Signal amplification and capacity expansion system

Abstract

The utility model provides a signal amplification capacity expansion system, which comprises a signal generator, an amplification circuit and a power divider, and the amplification circuit comprises an amplifier, a multiple adjusting unit and an output adjusting unit. Compared with the situation that the amplitude and the signal channel cannot meet the test requirement when a signal generator is directly used for testing, the signal amplification and expansion system based on the amplification circuit and the power divider is used for amplifying and expanding the signal source, the amplitude of signal injection is improved, the channel capable of being used for measurement is expanded at the same time, and the test efficiency is improved. The range of testable objects is expanded, and a customized signal source is not needed. Moreover, the output adjusting unit of the amplifying circuit adjusts the voltage switching rate of the output signal source of the amplifier, so that the voltage switching rate is controllable, the voltage waveform is changed in a monotonous rising manner at the changing edge, and the ringing phenomenon of the circuit is avoided.

Description

Technical Field

[0001] This utility model relates to the field of magnetic resonance imaging technology, and in particular to a signal amplification and expansion system. Background Technology

[0002] The safety assessment methods and guidelines for active implantable medical devices (AIMDs) in a magnetic resonance imaging (MRI) environment mainly refer to the international standard ISO / TS10974:2018. The gradient injection test in this standard requires the use of multiple signal sources. Currently, commercially available signal generators can provide a maximum of 20Vpp to the load, which is sufficient for testing implantable devices with short electrode leads or low induced voltages in an MRI environment. However, for implantable devices with longer electrode leads or higher induced voltages, the voltage applied to the electrodes needs to exceed 20Vpp. Therefore, custom signal sources are required to meet the voltage requirements. Furthermore, some implantable devices have multiple (up to dozens) electrodes. If voltage signal capacity is not increased, multiple custom signal sources are needed, which not only incurs high customization costs but also significantly occupies space, causing inconvenience in operation and use. Utility Model Content

[0003] The purpose of this invention is to provide a signal amplification and expansion system to solve the problems of existing active implant magnetic resonance gradient injection tests requiring customized signal sources to meet voltage requirements and having a limited number of signal channels.

[0004] The signal amplification and capacity expansion system of this utility model includes:

[0005] A signal generator is used to output at least one signal source;

[0006] An amplifier circuit includes an amplifier, a gain adjustment unit, and an output adjustment unit. The amplifier is connected to the signal generator to amplify the signal source. The gain adjustment unit is connected to the amplifier to adjust the amplification factor of the amplifier on the signal source. The output adjustment unit is connected to the amplifier to adjust the voltage switching rate of the amplifier outputting the signal source.

[0007] The power divider coupled to the output adjustment unit is used to expand the signal source after amplification by the amplifier from one channel to at least two channels.

[0008] Optionally, the multiplier adjustment unit includes a first resistor, a second resistor, and an adjustable resistor. The first end of the first resistor is connected to one of the input terminals of the amplifier, the second end of the first resistor is grounded, the two ends of the second resistor are respectively connected to the first end of the first resistor and the output terminal of the amplifier, and the adjustable resistor is connected in parallel with the second resistor.

[0009] Optionally, the output adjustment unit includes a fourth resistor, a fifth resistor, and a second capacitor. The first end of the fourth resistor is connected to the output terminal of the amplifier, and the second end of the fourth resistor is coupled to the power divider. The first end of the second capacitor is connected to the second end of the fourth resistor, and the second end of the second capacitor is grounded through the fifth resistor.

[0010] Optionally, the resistance of the fourth resistor is greater than or equal to 100 ohms and less than or equal to 300 ohms; and / or, the output adjustment unit adjusts the voltage switching rate to be greater than 36V / 7us.

[0011] Optionally, the amplification circuit further includes an input filtering unit, one end of which is connected to the signal generator, and the other end of which is connected to the amplifier.

[0012] Optionally, the signal amplification and expansion system further includes an output filter circuit connected to the output adjustment unit, and the output filter circuit is connected to the power divider.

[0013] Optionally, the output filter circuit includes a sixth resistor, a seventh resistor, an eighth resistor, and a fifth capacitor. The sixth resistor, the fifth capacitor, the seventh resistor, and the eighth resistor are connected in series between the output adjustment unit and ground. The power divider is connected between the sixth resistor and the fifth capacitor.

[0014] Optionally, the signal amplification and expansion system may further include a power supply unit connected to the amplifier.

