CN102944890A - PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system - Google Patents
PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system Download PDFInfo
- Publication number
- CN102944890A CN102944890A CN2012104401187A CN201210440118A CN102944890A CN 102944890 A CN102944890 A CN 102944890A CN 2012104401187 A CN2012104401187 A CN 2012104401187A CN 201210440118 A CN201210440118 A CN 201210440118A CN 102944890 A CN102944890 A CN 102944890A
- Authority
- CN
- China
- Prior art keywords
- passage
- detector
- integrated value
- value
- channel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention discloses a multianode PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system. The signal readout method comprises the following steps of: converting M*N array signals output by a detector into M channels of signals and N channels of signals on orthogonal directions by a symmetry charge distribution circuit; respectively carrying out amplification forming and digital integration processing on the M channels of signals and the N channels of signals to generate the integral numerical values of the processed M channels and N channels; transferring the integral numerical values of the processed M channels and N channels to a computer side; and calculating the position of the center of gravity in each channel direction with a local center of gravity method so as to determine the action position of a gamma photon on the detector. According to the scheme of the invention, noise brought by invalid channels can be eliminated in a process of obtaining the position information of a gamma example, and the positioning precision of the detector (especially a big-array output detector) is improved.
Description
Technical field
The present invention relates to nuclear detection technology and nuclear medicine technical field, and be particularly related to detector signal reading method and system based on multianode location-sensitive photomultiplier.
Background technology
At present based on scintillation crystal and photomultiplier (photomultiplier tube, PMT) nuclear detection technology has been widely used in positron emission computerized tomography (Positron EmissionComputed Tomography, PET) and single photon emission computerized tomography (Single PhotonEmission Computed Tomography, SPECT) be the nuclear medicine field of representative.
As the initial link in the imaging process, the spatial resolving power of detector has directly determined the spatial resolution index of imaging system, early stage detector adopts independent crystal and single pass PMT to be coupled one to one, this mode principle is simple, but because the PMT size does not cause more greatly resolution high and how much arrange very trouble, the enormous amount of required PMT is with high costs simultaneously.Occurred subsequently using a plurality of PMT to form array and crystal array coupling, utilized the position resolution of the distribution realization crystal array of passage of scintillation light, spatial resolution increases.Along with the development of PMT technology, some multianode position sensitive photo-multiplier tubes (Position Sensitive Photomultipler tube, PS-PMT) that are specifically designed to position sensing are developed out (such as H8500, the H9500 etc. of Hamamatsu).This class PS-PMT output anode is comprised of array usually, compares with single pass PMT, and the size of array element is less, and spatial resolving power is higher; Simultaneously the peripheral dead band of PS-PMT is less, arranges simply too much how much when adopting a plurality of PS-PMT to form more the large tracts of land array.
No matter be to adopt single PS-PMT or PS-PMT array, the output of detector is the array of a M * N normally, and resolution characteristic the best way the simplest is read the signal of this M * N passage separately exactly and is amplified respectively the processing such as shaping, but required like this data-acquisition system is very huge and expensive beyond doubt.By effective signal reading method M * N channel signal is reduced, can when reducing the data-acquisition system burden, obtain higher spatial resolving power.
Scheme of the prior art normally is converted to M * N array signal M channel signal and the N channel signal on the orthogonal directions.On each direction, respectively to corresponding M(or N) channel signal carries out preposition amplification and processes, again by adding circuit with each channel signal in proportion weight distribute, be transferred to and form processing in the shaping amplifier, be transferred to again the calculating of carrying out analog to digital conversion and barycentric coordinates on the integrated circuit board, wherein, this adding circuit is realized different weights by choosing different resistance values.
