WO2014185560A1 - Transducer having front-end processor, image diagnosis device and method for processing signal thereof - Google Patents

Abstract

A transducer having a front-end processor, an image diagnosis device and a method for processing a signal thereof are disclosed. The transducer, according to one embodiment of the present invention, comprises: an array element grouped as a plurality of sub-array groups; and a front-end processor including a plurality of sub-array beamforming units for forming reception beams by beamforming ultrasound analog signals, which are received from a subject through respective elements forming the array element, for each sub-array group.

Description

Transducer and Image Diagnostic Device with Front End Processor and Signal Processing Method

The present invention relates to an imaging technique, and more particularly, to an ultrasound imaging apparatus.

Recently, the rapidly developing electronics and signal processing technology, especially digital signal processing technology, has a significant impact on the field of imaging. The imaging device is a flower of a medical diagnostic device in that it can be seen without cutting the inside of the human body. An X-ray diagnostic apparatus, a magnetic resonance imaging (MRI) diagnostic apparatus, an ultrasonic diagnostic apparatus, and the like are used as the imaging apparatus, and each has advantages and disadvantages thereof. Among them, the ultrasound imaging apparatus has a merit that the real-time diagnosis is possible and the price is very low instead of the resolution being lowered. Accordingly, the ultrasound imaging apparatus has become an essential diagnostic device in almost all medical fields such as internal medicine, gynecology, pediatrics, urology, ophthalmology, radiology, and the demand is rapidly increasing.

Referring to the basic principle of the ultrasound imaging apparatus, the transducer converts the pulse of the electrical signal generated by the pulse generating module into an ultrasonic signal and transmits the ultrasonic signal to the object, and the ultrasonic signal reflected from the boundary of different media and returned back It converts the signal to the signal processing module of the main body. In this case, the signal processing module may include TGC (Time Gain Compensation), Echo Processing, Spectral Doppler Processor (SDP) / Color Doppler Processor (CDP), Digital Scan Converter (DSC), etc. After performing proper signal processing of, it displays as an image on the display.

According to an embodiment, a transducer, an image diagnosis apparatus, and a signal processing method including a front end processor performing sub-array beamforming to minimize ADC sampling rate, minimize data rate, and save power are proposed.

According to an exemplary embodiment, a transducer is received by performing beamforming for each sub array group on an array element grouped into a plurality of sub array groups and ultrasonic analog signals received from an object through each element constituting the array element. And a front end processor including a plurality of sub-array beamforming units forming a beam.

The front end processor may further include a plurality of ADCs configured to convert the reception beams formed for each sub array group into digital signals through the sub array beam forming unit.

Each sub-array beamforming unit mixes a plurality of first amplifiers for amplifying a signal received through each element in a sub-array group, and an oscillation signal having a predetermined phase difference with the signals amplified by each first amplifier. A plurality of mixers for outputting a mixing signal, a plurality of second amplifiers for amplifying the mixed signals output from each mixer, a summer for adding up signals amplified by the plurality of second amplifiers in the sub-array group, It may include a filter for extracting a predetermined band signal from the signal summed through the adder.

Each mixer can minimize the ADC sampling rate and data rate by mixing the RF signal amplified by each first amplifier and the oscillation signal generated by each local oscillator and frequency down-modulating the IF signal, which is an intermediate frequency band signal, respectively. have.

Each mixer outputs a signal whose frequency corresponds to the sum of the frequencies of the RF signal and the oscillation signal, and a signal whose frequency corresponds to the difference between the frequencies of the RF signal and the oscillation signal, and the transducer is different from the signal corresponding to the sum. The apparatus may further include a frequency selection filter for selecting and filtering a signal corresponding to a difference among the signals corresponding to the difference.

The transducer may further include an interface unit for transmitting the digitally converted signal through the front end processor to the back end processor of the main body. In this case, the interface unit may be a wireless interface transmitted using a wireless network. The interface unit may include a first air interface unit for transmitting image data and a second air interface unit for transmitting a control signal.

