criterion in an example of the operation of an ultrasonic diagnostic apparatus according to the first embodiment. [Figure 5] Figure 5 is a flowchart showing the detection process for the airborne state based on the second detection criterion in an example of the operation of an ultrasonic diagnostic device according to the first embodiment. [Figure 6] Figure 6 is a flowchart showing the calculation process for the degree of exposure to air in an example of the operation of an ultrasonic diagnostic device according to the first embodiment. [Figure 7] Figure 7 shows an example of the operation of an ultrasound diagnostic device according to the first embodiment, illustrating an ultrasound image taken when the device is left in the air with a shallow scan depth. [Figure 8] Figure 8 shows an example of the operation of an ultrasound diagnostic device according to the first embodiment, illustrating an ultrasound image taken when the device is left in the air at a deep scan depth. [Figure 9] Figure 9 shows an example of operation of an ultrasonic diagnostic device according to the first embodiment, illustrating the detection process for an airborne state based on the first detection criterion. [Figure 10] Figure 10 is a diagram showing the detection process for airborne conditions based on the first detection criterion, following Figure 9. [Figure 11] Figure 11 shows an example of operation of an ultrasonic diagnostic device according to the first embodiment, illustrating the detection process for an airborne state based on the second detection criterion. [Figure 12] Figure 12 is a flowchart showing the calculation process for the degree of exposure to air in an example of operation of an ultrasonic diagnostic device according to a first modified example of the first embodiment. [Figure 13] Figure 13 is a flowchart showing the process for determining whether the device is left in the air, in an example of operation of an ultrasonic diagnostic device according to a second modified example of the first embodiment. [Figure 14] Figure 14 is a flowchart showing the process for determining whether the device is left in the air, in an example of operation of an ultrasonic diagnostic device according to a third modified example of the first embodiment. [Figure 15] Figure 15 is a flowchart showing the detection process for an airborne state based on a second detection criterion in an example of operation of an ultrasonic diagnostic apparatus according to the second embodiment. [Figure 16] Figure 16 shows an example of operation of an ultrasonic diagnostic device according to the second embodiment, illustrating the detection process for an airborne state based on the second detection criterion. [Figure 17] Figure 17 is a flowchart showing the detection process for an airborne state based on the first detection criterion in an example of operation of an ultrasonic diagnostic device according to a modified version of the second embodiment. [Figure 18] Figure 18 shows an example of operation of an ultrasonic diagnostic device according to a modified version of the second embodiment, illustrating the detection process of an airborne state based on the first detection criterion. [Figure 19] FIG. 19 is a diagram showing a detection step of a state of being left in the air based on a first detection criterion following FIG. 18 in an operation example of an ultrasonic diagnostic apparatus according to a modified example of the second embodiment. [Figure 20] FIG. 20 is a block diagram showing a configuration example of an ultrasonic diagnostic apparatus according to the third embodiment. [Figure 21] FIG. 21 is a flowchart showing a determination step of being left in the air in an operation example of an ultrasonic diagnostic apparatus according to the third embodiment. [Figure 22] FIG. 22 is a flowchart showing a detection step of a state of being left in the air based on a first detection criterion, a second detection criterion, and a third detection criterion in an operation example of an ultrasonic diagnostic apparatus according to the third embodiment. [Figure 23] FIG. 23 is a flowchart showing a calculation step of the degree of being left in the air in an operation example of an ultrasonic diagnostic apparatus according to the third embodiment. [Figure 24] FIG. 24 is a flowchart showing a detection step of a state of being left in the air based on a second detection criterion in an operation example of an ultrasonic diagnostic apparatus according to the fourth embodiment. [Figure 25] FIG. 25 is a diagram showing a detection step of a state of being left in the air based on a second detection criterion in an operation example of an ultrasonic diagnostic apparatus according to the fourth embodiment. [Figure 26] FIG. 26 is a flowchart showing an operation example of an ultrasonic diagnostic apparatus according to the fifth embodiment. [Figure 27] FIG. 27 is a diagram showing an operation example of an ultrasonic diagnostic apparatus according to the fifth embodiment. [Figure 28] FIG. 28 is a flowchart showing an operation example of an ultrasonic diagnostic apparatus according to a modified example of the fifth embodiment. [Figure 29] FIG. 29 is a diagram showing an operation example of an ultrasonic diagnostic apparatus according to a modified example of the fifth embodiment. 【Embodiments for Carrying Out the Invention】 【0008】 The embodiments of the ultrasound diagnostic apparatus will be described below with reference to the drawings. In the following description, components having substantially the same function and configuration will be denoted by the same reference numeral, and redundant explanations will be given only when necessary. 【0009】 (First embodiment) Figure 1 is a block diagram showing an example of the configuration of an ultrasound diagnostic apparatus 1 according to the first embodiment. As shown in Figure 1, the ultrasound diagnostic apparatus 1 according to the first embodiment comprises an ultrasound probe 2, an input interface 3, an output interface 4, and a device body 5. The ultrasound probe 2, the input interface 3, and the output interface 4 are connected to the device body 5 in a communicative manner. 【0010】 The ultrasound probe 2 is a device that transmits ultrasound waves to subject P and receives reflected ultrasound waves (echoes) from subject P in order to acquire an ultrasound image of the subject P. 【0011】 The ultrasonic probe 2 has multiple transducers. The multiple transducers generate ultrasound based on a drive signal, such as a drive voltage, supplied from the main body of the device 5. The ultrasonic probe 2 also receives reflected waves from the subject P and converts them into electrical signals. That is, the ultrasonic probe 2 scans the subject P with ultrasound and receives reflected waves from the subject P. The transducers are provided with electrodes for supplying drive signals and inputting electrical signals of reflected waves. The transducers may be made of, for example, PZT (lead zirconate titanate) and PVDF (polyvinylidene fluoride). On the surface of the transducer, for example, an acoustic matching layer and an acoustic lens are arranged. On the back of the transducer, for example, a backing material is arranged. The acoustic matching layer, also called the λ / 4 layer, is a layer for efficiently transmitting and receiving ultrasound by reducing the impedance difference between the transducer and the living body. The acoustic lens is a structure that reduces friction with the living body surface during examination and focuses the ultrasound beam to improve slice resolution. The backing material is a structure that absorbs ultrasound from the rear and shortens the pulse width of ultrasound from the front. The ultrasonic probe 2 is detachably connected to the main body of the device 5. 【0012】 When ultrasound is transmitted from the ultrasound probe 2 to the subject P, the transmitted ultrasound is reflected one after another by discontinuities in acoustic impedance within the subject P's internal tissues, and the reflected wave signals are received by multiple transducers on the ultrasound probe 2. The amplitude of the received reflected wave signals depends on the difference in acoustic impedance at the discontinuities where the ultrasound is reflected. Furthermore, when the transmitted ultrasound pulse is reflected by a moving surface such as blood flow or the heart wall, the reflected wave signal undergoes a frequency shift due to the Doppler effect, depending on the velocity component of the moving object relative to the ultrasound transmission direction. 【0013】 The ultrasound probe 2 is, for example, a 1D array probe that scans the subject P in two dimensions. The ultrasound probe 2 may also be a 3D probe that scans the subject P in three dimensions, i.e., a mechanical 4D probe or a 2D array probe. 【0014】 The ultrasonic probe 2 is, for example, a linear probe in which the bio-contact surface on the probe head (not shown) that contacts the subject P is formed flat along the alignment direction of the transducer. The probe head is, for example, the acoustic lens described above. However, the ultrasonic probe 2 is not limited to a linear probe, and may be, for example, a convex probe in which the bio-contact surface is formed in a convex curved shape, or a sector probe in which the bio-contact surface is formed in a flat shape smaller than that of a linear probe. 【0015】 The input interface 3 shown in Figure 1 receives various instructions and information input operations from the operator. Specifically, the input interface 3 converts the input operations received from the operator into electrical signals and outputs them to the main unit 5 of the device. For example, the input interface 3 can be implemented by a trackball, switch buttons, mouse, keyboard, touchpad that performs input operations by touching the operating surface, touchscreen that integrates a display screen and a touchpad, a non-contact input circuit using an optical sensor, and an audio input circuit. Note that the input interface 3 is not limited to those equipped with physical operating components such as a mouse or keyboard. For example, an electrical signal processing circuit that receives electrical signals corresponding to input operations from an external input device located separately from the device and outputs these electrical signals to a control circuit is also included as an example of the input interface 3. 【0016】 The output interface 4 outputs various types of information. For example, the output interface 4 includes a display. The display converts the information and image data sent from the main unit 5 into electrical signals for display and outputs them. The display can be implemented as an LCD monitor, a CRT (Cathode Ray Tube) monitor, or a touch panel. The output interface 4 may also include a speaker. The speaker outputs predetermined sounds, such as beeps, to notify the operator of the processing status of the main unit 5. 【0017】 The main body of the device 5 includes a transmitting / receiving circuit 51, a memory 52, and a processing circuit 53. 【0018】 The transmitting / receiving circuit 51 is a circuit that supplies a drive signal to the ultrasonic probe 2 under the control of the processing circuit 53. The transmitting / receiving circuit 51 is also a circuit that performs various processing on the reflected wave signal received by the ultrasonic probe 2 to generate reflected wave data. 【0019】 The transmitting and receiving circuit 51 includes, for example, a pulse generator, a transmission delay unit, and a pulser, in order to supply a drive signal to the ultrasonic probe 2. The pulse generator repeatedly generates rate pulses at a predetermined rate frequency to form the transmitted ultrasonic waves. The transmission delay unit provides a delay time for each transducer necessary to focus the ultrasonic waves generated from the ultrasonic probe 2 into a beam and determine the transmission directivity, to each rate pulse generated by the pulse generator. The pulser applies a drive signal (drive pulse) to the ultrasonic probe 2 at a timing based on the rate pulse to which the delay time has been set. In other words, the transmission delay unit arbitrarily adjusts the transmission direction of the ultrasonic waves transmitted from the transducer surface by changing the delay time provided to each rate pulse. 【0020】 Furthermore, the transmitting and receiving circuit 51 generates reflected wave data by performing various processes on the reflected wave signal received by the ultrasonic probe 2, and therefore includes, for example, a preamplifier, an A / D (Analog / Digital) converter, a receiving delay unit, and an adder. The preamplifier amplifies the reflected wave signal for each channel. The A / D converter performs A / D conversion on the amplified reflected wave signal. The receiving delay unit provides the necessary delay time to determine the receiving directivity. The adder generates reflected wave data by summing the reflected wave signals processed by the receiving delay unit. The summing process of the adder emphasizes the reflected component from the direction corresponding to the receiving directivity of the reflected wave signal, and the overall beam for ultrasonic transmission and reception is formed by the receiving directivity and the transmitting directivity. Various forms can be selected for the output signal from the transmitting and receiving circuit 51, such as a signal containing phase information called an RF (Radio Frequency) signal, and amplitude information after envelope detection processing. 【0021】 In the example shown in Figure 1, the transmitting and receiving circuit 51 is located in the main body 5 of the device. However, it is not limited to being located in the main body 5; at least a portion of the transmitting and receiving circuit 51 may be located in the ultrasonic probe 2. 【0022】 Memory 52 is a non-transient storage device that stores various types of information, such as an HDD (Hard Disk Drive), optical disc, SSD (Solid State Drive), and integrated circuit storage device. Memory 52 stores, for example, a control program that controls the ultrasound diagnostic device 1 and various types of data used to execute this control program. In addition to HDDs and SSDs, Memory 52 may also be a drive device that reads and writes various types of information to portable storage media such as CDs (Compact Discs), DVDs (Digital Versatile Discs), and flash memory, or semiconductor memory elements such as RAM (Random Access Memory). 【0023】 The processing circuit 53 is a circuit that controls the operation of the entire ultrasound diagnostic apparatus 1 in response to electrical signals of input operations input from the input interface 3. For example, the processing circuit 53 includes an image generation function 531, a first detection function 532, a second detection function 533, a setting function 534, a determination function 535, and a control function 536. The first detection function 532 is an example of a first detection unit. The second detection function 533 is an example of a second detection unit. The setting function 534 is an example of a setting unit. The determination function 535 is an example of a determination unit. The control function 536 is an example of a control unit. 【0024】 Here, for example, the image generation function 531, the first detection function 532, the second detection function 533, the setting function 534, the decision function 535, and the control function 536, which are components of the processing circuit 53 shown in Figure 1, are each executed by the image generation function 531, the first detection function 532, the second detection function 533, the setting function 534, the decision function 535, and the control function 536, respectively, and are recorded in memory 52 in the form of a program that can be executed by a computer. The processing circuit 53 is, for example, a processor. The processor that constitutes the processing circuit 53 reads each program from memory 52 and executes it, thereby realizing the function corresponding to each program that has been read. In other words, the processing circuit 53 in the state in which each program has been read will have each of the functions shown in the processing circuit 53 of Figure 1. 【0025】 In Figure 1, the image generation function 531, the first detection function 532, the second detection function 533, the setting function 534, the decision function 535, and the control function 536 are shown to be implemented by a single processing circuit 53. However, the embodiments are not limited to this. For example, the processing circuit 53 may be composed of a combination of multiple independent processors, with each processor executing its own program to implement each processing function. Furthermore, each processing function of the processing circuit 53 may be implemented by appropriately distributing or integrating them across one or more processing circuits. 【0026】 The image generation function 531 generates an ultrasound image in response to a scan of the subject P using the ultrasound probe 2. More specifically, the image generation function 531 receives reflected wave data from the transmitting / receiving circuit 51, performs logarithmic amplification, envelope detection, etc., and generates data (B-mode data) in which signal intensity is expressed as brightness. The image generation function 531 also performs frequency analysis on velocity information from the reflected wave data received from the transmitting / receiving circuit 51, extracts blood flow, tissue, and contrast agent echo components due to the Doppler effect, and generates data (Doppler data) in which moving object information such as velocity, dispersion, and power is extracted for multiple points. Furthermore, the image generation function 531 may be capable of processing both 2D and 3D reflected wave data. That is, the image generation function 531 may generate 2D B-mode data from 2D reflected wave data and 3D B-mode data from 3D reflected wave data. Furthermore, the image generation function 531 may generate two-dimensional Doppler data from two-dimensional reflected wave data, and generate three-dimensional Doppler data from three-dimensional reflected wave data. 【0027】 The image generation function 531 generates a B-mode image from the B-mode data, representing the intensity of the reflected wave as brightness. For example, the image generation function 531 also generates a Doppler image from Doppler data, visualizing blood flow information. A Doppler image can be a velocity image data representing the average blood flow velocity, a dispersion image data representing the dispersion of blood flow, a power image data representing the power of blood flow, or a combination of these. The image generation function 531 can also generate color Doppler images, displaying blood flow information such as average velocity, dispersion, and power in color, or Doppler images, displaying a single blood flow information in grayscale. Furthermore, the image generation function 531 can generate an M-mode image from time-series data of B-mode data on a single scan line. Additionally, the image generation function 531 can generate Doppler waveforms from Doppler data, plotting blood flow and tissue velocity information over time. 【0028】 The first detection function 532 detects the state of the ultrasonic probe 2 being left in the air based on a first detection criterion. In the first embodiment, in detecting the state of being left in the air based on the first detection criterion, the first detection function 532 acquires a difference signal indicating the difference between two received signals received by the ultrasonic probe 2 at different times or at different raster positions for each of several different depths. The first detection function 532 then detects the state of being left in the air based on the number of difference signals among the difference signals acquired for each different depth whose magnitude exceeds a threshold. In the first embodiment, the operation of detecting the state of being left in the air based on the first detection criterion corresponds to the operation of detecting a multiple reflection image formed by multiple reflections that occur when ultrasonic waves are reflected multiple times between the transducer and the interface between the acoustic lens and the air. Therefore, in the first embodiment, the detection of the state of being left in the air based on the first detection criterion can also be called multiple reflection detection. 【0029】 The second detection function 533 detects the airborne state based on the second detection criterion. In the first embodiment, the second detection function 533 acquires the brightness of the received signal received by the ultrasonic probe 2 at multiple different depths. The second detection function 533 then detects the airborne state based on the number of received signals where the acquired brightness exceeds a threshold. In the first embodiment, the operation of detecting the airborne state based on the second detection criterion corresponds to the operation of detecting a white noise image. Therefore, in the first embodiment, the detection of the airborne state based on the second detection criterion can also be called white noise detection. 【0030】 The setting function 534 sets the scan conditions for the ultrasound scan performed by the ultrasound probe 2. For example, the setting function 534 sets at least one of the display depth and the scan depth as the first scan condition. The setting function 534 may further set the ultrasound scan frequency as the first scan condition. The setting function 534 sets the first scan conditions according to an input operation received by the input interface 3, for example. The setting function 534 may store the set scan conditions in the memory 52. 