For scheme of the prior art, the channel signal that participates in coordinate Calculation adopts weighting summation, and corresponding signal noise also is M(or N) result of passage stack.Therefore, output array is larger, and the noise of introducing is more, and the resolution characteristic of detector is poorer, and is relatively poor for the expansibility of extensive this scheme of detector.In addition, the distribution of each channel signal is to realize different weight allocation by choosing different resistance values, and resistance device has certain trueness error, thereby causes the linearity in the detector plane image relatively relatively poor.
Therefore, need badly in the industry and a kind ofly can in the process of obtaining γ example positional information, can effectively remove the noise that invalid passage brings, improve the scheme of the bearing accuracy of detector (especially large array output detector).
Summary of the invention
In view of the problems referred to above of the prior art, the invention provides a kind of detector signal reading method and system based on multianode location-sensitive photomultiplier.
Detector signal reading method based on multianode location-sensitive photomultiplier of the present invention comprises:
Step S1: the M of this detector output * N array signal is converted to M channel signal and the N channel signal on the orthogonal directions by symmetrical electric charge distributor circuit;
Step S2: respectively this M channel signal and N channel signal are amplified shaping and digital integration processing, generate the integration numerical value of M passage and N passage;
Step S3: according to the integration numerical value of this M passage and N passage, adopt the local gravity model appoach, calculate the centre of gravity place on each channel direction, thereby determine the active position of γ photon on detector.
Signal read-out system based on multianode position sensitive photo-multiplier tube detector of the present invention comprises:
Symmetrical electric charge distributor circuit is converted to M channel signal and the N channel signal on the orthogonal directions for the M that this detector is exported * N array signal;
Processing module is used for respectively this M channel signal and N channel signal being amplified shaping and digital integration processing, generates the integration numerical value of M passage and N passage;
Computing module is used for the integration numerical value according to this M passage and N passage, adopts the local gravity model appoach, calculates the centre of gravity place on each channel direction, thereby determines the active position of γ photon on detector.
The signal reading method that the present invention proposes can effectively be removed the noise that invalid passage brings in the process of obtaining γ example positional information, improved the bearing accuracy of detector (especially large array output detector).
Description of drawings
Fig. 1 a is the process flow diagram of the detector signal reading method based on PS-PMT of the present invention,
Fig. 1 b is depicted as the concrete schematic diagram based on the detector signal reading method of PS-PMT;
Fig. 2 is the schematic diagram of the SCD circuit in the technical solution of the present invention;
Fig. 3 is the schematic diagram of the digital integration in the technical solution of the present invention;
Fig. 4 is the schematic diagram of the channel screen in the technical solution of the present invention;
Fig. 5 is the detector scatter diagram of the embodiment of the invention.
Embodiment
The exemplary embodiments that embodies feature ﹠ benefits of the present invention will be described in detail in the following description.Be understood that the present invention can have at different embodiment various variations, its neither departing from the scope of the present invention, and explanation wherein and appended accompanying drawing be when the usefulness that explain in itself, but not in order to limit the present invention.
The invention provides a kind of detector signal reading method based on PS-PMT, the method can be removed the noise that invalid passage brings in the process of obtaining γ example positional information, and improves the bearing accuracy of detector (especially large array output detector).
Be depicted as the process flow diagram of the detector signal reading method based on PS-PMT of the present invention referring to Fig. 1 a, Fig. 1 b is depicted as the concrete schematic diagram of the method.Describe in conjunction with Fig. 1 a and Fig. 1 b, the method comprises:
Step S1: the M of this detector output * N array signal is converted to M channel signal and the N channel signal on the orthogonal directions by symmetrical electric charge distributor circuit.
In this step, the output anode of establishing detector is the anode signal of M * N array, and (wherein, M and N are natural number, are that 50, N is that the value of 40, M and N is relevant with the performance of detector such as M.) by symmetrical SCD circuit (Symmetric Charged Division, electric charge distributor circuit) (being illustrated in figure 2 as the schematic diagram of SCD circuit), be converted into the M channel signal (A on the orthogonal directions
1, A
2..., A
M) and N channel signal (B
1, B
2..., B
N).
Step S2: respectively this M channel signal and N channel signal are amplified shaping and digital integration processing, the M passage after generation is processed and the integration numerical value of N passage.
In this step, respectively to A
1, A
2..., A
MAnd B
1, B
2..., B
NSignal is done to amplify and is shaped and digital integration processing (as shown in Figure 3), obtains the integrated value y of each passage
1, y
2..., y
MAnd x
1, x
2..., x
NReferring to Fig. 3, the simulating signal that a) is depicted as detector output among the figure is through amplifying the waveform after being shaped, digital integration is such as the b among the figure) shown in, by certain clock period this waveform is divided into the equally spaced time interval exactly, and to the process of the range value of waveform in each time interval summation.Take the channel signal of detector output as voltage signal V as example, then this voltage signal V is carried out the waveform that integration is about to voltage signal V and be divided into the equally spaced time interval, and the process that the range value of the waveform of the voltage signal V in each time interval is sued for peace.
Step S3: this M passage after above-mentioned processing and the integration numerical value of N passage are transferred to computer terminal, adopt the local gravity model appoach, calculate the centre of gravity place on each channel direction, thereby determine the active position of γ photon on detector.
In this step, with integrated value y
1, y
2..., y
MAnd x
1, x
2..., x
NBe transferred to computing machine, adopt the TCOG algorithm to calculate barycentric coordinates, thereby determine the active position of γ example on surveying.With x
1, x
2..., x
NBe example, adopt the calculation process of TCOG algorithm as follows:
1) to N passage integrated value summation ∑ x
i=x
1+ ... + x
N, get and the certain proportion that is worth is threshold value x
0, computing formula is: x
0=(∑ x
i)/b; Wherein the value of b can be set according to the detection demand.
2) channel screen (such as Fig. 4): with each passage integrated value (x
i) and threshold value (x
0) compare, if x
i＞x
0, then make x
iBe x
i-x
0If x
i≤ x
0, then make x
iBe 0;
As shown in Figure 4, among Fig. 4 a) is the distribution plan of 24 channel signal integrated values on a direction, and wherein the signal amplitude of edge gateway is very little, is mainly noise, the threshold value that the dotted line representative calculates; B among Fig. 4) be the distribution plan of the 24 channel signal integrated values of threshold ratio after, can see passing threshold relatively on scheming, the edge gateway signal noise is disallowable, only has the channel signal of regional area to be retained participant position and calculates.
3) barycentric coordinates are calculated.
Computing formula for the barycentric coordinates X on the x direction is: X=(∑ i * x
i)/∑ x
i, wherein i is channel number, for the x direction, the i value is 1 to N, x
iFor to integrated value that should passage.
The channel signal of y direction is processed identical with the x direction with the method for center of gravity calculation, repeated no more herein.
Based on above-mentioned technical scheme, the embodiment of a kind of signal reading method based on the PS-PMT detector of the present invention is as follows:
Detector is by NaI scintillation crystal array (75 * 75) and 3 * 3 H8500(Hamamatsu) photomultiplier tube array forms.Crystal unit is 1.8mm * 1.8mm * 6mm, crystal interval 0.2mm, and the size of whole detector output anode array is 24 * 24.Under the irradiation of Na-22 source, calculate the barycentric coordinates of the example that at every turn detects according to this programme, and drafting obtains scatter diagram as shown in Figure 5, as shown in Figure 5, between points separately situation has reflected the spatial resolving power of detector on the scatter diagram, can find out from this figure that the present invention can have preferably spatial resolving power.
The beneficial effect of technical scheme of the present invention is as follows:
(1) object of channel screen is the digital integration value of each passage in the technical solution of the present invention, and the calculating of carrying out also is linear numerical evaluation, has reduced the noise that electronic devices and components bring under the analog signal processing mode, has improved the performance of detector.