According to another embodiment of the present invention, an imaging apparatus according to an embodiment of the present disclosure performs beamforming for each sub array group on ultrasonic analog signals received from an object through each element constituting an array element grouped into a plurality of sub array groups. And a main body including a transducer including a front end processor for digitally converting a received beam after forming the beam, and a back end processor for receiving a signal processed by the transducer and performing digital processing to generate an image. Furthermore, the imaging apparatus may further include an interface unit for wirelessly connecting the transducer and the main body.

According to another aspect of the present invention, there is provided a signal processing method using a transducer, including receiving an ultrasonic signal reflected from an object through each element constituting an array element grouped into a plurality of sub array groups, and sub arrays. Performing reception beamforming on ultrasonic signals received from each element in the sub-array group for each group to form a reception beam, converting the formed reception beam into a digital signal, and transmitting the converted digital signal to a main body It includes a step.

According to an embodiment, as the sub array beamforming is performed in the transducer having the front end processor, the number of channels can be reduced, the hardware configuration can be minimized, and power consumption can be minimized, thereby improving efficiency in operation time. In particular, the sub-array beamforming process modulates the high frequency signal into an intermediate frequency signal through a mixer to minimize the ADC sampling rate and minimize the data rate to reduce post processing burden and greatly reduce power consumption.

Furthermore, when connecting the transducer with the front-end processor and the back-end processor wirelessly, it is possible to escape the limitations of the length of wired cable from the physical side, and the signal quality and SNR performance caused by the cable capacitance from the electrical side. Deterioration can be prevented, and medical problems can prevent infection by wired cables.

1 is a block diagram of an imaging apparatus according to an embodiment of the present invention;

FIG. 2 is a detailed configuration diagram of the front end processor of FIG. 1 according to an embodiment of the present disclosure; FIG.

3 is a detailed configuration diagram of a sub-array beamforming unit of FIG. 2 according to an embodiment of the present invention;

4 to 6 are reference diagrams for describing a beamforming process of a sub array beamforming unit;

7 to 9 are reference diagrams for explaining down conversion of a mixer according to an embodiment of the present invention;

10 is a block diagram of an imaging apparatus according to a further embodiment of the present invention;

11 is a flowchart illustrating a signal processing method of a transducer according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention; In the following description of the present invention, detailed descriptions of related well-known functions or constructions may unnecessarily obscure the subject matter of the present invention, and detailed descriptions thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

1 is a block diagram of an image diagnosis apparatus according to an exemplary embodiment.

Referring to FIG. 1, an imaging apparatus includes a transducer 1 and a main body 2, and an array element 10 and a front end processor in the transducer 1. 12 is included, and a back end processor 20 is included in the main body 2.

In the image diagnosis apparatus illustrated in FIG. 1, only components related to the present exemplary embodiment are illustrated. Therefore, it will be understood by those skilled in the art that other general purpose components may be further included in addition to the components illustrated in FIG. 1.

The array element 10 includes elements, which may basically generate ultrasonic signals when voltage is independently applied, and receive ultrasonic signals for each element. In detail, when each element is electrically stimulated, an electrical signal is converted into an ultrasonic signal and transmitted to an object, for example, a human body, and the ultrasonic signal transmitted to the object is reflected at the boundary of the internal tissue of the object, The ultrasonic wave received at the element is converted into an electrical signal.

According to one embodiment, the array elements 10 are grouped into sub array groups. For example, if there are 12 elements constituting the array element 10, the elements may be grouped into a total of three groups so that there are four elements per one sub array group. In this case, the number of elements belonging to one sub array group may be determined in consideration of the image resolution.

According to the invention, the front end processor 12 is separated from the body 2 and located in the transducer 1. The front end processor 12 processes the ultrasonic analog signals received from the object through each element constituting the array element 10 for each sub array group and then digitally converts them. In this case, one channel for signal processing and transmission is formed for each sub array group. Then, the number of channels can be drastically reduced as compared with the case of forming channels for each element constituting the array element 10. For example, if four elements are grouped into one group, the number of channels can be reduced to 1/4. When the number of channels is reduced, hardware (H / W) configuration can be simplified, and the data rate is reduced, which is advantageous for signal transmission. In addition, power consumption can be minimized. The detailed configuration of the front end processor 12 will be described later with reference to FIG. 2.

