CN216317665U - SIPM signal reading circuit applied to PET detector and PET equipment - Google Patents

Abstract

The utility model provides a SIPM signal readout circuit applied to a PET detector and PET equipment, the SIPM signal readout circuit comprises a crystal array and a photomultiplier, the crystal array receives scanning radiation energy to generate an optical signal, the photomultiplier receives the optical signal and converts the optical signal into an electric signal, and the SIPM signal readout circuit further comprises: the carrier plate covers the surface of the crystal array and is aligned with the crystal array; the inductor is electrically connected with the photomultiplier and used for receiving a fast signal in the electric signals; the operational amplifier is electrically connected with the inductor and is used for positively amplifying the electric signal to form an amplified signal; the connector is electrically connected with the operational amplifier and used for transmitting the amplified signal to the PET detector; the photomultiplier tube transmits a standard signal of the electrical signals to the connector so that the connector receives the amplified signal and the standard signal at the same time. After the technical scheme is adopted, the time resolution can be improved, and meanwhile, the electric signals can be transmitted without distortion.

Description

SIPM signal reading circuit applied to PET detector and PET equipment

Technical Field

The utility model relates to the field of medical equipment, in particular to a SIPM signal reading circuit applied to a PET detector and PET equipment.

Background

Positron Emission Tomography (PET) is a detection device for Positron tracers, and has extremely high sensitivity and accurate quantification function. PET devices have become the best imaging technique for the diagnosis, clinical staging and efficacy assessment of diseases of the tumor, nervous and cardiovascular systems. The PET Detector (Detector) is an important component of a molecular imaging device such as PET. The material combination, the structural design and the performance of the PET detector directly influence the application of molecular imaging equipment such as PET in clinic and scientific research, and the quality of the detector directly determines the quality of a PET system.

In the PET detector, an electric signal formed by a photomultiplier (SIPM photoelectric converter) covering the surface of a crystal array is directly transmitted to a PET detector or a test platform DAQ at the later stage, so that the time resolution is high in the detection process without any treatment, and the signal has certain noise.

In this regard, there is a need for a novel SIPM signal readout circuit for PET detectors that generates a clean, noise-free electrical signal.

SUMMERY OF THE UTILITY MODEL

In order to overcome the technical defects, the utility model aims to provide a SIPM signal readout circuit applied to a PET detector and a PET device, which can improve the time resolution and transmit an electric signal without distortion.

The utility model discloses a SIPM signal reading circuit applied to a PET detector, which comprises a crystal array and a photomultiplier, wherein the crystal array receives scanning radiation energy to generate an optical signal, the photomultiplier receives the optical signal and converts the optical signal into an electric signal,

the SIPM signal sensing circuit further includes:

the carrier plate covers the surface of the crystal array and is aligned with the crystal array;

the inductor is electrically connected with the photomultiplier and used for receiving a fast signal in the electric signals;

the operational amplifier is electrically connected with the inductor and is used for positively amplifying the electric signal to form an amplified signal;

the connector is electrically connected with the operational amplifier and used for transmitting the amplified signal to the PET detector;

the photomultiplier tube transmits a standard signal of the electrical signals to the connector so that the connector receives the amplified signal and the standard signal at the same time.

Preferably, the crystal array is 8 x 8, and the size of the carrier plate is the same as that of the crystal array;

the photomultiplier tubes are arranged in an 8-by-8 array, correspond to the crystals in the crystal array one by one, and output fast signals by taking 4-by-4 as one path, thereby outputting 4 paths of fast signals.

Preferably, the SIPM signal sensing circuit further includes:

and the signal transformer is electrically connected between the photomultiplier and the inductor and is used for impedance matching of the fast signal.

Preferably, the signal transformer is at RF radio frequency level, having a maximum frequency, the threshold of the maximum frequency being 3 GHz.

The utility model also discloses PET equipment comprising the SIPM signal readout circuit.

After the technical scheme is adopted, compared with the prior art, the method has the following beneficial effects:

1. by using the impedance matching of the signal transformer, the signal voltage and the signal power can be transmitted without distortion;

2. after the first-stage processing of the fast signals and amplification, clean and noiseless electric signals are formed, the processing of the detector-stage signals and data of the later stage is greatly facilitated, and the time resolution is finally improved.

Drawings

Fig. 1 is a schematic structural diagram of a crystal array and a carrier according to a preferred embodiment of the utility model;

fig. 2 is a schematic circuit diagram of a SIPM signal readout circuit according to a preferred embodiment of the present invention.

Detailed Description

The advantages of the utility model are further illustrated in the following description of specific embodiments in conjunction with the accompanying drawings.

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.

In the description of the present invention, unless otherwise specified and limited, it is to be noted that the terms "mounted," "connected," and "connected" are to be interpreted broadly, and may be, for example, a mechanical connection or an electrical connection, a communication between two elements, a direct connection, or an indirect connection via an intermediate medium, and specific meanings of the terms may be understood by those skilled in the art according to specific situations.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in themselves. Thus, "module" and "component" may be used in a mixture.

Referring to fig. 1 and 2, the SIPM signal readout circuit applied to the PET detector includes a crystal array and a photomultiplier, the crystal array is disposed in the PET detector, and when the PET detector operates, the energy of the generated scanning radiation is received by the crystal array, so as to determine the pathological changes in the human body through energy loss and phase. After the crystal array receives the scanning radiation energy, the scintillation crystal excited by the energy emits fluorescence to generate an optical signal, and the photomultiplier is arranged at the lower stage of the crystal array, receives the optical signal and converts the optical signal into an electric signal. In the present embodiment, the electric signal generated by the photomultiplier is processed, and specifically, the SIPM (photomultiplier) signal readout circuit further includes: the carrier plate can be a circuit board pasted with SIPM, covers the surface of the crystal array and is aligned with the crystal array, so that the full digital output of an electric signal is realized; the inductor is electrically connected with the photomultiplier, reduces impedance influence and receives a fast signal in the electric signal; the operational amplifier is electrically connected with the inductor and is used for positively amplifying the electric signal, and the amplification factor can be the conventional positive multiple of the operational amplifier to form an amplified signal; and the connector is electrically connected with the operational amplifier and used for forwarding the amplified signal to the PET detector or a next-stage test platform. Meanwhile, the photomultiplier tube transmits a standard signal among the electrical signals to the connector, so that the connector receives the amplified signal and the standard signal at the same time. Through the configuration, the electric signal of the design of the carrier plate is divided into multiple paths, so that the phenomena that the single SIPM photoelectric conversion signal is too small and is not easy to collect in the prior art are avoided. Meanwhile, the use of the inductor and the operational amplifier is combined, so that on one hand, the impedance influence can be reduced, on the other hand, the amplified signal is more accurate in detection of the PET detector and data utilization of the test platform, and for the next stage, the obtained detection result is more accurate.

In a preferred embodiment, the crystal array is 8 x 8, and the size of the carrier plate is the same as that of the crystal array; the photomultiplier is 8 × 8, 64 chips in total, and the physical layer and the crystal size are kept consistent, so that an output signal is formed; the carrier plate divides the output signal into 4 × 4 basic transmission paths, namely 4 × 4 is output to generate 4 paths of fast signals; meanwhile, the standard signals which are not decomposed are sent to the connector together for synchronous use and verification of the connector.

Furthermore, the SIPM signal readout circuit further includes a signal transformer electrically connected between the photomultiplier and the inductor for impedance matching of the fast signal, wherein the signal transformer is in RF radio frequency class, has a highest frequency, and the threshold of the highest frequency is 3GHz, and is mainly used for impedance matching.

When the SIPM signal readout circuit of any of the above embodiments is provided and the fast signal obtained by the SIPM signal readout circuit is compared with the standard signal obtained without the SIPM signal readout circuit, it is obvious that the time resolution of the standard signal obtained without the SIPM signal readout circuit is 461PS, and the time resolution of the fast signal obtained by the SIPM signal readout circuit is 374PS, and the time resolution is greatly reduced under the time composite data processing performed after the two signals are transmitted to the PET detector.

Having the SIPM signal readout circuit of any of the embodiments described above, it can be applied to a PET device.

It should be noted that the embodiments of the present invention have been described in terms of preferred embodiments, and not by way of limitation, and that those skilled in the art can make modifications and variations of the embodiments described above without departing from the spirit of the utility model.

Claims (5)

1. A SIPM signal readout circuit for a PET detector, comprising a crystal array to receive scanning radiation energy to generate an optical signal and a photomultiplier tube to receive the optical signal and convert it to an electrical signal,

the SIPM signal sensing circuit further includes:

the carrier plate covers the surface of the crystal array and is aligned with the crystal array;

the inductor is electrically connected with the photomultiplier and receives a fast signal in the electric signals;

the operational amplifier is electrically connected with the inductor and is used for positively amplifying the electric signal to form an amplified signal;

the connector is electrically connected with the operational amplifier and used for transmitting the amplified signal to the PET detector;

the photomultiplier tube sends a standard signal in the electrical signals to the connector so that the connector receives the amplified signal and the standard signal simultaneously.

2. The SIPM signal readout circuit of claim 1,

the crystal array is 8-by-8, and the size of the carrier plate is the same as that of the crystal array;

the photomultiplier is arranged in an 8-by-8 array, corresponds to the crystals in the crystal array one by one, and outputs a fast signal by taking 4-by-4 as one path, thereby outputting 4 paths of fast signals.

3. The SIPM signal readout circuit of claim 2,

the SIPM signal sensing circuit further includes:

and the signal transformer is electrically connected between the photomultiplier and the inductor and is used for impedance matching of the fast signal.

4. The SIPM signal readout circuit of claim 3,

the signal transformer is in RF radio frequency level and has a highest frequency, and the threshold value of the highest frequency is 3 GHz.

5. A PET device comprising a SIPM signal readout circuit as claimed in any one of claims 1-4.

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