(2) compared with prior art, the channel screen in the technical solution of the present invention and barycentric coordinates are calculated and are all finished at computer terminal, have avoided thus the limitation that electronics is processed, and expansibility is strong.
(3) threshold value in the technical solution of the present invention is set at computer terminal, so that the debugging of detector is more convenient and flexible.
In addition, participate in the y that TCOG calculates in the technical solution of the present invention
1, y
2..., y
MAnd x
1, x
2..., x
NTo the digital integration value of channel signal waveform separately.Because the waveform of each channel signal is basically identical, the peak value of waveform is proportional with the digital integration value, therefore scheme as an alternative, and also can directly choosing separately, the peak value of channel signal waveform carries out the calculating of local gravity model appoach.
The present invention also provides a kind of signal read-out system based on multianode position sensitive photo-multiplier tube detector, comprising:
Symmetrical electric charge distributor circuit is converted to M channel signal and the N channel signal on the orthogonal directions for the M that this detector is exported * N array signal;
Processing module is used for respectively this M channel signal and N channel signal being amplified shaping and digital integration processing, generates the integration numerical value of M passage and N passage;
Computing module is used for the integration numerical value according to this M passage and N passage, adopts the local gravity model appoach, calculates the centre of gravity place on each channel direction, thereby determines the active position of γ photon on detector.
Wherein, this computing module can be a computing machine, with the limitation of avoiding electronics to process, improves expansibility.
Those skilled in the art should recognize change and the retouching of doing in the situation that does not break away from the scope and spirit of the present invention that the appended claim of the present invention discloses, all belong within the protection domain of claim of the present invention.
Claims (8)
1. the detector signal reading method based on multianode location-sensitive photomultiplier is characterized in that, comprising:
Step S1: the M of this detector output * N array signal is converted to M channel signal and the N channel signal on the orthogonal directions by symmetrical electric charge distributor circuit;
Step S2: respectively this M channel signal and N channel signal are amplified shaping and digital integration processing, generate the integration numerical value of M passage and N passage;
Step S3: according to the integration numerical value of this M passage and N passage, adopt the local gravity model appoach, calculate the centre of gravity place on each channel direction, thereby determine the active position of γ photon on detector.
2. method according to claim 1 is characterized in that, the integration numerical value of this M passage and N passage is transferred to computer terminal, is calculated the coordinate of the center of gravity on each channel direction by computer terminal.
3. method according to claim 1, it is characterized in that, the computing method of this local gravity model appoach are: for the M channel signal on the same direction or N channel signal, get the predetermined ratio of cumulative and value of each passage integrated value as threshold value, each passage integrated value and this threshold value are compared, if a passage integrated value, then directly is set to this passage integrated value zero less than this threshold value; If a passage integrated value greater than this threshold value, is then got the difference of this passage integrated value and this threshold value as the integrated value of this passage; According to the integrated value of each passage, calculate the coordinate of the center of gravity on each channel direction.
4. method according to claim 3 is characterized in that, the method for calculating the barycentric coordinates X on the channel direction wherein is: X=(∑ i * x
i)/∑ x
i, wherein i is channel number, x
iFor to integrated value that should passage.
5. the signal read-out system based on multianode position sensitive photo-multiplier tube detector is characterized in that, comprising:
Symmetrical electric charge distributor circuit is converted to M channel signal and the N channel signal on the orthogonal directions for the M that this detector is exported * N array signal;
Processing module is used for respectively this M channel signal and N channel signal being amplified shaping and digital integration processing, generates the integration numerical value of M passage and N passage;
Computing module is used for the integration numerical value according to this M passage and N passage, adopts the local gravity model appoach, calculates the centre of gravity place on each channel direction, thereby determines the active position of γ photon on detector.
6. system according to claim 1 is characterized in that, described computing module is a computing machine, and this processing module is transferred to this computing machine with the integration numerical value of this M passage and N passage, is calculated the coordinate of the center of gravity on each channel direction by this computing machine.