【0031】 The determination function 535 determines the degree of airborne abandonment, which indicates the likelihood of an airborne abandonment state, based on the detection results of the first detection function 532, the detection results of the second detection function 533, and the first scan conditions set by the setting function 534. For example, the determination function 535 determines the degree of airborne abandonment by weighting and adding the detection results of the airborne abandonment state based on the first detection criterion and the detection results of the airborne abandonment state based on the second detection criterion. The determination function 535 may also use at least one of the display depth and scan depth as the first scan condition for weighting. In this case, the determination function 535 may weight the detection result of the airborne abandonment state based on the second detection criterion more heavily the larger at least one of the display depth and scan depth is. Alternatively, the determination function 535 may weight the detection result of the airborne abandonment state based on the first detection criterion more heavily the smaller at least one of the display depth and scan depth is. 【0032】 The control function 536 controls a second ultrasonic scan condition that differs from the first scan condition, according to the degree of air exposure determined by the determination function 535. For example, the control function 536 controls at least one of the scan condition related to heat generation and the scan angle as the second scan condition. The control function 536 may also control the acoustic output of the ultrasonic probe 2 as the scan condition related to heat generation. The control function 536 may control the acoustic output by controlling at least one of the voltage applied to the ultrasonic probe 2 and the pulse repetition frequency of the ultrasound (i.e., pulse wave). The control function 536 may also control the scan condition related to heat generation by controlling the scan parameters related to heat generation. In this case, the control function 536 may control the scan parameters so that they have parameter values ​​between a target parameter value during air exposure and a parameter value during normal scanning, according to the degree of air exposure determined by the determination function 535. 【0033】 Next, an example of the operation of the ultrasound diagnostic apparatus 1 according to the first embodiment configured as described above will be explained. 【0034】 First, as shown in Figure 2, the setting function 534 sets the scan conditions (i.e., the first scan conditions) according to the scan condition setting operation received by the input interface 3 (step S1). 【0035】 After setting the scan conditions, the determination function 535 determines whether or not the ultrasonic probe 2 is left in the air (step S2). 【0036】 Figure 3 is a flowchart showing the process for determining whether the ultrasonic probe 2 is being left in the air in an example of operation of the ultrasonic diagnostic device 1 according to the first embodiment. As shown in Figure 3, in determining whether the ultrasonic probe 2 is being left in the air (step S2), first, the first detection function 532 detects the state of the ultrasonic probe 2 being left in the air based on the first detection criterion (step S21). Then, the second detection function 533 detects the state of being left in the air based on the second detection criterion (step S22). 【0037】 Figure 7 shows an ultrasound image taken when the ultrasound diagnostic device 1 is left in the air with a shallow scan depth, in an example of operation according to the first embodiment. Figure 8 shows an ultrasound image taken when the ultrasound diagnostic device 1 is left in the air with a deep scan depth, in an example of operation according to the first embodiment. In Figures 7 and 8, arrow d indicates the direction in which the depth increases from the biological contact surface of the ultrasound probe 2 toward the interior of the subject P. 【0038】 As shown in Figures 7 and 8, when the ultrasound probe 2 is left in the air, the image generation function 531 generates a characteristic ultrasound image that includes a multiple reflection image I1 located in a shallow multiple reflection region A1 and a white noise image I2 located in a deep white noise region A2. However, as shown in Figure 7, when the scan depth is shallow, the multiple reflection image I1 occupies most of the ultrasound image. On the other hand, as shown in Figure 8, when the scan depth is deep, the white noise image I2 occupies most of the ultrasound image. 【0039】 In the first embodiment, the detection of an airborne state based on the first detection criterion corresponds to the operation of detecting the multiple reflection image I1. Also in the first embodiment, the detection of an airborne state based on the second detection criterion corresponds to the operation of detecting the white noise image I2. As shown in Figure 7, when the scan depth is shallow, the white noise image I2 is hardly detected. Therefore, if the presence or absence of an airborne state is determined based only on the detection result of the white noise image I2 when the scan depth set by the setting function 534 is shallow, the determination accuracy will decrease. On the other hand, as shown in Figure 8, when the scan depth is deep, the multiple reflection image I1 is hardly detected. Also, when the scan depth is deep, the image of the area near the surface of the living body during a biological scan is similar to the multiple reflection image I1. Therefore, when the scan depth is deep, it is difficult to distinguish the multiple reflection image I1 from the image of the area near the surface of the living body. Therefore, if the presence or absence of an airborne state is determined based only on the detection result of the multiple reflection image I1 when the scan depth set by the setting function 534 is deep, the determination accuracy will also decrease. Therefore, in order to improve the accuracy of the determination, the determination function 535 performs an aerial abandonment determination that takes into account both the detection result based on the first detection criterion and the detection result based on the second detection criterion, according to the scan conditions set by the setting function 534, as described below. 【0040】 Figure 4 is a flowchart showing the process of detecting the airborne state based on the first detection criterion in an example of operation of the ultrasound diagnostic apparatus 1 according to the first embodiment. As shown in Figure 4, in detecting the airborne state based on the first detection criterion (step S21), first, the first detection function 532 calculates the difference signal for each of the multiple samples assigned to multiple different depths (step S211). 【0041】 Figure 9 shows the detection process for an airborne state based on a first detection criterion in an example of operation of the ultrasound diagnostic apparatus 1 according to the first embodiment. The horizontal axis in Figure 9 represents the depth of the ultrasound scan and the sample number. The sample number is assigned at regular intervals of depth. The vertical axis in Figure 9 represents the amplitude of the received signal. In the example shown in Figure 9, the first detection function 532 acquires two received signals SIG1 and SIG2 for each sample (i.e., each depth) received by the ultrasound probe 2 at different times or different raster positions. The two received signals SIG1 and SIG2 for each sample are, for example, received signals from different frames at the same depth, or received signals from different scan direction positions (i.e., beam direction positions) in the same frame at the same depth. Figure 10 shows the detection process for an airborne state based on a first detection criterion, following Figure 9. The horizontal axis in Figure 10 represents the depth of the ultrasound scan and the sample number. The vertical axis in Figure 10 represents the amplitude difference. In the example shown in Figure 10, the first detection function 532 calculates the difference signal for each sample shown in Figure 10 by calculating the difference between the signal values ​​of two received signals, SIG1 and SIG2, for each sample. 【0042】 After calculating the difference signal for each sample, the first detection function 532 obtains the number of samples N1 of the difference signal whose magnitude (i.e., amplitude difference) exceeds a threshold, as shown in Figure 4 (step S212). In the example shown in Figure 10, the threshold for the magnitude of the difference signal is indicated by TH. 【0043】 After obtaining the number of samples N1 of the difference signal whose magnitude exceeds the threshold, the first detection function 532 calculates a first coefficient that indicates the detection result of the airborne state based on the first detection criterion, as shown in Figure 4 (step S213). Specifically, the first detection function 532 calculates the first coefficient according to the following formula. First coefficient = 1 - N1 / total number of samples (1) 【0044】 For example, if the total number of samples is 300,000 and the number of samples N1 of difference signals above the threshold is 12,000, the first detection function 532 calculates 0.96 as the first coefficient. When left in the air, the number of samples N1 of difference signals above the threshold is significantly less than the number of samples below the threshold. Therefore, when left in the air, the number of samples N1 of difference signals above the threshold can be quickly obtained, and the first coefficient can be quickly calculated. Note that in formula (1), N1 / total number of samples is calculated for all samples. In contrast, N1 may be the number of samples of difference signals above the threshold from a limited range (i.e., within the depth range) rather than the total number of samples. In this case, the first coefficient can be obtained by subtracting the value obtained by dividing N1 by the number of samples within the limited range from 1. 【0045】 Figure 5 is a flowchart showing the process of detecting the airborne state based on the second detection criterion in an example of operation of the ultrasound diagnostic apparatus 1 according to the first embodiment. As shown in Figure 5, in the detection of the airborne state based on the second detection criterion (step S22), first, the second detection function 533 acquires the brightness for each of the multiple samples assigned to multiple different depths (step S221). 【0046】 Figure 11 shows the detection process for the airborne state based on the second detection criterion in an example of operation of the ultrasound diagnostic apparatus 1 according to the first embodiment. The horizontal axis in Figure 11 represents the brightness for each sample. The vertical axis in Figure 11 represents the number of samples. In the example shown in Figure 11, the second detection function 533 acquires the brightness for each sample by generating a brightness histogram showing the distribution of brightness for each sample. 【0047】 After obtaining the luminance for each sample, the second detection function 533 obtains the number of samples N2 with luminance exceeding the threshold, as shown in Figure 5 (step S222). In the example shown in Figure 11, the luminance threshold is indicated by TH. 【0048】 After obtaining the number of samples N2 with brightness exceeding the threshold, the second detection function 533 calculates a second coefficient that indicates the detection result of the airborne state based on the second detection criterion, as shown in Figure 5 (step S223). Specifically, the second detection function 533 calculates the second coefficient according to the following formula. Second coefficient = 1 - N2 / total number of samples (2) 【0049】 For example, if the total number of samples is 300,000 and the number of samples N2 with brightness above the threshold is 15,000, the second detection function 533 calculates 0.95 as the second coefficient. When left in the air, the number of samples N2 with brightness above the threshold is significantly less than the number of samples with brightness below the threshold. Therefore, when left in the air, the number of samples N2 with brightness above the threshold can be quickly obtained, and the second coefficient can be quickly calculated. Note that in formula (2), N2 / total number of samples is calculated for all samples. In contrast, N2 may be the number of samples with brightness above the threshold from a limited range (i.e., within the depth range) rather than the total number of samples. In this case, the second coefficient can be obtained by subtracting the value obtained by dividing N2 by the number of samples within the limited range from 1. 【0050】 After the airborne state is detected, as shown in Figure 3, the determination function 535 calculates the degree of airborne abandonment based on the detection result of the first detection function 532, the detection result of the second detection function 533, and the scan conditions set by the setting function 534 (step S23). 【0051】 Figure 6 is a flowchart showing the calculation process for the airborne depth in an example of the operation of the ultrasound diagnostic apparatus 1 according to the first embodiment. As shown in Figure 6, in the calculation of the airborne depth (step S23), first, the determination function 535 obtains the depth of the multiple reflection region, which is the upper limit of the depth suitable for detection based on the first detection criterion, according to the set scan frequency (step S231). The depth of the multiple reflection region may be automatically set by the setting function 534 according to the scan conditions set by the setting function 534. The scan frequency may be set by the setting function 534 according to the input operation received by the input interface 3. Alternatively, the scan frequency may be automatically set by the setting function 534 according to the scan depth set by the setting function 534. 【0052】 After obtaining the depth of the multiple reflection region, the determination function 535 calculates the weights of the first coefficient and the weights of the second coefficient based on the ratio of the depth of the multiple reflection region to the set scan depth (step S232). 【0053】 Specifically, the decision function 535 calculates the weights of the first coefficient and the second coefficient according to the following formula. Weight of the first coefficient = Depth of the multiple reflection region / Scan depth (3) Weight of the second coefficient = 1 - Weight of the first coefficient (4) 【0054】 For example, if the depth of the multiple reflection region is 1.5 cm and the scan depth is 4 cm, the weight of the first coefficient is 0.38. The weight of the second coefficient is 0.62. 【0055】 According to the method for calculating the weights of the first and second coefficients based on equations (3) and (4), the weight of the second coefficient can be increased as the scan depth increases. As shown in Figure 8, the white noise region A2 becomes larger as the scan depth increases. Therefore, increasing the weight of the second coefficient, which indicates the detection result of the white noise image I2, as the scan depth increases leads to an improvement in the detection accuracy of the airborne state. 【0056】 Furthermore, according to the calculation method for the weights of the first and second coefficients based on equations (3) and (4), the weight of the first coefficient can be increased as the scan depth decreases. As shown in Figure 7, the multiple reflection region A1 becomes larger as the scan depth decreases. Therefore, increasing the weight of the first coefficient, which indicates the detection result of the multiple reflection image I1, as the scan depth decreases leads to an improvement in the detection accuracy of the airborne state. 【0057】 After calculating the weights of the first coefficient and the second coefficient, the determination function 535 calculates the degree of airborne neglect by weighting and adding the first coefficient and the second coefficient using the calculated weights, as shown in Figure 6 (step S233). 【0058】 Specifically, the decision function 535 calculates the degree of airborne neglect according to the following formula. Degree of being left in the air = Weight of the first coefficient × First coefficient + Weight of the second coefficient × Second coefficient (5) 【0059】 For example, if the first coefficient is 0.96, the second coefficient is 0.95, the weight of the first coefficient is 0.38, and the weight of the second coefficient is 0.62, then the degree of airborne neglect is 0.95. 【0060】 After calculating the degree of airborne neglect, the determination function 535 determines whether the calculated degree of airborne neglect exceeds a threshold, as shown in Figure 3 (step S24). The threshold for the degree of airborne neglect may be 0.0. 【0061】 If the degree of airborne exposure exceeds a threshold (Step S24: YES), the control function 536 calculates the degree of acoustic output suppression (Step S25). When calculating the degree of acoustic output suppression, the determination function 535 determines that the ultrasonic probe 2 is airborne (Step S2: YES). 【0062】 The control function 536 calculates the degree of acoustic output suppression O3 (%) based on the acoustic output O1 (%) during a normal biological scan, the target acoustic output O2 (%) when the degree of airborne exposure is 1.00 (i.e., when the probability of airborne exposure is 100%), and the degree of airborne exposure. The degree of acoustic output suppression O3 is a parameter that expresses the suppressed acoustic output as a percentage. Specifically, the control function 536 calculates the degree of acoustic output suppression O3 according to the following formula. O3=(O1-O2)×Airborne degree (6) 【0063】 For example, if the acoustic output O1 during a normal bioscan is 100% and the air exposure level is 1.00, and the target acoustic output O2 is 50% and the air exposure level is 0.95, then the degree of acoustic output suppression O3 is 48%. 【0064】 On the other hand, if the degree of airborne exposure does not exceed the threshold (step S24: NO), the determination function 535 determines that the ultrasonic probe 2 is not airborne (step S2: NO). 【0065】 If the ultrasound probe 2 is not left in the air (step S2: NO), the control function 536 maintains or restores the acoustic output to the acoustic output during a normal bioscan, as shown in Figure 2 (step S3). On the other hand, if the ultrasound probe 2 is left in the air (step S2: YES), the control function 536 suppresses the acoustic output according to the calculated acoustic output suppression degree O3 (step S4). 【0066】 If the inspection is performed under the control of the acoustic output in step S3 or step S4 and the inspection is terminated (step S5: YES), the processing circuit 53 terminates the process. On the other hand, if the inspection is not terminated (step S5: NO), the processing circuit 53 determines whether the scan conditions have been changed according to the input operation received at the input interface 3 (step S6). 【0067】 If the scan conditions are changed (step S6: YES), the setting function 534 sets the changed scan conditions (step S1). On the other hand, if the scan conditions are not changed (step S6: NO), the determination function 535 repeatedly determines whether or not the device is left in the air (step S2). 【0068】 As described above, in the first embodiment, the first detection function 532 and the second detection function 533 each detect the airborne state based on different detection criteria. The setting function 534 sets the scan conditions for the ultrasonic scan by the ultrasonic probe 2. The determination function 535 determines the degree of airborne state, which indicates the likelihood of the airborne state, based on the detection result of the first detection function 532, the detection result of the second detection function 533, and the scan conditions set by the setting function 534. 【0069】 This allows the operation of the ultrasound probe 2 to be controlled using the degree of exposure to air determined based on the detection results based on the first detection criterion, the detection results based on the second detection criterion, and the scan conditions. As a result, it is possible to suppress the deterioration of the ultrasound probe 2 and improve the inspection efficiency at the same time. 【0070】 In the first embodiment, the setting function 534 sets at least one of the display depth and the scan depth as the first scan condition. 【0071】 This allows the determination function 535 to appropriately determine the degree of airborne exposure based on at least one of the display depth and the scan depth, thereby more effectively achieving both suppression of ultrasound probe 2 degradation and improvement of inspection efficiency. 【0072】 Furthermore, in the first embodiment, the control function 536 controls a second ultrasonic scan condition that is different from the first scan condition, according to the degree of airborne exposure determined by the determination function 535. 【0073】 This allows the control function 536 to control the second scanning conditions according to the degree of exposure to air, thereby more effectively achieving both suppression of ultrasound probe 2 degradation and improvement of inspection efficiency. 【0074】 In the first embodiment, the control function 536 controls at least one of the scan conditions related to heat generation and the scan angle as a second scan condition. 【0075】 As a result, the control function 536 can control at least one of the scanning conditions and scanning angle related to heat generation according to the degree of exposure to air, thereby more effectively achieving both suppression of deterioration of the ultrasound probe 2 and improvement of inspection efficiency. 【0076】 In the first embodiment, the control function 536 controls the acoustic output of the ultrasonic probe 2 as a scan condition related to heat generation. 【0077】 This allows the control function 536 to control the acoustic output according to the degree of exposure to air, thereby more effectively suppressing the deterioration of the ultrasound probe 2 and improving inspection efficiency. 【0078】 In the first embodiment, the control function 536 controls the acoustic output by controlling at least one of the voltage applied to the ultrasonic probe 2 and the ultrasonic pulse repetition frequency according to the degree of exposure to air. 【0079】 As a result, the control function 536 can appropriately control the acoustic output by controlling at least one of the applied voltage and pulse repetition frequency according to the degree of exposure to air. 【0080】 Furthermore, in the first embodiment, the first detection function 532, in detecting the airborne state based on the first detection criterion, acquires a difference signal indicating the difference between two received signals received by the ultrasonic probe 2 at different times or positions for each of several different depths. The first detection function 532 also detects the airborne state based on the number of difference signals among the difference signals acquired for each different depth whose magnitude exceeds a threshold. 【0081】 As a result, the first detection function 532 can detect the state of being left in the air by detecting multiple reflection images, thus enabling proper detection of the state of being left in the air. 【0082】 Furthermore, in the first embodiment, the second detection function 533 acquires the brightness of the received signal received by the ultrasonic probe 2 at multiple different depths when detecting the airborne state based on the second detection criterion. The second detection function 533 also detects the airborne state based on the number of received signals when the acquired brightness exceeds a threshold. 【0083】 This allows the second detection function 533 to detect the state of being left in the air by detecting a white noise image, thereby enabling proper detection of the state of being left in the air. 【0084】 Furthermore, in the first embodiment, the determination function 535 performs weighting using at least one of the display depth and scan depth as a scan condition. The determination function 535 increases the weight of the detection result of the airborne state based on the second detection criterion as the display depth and scan depth are larger. 【0085】 This allows for a more accurate determination of the degree of airborne presence, as the weight given to detecting white noise images increases with a greater display depth and scan depth. 【0086】 Furthermore, in the first embodiment, the determination function 535 increases the weight of the detection result of the airborne state based on the first detection criterion as the display depth and scan depth are smaller. 【0087】 This allows for a more accurate determination of the degree of airborne presence, as the smaller at least one of the display depth and scan depth, the greater the weight given to detecting multiple reflection images. 【0088】 Furthermore, in the first embodiment, the control function 536 controls the scanning conditions related to heat generation by controlling the scan parameters related to heat generation. The control function 536 controls the scan parameters so that they have parameter values ​​between the target parameter values ​​when left in the air and the parameter values ​​when scanning normally, according to the degree of air-standing determined by the determination function 535. 【0089】 This allows for appropriate control of scan parameters according to the degree of exposure to air, thereby more effectively suppressing the deterioration of the ultrasound probe 2 and improving inspection efficiency. 【0090】 (First variation) Next, we will describe a first modification of the first embodiment in which the weights of the first and second coefficients are calculated in a different way, focusing on the differences from the embodiment described above. Figure 12 is a flowchart showing the calculation process of the air exposure rate in an example of operation of the ultrasonic diagnostic device 1 according to the first modification of the first embodiment. 【0091】 Figure 6 illustrates an example of calculating the weights of the first and second coefficients based on the ratio of the depth of the multiple reflection region to the scan depth. In contrast, in the example shown in Figure 12, the determination function 535 calculates the weights of the first and second coefficients based on the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs (step S232A). 【0092】 If the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 0% to 24%, the determination function 535 may calculate 0 as the weight of the first coefficient and 1.0 as the weight of the second coefficient. If the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 25% to 75%, the determination function 535 may calculate 0.5 as the weight of the first coefficient and 0.5 as the weight of the second coefficient. If the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 76% to 100%, the determination function 535 may calculate 1.0 as the weight of the first coefficient and 0 as the weight of the second coefficient. 【0093】 As shown in the example in Figure 12, the weights can be changed in stages, which reduces the load on the processing circuit 53 to calculate the weights. 【0094】 (Second variation) Next, we will describe a second modification of the first embodiment, which changes the detection criteria used to detect the airborne state according to the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs, focusing on the differences from the embodiment described above. Figure 13 is a flowchart showing the airborne state determination process in an example of operation of the ultrasonic diagnostic device 1 according to the second modification of the first embodiment. 【0095】 In the example shown in Figure 13, first, the determination function 535 obtains the depth of the multiple reflection region, which is the upper limit of the depth suitable for detection based on the first detection criterion, according to the set scan frequency (step S200). 【0096】 After obtaining the depth of the multiple reflection region, the determination function 535 selects a detection criterion for the airborne state based on the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs (step S201). 【0097】 If the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 0% to 24%, the determination function 535 may select the second detection criterion. If the second detection criterion is selected, the determination function 535 calculates the second coefficient as the degree of airborne presence. Furthermore, if the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 25% to 75%, the determination function 535 may select both the first and second detection criteria. Furthermore, if the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 76% to 100%, the determination function 535 may select the first detection criterion. If the first detection criterion is selected, the determination function 535 calculates the first coefficient as the degree of airborne presence. 【0098】 As shown in the example in Figure 13, the state of being left in the air can be more appropriately detected using a suitable detection criterion corresponding to the depth of the multiple reflection region. 【0099】 (Third variation) Next, we will describe a third modification of the first embodiment, in which a coefficient used to calculate the degree of airborne exposure is selected according to the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs, focusing on the differences from the embodiment described above. Figure 14 is a flowchart showing the airborne exposure determination process in an example of operation of the ultrasound diagnostic device 1 according to the third modification of the first embodiment. 【0100】 In the example shown in Figure 14, the determination function 535 obtains the depth of the multiple reflection region according to the set frequency after the first and second coefficients have been calculated (steps S21 and S22) (step S200). 【0101】 After obtaining the depth of the multiple reflection region, the determination function 535 selects a coefficient for the airborne state to be used in calculating the airborne state based on the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs (step S203). 【0102】 If the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 0% to 24%, the determination function 535 may select the second coefficient. If the second coefficient is selected, the determination function 535 calculates the airborne void as is using the second coefficient. Furthermore, if the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 25% to 75%, the determination function 535 may select both the first and second coefficients. Furthermore, if the ratio category to which the ratio of the depth of the multiple reflection region to the scan depth belongs is 76% to 100%, the determination function 535 may select the first coefficient. If the first coefficient is selected, the determination function 535 calculates the airborne void as is using the first coefficient. 【0103】 (Second embodiment) Next, we will describe a second embodiment that uses the PS (Pulse Subtraction) method to detect the airborne state based on the second detection criterion, focusing on the differences from the embodiment described above. 【0104】 Up to this point, we have described an example in which the second detection function 533 detects the airborne state based on the second detection criterion by detecting a white noise image (i.e., detection using a luminance histogram). In contrast, in the second embodiment, the second detection function 533 detects the airborne state based on the second detection criterion by using the PS method. The PS method is also called the phase inversion method or PI (Pulse Inversion) method. The PS method is one of the imaging modes of an ultrasound diagnostic device and is a method of adding the received signals of each pulse when pulses with inverted phases are irradiated. The fundamental frequencies of the received signals of each pulse are in opposite phases to each other, and the harmonic components are in phase to each other, so only the harmonic components are detected in the received signal after addition. 【0105】 In the PS method, there is a characteristic relationship between the received signal before summation and the received signal after summation: if the received signal is from a noise image, the amplitude increases after summation; if the received signal is from a biological image, the amplitude decreases after summation. This relationship is the opposite of the relationship during normal scanning. Using this characteristic relationship, the second detection function 533 detects the state of being left in the air. 【0106】 Specifically, the second detection function 533 generates a composite signal by combining the first received signal received when the first transmission signal was transmitted and the second received signal received when the second transmission signal, which is the first transmission signal with the polarity reversed, was transmitted. The second detection function 533 then detects the airborne state based on a comparison between the amplitude of the composite signal and the amplitude of the first received signal. 【0107】 More specifically, the second detection function 533, in detecting the airborne state based on the second detection criterion, acquires the results of a comparison of the magnitude relationship between the amplitude of the composite signal and the amplitude of the first received signal at multiple different depths. The second detection function 533 then detects the airborne state based on the number of comparison results among the acquired magnitude relationship comparison results in which the amplitude of the composite signal is greater than the amplitude of the first received signal. 【0108】 Next, an example of operation of the ultrasound diagnostic apparatus 1 according to the second embodiment configured as described above will be explained. Figure 15 is a flowchart showing the detection process of the airborne state based on the second detection criterion in the example of operation of the ultrasound diagnostic apparatus 1 according to the second embodiment. 【0109】 First, as shown in Figure 15, the second detection function 533 acquires the result of comparing the magnitude relationship between the amplitude of the first received signal and the amplitude of the combined signal for each sample (step S221A). The second detection function 533 may store the acquired comparison result in the memory 52. 【0110】 Figure 16 shows an example of operation of the ultrasound diagnostic apparatus 1 according to the second embodiment, illustrating the detection process of the airborne state based on the second detection criterion. In Figure 16, the horizontal axis represents the depth of the ultrasound scan and the sample number. In Figure 16, the vertical axis represents brightness, i.e., amplitude. In Figure 16, SIG1 is the first received signal. In Figure 16, SIG1+SIG2 is a composite signal obtained by combining the first received signal SIG1 and the second received signal SIG2. In the example shown in Figure 16, the amplitude of the composite signal SIG1+SIG2 is greater than the amplitude of the first received signal SIG1 in the deep depth region. 【0111】 After obtaining the comparison results, the second detection function 533 obtains the sample number N3 of samples in which the amplitude of the composite signal is greater than the amplitude of the first received signal (step S222A). 【0112】 After obtaining the sample size N3, the second detection function 533 calculates a second coefficient that indicates the detection result based on the second detection criterion, based on the obtained sample size N3 (step S223A). Specifically, the second detection function 533 calculates the second coefficient according to the following formula. Second coefficient = N3 / total number of samples (7) 【0113】 For example, if the total number of samples is 300,000 and the number of samples N3 in which the amplitude of the composite signal is greater than the amplitude of the first received signal is 270,000, then the second coefficient is 0.90. 【0114】 As described above, in the second embodiment, the second detection function 533 generates a composite signal by combining the first received signal received when the first transmission signal was transmitted and the second received signal received when the second transmission signal, which is the first transmission signal with the polarity reversed, was transmitted, in detecting the airborne state based on the second detection criterion. The second detection function 533 also detects the airborne state based on the comparison result between the amplitude of the composite signal and the amplitude of the first received signal. 【0115】 This eliminates the need to set specific thresholds based on conditions, making it easy to detect when a device is left unattended in the air. 【0116】 In the second embodiment, the second detection function 533, in detecting the airborne state based on the second detection criterion, acquires the results of a comparison of the magnitude relationship between the amplitude of the composite signal and the amplitude of the first received signal for each of several different depths. The second detection function 533 also detects the airborne state based on the number of comparison results among the acquired magnitude relationship comparison results in which the amplitude of the composite signal is larger than the amplitude of the first received signal. 【0117】 This allows the second coefficient to be calculated based on the ratio shown in equation (7), thus avoiding detection errors in the airborne state caused by threshold setting. 【0118】 (modified version) Next, a modified version of the second embodiment, which uses the interval and attenuation of multiple reflections to detect the airborne state based on the first detection criterion, will be described, focusing on the differences from the embodiment described above. Up to this point, an example has been described in which the first detection function 532 detects the airborne state based on the difference signal. In contrast, in the modified version of the second embodiment, the first detection function 532 uses the interval and attenuation of multiple reflections to detect the airborne state based on the first detection criterion. 【0119】 Specifically, in detecting the airborne state based on the first detection criterion, the first detection function 532 acquires at least one of the interval of multiple reflections and the attenuation of the ultrasonic waves from the received signal received from a depth within a set range close to the position of the ultrasonic probe 2. The interval of multiple reflections may be acquired as the peak interval of the received signal. Then, the first detection function 532 detects the airborne state based on at least one of the acquired interval of multiple reflections and the attenuation. 【0120】 Figure 17 is a flowchart showing the detection process for an airborne state based on a first detection criterion in an example of operation of the ultrasonic diagnostic device 1 according to a modified version of the second embodiment. In the example shown in Figure 17, first, the first detection function 532 acquires the interval of multiple reflections and the attenuation amount from the received signal of the multiple reflection region A1 as a depth within a set range (step S211A). Figure 18 is a diagram showing the detection process for an airborne state based on a first detection criterion in an example of operation of the ultrasonic diagnostic device 1 according to a modified version of the second embodiment. The horizontal axis in Figure 18 is depth (cm). The vertical axis in Figure 18 is amplitude (dB). In the example shown in Figure 18, the first detection function 532 acquires the peak interval of the received signal in the multiple reflection region A1 as the interval of multiple reflections. Also, in the example shown in Figure 18, the first detection function 532 acquires the decrease in amplitude between peaks of the received signal in the multiple reflection region A1 as the attenuation amount. 【0121】 After acquiring the interval and attenuation of multiple reflections, the first detection function 532 calculates the average value a1 of the interval and the average value b1 of the attenuation, as shown in Figure 17. The first detection function 532 also acquires a reference value a0 of the interval and a reference value b0 of the attenuation (step S212A). The first detection function 532 may also acquire the reference value a0 of the interval and the reference value b0 of the attenuation stored in the memory 52. ​​Figure 19 is a diagram showing the detection process of the airborne state based on the first detection criterion following Figure 18 in an example of operation of the ultrasonic diagnostic device 1 according to a modified example of the second embodiment. In the example shown in Figure 19, the first detection function 532 acquires 0.113 (cm) as the average value a1 of four samples of the interval of multiple reflections. Also in the example shown in Figure 19, the first detection function 532 acquires 6.13 (dB) as the average value b1 of four samples of the attenuation. 【0122】 After calculating the average values ​​a1 and b1 of the interval and attenuation of multiple reflections and obtaining the reference values ​​a0 and b0 of the interval and attenuation of multiple reflections, the first detection function 532 calculates a first coefficient based on the average value a1 of the interval and attenuation of multiple reflections, the average value b1 of the attenuation, the reference value a0 of the interval and attenuation, and the reference value b0 of the attenuation, as shown in Figure 17 (step S213A). Specifically, the first detection function 532 calculates the first coefficient according to the following formula. First coefficient = 1 - ((a1 - a0) / a0 + (b1 - b0) / b0) (8) 【0123】 As shown in Figure 19, when the average value a1 of the multiple reflection interval is 0.113 (cm), the average value b1 of the attenuation is 6.13 (dB), the reference value a0 of the multiple reflection interval is 0.11 (cm), and the reference value b0 of the attenuation is 6 (dB), the first coefficient is 0.95. 【0124】 As shown in the example in Figure 17, the first coefficient can be calculated by analyzing the received signal, thereby improving the degree of freedom in detecting the airborne state. 【0125】 (Third embodiment) Next, we will describe a third embodiment in which the degree of airborne exposure is determined based on the detection results of the airborne exposure state based on the third detection criterion, focusing on the differences from the embodiments described above. Figure 20 is a block diagram showing an example of the configuration of the ultrasound diagnostic apparatus 1 according to the third embodiment. Up to this point, we have described examples in which the degree of airborne exposure is determined based on the detection results of the airborne exposure state based on the first detection criterion and the detection results of the airborne exposure state based on the second detection criterion. In contrast, the ultrasound diagnostic apparatus 1 according to the third embodiment is configured to determine the degree of airborne exposure based on the detection results of the airborne exposure state based on the third detection criterion. 【0126】 Specifically, as shown in Figure 20, the processing circuit 53 of the third embodiment further includes a third detection function 537 in addition to the configuration shown in Figure 1. The third detection function 537 detects the state of the ultrasonic probe 2 being left in the air based on a third detection criterion. The determination function 535 determines the degree of being left in the air based on the detection result of the third detection function 537. 【0127】 Figure 21 is a flowchart showing the process for determining whether the device is left in the air, in an example of operation of the ultrasound diagnostic device 1 according to the third embodiment. Figure 22 is a flowchart showing the process for detecting the state of being left in the air based on the first detection criterion, the second detection criterion, and the third detection criterion, in an example of operation of the ultrasound diagnostic device 1 according to a modified example of the third embodiment. Figure 23 is a flowchart showing the process for calculating the degree of being left in the air, in an example of operation of the ultrasound diagnostic device 1 according to the third embodiment. 【0128】 In the example shown in Figure 21, the third detection function 537 detects the airborne state based on the third detection criterion (step S26). Specifically, in the example shown in Figure 22, the third detection function 537 detects the airborne state based on the third detection criterion using the PS method described in the second embodiment. That is, first, as shown in Figure 22, the third detection function 537 obtains the comparison result of the magnitude relationship between the amplitude of the first received signal and the amplitude of the composite signal for each sample (step S261). After obtaining the comparison result, the third detection function 537 obtains the number of samples N3 in which the amplitude of the composite signal is greater than the amplitude of the first received signal (step S262). After obtaining the number of samples N3, the third detection function 537 calculates a third coefficient that indicates the detection result based on the third detection criterion based on the obtained number of samples N3 (step S263). Specifically, the third detection function 537 calculates the third coefficient according to the following formula. Third coefficient = N3 / total sample size (9) 【0129】 In the example shown in Figure 23, first, the determination function 535 obtains the depth of the multiple reflection region, which is the upper limit of the depth suitable for detection based on the first detection criterion, according to the set scan frequency (step S231). After obtaining the depth of the multiple reflection region, the determination function 535 calculates the weights of the first coefficient, the second coefficient, and the third coefficient based on the ratio of the depth of the multiple reflection region to the set scan depth (step S232B). 【0130】 Specifically, the decision function 535 calculates the weights of the first coefficient, the second coefficient, and the third coefficient according to the following formula. Weight of the first coefficient = Depth of the multiple reflection region / Scan depth (3) Weight of the second coefficient = (1 - Weight of the first coefficient) / 2 (10) Weight of the third coefficient = (1 - Weight of the first coefficient) / 2 (11) 【0131】 For example, if the depth of the multiple reflection region is 1.5 cm and the scan depth is 4 cm, the weight of the first coefficient is 0.38. The weight of the second coefficient is 0.31. The weight of the third coefficient is 0.31. 【0132】 The weights of the second and third coefficients may be changed according to the scan conditions set by the setting function 534. For example, if "PS On" is set as the scan condition, the determination function 535 may calculate 0 as the weight of the second coefficient and 0.62 as the weight of the third coefficient. On the other hand, if "PS Off" is set as the scan condition, the determination function 535 may calculate 0.62 as the weight of the second coefficient and 0 as the weight of the third coefficient. 【0133】 After calculating the weights of the first coefficient, the second coefficient, and the third coefficient, the decision function 535 calculates the degree of airborne neglect by weighting and adding the first, second, and third coefficients using the calculated weights (step S233B). 【0134】 Specifically, the decision function 535 calculates the degree of airborne neglect according to the following formula. Degree of being left in the air = Weight of the first coefficient × First coefficient + Weight of the second coefficient × Second coefficient + Weight of the third coefficient × Third coefficient (12) 【0135】 For example, if the first coefficient is 0.96, the second coefficient is 0.95, the third coefficient is 0.90, the weight of the first coefficient is 0.38, the weight of the second coefficient is 0.31, and the weight of the third coefficient is 0.31, then the degree of airborne neglect is 94%. 【0136】 As described above, in the third embodiment, the third detection function 537 detects the state of the ultrasonic probe 2 being left in the air based on the third detection criterion. The determination function 535 determines the degree of being left in the air based on the detection result of the third detection function 537. 【0137】 This allows for more accurate detection of the airborne state using three types of detection criteria, and thus more accurate determination of the degree of airborne neglect. The determination function 535 may also determine the degree of airborne neglect based on the airborne state detected based on four or more types of detection criteria. 【0138】 (Fourth embodiment) Next, a fourth embodiment that detects the airborne state based on the presence or absence of biological signals will be described, focusing on the differences from the embodiments described above. In the fourth embodiment, the second detection function 533 detects the airborne state based on the second detection criterion by comparing a previously acquired noise image with the currently acquired ultrasound image. More specifically, the second detection function 533 compares a previously acquired noise image with the currently acquired ultrasound image in a region having a depth greater than or equal to a set depth, and detects the airborne state based on the comparison result. The region having a depth greater than or equal to a set depth is, for example, the white noise region A2. 【0139】 Figure 24 is a flowchart showing the detection process for the airborne state based on the second detection criterion in an example of operation of the ultrasound diagnostic apparatus 1 according to the fourth embodiment. In the example shown in Figure 24, first, the second detection function 533 compares a previously acquired noise image with the currently acquired ultrasound image (step S221C). The previously acquired noise image is stored in, for example, memory 52. ​​The currently acquired ultrasound image is, for example, the latest ultrasound image generated by the image generation function 531. 【0140】 Figure 25 shows the detection process for the airborne state based on the second detection criterion in an example of the operation of the ultrasound diagnostic device 1 according to the fourth embodiment. In the example shown in Figure 25, the previously acquired noise image has an image within the white noise region A2 that is similar to the white noise image I2 (see Figures 7 and 8). Also, in the example shown in Figure 25, the current ultrasound image is a scan image of a living organism. 【0141】 After comparing the previously acquired noise image with the currently acquired ultrasound image, the second detection function 533 determines the presence or absence of a biological signal, as shown in Figure 24 (step S222C). For example, the second detection function 533 may determine the presence of a biological signal based on the fact that the difference between the average brightness of the previously acquired noise image and the average brightness of the currently acquired ultrasound image in the white noise region A2 is greater than or equal to a threshold. 【0142】 After determining the presence or absence of a biological signal, the second detection function 533 calculates a second coefficient based on the determination result of the presence or absence of a biological signal, as shown in Figure 24 (step S223C). For example, if the second detection function 533 determines that a biological signal is present, it calculates 0 as the second coefficient. On the other hand, if the second detection function 533 determines that there is no biological signal, it calculates a value close to 1 as the second coefficient. The second detection function 533 may calculate a value close to 1 as the second coefficient as the difference between the average brightness of the previously acquired noise image and the average brightness of the currently acquired ultrasound image is closer to 0. 【0143】 As described above, in the fourth embodiment, the second detection function 533 detects the airborne state based on the second detection criterion by comparing a previously acquired noise image with the currently acquired ultrasonic image. 【0144】 This allows for easy detection of whether an object is left airborne based on the presence or absence of biological signals. 【0145】 (Fifth embodiment) Next, we will describe a fifth embodiment in which the airborne state is detected for each raster, focusing on the differences from the embodiments described above. Up to this point, we have described examples in which the first detection function 532 and the second detection function 533 detect the airborne state for each ultrasound image, i.e., for each frame. In contrast, in the fifth embodiment, the first detection function 532 and the second detection function 533 detect the airborne state for each raster. Furthermore, the determination function 535 determines the degree of airborne state for each raster based on the detection results of the first detection function 532 and the second detection function 533. Furthermore, the control function 536 controls the acoustic output for each raster based on the degree of airborne state determined by the determination function 535. 【0146】 Figure 26 is a flowchart showing an example of operation of the ultrasound diagnostic apparatus 1 according to the fifth embodiment. In the example shown in Figure 26, the determination of whether or not the device is airborne (step S2) and the maintenance or restoration of the acoustic output (step S3) or suppression of the acoustic output (step S4) based on the result of the determination proceed for each raster until the final raster (step S7: YES). The content of the determination of whether or not the device is airborne (step S2) may be the content described in any of the first to fourth embodiments or their modifications. In other words, in the fifth embodiment, the specific manner in which the determination of whether or not the device is airborne and the control of the scan conditions according to the result of the determination are performed for each raster is not particularly limited. 【0147】 Figure 27 shows an example of operation of the ultrasound diagnostic apparatus 1 according to the fifth embodiment. In the example shown in Figure 27, the first detection function 532 and the second detection function 533 calculate a first coefficient and a second coefficient close to 1 for the raster of the airborne area A3 where no biological signals exist. The determination function 535 calculates an airborne degree close to 100 (%) for the raster of the airborne area A3. The control function 536 suppresses the acoustic output for the raster of the airborne area A3. On the other hand, the first detection function 532 and the second detection function 533 calculate a first coefficient and a second coefficient close to 0 for the raster of the biological scan area A4 where biological signals exist. The determination function 535 calculates an airborne degree close to 0 (%) for the raster of the biological scan area A4. The control function 536 maintains or restores the acoustic output for the raster of the biological scan area A4 to the acoustic output during normal scanning. 【0148】 As described above, in the fifth embodiment, the first detection function 532 and the second detection function 533 detect the state of being left in the air for each raster. The determination function 535 determines the degree of being left in the air for each raster. The control function 536 controls the second scan conditions for each raster. 【0149】 This makes it possible to suppress unnecessary heat generation in areas of poor biological contact (i.e., airborne region A3) of the ultrasound probe 2 during biological scanning. 