CN106175838B - Backscattering ultrasonic bone diagnosis system based on array probe - Google Patents

Abstract

The invention belongs to the technical field of medical instruments, specifically a backscattered ultrasound bone diagnosis system based on an array probe. The system of the invention includes: ARM processor, FPGA, LCD display, multi-channel analog-to-digital conversion circuit, multi-channel high-voltage isolation receiving circuit, multi-channel high-voltage pulse transmitting circuit, pressure sensor detection circuit, and integrated ultrasonic probe. The present invention uses an integrated ultrasonic array probe to detect bone quality. Each small ultrasonic transducer in the array separately excites ultrasonic pulses and receives backscattered signals to complete bone quality detection at each location point, and then the processor detects the bone quality. The diagnostic results of each point are averaged to improve the accuracy and stability of the measurement data; on the other hand, a pressure sensor circuit is added around the ultrasonic probe array to detect the pressure between the ultrasonic probe and the part to be measured. Only when the pressure Ultrasonic detection is performed when the value is within the specified range, thereby improving the stability of the diagnostic results.

Description

A backscattered ultrasound bone diagnosis system based on array probe

Technical field

The invention belongs to the technical field of medical instruments, and specifically relates to a backscattered ultrasound bone diagnosis system based on an array probe.

Background technique

Ultrasound is considered to be a method with great potential for bone diagnosis due to its unique advantages of being non-destructive, free of ionizing radiation, real-time, cheap and portable. Ultrasound diagnosis methods of bone are mainly divided into ultrasonic transmission method and backscattering method. The ultrasonic transmission method developed earlier and is now widely used, while the ultrasonic backscattering method has attracted more and more attention from researchers in recent years. Compared with the transmission method, the ultrasonic backscattering method has the following advantages: the backscattering method can reflect bone microstructure information; only a single ultrasound probe is required for transmitting and receiving, unlike the transmission method which requires two probes, one for transmitting and one for receiving; The measurement is performed on the bone and can also be measured on other skeletal parts. However, in actual use, whether it is the ultrasonic transmission method or the ultrasonic backscattering method, the measurement results are affected to a certain extent by the probe fitting pressure and placement position. When performing backscatter testing at the calcaneus, if the probe is not tightly attached to the ankle, the correct ultrasound backscatter signal will not be received; and if the pressure of the probe being attached to the ankle is too high, the thickness of the soft tissue will be changed. And density also has a certain impact on the detection results of backscattered signals. On the other hand, since the bone microstructure, soft tissue thickness, and density at different locations of the calcaneus are slightly different, there are some differences in the detection results at different locations. The above two reasons reduce the accuracy and stability of ultrasonic backscattering detection.

Contents of the invention

The object of the present invention is to provide a backscattered ultrasound bone diagnosis system with high detection accuracy and good stability.

The backscattered ultrasound bone diagnosis system provided by the present invention is based on an array probe and includes: ARM processor, FPGA, LCD display, multi-channel analog-to-digital conversion circuit, multi-channel high-voltage isolation receiving circuit, multi-channel high-voltage pulse transmitting circuit, Pressure sensor detection circuit, integrated ultrasonic probe; including:

The integrated ultrasonic probe is composed of a probe shell protective layer, a small ultrasonic probe array, a pressure sensor and a coupling liquid. The array of small ultrasonic probes is sealed in a protective layer of the probe shell filled with coupling liquid. Each small ultrasonic probe can independently send and receive ultrasonic signals; the pressure sensor is buried under the protective layer of the probe shell in the outer ring and is used to detect the integrated ultrasonic probe. The pressure between the sample and the bone sample to be tested. Among them, the number N of ultrasonic probes can be 5-25, and in one embodiment is 9; the probes in the ultrasonic probe array are arranged in a symmetrical pattern.

The pressure sensor detection circuit is used to measure the impedance between the pressure sensor electrodes to detect the pressure value and convert it into a digital signal through the analog-to-digital conversion circuit; the FPGA reads the pressure value and transmits it to the ARM processor through the bus . The ARM processor displays the pressure value on the display and prompts the user to adjust the pressure to the correct range.

The software program runs on the ARM processor to control the FPGA and obtain data through the high-speed bus interface; the FPGA first controls the pressure sensor detection circuit to obtain the pressure value on the surface of the integrated ultrasonic probe, and the ARM processor displays the pressure value on the LCD display on the interface to prompt the user to increase or decrease the pressure of the probe; when the pressure value is within the correct range, the FPGA controls multiple high-voltage pulse transmitting circuits, sequentially drives each small ultrasonic probe to send ultrasonic pulse signals, and controls the corresponding The high-voltage isolation receiving circuit and high-speed analog-to-digital conversion circuit of the channel collect backscattered signals; the FPGA transmits the received ultrasonic backscattered signals to the ARM processor through the high-speed bus.