2 is a detailed block diagram of the front end processor 12 of FIG. 1 according to an exemplary embodiment.

1 and 2, the front end processor 12 may include a plurality of sub-array beamforming units 120-1, 120-2,..., 120-n and a plurality of ADCs 122-1, 122-2,. -n). In FIG. 2, it is assumed that the array elements 10 are grouped into n sub-array groups. The transducer 1 includes n sub-array beamforming units 120-1, 120-2,. -n) and n ADCs 122-1, 122-2, ..., 122-n.

Each sub array beamforming unit 120-1, 120-2,..., 120-n performs sub array beamforming for focusing ultrasonic signals received from each element of the sub array group for each sub array group. To perform. For example, if you want to focus on a point through receive beamforming, the time from which the signal from the desired focus reaches each element is slightly different, and the phases are aligned by delaying the phases of the signals differently so that the time is the same. Then all add up. As described above, as the sub-array beamforming is performed, the number of channels can be reduced, the hardware configuration can be minimized, and further, power consumption can be minimized, which may be advantageous for operation.

Each ADC 122-1, 122-2, ..., 122-n converts the beamformed signal into a digital signal for each sub array group through the sub array beamforming units 120-1, 120-2, ..., 120-n. do. When a channel is formed for each element constituting the array element 10, an ADC is required for each element. However, in the case of grouping the array elements 10 into sub-array groups and converting the ADC to the sub-array groups, the channel is formed for each sub-array group so that the number of channels is reduced. The number of ADCs can be drastically reduced compared to the case of forming channels. ADCs are advanced devices that are costly and power consuming. Therefore, reducing the number of ADCs can reduce product manufacturing costs, simplify circuit configuration, and reduce power consumption.

3 is a detailed block diagram of the sub-array beamforming unit 120-1, 120-2,..., 120-n of FIG. 2 according to an embodiment of the present invention.

Referring to FIG. 3, the sub-array beamforming units 120-1, 120-2,..., 120-n may include a plurality of first amplifiers 1200-1, 1200-2,. (1220-1,1220-2, ..., 1220m), a plurality of second amplifiers 1230-1,1230-2, ..., 1230-m, a single summer 1240, and a single filter ( 1250). In FIG. 3, a case in which m elements are included in one sub array group is illustrated, and m first amplification units 1200-1, 1200-2,. Mixers 1220-1, 1220-2, ..., 1220-m, and m second amplifiers 1230-1, 1230-2, ..., 1220-m.

The plurality of first amplifiers 1200-1, 1200-2,..., 1200-m amplify a signal received through each element in the sub array group. In this case, the plurality of first amplifiers 1200-1, 1200-2,..., 1200-m may be low noise amplifiers (LNAs).

The plurality of mixers 1220-1, 1220-2,..., 1220-m have oscillations having a predetermined phase difference with respect to the signals amplified by the first amplifiers 1200-1, 1200-2,. The signals are mixed to output a mixed signal. An oscillating signal having a predetermined phase difference may be generated from a local oscillating signal generator 1210-1, 1210-2,... Here, 'mixed' is generated by the signals amplified by the first amplifiers 1200-1,1200-2, ..., 1200-m and the local oscillators 1210-1, 1210-2, ..., 1120-m. It can be used to mean multiply the oscillation signal.

According to an embodiment, each mixer 1220-1, 1220-2,..., 1220-m is a high frequency band amplified by each of the first amplifiers 1200-1, 1200-2,. The RF signal and the oscillation signals generated by the local oscillators 1210-1, 1210-2,..., 1520-m are mixed and frequency modulated into intermediate frequency signals. In this case, the sampling rate of the ADC can be minimized and the data rate can be minimized, thereby reducing the post processing burden in the later stage. In addition, power consumption can be significantly reduced. The sampling rate refers to the number of samplings that can convert an analog signal into a digital signal within a given time, and the data rate refers to the amount of data transferred from one point to another within a given time. Embodiments of the mixing process of the mixers 1220-1, 1220-2, ..., 1220-m will be described in detail later with reference to FIGS.