[0015] Optionally, the power supply unit includes a first voltage source and a second voltage source. The positive terminal of the first voltage source is connected to the positive power supply terminal of the amplifier, and the negative terminal of the first voltage source is grounded. The negative terminal of the second voltage source is connected to the negative power supply terminal of the amplifier, and the positive terminal of the second voltage source is grounded.

[0016] Optionally, a voltage regulator capacitor is provided between the positive and negative terminals of the first voltage source and between the positive and negative terminals of the second voltage source. A decoupling capacitor and a bypass capacitor connected in parallel with the decoupling capacitor are provided between the positive terminal of the first voltage source and ground, and between the negative terminal of the second voltage source and ground. The negative terminal of the first voltage source and the positive terminal of the second voltage source are short-circuited.

[0017] This invention's signal amplification and expansion system addresses the limitations of directly using a signal generator, which often results in insufficient amplitude and signal channels for testing. By employing an amplifier circuit and power divider-based system, the system amplifies and expands the signal source, increasing the injected signal amplitude and expanding the range of measurable channels, thus broadening the scope of testable objects without requiring a custom signal source. Furthermore, the amplifier circuit's output adjustment unit regulates the voltage switching rate of the amplifier's output signal source, ensuring a controllable switching rate and a monotonically increasing voltage waveform at the change edges, preventing ringing in the circuit. Attached Figure Description

[0018] Those skilled in the art will understand that the accompanying drawings are provided to better understand the present invention and do not constitute any limitation on the scope of the present invention. Wherein:

[0019] Figure 1 This is a schematic diagram of a signal amplification and expansion system according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of an amplifier circuit according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the output filter circuit according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of a power supply unit according to an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, advantages, and features of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the objectives of the embodiments of this utility model. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may emphasize different aspects and sometimes use different scales.

[0024] As used in this invention, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to include the meaning of “and / or”; the term “a number” is generally used to include the meaning of “at least one”; and the term “at least two” is generally used to include the meaning of “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature. “One end” and “the other end,” as well as “proximal end” and “far end,” generally refer to two corresponding parts, including not only endpoints. The terms “installed,” “connected,” and “joined” should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements or the interaction between two elements. Furthermore, as used in this invention, the phrase "one element is disposed on another element" generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements. This connection, coupling, cooperation, or transmission can be direct or indirect through an intermediate element, and should not be construed as indicating or implying a spatial positional relationship between the two elements. That is, one element can be located arbitrarily inside, outside, above, below, or to one side of the other element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Figure 1 This is a schematic diagram of a signal amplification and expansion system according to an embodiment of this utility model. (See attached diagram.) Figure 1This utility model schematically provides a signal amplification and expansion system for use in magnetic resonance gradient injection testing of active implants. The system includes an amplification module 20 and a power divider 30. The amplification module 20 is connected to a signal generator 10, which generates at least one signal source VPP, a voltage signal. The amplification module 20 amplifies the signal source VPP, and the amplification factor can be adjusted according to actual needs. The power divider 30 is connected to the amplification module 20 and expands the amplified signal source VPP from one channel to at least two channels, for example, expanding one signal source VPP to four signal sources VPP. Each signal source VPP is loaded onto a corresponding load 40, such as an electrode. It should be noted that the number of power dividers 30 corresponds one-to-one with the number of signal sources VPP, and the power divider expands the corresponding amplified signal source VPP. For example, signal generator 10 generates two signal sources VPP. After processing by amplification module 20, the two amplified signal sources VPP are output. Two power dividers 30 expand the capacity of these two amplified signal sources VPP respectively. In this embodiment, the power divider 30 has the characteristics of high isolation, low loss, large number of expansions, and no signal distortion in the frequency band used for gradient injection testing. Thus, compared with the inability to meet the test requirements in terms of amplitude and signal channels when directly using signal generator 10, this utility model uses a signal amplification and expansion system based on amplification module 20 and power divider 30 to amplify and expand the signal source VPP, thereby increasing the amplitude of signal injection, expanding the channels that can be used for measurement, expanding the range of testable objects, eliminating the need for customized signal source VPP, and reducing equipment cost and space occupation.