The working process and principle are as follows: when the pressure value detected by the pressure sensor detection circuit is within the correct range, the FPGA controls the multi-channel high-voltage pulse transmitting circuit to control the first small ultrasonic transducer to send an ultrasonic pulse excitation signal; the ultrasonic wave passes through the small ultrasonic The interface between the transducer and the coupling liquid passes through the interface between the coupling liquid and the probe protective layer, and then penetrates the ultrasonic coupling agent to reach the bone sample to be measured; the ultrasonic wave is backscattered in the bone sample, and the resulting backscattered backscatter returns The wave signal penetrates the ultrasonic coupling agent, then passes through the interface between the probe protective layer and the coupling liquid, and then passes through the interface between the coupling liquid and the small ultrasonic transducer, and is received by the small ultrasonic transducer and converted into an electrical signal. The FPGA controls the multi-channel high-voltage isolation receiving circuit to receive the signal of the corresponding channel, performs filtering and amplification, and then controls the corresponding channel in the multi-channel analog-to-digital conversion circuit to perform analog-to-digital conversion to collect the backscattered signal of this channel. Subsequently, the FPGA repeats the above process and controls the signal transmission and reception of other channels of small ultrasonic probes in turn.

After collecting the ultrasonic backscattered signals of all N channels, the FPGA sends these signals to the ARM processor through the high-speed bus. The ARM processor calculates multiple backscattering parameters such as apparent integrated backscattering coefficient (AIB), backscattering spectrum center of mass shift (SCS), and backscattering coefficient (BSC) for the backscattered signal received by each small ultrasonic probe. , and average the calculation results of these small ultrasound probe channels. Based on the averaged backscattering parameters, the bone condition is diagnosed and displayed on the LCD display.

The innovation of this invention is: 1) An ultrasonic array probe is used to detect bone quality. Each small ultrasonic transducer in the array separately excites ultrasonic pulses and receives backscattered signals, and detects bone quality at each location point. The ARM processor then averages the diagnostic results at each point, thereby improving the accuracy and stability of the measurement data. 2) A pressure sensor circuit is used around the ultrasonic probe array to detect the pressure between the ultrasonic probe and the site to be measured. Ultrasonic detection is performed only when the pressure value is within the specified range, thereby improving the stability of the diagnostic results.

The present invention is very different from the existing ultrasonic array imaging equipment based on the principle of ultrasonic reflection. Existing imaging equipment based on ultrasonic arrays performs imaging by emitting ultrasonic waves at each point of the object to be measured, and then converting the amplitude of the reflected wave signal into a pixel value. This technique utilizes only a single scalar information, the amplitude of the reflected wave signal. When the present invention uses each small ultrasonic probe in the ultrasonic array, it obtains a complete backscattered waveform, and calculates the backscattered parameters from the entire waveform. The present invention uses an ultrasonic array in order to perform regional averaging on the detection results of multiple different position points, thereby improving the accuracy and stability of backscattering detection. In addition, the present invention uses a pressure sensor to detect the pressure between the integrated ultrasonic probe and the object being measured, thereby ensuring that the fitting pressure is within a reasonable range during each detection and improving the stability and repeatability of detection.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples.

Figure 1 is a structural diagram of a backscattered ultrasound bone diagnosis system based on a probe array according to the present invention.

Figure 2 is a structural diagram of the integrated ultrasonic probe in the present invention. In Figure 2, only three small ultrasound probes are drawn for clarity of drawing. In one embodiment, 9 probes are used to form a 3*3 array, as shown in Figure 3.

Figure 3 is a top structural view of the integrated ultrasonic probe in the present invention.

Numbers in the figure: 1 is ARM processor, 2 is FPGA, 3 is multi-channel analog-to-digital conversion circuit, 4 is multi-channel high-voltage isolation receiving circuit, 5 is pressure sensor detection circuit, 6 is multi-channel high-voltage pulse transmitting circuit, and 7 is Integrated ultrasound probe, 8 is the ultrasonic coupling agent, 9 is the bone sample. 7.1 is the protective layer of the probe shell, 7.2 is the pressure sensor, 7.3 is the pressure sensor electrode, 7.4 is the small ultrasonic probe array, 7.5 is the small ultrasonic probe electrode, 7.6 is the coupling liquid, and 7.7 is the inner wall of the probe shell.