The plurality of second amplifiers 1230-1, 1230-2,..., 1200-m amplify the mixed signals output from the mixers 1220-1, 1220-2,. The summer 1240 sums the signals amplified by the plurality of second amplifiers 1230-1, 1230-2,. The filter 1250 extracts a predetermined band signal from the signal summed up through the summer 1240. In this case, the filter 1250 may be a low pass filter (LPF).

Meanwhile, although beamforming is implemented using a phase rotation circuit in FIG. 3, beamforming may be implemented using a time delay circuit. For example, if you want to focus on a point through receive beamforming, the time from which the signal from the desired focus arrives at each element is slightly different. You can also use the method.

Meanwhile, only components related to the present embodiment are shown in FIG. 3. Therefore, it will be understood by those of ordinary skill in the art that other general-purpose components may be further included in addition to the components illustrated in FIG. 3.

4 to 6 are reference diagrams for explaining a beamforming process of the sub array beamforming units 120-1, 120-2, ..., 120-n.

In detail, FIG. 4 illustrates n sub-array beamforming units 120-1, 120-2,..., 120-n when there are n sub-array beamforming units 120-1, 120-2,. This is an expanded drawing.

FIG. 5 illustrates a local oscillation output signal generation and signal synthesis process using a single local oscillator 1210 in each sub array beamforming unit 120-1, 120-2, ..., 120-n. That is, a single local oscillator 1210 generates a local oscillation output signal, and the generated local oscillation output signals are respectively MUX 1260-1, 1260-2,. 1220-1, 1220-2, ..., 1220-m, and each mixer 1220-1, 1220-2, ..., 1220-m has a local oscillator 1210 and each mixer 1220-1, 1220. A signal input through -2, ..., 1220-m and the signals amplified by each of the first amplifiers 1200-1, 1200-2, ..., 1200-m are mixed to output a mixing signal.

FIG. 6 illustrates a phase rotation process of the sub-array beamforming units 120-1, 120-2,..., 120-n, and the first amplification units 1200-1, 1200-2,. Since the received signals provided through the phases are different from each other, phase rotation for each received signal is applied to align the phases to have the same phase.

7 to 9 are reference diagrams for explaining down conversion of a mixer according to an embodiment of the present invention.

In detail, FIG. 7 illustrates that the mixer (1220-1,1220-2, ..., 1220-m of FIG. 3) is amplified by the first amplification unit (1200-1,1200-2, ..., 1200-m of FIG. 3). The frequency signal of each signal when downconverting to an IF signal by mixing the received RF signal and the LO signal which is an oscillation signal generated from the local oscillator (1210-1,1210-2, ..., 1120-m in FIG. 3). The graph shown. In FIG. 7, the x-axis represents the magnitude of the frequency of the signal, and the y-axis represents the power of the signal.

According to an embodiment, when the RF signal and the LO signal, which are signals input to the mixers 1220-1, 1220-2, ..., 1220-m, are represented by vRF and vLO, respectively, the vRF and vLO signals may be represented by Equation 1 below. same.

Equation 1

At this time, the mixers 1220-1, 1220-2, ..., 1220-m mix input signals vRF and vLO, and the signal output as a result of the mixing becomes vRF x vLO, as shown in Equation 2. Equation 2 uses the trigonometric formula of Equation 3.

Equation 2

Equation 3

FIG. 8 is a graph showing the frequency magnitude of a mixed signal that can be generated when the RF signal and the LO signal are mixed through the mixers 1220-1, 1220-2,..., 1220-m according to an embodiment of the present invention. . In FIG. 8, the x-axis represents the magnitude of the frequency of the signal, and the y-axis represents the power of the signal.