7. system according to claim 5, it is characterized in that, the computing method of this local gravity model appoach are: for the M channel signal on the same direction or N channel signal, get the predetermined ratio of cumulative and value of each passage integrated value as threshold value, each passage integrated value and this threshold value are compared, if a passage integrated value, then directly is set to this passage integrated value zero less than this threshold value; If a passage integrated value greater than this threshold value, is then got the difference of this passage integrated value and this threshold value as the integrated value of this passage; According to the integrated value of each passage, calculate the coordinate of the center of gravity on each channel direction.
8. system according to claim 7 is characterized in that, the method for calculating the barycentric coordinates X on the channel direction wherein is: X=(∑ i * x
i)/∑ x
i, wherein i is channel number, x
iFor to integrated value that should passage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210440118.7A CN102944890B (en) | 2012-11-06 | 2012-11-06 | PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210440118.7A CN102944890B (en) | 2012-11-06 | 2012-11-06 | PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102944890A true CN102944890A (en) | 2013-02-27 |
| CN102944890B CN102944890B (en) | 2015-06-24 |
Family
ID=47727851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210440118.7A Active CN102944890B (en) | 2012-11-06 | 2012-11-06 | PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102944890B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103645491A (en) * | 2013-11-25 | 2014-03-19 | 中国科学院高能物理研究所 | Method, device and system for radioactive source positioning |
| CN104539243A (en) * | 2014-12-12 | 2015-04-22 | 北京永新医疗设备有限公司 | Position reading-out device of gamma rays and position reading-out system of gamma rays |
| CN106580359A (en) * | 2016-12-02 | 2017-04-26 | 中国科学院深圳先进技术研究院 | Method and device for signal processing of detector |
| CN107874773A (en) * | 2017-10-16 | 2018-04-06 | 中派科技（深圳）有限责任公司 | Photon detection method, apparatus, equipment and system and storage medium |
| CN110426730A (en) * | 2019-07-19 | 2019-11-08 | 东软医疗系统股份有限公司 | Signal read circuit, signal reading method and device |
| CN113850093A (en) * | 2021-09-08 | 2021-12-28 | 中国原子能科学研究院 | Positioning method, detecting device and storage medium |
| US11510636B2 (en) | 2017-06-30 | 2022-11-29 | Shanghai United Imaging Healthcare Co., Ltd. | System and method for positron emission tomography |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050199794A1 (en) * | 2004-03-15 | 2005-09-15 | Medhat Mickael | Spectral gamma ray logging-while-drilling system |
| CN201197713Y (en) * | 2008-05-12 | 2009-02-25 | 丁厚本 | Structure of portable type multifunctional micro-dose medical CT machine |
-
2012
- 2012-11-06 CN CN201210440118.7A patent/CN102944890B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20050199794A1 (en) * | 2004-03-15 | 2005-09-15 | Medhat Mickael | Spectral gamma ray logging-while-drilling system |
| CN201197713Y (en) * | 2008-05-12 | 2009-02-25 | 丁厚本 | Structure of portable type multifunctional micro-dose medical CT machine |
Non-Patent Citations (2)
| Title |
|---|
| 肖腾飞: "《多阳极光电倍增管读出ASIC设计》", 《核电子学与探测技术》, vol. 32, no. 9, 30 September 2012 (2012-09-30), pages 1004 * |
| 赵翠兰等: "多阳极位置灵敏光电倍增管位置读出电路的设计实现", 《原子核物理评论》, vol. 27, no. 01, 31 March 2010 (2010-03-31), pages 64 - 66 * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103645491A (en) * | 2013-11-25 | 2014-03-19 | 中国科学院高能物理研究所 | Method, device and system for radioactive source positioning |
| CN103645491B (en) * | 2013-11-25 | 2016-12-07 | 中国科学院高能物理研究所 | Radioactive source localization method, Apparatus and system |
