Ultrasonic wave transmitting and receiving device and control method thereof

Abstract

The invention provides an ultrasonic transceiving device and a control method thereof. The ultrasonic wave transmitting and receiving device comprises a plurality of coupled ultrasonic wave transmitting and receiving units. Each ultrasonic wave transceiving unit comprises a plurality of ultrasonic wave oscillators; the driving bias circuit is coupled to the plurality of ultrasonic oscillators, and the driving bias circuit is used for receiving alternating current voltage; and a switching circuit coupled to the driving bias circuit, the switching circuit having a plurality of switching paths, the plurality of switching paths corresponding to a plurality of impedance values or a plurality of inductance values, the switching circuit is used for switching a system driving signal to pass through one of the switching paths according to a mode selection signal to serve as the alternating voltage and transmitting the alternating voltage to the driving bias circuit.

Description

Technical Field

[0001] The present invention relates to the field of ultrasound, and in particular to an ultrasound transceiver and a control method thereof. Background Art

[0002] Capacitive micromachined ultrasonic transducer (CMUT) is an ultrasonic transducer manufactured using microelectromechanical systems (MEMS) technology. CMUT is mainly composed of miniature parallel capacitor plates, which can vibrate under the action of voltage to transmit and receive ultrasonic waveforms. Because the resonant cavity has the characteristics of film vibration, it is also called an ultrasonic oscillator.

[0003] CMUTs have several advantages over traditional piezoelectric ultrasonic transducers (PZTs), including the following. (1) Bandwidth: CMUTs typically have a wider bandwidth, which enables them to provide higher resolution in medical imaging, material detection, and other applications. (2) Integration: Because CMUTs are manufactured using MEMS technology, they are easier to integrate with other electronic components (such as amplifiers, filters, etc.) on the same chip. (3) Size: CMUTs can be made very small, which is an important advantage for applications that require small transducers (such as endoscopes). (4) Flexibility: CMUTs can be designed in a variety of shapes and sizes, allowing them to adapt to a variety of different application requirements. (5) Production cost: Because CMUTs use standard semiconductor process technology, they have potential cost advantages.

[0004] CMUT is widely used in medical ultrasound imaging, non-destructive testing and other fields. Due to its excellent performance characteristics, CMUT is gradually receiving more and more attention and application.

[0005] CMUT can be used to perform ultrasound imaging to see internal soft tissue body structures. When ultrasound pulses are sent into the tissue, sound waves of different amplitudes can be reflected back to the detector. These reflected sound waves can be recorded and displayed as an image. The intensity (amplitude) of the ultrasound waves and the time it takes for the ultrasound waves to travel through the body can be used to produce ultrasound images. For example, the image can show a two-dimensional cross-section of the tissue, blood flow, the presence of specific molecules, the hardness of the tissue, or the anatomy of a three-dimensional area.

[0006] However, the ultrasonic transceiver currently made of CMUT may have the disadvantage of poor color sensitivity, resulting in a poor signal-to-noise ratio (SNR). In addition, the ultrasonic transceiver currently made of CMUT may also have the problem of insufficient resolution.

[0007] Therefore, the industry currently needs an ultrasonic transceiver device made of CMUT to improve the shortcomings of the current technology. Summary of the invention

[0008] The object of the present invention is to provide an ultrasound transceiver and a control method thereof. The ultrasound transceiver has high color sensitivity and can generate high-resolution images and appropriate blood flow color intensity according to different image requirements (such as brightness mode, color mode, etc.), thereby effectively improving image quality.

[0009] To achieve the above object, the present invention provides an ultrasonic transceiver and a control method thereof. The ultrasonic transceiver comprises a plurality of coupled ultrasonic transceiver units.