[0026] Figure 2 This is a schematic diagram of an amplifier circuit according to an embodiment of the present invention. (See attached diagram.) Figure 2The amplification module 20 includes an amplification circuit 21, which includes an amplifier U, a gain adjustment unit 211, and an output adjustment unit 212. The amplifier U is coupled to the signal generator 10 and amplifies the filtered signal source VPP. For example, the amplification circuit also includes an input filtering unit. One end of the input filtering unit is connected to the signal generator, and the other end is connected to the amplifier U. The input filtering unit filters the signal source and outputs it to the amplifier U. In one embodiment, the input filtering unit is configured as an RC network consisting of a first capacitor C1 and a third resistor R3. Exemplarily, the first end of the third resistor R3 is connected to the signal generator 10 to obtain the signal source VPP, and the second end of the third resistor R3 is connected to the non-inverting input of the amplifier U. The second end of the third resistor R3 is grounded through the first capacitor C1, and the inverting input of the amplifier U is grounded. The gain adjustment unit 211 is connected to the amplifier U, specifically between the inverting input and the output of the amplifier U, and is used to adjust the amplification factor of the amplifier U for the signal source VPP. The output adjustment unit 212 is coupled to the power divider 30 and is used to adjust the voltage switching rate of the output signal source VPP of the amplifier U, ensuring that the voltage waveform shows a monotonically increasing change at the edge of change, for example, adjusting the voltage switching rate to be greater than 36V / 7us. It should be noted that there is at least one amplifier circuit 21, corresponding one-to-one with the signal source VPP.

[0027] For example, the gain adjustment unit 211 includes a first resistor R1, a second resistor R2, and an adjustable resistor Rx. The first end of the first resistor R1 is connected to one of the input terminals of the amplifier U, and the second end of the first resistor R1 is grounded. The two ends of the second resistor R2 are connected to the first end of the first resistor R1 and the output terminal of the amplifier U, respectively. The adjustable resistor Rx is connected in parallel with the second resistor R2. Thus, utilizing the concept of virtual short, the gain of the amplifier U is adjusted by changing the ratio of the parallel structure of the second resistor R2 and the adjustable resistor Rx to the resistance of the first resistor R1. Essentially, changing the resistance of the adjustable resistor Rx achieves adjustable gain for the amplifier U. Preferably, the adjustable resistor Rx is a thermistor, whose resistance decreases as temperature rises, thus suppressing temperature drift in the amplifier U.

[0028] For example, the output adjustment unit 212 includes a fourth resistor R4 and a second capacitor C2. The first end of the fourth resistor R4 is connected to the output terminal of the amplifier U, and the second end of the fourth resistor R4 is coupled to the power divider 30. The first end of the second capacitor C2 is connected to the second end of the fourth resistor R4, and the second end of the second capacitor C2 is grounded. By reasonably setting the values ​​of the fourth resistor R4, the second capacitor C2, and the fifth resistor R5, the output resistance is kept low, the output voltage switching rate is greater than 36V / 7us, and the circuit does not experience ringing. The voltage always changes monotonically at the edge of the waveform change. The fourth resistor R4 affects the output resistance of the amplifier U. Considering that a smaller fourth resistor R4 cannot always reduce the output resistance of the amplifier U and may cause distortion of the output voltage waveform, the inventors, through multiple experiments, have found that the optimal value range for the fourth resistor R4 is greater than or equal to 100 ohms and less than or equal to 300 ohms.

[0029] Preferably, the amplification module 20 further includes an output filter circuit 22 connected to the output adjustment unit 212, and the output filter circuit 22 is connected to the power divider 30. The signal output by the amplifier U is filtered by the output filter circuit 22 and then output to the power divider 30.

[0030] Figure 3 This is a schematic diagram of the output filter circuit according to an embodiment of the present invention. For example, see [reference needed]. Figure 3 The output filter circuit 22 includes a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a fifth capacitor C5. The sixth resistor R6, the fifth capacitor C5, the seventh resistor R7 and the eighth resistor R8 are connected in series between the output adjustment unit 212 and ground. The power divider 30 is connected between the sixth resistor R6 and the fifth capacitor C5.

[0031] Furthermore, the amplification module 20 also includes a power supply unit 23 connected to the amplifier U to supply power to the amplifier U. In one embodiment, the power supply unit 23 provides dual power supply (positive and negative power supply) to the amplifier U.

[0032] Figure 4 This is a schematic diagram of a power supply unit according to an embodiment of the present invention. For example, see [reference needed]. Figure 4 The power supply unit 23 includes a first voltage source U1 and a second voltage source U2 connected in series. The positive terminal of the first voltage source U1 is connected to the positive power supply terminal of the amplifier U, and the negative terminal of the first voltage source U1 is grounded. The negative terminal of the second voltage source U2 is connected to the negative power supply terminal of the amplifier U, and the positive terminal of the second voltage source U2 is grounded. In this way, the first voltage source U1 provides a positive power supply VCC1 to the amplifier U, and the second voltage source U2 provides a negative power supply VCC2 to the amplifier U, thereby realizing dual power supply for the amplifier U.