| CN104539243A (en) * | 2014-12-12 | 2015-04-22 | 北京永新医疗设备有限公司 | Position reading-out device of gamma rays and position reading-out system of gamma rays |
| CN104539243B (en) * | 2014-12-12 | 2017-11-21 | 北京永新医疗设备有限公司 | The position read out device of gamma rays and the position read-out system of gamma rays |
| CN106580359A (en) * | 2016-12-02 | 2017-04-26 | 中国科学院深圳先进技术研究院 | Method and device for signal processing of detector |
| CN106580359B (en) * | 2016-12-02 | 2020-04-14 | 中国科学院深圳先进技术研究院 | Detector signal processing method and device |
| US11510636B2 (en) | 2017-06-30 | 2022-11-29 | Shanghai United Imaging Healthcare Co., Ltd. | System and method for positron emission tomography |
| CN107874773A (en) * | 2017-10-16 | 2018-04-06 | 中派科技（深圳）有限责任公司 | Photon detection method, apparatus, equipment and system and storage medium |
| CN107874773B (en) * | 2017-10-16 | 2020-12-08 | 中派科技（深圳）有限责任公司 | Photon detection method, device, equipment and system and storage medium |
| CN110426730A (en) * | 2019-07-19 | 2019-11-08 | 东软医疗系统股份有限公司 | Signal read circuit, signal reading method and device |
| CN110426730B (en) * | 2019-07-19 | 2022-11-01 | 东软医疗系统股份有限公司 | Signal reading circuit, signal reading method and device |
| CN113850093A (en) * | 2021-09-08 | 2021-12-28 | 中国原子能科学研究院 | Positioning method, detecting device and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102944890B (en) | 2015-06-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102944890B (en) | PS-PMT (position sensitive-photomultiplier tube) based detector signal readout method and system | |
| CN102288982B (en) | Scintillator-based two-dimensional position detection system | |
| CN105182402B (en) | A kind of bearing calibration of scintillation crystal detectors gain and device | |
| CN104035122A (en) | Method and device for correcting energy value | |
| US8247780B2 (en) | High density, proportional-mode, APD arrays for individual scintillator readout in PET applications | |
| JP6679715B2 (en) | Detector signal readout channel multiplexing method | |
| CN1971652B (en) | Method and apparatus for processing of detector signals | |
| CN104635255A (en) | Scintillator neutron detector system and digital reading system thereof | |
| CN108646284B (en) | Gamma-spectrum combined detection system and gamma-spectrum measurement method | |
| CN111953350A (en) | SiPM array reading device and method based on gravity center method | |
| CN116381772A (en) | Real-time energy response correction method, system and terminal for dose rate meter | |
| CN104614757B (en) | The method and system of photoelectric conversion module gain in a kind of demarcation gamma camera | |
| WO2020114330A1 (en) | Method for locating hit point of ray in scintillation crystal, and system therefor | |
| Wang et al. | Obtaining low energy γ dose with CMOS sensors | |
| CN104382611B (en) | Correction method and device of output energy of photomultiplier | |
| CN115420226A (en) | Ray action position positioning device and method based on pulse width | |
| CN210294543U (en) | SiPM-based digital radiation detection module | |
| US10616521B2 (en) | Imaging device for detecting sparse event information in a pixel array | |
| JP3323323B2 (en) | Scintillation camera | |
| US11774608B2 (en) | Sensor layout for direct converter detector | |
| CN109490940B (en) | Method for testing light-emitting decay time of scintillator array | |
| Tumer et al. | Performance of RENA-3 IC with position-sensitive solid-state detectors | |
| CN104730566A (en) | Method and system for calibrating average protector response function of photovoltaic conversion modules | |
| Salçin et al. | Design considerations for the next-generation MAPMT-based monolithic scintillation camera | |
| CN110770604B (en) | Radiation detection device and nuclear medicine diagnosis device provided with same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |