Patent US4852056A successfully refreshed from Google Patents.
US4852056A
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Multiple sensor position locating system
Assignee: BOARD OF REGENTS ACTING FOR AND ON BEHALF OF UNIVERSITY OF MICHIGAN ANN ARBOR MI 48109 A MI CORP
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Filing: 1986-06-20
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Granted: 1989-07-25
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Expires: 2006-06-20
Abstract
Abstract A system for locating the position of a source of a detachable emittance is particularly adapted for locating the position of a scintillation event in a scintillation crystal which has arranged adjacent thereto a plurality of photomultiplier tubes arranged in a predetermined configuration for detecting the scintillation event. In a single photon emission computer tomography (SPECT) embodiment, a system which utilizes the present invention is initialized by storing weighting factors which are derived from placing a source of radiation in a plurality of known locations. The output values of the photomultiplier tubes are stored in a calibration file and subjected to a mathematical process to produce the weighting factors which are subsequently stored in a memory. During operation of the system, the signal values from the photomultiplier tubes are combined with the weighting factors to produce weighted signals which are then summed together to produce a composite weighted signal. The addresses of the weighting factors are correlated to position information; the correct position information being determined in response to the composite weighted signal assuming a predetermined value.
Inventors
- 👤 W. Leslie Rogers
- 👤 Neal H. Clinthorne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:45
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/164; G01T1/1641; G01T1/1644
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
190 words
A system for locating a position of a source of a detectable emittance, the system comprising: a plurality of sensors arranged in a predetermined configuration with respect to one another, each for detecting the detectable emittance and producing at an associated output thereof a respective sensor signal having a sensor signal value which is substantially responsive to the detectable emittance impinging on said associated sensor; memory means for storing a plurality of weighting values, each associated with a respective one of said sensors, said weighting values being responsive to a sensor response characteristic of said associated one of said sensors and corresponding to a predetermined distance value; arithmetic combiner means having a first input for receiving at least one of said sensor signals, and a second input for receiving a weighting value from said memory means, for producing at an output thereof a composite weighted signal having a composite weighted signal value responsive to said sensor signal value and said weighting value, said weighted signal values being established in accordance with the relationship: ##EQU5## and position encoder means for producing a position value responsive to said composite weighted signal value.
Claim 2
Independent Claim
190 words
A system for locating a position of a source of a detectable emittance, the system comprising: a plurality of sensors arranged in a predetermined configuration with respect to one another, each for detecting the detectable emittance and producing at an associated output thereof a respective sensor signal having a sensor signal value which is substantially responsive to the detectable emittance impinging on said associated sensor; memory means for storing a plurality of weighting values, each associated with a respective one of said sensors, said weighting values being responsive to a sensor response characteristic of said associated one of said sensors and corresponding to a predetermined distance value; arithmetic combiner means having a first input for receiving at least one of said sensor signals, and a second input for receiving a weighting value from said memory means, for producing at an output thereof a composite weighted signal having a composite weighted signal value responsive to said sensor signal value and said weighting value, said weighted signal values being established in accordance with the relationship: ##EQU5## and position encoder means for producing a position value responsive to said composite weighted signal value.
Claim 3
Dependent Claim
33 words
The system of claim 1 wherein there is further provided range selector means responsive to said sensor signals for identifying one of said sensors as having associated therewith a highest sensor signal value.
Claim 4
Dependent Claim
107 words
The system of claim 2 wherein said range selector comprises: a plurality of comparator means, each associated with one of said sensors and producing a respective comparator output signal having first and second states, each of said comparator means being coupled to one another whereby only a one of said comparator means associated with said sensor having highest sensor signal value produces said comparator output signal in said second state; and memory address control means for recalling at least selected ones of said weighting values from said memory means in response to said one of said comparator means producing said comparator output signal in said second state.
Claim 5
Dependent Claim
48 words
The system of claim 1 wherein there is further provided a plurality of first sample and hold means, each associated with a respective one of said sensors, for producing at an output thereof a signal corresponding to said sensor signal value of said associated one of said sensors.
Claim 6
Dependent Claim
74 words
The system of claim 4 wherein there are further provided: a plurality of second sample and hold means, each associated with a respective one of said sensors, for producing at an output thereof a signal corresponding to said sensor signal value of said associated one of said sensors; and multiplex means for producing at an output thereof a signal corresponding to an output signal selectably of said first and second sample and hold means.
Claim 7
Dependent Claim
100 words
The system of claim 1 wherein said arithmetic combiner means comprises: a plurality of converter means each for receiving at a first input thereof a converter input signal having a magnitude corresponding to a respectively associated one of said sensor signal values, receiving at a second input thereof a respectively associated one of said weighting values, and producing at an output thereof a converter output signal having associated therewith a weighted sensor signal value; and summing means for receiving said weighted sensor signal values and producing at an output thereof said composite weighted signal having said composite weighted signal value.