Referring to FIG. 8, according to an embodiment, the mixers 1220-1, 1220-2,..., 1220-m may have a signal whose frequency corresponds to the sum of the frequencies of the RF signal and the LO signal (LO + RF signal). And output a signal (LO-RF signal) whose frequency corresponds to the difference between the frequencies of the RF signal and the LO signal. In FIG. 8, it is assumed that the frequency magnitude of the LO signal is greater than the frequency magnitude of the RF signal. However, the frequency magnitude of the LO signal may be smaller than the frequency magnitude of the RF signal. If the frequency magnitude of the LO signal is smaller than the frequency magnitude of the RF signal, the signal corresponding to the difference between the frequencies of the RF signal and the LO signal becomes an RF-LO signal.

FIG. 9 is a circuit diagram illustrating an additional frequency selection filter 1270 for selecting a signal having a predetermined frequency from among mixed signals output through the mixer 1220 according to an embodiment of the present invention.

Referring to FIG. 9, the frequency selection filter 1270 selects and filters a LO-RF signal corresponding to a difference from a signal LO-RF signal corresponding to a difference between the LO + RF signal described above with reference to FIG. 8. The frequency of the LO-RF signal corresponds to IF. In FIG. 9, the frequency select filter 1270 is positioned in front of the second amplifier 1230, but the frequency select filter 1270 may be positioned after the second amplifier 1230.

10 is a block diagram of an imaging apparatus according to a further embodiment of the present invention.

Referring to FIG. 10, the imaging apparatus includes an array element 10, a plurality of sub array beamforming units 120-1, 120-2,..., 120-n, and a plurality of ADCs 122-1, 122-2,. n), FPGA 124, interface 126, and back end processor 20.

The functions of the array element 10, the plurality of sub-array beamforming units 120-1, 120-2,..., 120-n and the plurality of ADCs 122-1, 122-2,. It is as mentioned above in 3. Also in the imaging apparatus of FIG. 10, the sub-array beamforming units 120-1, 120-2,..., 120-n and the plurality of ADCs 122-1, 122-2,. n) is included.

The FPGA 124 receives the digitally converted signals through the plurality of ADCs 122-1, 122-2, ..., 122-n, processes them through filters and decimators, performs digital beamforming, and processes the processed digital signals. It stores in the memory and outputs various control signals.

The interface unit 126 is a means for connecting the transducer 1 and the back end processor 20 of the main body 2 to transmit the image data and control signals processed by the FPGA 124 to the back end processor 20. do. The interface unit 126 may transmit and receive image data and control signals using wired serial communication, wired or wireless networks, and the like. In this case, the network includes the Internet, a local area network (LAN), a wireless local area network (WLAN), a wide area network (WAN), a personal area network (PAN), and the like, but is not limited thereto. It can be another kind of network capable of transmitting and receiving. The back end processor 20 may include a digital scan converter (DSC), a post processor, an image display, and the like.

Hereinafter, when the transducer 1 and the back end processor 20 are wirelessly connected, the configuration and effects of the present invention will be described later.

In general, the image diagnosis apparatus is formed of a main body consisting of a front end processor and a back end processor is formed separately from the transducer. In this case, a cable is connected between the transducer and the main body, and in this case, problems may occur in electrical, physical, and medical aspects. For example, the cable capacitance on the electrical side can lead to signal degradation and signal to noise ratio (SNR) performance degradation, the physical side to ergonomic burden, and the medical side to infectious issues. May occur.

However, according to one embodiment of the present invention, by moving the front end processor located in the main body 2 to the transducer 1, to solve the above problems. For example, when the transducer 1 and the back end processor 20 are wirelessly connected through a wireless interface, the length of the wired cable is physically separated by physically separating the transducer 1 and the back end processor 20. You can escape from the constraints. On the electrical side, signal degradation due to cable capacitance and SNR performance can be prevented. In addition, the medical problem can be prevented from wired cable infection problem. The medical effect can be applied to operating room, emergency room or other anesthesia where a sterile environment is required. Furthermore, the medical effect can be applied to the fields of needle visualization, vascular access, and nerve blocks. .

11 is a flowchart illustrating a signal processing method of the transducer 1 according to an embodiment of the present invention.

1 and 11, the transducer 1 receives an ultrasonic signal reflected from an object through each element constituting the array element 10 grouped into a plurality of sub array groups (600).

Subsequently, reception beamforming is performed on ultrasonic signals received from each element in the sub-array group for each sub-array group to form a reception beam (610). According to an embodiment, the transducer 1 amplifies a signal received through each element in a sub-array group, mixes an oscillation signal having a predetermined phase difference by using a mixer for the amplified signal, and mixes the mixed signal. After outputting, amplify the mixing signal. The signals amplified in the sub-array group are summed, and then a predetermined band signal is extracted from the summed signal. In this case, the mixer may minimize the sampling rate and data rate of the ADC by frequency modulating the amplified high frequency band signal into an intermediate frequency band signal.

Subsequently, the transducer 1 converts a reception beam formed for each sub array group into a digital signal using an ADC (620). In operation 630, the digital signal converted by the ADC for each sub array group is transmitted to the back end processor 20 of the main body 2.

In the meantime, the present embodiment has been described as a method related to an ultrasound image for convenience of description with reference to the embodiments of the present invention. However, the present invention is not limited thereto, and various ultrasound imaging techniques such as elastic images, radar and sound signals are provided. It can be appreciated by those skilled in the art that the present invention can be applied to a process.

So far, the present invention has been described with reference to the embodiments. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (11)

Array elements grouped into a plurality of sub array groups; And A front end processor including a plurality of sub array beamformers configured to form a reception beam by performing beamforming for each sub array group on ultrasonic analog signals received from an object through each element of the array element; Transducer comprising a. The processor of claim 1, wherein the front end processor comprises: A plurality of ADCs for converting the reception beams formed for each sub array group through the sub array beam forming unit into digital signals; Transducer characterized in that it further comprises. The method of claim 1, wherein each sub-array beamforming unit, A plurality of first amplifiers for amplifying an RF signal received through each element in the sub array group; A plurality of mixers for outputting a mixing signal by mixing the oscillation signals generated by the local oscillator with the RF signals amplified by each first amplifier; A plurality of second amplifiers for amplifying the mixed signals output from each mixer; A summer for adding up signals amplified by the plurality of second amplifiers in a sub array group; And A filter for extracting a predetermined band signal from the signal summed through the adder; Transducer comprising a. The method of claim 3, wherein each mixer, The RF signal amplified by each first amplification unit and the oscillation signal generated by each local oscillator are mixed and frequency down-modulated to IF signal, which is an intermediate frequency band signal, respectively, to minimize the sampling rate and data rate of the ADC. . The method of claim 4, wherein each mixer, Outputs a signal whose frequency corresponds to the sum of the frequencies of the RF signal and the oscillation signal, and a signal whose frequency corresponds to the difference between the frequencies of the RF signal and the oscillation signal, The transducer may include a plurality of frequency selection filters for selecting and filtering a signal corresponding to a difference among a signal corresponding to the sum and a signal corresponding to a difference output through each mixer; Transducer characterized in that it further comprises. The method of claim 1, wherein the transducer, An interface unit for transmitting the digitally converted signal to the back end processor of the main body through the front end processor; Transducer characterized in that it further comprises. The method of claim 6, wherein the interface unit, Transducer characterized in that the wireless interface for transmitting using a wireless network. The method of claim 7, wherein the interface unit, A first air interface unit for transmitting image data; And A second air interface unit for transmitting a control signal; Transducer comprising a. A front end that forms a receive beam by performing beamforming for each sub array group on ultrasonic analog signals received from an object through each element constituting an array element grouped into a plurality of sub array groups, and then digitally converts the receive beam. A transducer comprising a processor; And A main body including a back end processor for receiving a signal processed by the transducer and performing digital processing to generate an image; Imaging apparatus comprising a. The method of claim 9, An interface unit for wirelessly connecting the transducer and the main body; Imaging apparatus further comprises a. Receiving, via each element constituting an array element grouped into a plurality of sub-array groups, an ultrasonic signal reflected from the object; Forming a reception beam by performing reception beamforming on ultrasonic signals received from each element in the sub array group for each sub array group; Converting the formed reception beam into a digital signal; And Transmitting the converted digital signal to a main body; Signal processing method using a transducer, characterized in that it comprises a.

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