[0010] Wherein, each of the ultrasonic transceiver units comprises:

[0011] Multiple ultrasonic oscillators;

[0012] A driving bias circuit coupled to the plurality of ultrasonic oscillators, the driving bias circuit being used for selectively outputting an alternating voltage and a direct voltage to the plurality of ultrasonic oscillators; and

[0013] A switching circuit coupled to the driving bias circuit, the switching circuit having a plurality of switching paths, the plurality of switching paths corresponding to a plurality of impedance values ​​or a plurality of inductance values;

[0014] The switching circuit receives a system driving signal, and is used to switch the system driving signal through one of the plurality of switching paths according to a mode selection signal and transmit the system driving signal to the driving bias circuit.

[0015] Preferably, the plurality of ultrasonic transceiver units are connected in parallel or in series; and

[0016] In each of the ultrasonic transceiver units, the plurality of ultrasonic oscillators are connected in series.

[0017] Preferably, in each of the ultrasonic transceiver units, the driving bias circuit includes a capacitor and a resistor, the capacitor is coupled between the switching circuit and the plurality of ultrasonic oscillators, and the resistor is coupled between the DC voltage source and the plurality of ultrasonic oscillators.

[0018] Preferably, in each of the ultrasonic transceiver units, the switching circuit includes a plurality of multiplexers and a plurality of inductors, the plurality of multiplexers are controlled by the mode selection signal to perform switching, and the plurality of inductors have different inductance values.

[0019] Preferably, in each of the ultrasonic transceiver units,

[0020] When operating in the first mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a first switching path of the multiple switching paths; and

[0021] When operating in the second mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a second switching path of the multiple switching paths.

[0022] Preferably, the control method of the ultrasonic transceiver includes:

[0023] When ultrasonic wave emission is performed, the mode selection signal is sent out so that the system driving signal passes through one of the plurality of switching paths and is transmitted to the driving bias circuit, so that the driving bias circuit drives the plurality of ultrasonic oscillators, so that the plurality of ultrasonic oscillators emit ultrasonic waves.

[0024] Preferably, the plurality of ultrasonic transceiver units are connected in parallel; and

[0025] In each of the ultrasonic transceiver units, the plurality of ultrasonic oscillators are connected in series.

[0026] Preferably, in each of the ultrasonic transceiver units, the driving bias circuit includes a capacitor and a resistor, the capacitor is coupled between the switching circuit and the plurality of ultrasonic oscillators, and the resistor is coupled between the DC voltage source and the plurality of ultrasonic oscillators.

[0027] Preferably, in each of the ultrasonic transceiver units, the switching circuit includes a plurality of multiplexers and a plurality of inductors, the plurality of multiplexers are controlled by the mode selection signal to perform switching, and the plurality of inductors have different inductance values;

[0028] Wherein, in each of the ultrasonic transceiver units,

[0029] When operating in the first mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a first switching path of the multiple switching paths; and

[0030] When operating in the second mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a second switching path of the multiple switching paths.

[0031] Preferably, an ultrasonic transceiver comprises:

[0032] A plurality of coupled ultrasonic transceiver units,

[0033] Wherein, each of the ultrasonic transceiver units comprises:

[0034] Multiple ultrasonic oscillators;

[0035] A driving bias circuit coupled to the plurality of ultrasonic oscillators, the driving bias circuit being used to receive an alternating current voltage; and

[0036] A switching circuit is coupled to the driving bias circuit, and the switching circuit has multiple switching paths, and the multiple switching paths correspond to multiple impedance values ​​or multiple inductance values; wherein the switching circuit receives a system driving signal, and the switching circuit is used to switch the system driving signal through one of the multiple switching paths according to a mode selection signal to be used as the AC voltage and transmit the AC voltage to the driving bias circuit.