[0033] Preferably, voltage regulator capacitors (C6 to C11) are provided between the positive and negative terminals of the first voltage source U1 and the positive and negative terminals of the second voltage source U2. Further, there are multiple voltage regulator capacitors connected in parallel. A decoupling capacitor C3 and a bypass capacitor C4 connected in parallel with the decoupling capacitor C3 are provided between the positive terminal of the first voltage source U1 and ground, and between the negative terminal of the second voltage source U2 and ground. The provision of voltage regulator capacitors, decoupling capacitor C3, and bypass capacitor C4 ensures stable power output.

[0034] Preferably, the negative terminal of the first voltage source U1 and the positive terminal of the second voltage source U2 are short-circuited. This allows the voltage output to be doubled.

[0035] Although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. For any person skilled in the art, many possible variations and modifications can be made to the technical solutions of the present invention based on the disclosed technical content, or equivalent embodiments can be modified accordingly, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A signal amplification and expansion system, characterized in that, include: A signal generator is used to output at least one signal source; An amplifier circuit includes an amplifier, a gain adjustment unit, and an output adjustment unit. The amplifier is connected to the signal generator to amplify the signal source. The gain adjustment unit is connected to the amplifier to adjust the amplification factor of the amplifier on the signal source. The output adjustment unit is connected to the amplifier and is used to adjust the voltage switching rate of the signal source output by the amplifier; The power divider coupled to the output adjustment unit is used to expand the signal source after amplification by the amplifier from one channel to at least two channels.

2. The signal amplification and capacity expansion system according to claim 1, characterized in that, The multiplier adjustment unit includes a first resistor, a second resistor, and an adjustable resistor. The first end of the first resistor is connected to one of the input terminals of the amplifier, the second end of the first resistor is grounded, the two ends of the second resistor are respectively connected to the first end of the first resistor and the output terminal of the amplifier, and the adjustable resistor is connected in parallel with the second resistor.

3. The signal amplification and capacity expansion system according to claim 1, characterized in that, The output adjustment unit includes a fourth resistor, a fifth resistor, and a second capacitor. The first end of the fourth resistor is connected to the output terminal of the amplifier, and the second end of the fourth resistor is coupled to the power divider. The first end of the second capacitor is connected to the second end of the fourth resistor, and the second end of the second capacitor is grounded through the fifth resistor.

4. The signal amplification and capacity expansion system according to claim 3, characterized in that, The resistance of the fourth resistor is greater than or equal to 100 ohms and less than or equal to 300 ohms; and / or, the output adjustment unit adjusts the voltage switching rate to be greater than 36V / 7us.

5. The signal amplification and capacity expansion system according to claim 1, characterized in that, The amplifier circuit also includes an input filter unit, one end of which is connected to the signal generator and the other end of which is connected to the amplifier.

6. The signal amplification and capacity expansion system according to claim 1, characterized in that, The signal amplification and expansion system also includes an output filter circuit connected to the output adjustment unit, and the output filter circuit is connected to the power divider.

7. The signal amplification and capacity expansion system according to claim 6, characterized in that, The output filter circuit includes a sixth resistor, a seventh resistor, an eighth resistor, and a fifth capacitor. The sixth resistor, the fifth capacitor, the seventh resistor, and the eighth resistor are connected in series between the output adjustment unit and ground. The power divider is connected between the sixth resistor and the fifth capacitor.

8. The signal amplification and capacity expansion system according to claim 1, characterized in that, The signal amplification and expansion system also includes a power supply unit connected to the amplifier.

9. The signal amplification and capacity expansion system according to claim 8, characterized in that, The power supply unit includes a first voltage source and a second voltage source. The positive terminal of the first voltage source is connected to the positive power supply terminal of the amplifier, and the negative terminal of the first voltage source is grounded. The negative terminal of the second voltage source is connected to the negative power supply terminal of the amplifier, and the positive terminal of the second voltage source is grounded.

10. The signal amplification and capacity expansion system according to claim 9, characterized in that, A voltage stabilizing capacitor is provided between the positive and negative terminals of the first voltage source and between the positive and negative terminals of the second voltage source. A decoupling capacitor and a bypass capacitor connected in parallel with the decoupling capacitor are provided between the positive terminal of the first voltage source and ground, and between the negative terminal of the second voltage source and ground. The negative terminal of the first voltage source and the positive terminal of the second voltage source are short-circuited.

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