【0150】 (modified version) Next, we will describe a modified version of the fifth embodiment, which changes the settings for the non-contact scanning conditions, focusing on the differences from the embodiments described above. Figure 28 is a flowchart showing an example of the operation of the ultrasonic diagnostic device 1 according to the modified version of the fifth embodiment. 【0151】 In the example shown in Figure 28, the setting function 534 determines whether there are any non-contact areas where the ultrasound probe 2 is not in contact with the living body (step S8) after it has completed controlling the acoustic output based on the determination of whether or not the probe is left in the air until the final raster (step S7: YES). In other words, the setting function 534 determines whether or not there are any non-contact areas on the premise that the current scanning status is a living body scan and not left in the air. 【0152】 If there are non-contact areas (Step S8: YES), the setting function 534 changes the settings for scanning the non-contact areas (Step S9). On the other hand, if there are no non-contact areas (Step S8: NO), the setting function 534 does not change the settings for scanning the non-contact areas and proceeds to Step S5. 【0153】 Figure 29 shows an example of operation of an ultrasonic diagnostic device according to a modified version of the fifth embodiment. In the example shown in Figure 29, the setting function 534 changes the setting of the scan line angle, i.e., the scan angle, indicated by the arrow in the figure, so that the airborne area A3, which is a non-contact area, can be scanned. 【0154】 As shown in the example in Figure 28, even if there are areas of poor biological contact with the ultrasound probe 2 during a biological scan, biological information from those areas can be obtained. Therefore, the examination efficiency can be further improved. 【0155】 In the above explanation, the term "processor" refers to circuits such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an Application Specific Integrated Circuit (ASIC), or a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). A processor functions by reading and executing a program stored in a memory circuit. Alternatively, instead of storing the program in a memory circuit, the processor may be configured to directly incorporate the program into its circuitry. In this case, the processor functions by reading and executing the program incorporated into the circuitry. Furthermore, a processor is not limited to being a single circuit; it may also be composed of multiple independent circuits combined to form a single processor and achieve its functions. Additionally, the multiple components shown in Figure 1 may be integrated into a single processor to achieve its functions. 【0156】 The embodiments and modifications described above may be combined as appropriate. For example, the calculation of the first coefficient based on the interval and attenuation of multiple reflections shown in Figure 17 may be combined with the calculation of the second coefficient based on the luminance histogram shown in Figure 5. 【0157】 According to at least one embodiment described above, it is possible to achieve both suppression of ultrasound probe degradation and improvement of inspection efficiency. 【0158】 Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel apparatus and methods described herein can be implemented in a variety of other forms. Furthermore, various omissions, substitutions, and modifications can be made to the embodiments of the apparatus and methods described herein, without departing from the spirit of the invention. The appended claims and equivalents are intended to include such embodiments and modifications that are included in the scope and spirit of the invention. [Explanation of symbols] 【0159】 1. Ultrasound diagnostic equipment 2. Ultrasound probe 532 First detection function 533 Second detection function 534 Settings function 535 Decision function 536 Control Functions 537 Third detection function

Claims

[Claim 1] At least two detection units that detect the state of the ultrasonic probe being left in the air based on different detection criteria, A setting unit for setting the scan conditions for ultrasonic scanning using the aforementioned ultrasonic probe, A determination unit determines the degree of airborne abandonment, which indicates the likelihood of the airborne abandonment state, based on the detection result of the detection unit and the scan conditions set by the setting unit. An ultrasound diagnostic device equipped with the following features. [Claim 2] The ultrasound diagnostic apparatus according to claim 1, wherein the setting unit sets at least one of the display depth and the scan depth as a first scan condition. [Claim 3] The ultrasonic diagnostic apparatus according to claim 2, further comprising a control unit that controls a second scan condition for the ultrasonic scan, which is different from the first scan condition, according to the degree of air exposure determined by the determination unit. [Claim 4] The ultrasonic diagnostic apparatus according to claim 3, wherein the control unit controls at least one of the scan conditions related to heat generation and the scan angle as the second scan conditions. [Claim 5] The ultrasonic diagnostic apparatus according to claim 4, wherein the control unit controls the acoustic output of the ultrasonic probe as a scan condition related to the heat generation. [Claim 6] The ultrasonic diagnostic apparatus according to claim 5, wherein the control unit controls the acoustic output by controlling at least one of the voltage applied to the ultrasonic probe and the pulse repetition frequency of the ultrasonic waves. [Claim 7] The at least two detection units include a first detection unit that detects the airborne state based on a first detection criterion, and a second detection unit that detects the airborne state based on a second detection criterion, The ultrasonic diagnostic apparatus according to claim 1, wherein the first detection unit, in detecting the state of being left in the air based on the first detection criterion, acquires a difference signal indicating the difference between two received signals received by the ultrasonic probe at different times or different locations for each of a plurality of different depths, and detects the state of being left in the air based on the number of difference signals among the difference signals acquired for each of the different depths whose magnitude exceeds a threshold. [Claim 8] The at least two detection units include a first detection unit that detects the airborne state based on a first detection criterion, and a second detection unit that detects the airborne state based on a second detection criterion, The ultrasonic diagnostic apparatus according to claim 1, wherein the first detection unit, in detecting the airborne state based on the first detection criterion, obtains at least one of the interval and attenuation of multiple reflections of ultrasound from the received signal received from a depth within a set range close to the position of the ultrasonic probe, and detects the airborne state based on at least one of the obtained interval and attenuation. [Claim 9] The ultrasonic diagnostic apparatus according to claim 7 or 8, wherein the second detection unit detects the airborne state based on the second detection criterion by comparing the amplitude of a composite signal obtained by combining a first received signal received when a first transmission signal is transmitted and a second received signal received when a second transmission signal with the polarity of the first transmission signal is transmitted with the amplitude of the first received signal. [Claim 10] The ultrasonic diagnostic apparatus according to claim 9, wherein the second detection unit, in detecting the airborne state based on the second detection criterion, acquires a comparison result of the magnitude relationship between the amplitude of the composite signal and the amplitude of the first received signal for each of a plurality of different depths, and detects the airborne state based on the number of comparison results among the acquired magnitude relationship comparison results in which the amplitude of the composite signal is greater than the amplitude of the first received signal. [Claim 11] The ultrasonic diagnostic apparatus according to claim 7 or 8, wherein the second detection unit, in detecting the airborne state based on the second detection criterion, acquires the brightness of the received signal received by the ultrasonic probe at a plurality of different depths, and detects the airborne state based on the number of received signals when the acquired brightness exceeds a threshold. [Claim 12] The ultrasound diagnostic apparatus according to claim 7 or 8, wherein the second detection unit detects the airborne state based on the second detection criterion, by comparing a previously acquired noise image with a currently acquired ultrasound image. [Claim 13] The ultrasonic diagnostic apparatus according to claim 7 or 8, wherein the determination unit determines the degree of airborne exposure by weighting and adding the detection result of the airborne exposure state based on the first detection criterion and the detection result of the airborne exposure state based on the second detection criterion. [Claim 14] The ultrasonic diagnostic apparatus according to claim 13, wherein the determination unit performs the weighting using at least one of the display depth and the scan depth as the scan condition, and the greater the value of the detection result of the airborne state based on the second detection criterion, the greater the value of the display depth and the scan depth. [Claim 15] The ultrasonic diagnostic apparatus according to claim 14, wherein the determination unit increases the weight of the detection result of the airborne state based on the first detection criterion as the smaller at least one of the display depth and the scan depth becomes. [Claim 16] The ultrasonic diagnostic apparatus according to claim 4, wherein the control unit controls the scan conditions related to heat generation by controlling the scan parameters related to heat generation, and controls the scan parameters so that they have a parameter value between a target parameter value during air-standing and a parameter value during normal scanning, according to the degree of air-standing determined by the determination unit. [Claim 17] The detection unit detects the state of being left in the air for each raster, The determination unit determines the degree of air exposure for each raster, The ultrasonic diagnostic apparatus according to claim 3, wherein the control unit controls the second scan condition for each raster. [Claim 18] The at least two detection units further include a third detection unit that detects the airborne state based on a third detection criterion. The ultrasonic diagnostic apparatus according to claim 7 or 8, wherein the determination unit determines the degree of air exposure based on the detection result of the third detection unit.

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