[0037] Compared with the prior art, the driving bias circuit in the ultrasonic transceiver provided by the present invention is used to selectively output AC voltage and DC voltage to multiple ultrasonic oscillators; the switching circuit has multiple switching paths, and the multiple switching paths correspond to multiple impedance values ​​or inductance values. The switching circuit receives a system driving signal from the system side (for example, but not limited to the host), and the switching circuit is controlled by a mode selection signal, and then switches the system driving signal through one of the switching paths and transmits it to the driving bias circuit to match different inductances or impedances. The pulse echo waveform of the ultrasonic oscillator can be changed through impedance matching, thereby effectively improving the color sensitivity of the ultrasonic transceiver and improving the quality of ultrasonic imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 An ultrasonic oscillator according to an embodiment of the present invention is shown;

[0039] Figure 2 An ultrasonic transceiver unit according to an embodiment of the present invention is shown;

[0040] Figure 3 An ultrasonic transceiver device according to an embodiment of the present invention is illustrated;

[0041] 4A to 4D FIG. 1 shows a pulse echo waveform of an ultrasonic oscillator according to an embodiment of the present invention;

[0042] Figure 5A A diagram showing that the pulse echo waveform of a conventional ultrasonic oscillator is a positive pulse;

[0043] Figure 5B A diagram showing that the pulse echo waveform of an ultrasonic oscillator according to an embodiment of the present invention is a positive and negative pulse;

[0044] Fig. 6A The positive and negative pulse echo waveforms of the ultrasonic oscillator according to one embodiment of the present invention when operating in the color mode are shown;

[0045] Figure 6B The positive and negative pulse echo waveforms of the ultrasonic oscillator according to one embodiment of the present invention are shown when operating in the brightness mode. DETAILED DESCRIPTION

[0046] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0047] Certain words are used in the specification and claims to refer to specific components. Those with ordinary knowledge in the field should understand that manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but rather use differences in components' functions as the criteria for distinction. The term "including" mentioned throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to".

[0048] Figure 1 An ultrasonic oscillator according to an embodiment of the present invention is shown. The ultrasonic oscillator according to an embodiment of the present invention may be implemented by, for example but not limited to, a capacitive micro-electromechanical ultrasonic transducer (CMUT) or an ultrasonic oscillator. The ultrasonic oscillator 100 according to an embodiment of the present invention includes: a substrate 110, a membrane 120, a cavity 130, an upper electrode 140, a lower electrode 145, and an insulating layer 150.

[0049] The substrate 110 is typically glass or silicon or other semiconductor materials and serves as the basis for the CMUT structure.

[0050] The thin film plate 120 is usually made of silicon or other similar materials and metal electrodes. It is the active part of the CMUT and is used to generate and receive ultrasonic waves. The thin film plate 120 is composed of a very thin semiconductor or metal film or insulating layer.

[0051] The chamber 130 is located in the space between the thin film sheet 120 and the substrate 110, forming a capacitor. The chamber 130 is usually a vacuum or air.

[0052] The upper electrode 140 is located on the thin film sheet 120, and the lower electrode 145 is located on the substrate 110. The upper electrode 140 receives a DC voltage or an AC voltage. The lower electrode 145 is, for example, grounded.

[0053] The insulating layer 150 is used to provide insulation to prevent direct electrical contact between the thin film sheet 120 and the lower electrode 145. Short circuits and damage can be prevented, especially under high voltage driving conditions.

[0054] The operating principle of CMUT is as follows.

[0055] Transmitting ultrasonic waves: When an AC voltage or a DC voltage is applied between the two electrodes (140 and 145), the thin film sheet 120 vibrates due to electrostatic attraction and capacitance changes. This vibration generates pressure waves, which in turn form ultrasonic waves.

[0056] Receiving Ultrasonic Waves: When the ultrasonic waveform hits the thin film sheet 120, the thin film sheet 120 will produce a tiny vibration. This vibration changes the capacitance in the chamber 130, thereby producing a voltage change between the electrodes.

[0057] The basic description of how to use the ultrasonic oscillator 100 (CMUT) to form an image by transmitting and receiving ultrasonic waves is as follows.

[0058] In the ultrasonic wave transmitting part, an AC voltage is applied to the upper electrode 140 of the CMUT, which causes the distance between the thin film plate 120 and the lower electrode 145 opposite to it to change. Due to the movement of the thin film plate 120, the surrounding medium (usually water or biological tissue) is affected by pressure waves. These pressure waves propagate in the form of ultrasonic waves.

[0059] As for the part of receiving ultrasound waves, when the ultrasound waves emitted by the CMUT encounter the interface of materials with different density or elasticity, a reverberation wave is generated. When the reverberation wave returns to the CMUT, it causes vibrations to the thin film plate 120, causing the thin film plate 120 to deform. The deformation of the thin film plate 120 changes the voltage of the CMUT, and this voltage change can be converted into an electrical signal.

[0060] As for forming images, the collected CMUT electrical signals are processed by signal processing algorithms to extract useful information. And through mathematical algorithms, these electrical signals are converted into ultrasonic images.

[0061] Figure 2 The ultrasonic transceiver unit 200 according to one embodiment of the present invention includes: one or more ultrasonic oscillators S1 -SN (N is a positive integer, N>1); a driving bias circuit 210 and a switching circuit 220 .

[0062] The multiple ultrasonic oscillators S1-SN are connected in series or in parallel. Of course, the present invention is not limited thereto, and other coupling relationships are also within the spirit of the present invention.

[0063] The driving bias circuit 210 is coupled to the plurality of ultrasonic oscillators S1-SN. The driving bias circuit 210 is used to selectively output an alternating voltage AC and a direct voltage DC to the upper electrodes 140 of the plurality of ultrasonic oscillators S1-SN. The driving bias circuit 210 includes a capacitor C and a resistor R. The capacitor C is coupled between the switching circuit 220 and the plurality of ultrasonic oscillators S1-SN. The resistor R is coupled between a direct voltage source and the plurality of ultrasonic oscillators S1-SN. The direct voltage source is used to provide a direct voltage DC to the plurality of ultrasonic oscillators S1-SN.

[0064] The switching circuit 220 is coupled to the driving bias circuit 210. The switching circuit 220 has multiple switching paths, and the multiple switching paths correspond to multiple impedance values ​​or inductance values. For example but not limited to, the switching circuit 220 includes multiple multiplexers and multiple inductors. Here, the switching circuit 220 includes two multiplexers 221 and 222, and two inductors 223 and 224 as an example, but it should be known that the present case is not limited to this. The multiplexers 221 and 222, and the inductor 223 form a first switching path, and the multiplexers 221 and 222, and the inductor 224 form a second switching path. In other embodiments of the present case, the components 223 and 224 can also be zero-ohm resistors, which are all within the spirit of the present case.

[0065] The switching circuit 220 receives a voltage signal from a system side 240 (eg, but not limited to, a host). The multiplexers 221 and 222 are controlled by a mode selection signal CL to perform switching to match different inductances or impedances.

[0066] The inductors 223 and 224 have different inductance values. For example, but not limited to, the inductance values ​​or impedances of the inductors 223 and 224 are 0 ohm (equivalent to a straight line) and 4.7 μH, respectively.

[0067] When operating in the color mode (also referred to as the first mode), the mode selection signal CL controls the multiplexers 221 and 222, so that the driving signal (also referred to as the system driving signal) transmitted from the system side 240 is transmitted to the driving bias circuit 210 as an alternating current voltage AC through the first switching path (including the inductor 223 (0 ohm)).

[0068] On the contrary, when operating in the brightness mode (B mode, Brightness Mode) (also referred to as the second mode), the mode selection signal CL controls the multiplexers 221 and 222, so that the driving signal transmitted from the system side 240 is transmitted to the driving bias circuit 210 as an alternating voltage AC through the second switching path (including the inductor 224 (4.7 μH)). When the system driving signal is transmitted to the driving bias circuit 210 through the first switching path or the second switching path, the driving bias circuit 210 drives the plurality of ultrasonic oscillators S1-SN so that the plurality of ultrasonic oscillators S1-SN emit ultrasonic waves.

[0069] Figure 3 An ultrasonic transceiver device according to an embodiment of the present invention is shown. The ultrasonic transceiver device 300 according to an embodiment of the present invention comprises a plurality of ultrasonic transceiver units 200, wherein the plurality of ultrasonic transceiver units 200 are connected in parallel.

[0070] 4A to 4D The waveform of the pulse-echo of the ultrasonic oscillator according to one embodiment of the present invention is shown. In one embodiment of the present invention, the waveform of the ultrasonic oscillator 100 can be changed by changing the DC voltage applied to the ultrasonic oscillator 100. Figure 4A Picture to Figure 4D In the figure, the horizontal axis represents time, and the vertical axis represents the electrical signal of the pulse echo waveform (its unit is voltage). 4A to 4D What is displayed is the electrical signal after the received pulse echo waveform is converted.

[0071] At 4A to 4D In the embodiment, the DC voltages applied are 155 V, 166 V, 177 V and 200 V. When the DC voltage applied is 155 V, the thin film sheet 120 collapses and contacts the chamber 130 .

[0072] Figure 5A The figure shows that the pulse echo waveform of the conventional ultrasonic oscillator is a positive pulse, and Figure 5B The diagram shows that the pulse echo waveform of the ultrasonic oscillator 100 according to one embodiment of the present invention is a positive and negative pulse. Figure 5A and Figure 5B Used to display blood flow images created by ultrasound. FIG. 5A to FIG. 5B Displayed is the converted image of the received pulse echo waveform.

[0073] exist Figure 5A When the pulse echo waveform of the conventional ultrasonic oscillator is a positive pulse, it has the disadvantage of poor color sensitivity, resulting in a poor blood flow signal-to-noise ratio (SNR).

[0074] Therefore, in one embodiment of the present case, if Figure 5B As shown, the DC voltage can be changed to make the pulse echo waveform of the ultrasonic oscillator 100 according to an embodiment of the present invention positive and negative pulses, which will have high color sensitivity to improve the quality of blood flow images in color mode.

[0075] Fig. 6A The waveforms of positive and negative pulse echoes of the ultrasonic oscillator according to one embodiment of the present invention are shown when the ultrasonic oscillator operates in the color mode (such as when the signal passes through the inductor 223 (0 ohm)). Figure 6B The waveforms of positive and negative pulse echoes of the ultrasonic oscillator according to one embodiment of the present invention when operating in brightness mode (such as when the signal passes through the inductor 224 (4.7 μH)). FIG. 6A to FIG. 6B What is displayed is the electrical signal after the received pulse echo waveform is converted.

[0076] In one embodiment of the present case, by “impedance matching”, the pulse echo waveform of the ultrasonic oscillator 100 according to one embodiment of the present case can be a positive and negative pulse echo waveform regardless of operating in the brightness mode or the color mode.

[0077] That is, similar to Figure 5B Through “impedance matching”, the ultrasonic oscillator 100 according to an embodiment of the present invention can have high color sensitivity to improve image quality, regardless of operating in brightness mode or color mode.

[0078] As can be seen from the above, in one embodiment of the present invention, since the ultrasonic oscillator 100 needs to be driven by a DC voltage or an AC voltage, the pulse echo waveform can be changed through impedance matching. Therefore, the ultrasonic oscillator 100 according to one embodiment of the present invention can produce high-resolution images and appropriate blood flow color intensity in response to different image requirements (such as brightness mode, color mode, etc.).

[0079] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. An ultrasonic transceiver, characterized in that: include: A plurality of coupled ultrasonic transceiver units, Wherein, each of the ultrasonic transceiver units comprises: Multiple ultrasonic oscillators; A driving bias circuit coupled to the plurality of ultrasonic oscillators, the driving bias circuit being used for selectively outputting an alternating voltage and a direct voltage to the plurality of ultrasonic oscillators; and A switching circuit coupled to the driving bias circuit, the switching circuit having a plurality of switching paths, the plurality of switching paths corresponding to a plurality of impedance values ​​or a plurality of inductance values; The switching circuit receives a system driving signal, and is used to switch the system driving signal through one of the plurality of switching paths according to a mode selection signal and transmit the system driving signal to the driving bias circuit.

2. The ultrasonic transceiver according to claim 1, characterized in that: The plurality of ultrasonic transceiver units are connected in parallel or in series; and In each of the ultrasonic transceiver units, the plurality of ultrasonic oscillators are connected in series.

3. The ultrasonic transceiver according to claim 1, wherein: In each of the ultrasonic transceiver units, the driving bias circuit includes a capacitor and a resistor, the capacitor is coupled between the switching circuit and the plurality of ultrasonic oscillators, and the resistor is coupled between a DC voltage source and the plurality of ultrasonic oscillators.

4. The ultrasonic transceiver according to claim 1, wherein: In each of the ultrasonic transceiver units, the switching circuit includes a plurality of multiplexers and a plurality of inductors. The plurality of multiplexers are controlled by the mode selection signal to perform switching. The inductance values ​​of the plurality of inductors are different.

5. The ultrasonic transceiver according to claim 4, characterized in that: In each of the ultrasonic transceiver units, When operating in the first mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through the first switching path of the multiple switching paths; as well as When operating in the second mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a second switching path of the multiple switching paths.

6. A method for controlling an ultrasonic transceiver, for controlling the ultrasonic transceiver as claimed in claim 1, characterized in that: The control method includes: When ultrasonic wave emission is performed, the mode selection signal is sent out so that the system driving signal passes through one of the plurality of switching paths and is transmitted to the driving bias circuit, so that the driving bias circuit drives the plurality of ultrasonic oscillators, so that the plurality of ultrasonic oscillators emit ultrasonic waves.

7. The control method of the ultrasonic transceiver according to claim 6, characterized in that: The plurality of ultrasonic transceiver units are connected in parallel; and In each of the ultrasonic transceiver units, the plurality of ultrasonic oscillators are connected in series.

8. The control method of the ultrasonic transceiver according to claim 6, characterized in that: In each of the ultrasonic transceiver units, the driving bias circuit includes a capacitor and a resistor. The capacitor is coupled between the switching circuit and the plurality of ultrasonic oscillators, and the resistor is coupled between a DC voltage source and the plurality of ultrasonic oscillators.

9. The control method of the ultrasonic transceiver according to claim 6, characterized in that: In each of the ultrasonic transceiver units, the switching circuit includes a plurality of multiplexers and a plurality of inductors, the plurality of multiplexers are controlled by the mode selection signal to perform switching, and the plurality of inductors have different inductance values; Wherein, in each of the ultrasonic transceiver units, When operating in the first mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a first switching path of the multiple switching paths; and When operating in the second mode, the mode selection signal controls the multiplexers so that the system driving signal is transmitted to the driving bias circuit through a second switching path of the multiple switching paths.

10. An ultrasonic transceiver, characterized in that: include: A plurality of coupled ultrasonic transceiver units, Wherein, each of the ultrasonic transceiver units comprises: Multiple ultrasonic oscillators; A driving bias circuit coupled to the plurality of ultrasonic oscillators, the driving bias circuit being used to receive an alternating current voltage; and A switching circuit is coupled to the driving bias circuit, and the switching circuit has multiple switching paths, and the multiple switching paths correspond to multiple impedance values ​​or multiple inductance values; wherein the switching circuit receives a system driving signal, and the switching circuit is used to switch the system driving signal through one of the multiple switching paths according to a mode selection signal to be used as the AC voltage and transmit the AC voltage to the driving bias circuit.

Images