Detailed ways

As shown in Figure 1, the backscattered ultrasound bone diagnosis system based on the probe array of the present invention includes: ARM processor 1, FPGA2, multi-channel analog-to-digital conversion circuit 3, multi-channel high-voltage isolation receiving circuit 4, and pressure sensor detection circuit 5 , multi-channel high-voltage pulse transmitting circuit 6, integrated ultrasonic probe 7, ultrasonic coupling agent 8.

As shown in Figures 2 and 3, the integrated ultrasonic probe in the present invention includes: probe shell protective layer 7.1, pressure sensor 7.2, pressure sensor electrode 7.3, small ultrasonic probe array 7.4, small ultrasonic probe electrode 7.5, coupling liquid 7.6, Probe housing inner wall 7.7. In the figure, the integrated ultrasonic probe can be divided into two parts: an inner ring and an outer ring. Below the probe protective layer 7.1 in the inner ring, with the probe housing inner wall 7.7 as the boundary, there is a cylindrical cavity. The cavity is filled with coupling liquid 7.6. In this embodiment, the coupling liquid 7.6 used is a water-soluble polymer gel with electrical insulation ability and low sound attenuation coefficient. Place a small ultrasonic probe array 7.4 in the cavity, close to the upper wall of the probe shell protective layer 7.1. The probes in the array are arranged in a symmetrical pattern. In this embodiment, 9 small ultrasonic probes are used and arranged in a 3*3 array, as shown in Figure 3. The small ultrasonic probe electrode 7.5 is led out through the bottom of the probe. In this embodiment, the pressure sensor 7.2 is a metal strain gauge pressure sensor, which is buried in the outer ring of the probe shell protective layer 7.1 to avoid blocking the signal transmission and reception of the small ultrasonic probe 7.4. The pressure sensor electrode 7.3 is hidden in the outer wall of the cavity and is led out through the bottom of the probe.

When the integrated ultrasonic probe 7 is pressed against the surface of the bone sample 9 to be measured, the metal strain gauge in the pressure sensor 7.2 will deform, resulting in a change in the impedance of the metal strain gauge. The pressure sensor detection circuit 5 measures the impedance between the pressure sensor electrodes 7.3 by applying pressure to obtain flow, thereby detecting the pressure value and converting the analog-to-digital signal into a digital signal. FPGA2 reads the pressure value and transmits it to ARM processor 1 through the bus. The ARM processor 1 displays the pressure value on the display and prompts the user to adjust the pressure to the correct range.

When the pressure value is within the correct range, FPGA2 controls the multi-channel high-voltage pulse transmitting circuit 6 to control the first probe in the small ultrasonic probe array 7.4 to send an ultrasonic pulse excitation signal. The ultrasonic wave passes through the interface between the small ultrasonic probe and the coupling liquid 7.6, then passes through the interface between the coupling liquid 7.6 and the probe protective layer 7.1, and then penetrates the ultrasonic coupling agent 8 to reach the bone sample 9 to be measured. The ultrasonic wave is backscattered in the bone sample 9, and the generated backscattered echo signal penetrates the ultrasonic coupling agent 8, then passes through the interface between the probe protective layer 7.1 and the coupling liquid 7.6, and then passes between the coupling liquid 7.6 and the small ultrasonic probe 7.4 The interface between them is received by the small ultrasonic probe 7.4 and converted into electrical signals. FPGA2 controls the multi-channel high-voltage isolation receiving circuit 4 to receive the signal of the corresponding channel, performs filtering and amplification, and then controls the corresponding channel in the multi-channel analog-to-digital conversion circuit 3 to perform analog-to-digital conversion to collect the backscattered signal of this channel. Subsequently, FPGA2 repeats the above process and controls the signal transmission and reception of other channels of small ultrasonic probes in turn.

After collecting the ultrasonic backscattered signals of all 9 channels, FPGA2 sends these signals to the ARM processor 1 through the high-speed bus. ARM processor 1 calculates backscattering parameters such as apparent integrated backscattering coefficient (AIB), backscattering spectrum center of mass shift (SCS), and backscattering coefficient (BSC) for the backscattering signal of each channel, and then calculates the backscattering parameters of the 9 channels. The parameter calculation results are averaged. Based on the averaged backscattering parameters, the bone condition is diagnosed and displayed on the LCD display 10 .

In this embodiment, ARM processor 1 and FPGA2 communicate through a high-speed bus interface. ARM processor 1 sends control commands to FPGA2 through this bus and reads the collected backscattered signals from FPGA2. The bus can use an external parallel bus or a serial bus of the ARM processor. In this embodiment, the SPI serial bus is used. The ARM processor 1 displays the collected waveforms, pressure sensor detection values, calculated diagnosis results and other information on the LCD display 10 .

In this embodiment, the center frequency of the small ultrasonic probe used is 3.5MHz, and the frequency of the transmitted ultrasonic pulse signal is generated by the internal logic of FPGA2 and is also configured at 3.5MHz. The ultrasonic coupling agent 8 is an ultrasonic coupling agent commonly used in ultrasound medicine.

Claims (3)

1. A backscattered ultrasound bone diagnosis system based on an array probe, characterized by including: an ARM processor, an FPGA, an LCD display, a multi-channel analog-to-digital conversion circuit, a multi-channel high-voltage isolation receiving circuit, and a multi-channel high-voltage pulse transmitter Circuit, pressure sensor detection circuit, integrated ultrasonic probe; including: The integrated ultrasonic probe is composed of a probe shell protective layer, a small ultrasonic probe array, a pressure sensor and a coupling liquid; the small ultrasonic probe array is sealed in the probe shell protective layer filled with coupling liquid, and each small ultrasonic probe can independently send, Receive ultrasonic signals; the pressure sensor is buried under the protective layer of the probe shell on the outer ring and is used to detect the pressure between the integrated ultrasonic probe and the bone sample to be measured; The pressure sensor detection circuit is used to measure the impedance between the pressure sensor electrodes to detect the pressure value and convert it into a digital signal through the analog-to-digital conversion circuit; the FPGA reads the pressure value and transmits it to the ARM processor through the bus ;The ARM processor displays the pressure value on the display and prompts the user to adjust the pressure to the correct range; The software program runs on the ARM processor to control the FPGA and obtain data through the high-speed bus interface; the FPGA first controls the pressure sensor detection circuit to obtain the pressure value on the surface of the integrated ultrasonic probe, and the ARM processor displays the pressure value on the LCD display on the interface to prompt the user to increase or decrease the pressure of the probe; when the pressure value is within the correct range, the FPGA controls multiple high-voltage pulse transmitting circuits, sequentially drives each small ultrasonic probe to send ultrasonic pulse signals, and controls the corresponding The high-voltage isolation receiving circuit and high-speed analog-to-digital conversion circuit of the channel collect backscattered signals; the FPGA transmits the received ultrasonic backscattered signals to the ARM processor through the high-speed bus. 2. The backscattered ultrasound bone diagnosis system based on the array probe according to claim 1, characterized in that the system working process is as follows: when the pressure value detected by the pressure sensor detection circuit is within the correct range, the FPGA controls the multi-channel The high-voltage pulse transmitting circuit controls the first small ultrasonic transducer to send an ultrasonic pulse excitation signal; the ultrasonic wave passes through the interface between the small ultrasonic transducer and the coupling liquid, then passes through the interface between the coupling liquid and the probe protective layer, and then passes through The ultrasonic coupling agent reaches the bone sample to be tested; the ultrasonic wave is backscattered in the bone sample, and the generated backscattered echo signal penetrates the ultrasonic coupling agent, and then passes through the interface between the probe protective layer and the coupling liquid, and then passes through the coupling liquid and the coupling liquid. The interface between small ultrasonic transducers is received by the small ultrasonic transducers and converted into electrical signals; the FPGA controls the multi-channel high-voltage isolation receiving circuit to receive the signals of the corresponding channels, filter and amplify them, and then controls the multi-channel analog-to-digital conversion. The corresponding channel in the circuit performs analog-to-digital conversion and collects the backscattered signal of this channel; the FPGA repeats the above process and controls the signal transmission and reception of the small ultrasonic probe in other channels in turn. 3. The backscattered ultrasound bone diagnosis system based on the array probe according to claim 2, characterized in that, after collecting the ultrasonic backscattered signals of all channels, the FPGA sends these signals to the ARM processor through the high-speed bus; The ARM processor calculates the apparent integrated backscattering coefficient, backscattering spectrum center of mass offset, and backscattering coefficient for the backscattered signal received by each small ultrasound probe, and averages the calculation results of these small ultrasound probe channels. The averaged backscatter parameters are used to diagnose the bone condition and are displayed on the LCD display.