Claim 8
Dependent Claim
28 words
The system of claim 6 wherein said outputs of said plurality of converter means each comprise complementary outputs corresponding to positive and negative weighted sensor signal values, respectively.
Claim 9
Dependent Claim
26 words
The system of claim 7 wherein there is further provided detector means for producing a detector output signal responsive to a predetermined composite weighted signal value.
Claim 10
Dependent Claim
14 words
The system of claim 8 wherein said predetermined composite weighted signal value is zero.
Claim 11
Dependent Claim
166 words
An arrangement for locating a position of a scintillation event in a predetermined region, the arrangement comprising: a plurality of photomultiplier elements (PME) arranged in an array configuration with respect to one another, each for detecting the scintillation event and producing a PME signal having a PME signal value which is related to a distance between said PME and the scintillation event; weighting means for applying a respectively associated plurality of weighting values to at least selected ones of said PME signal values to produce a corresponding plurality of weighted PME signal values, said weighting values being responsive to a response characteristic of said respectively associated selected ones of said PMEs, and established in accordance with the relationship: ##EQU6## summing means for combining said weighted PME signal values to produce a composite PME signal; and correlator means for correlating said plurality of weighting values to distance values whereby a distance value of the scintillation event is selected when said composite PME signal assumes a predetermined value.
Claim 12
Dependent Claim
166 words
An arrangement for locating a position of a scintillation event in a predetermined region, the arrangement comprising: a plurality of photomultiplier elements (PME) arranged in an array configuration with respect to one another, each for detecting the scintillation event and producing a PME signal having a PME signal value which is related to a distance between said PME and the scintillation event; weighting means for applying a respectively associated plurality of weighting values to at least selected ones of said PME signal values to produce a corresponding plurality of weighted PME signal values, said weighting values being responsive to a response characteristic of said respectively associated selected ones of said PMEs, and established in accordance with the relationship: ##EQU6## summing means for combining said weighted PME signal values to produce a composite PME signal; and correlator means for correlating said plurality of weighting values to distance values whereby a distance value of the scintillation event is selected when said composite PME signal assumes a predetermined value.
Claim 13
Dependent Claim
41 words
The arrangement of claim 10 wherein said weighting means comprises: weight memory means for storing said plurality of weighting values; and multiplier means for producing said weighted PME signal values in response to said PME signal values and said weighting values.
Claim 14
Dependent Claim
38 words
The arrangement of claim 11 wherein said correlator means comprises a position ROM having an input for receiving address data corresponding to said weighting values in said weight memory and an output for producing a corresponding positional value.
Claim 15
Dependent Claim
22 words
The arrangement of claim 10 further comprising weighting range selector means for identifying a positional range in which the scintillation event occurred.
Claim 16
Dependent Claim
31 words
The arrangement of claim 13 wherein said weighting range selector means comprises PME identifier means for identifying a one of said PMEs which has a highest PME signal value associated therewith.
Claim 17
Dependent Claim
20 words
The arrangement of claim 10 wherein there is further provided sample and hold means for holding a PME signal value.
Claim 18
Dependent Claim
25 words
The arrangement of claim 15 wherein there is further provided multiplexer means for selecting between first and second ones of said sample and hold means.
Claim 19
Independent Claim
132 words
A method of determining a position of a source of a detectable emittance, the method comprising the steps of: receiving a plurality of sensor signals, each having a sensor signal value responsive to the detectable emittance, from a respective plurality of sensors arranged in a predetermined configuration with respect to one another; combining said sensor signal values with respectively associated weighting factors responsive to sensor response characteristics of said respective plurality of said sensors and to corresponding predetermined distance values, to produce a plurality of weighted sensor signal values, said weighting factors being produced in accordance with the relationship: ##EQU7## further combining said weighted sensor signal values to form a composite weighted sensor signal having an associated composite weighted sensor signal value; and correlating said weighting factors with respectively associated position information.
Claim 20
Independent Claim
132 words
A method of determining a position of a source of a detectable emittance, the method comprising the steps of: receiving a plurality of sensor signals, each having a sensor signal value responsive to the detectable emittance, from a respective plurality of sensors arranged in a predetermined configuration with respect to one another; combining said sensor signal values with respectively associated weighting factors responsive to sensor response characteristics of said respective plurality of said sensors and to corresponding predetermined distance values, to produce a plurality of weighted sensor signal values, said weighting factors being produced in accordance with the relationship: ##EQU7## further combining said weighted sensor signal values to form a composite weighted sensor signal having an associated composite weighted sensor signal value; and correlating said weighting factors with respectively associated position information.
Claim 21
Dependent Claim
44 words
The method of claim 17 wherein there is provided the further step of predefining a range in which the source of detectable emittance is located by identifying a one of said sensors having the largest of said plurality of sensor signal values associated therewith.
References Cited (Backward Citations)
US4593198A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |