# US 2024/0188918 A1 · Timer-based amplitude correction method for photon counting computed tomography > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2024/0188918 A1 - Document ID: US20240188918A1 - Status: Published application - Kind: A1 - Application number: 18/065,385 - Filed: 2022-12-13 - Published: 2024-06-13 - Earliest claimed: 2022-12-13 - Assignees: Analog Devices, Inc. - Applicants: Analog Devices, Inc. - Inventors: Sunrita PODDAR; Patrick S. RIEHL; Matthew A. WOODRUFF - Web page: https://patentgrep.com/patent/US20240188918A1 ## CPC - G01T 1/171: {Compensation of dead-time counting losses} - G01R 29/0273: {the pulse characteristic being duration, i.e. width (indicating that frequency of pulses is above or below a certain limit)} - A61B 6/5258: {involving detection or reduction of artifacts or noise} - A61B 2560/0223: of calibration, e.g. protocols for calibrating sensors - G01T 1/40: Stabilisation of spectrometers - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract One embodiment is a method of deconvolving overlapping first and second pulses in a photon-counting CT scanning system, the method comprising detecting a first pulse event having a first detected level; detecting a second pulse event having a second detected level; determining an amount of time that elapses between the detected first pulse event and the detected second pulse event; and reconstructing the first pulse and the second pulse using the first and second detected levels, the duration of time between the first and second pulse events, and a known pulse shape. ## Claims ### Claim 1 A method of deconvolving overlapping pulses in a photon-counting CT scanning system, the method comprising: detecting a number of events in a sequence of discriminator codes; determining amounts of time that elapsed between successive ones of the detected events; and reconstructing a most likely sequence of events that caused a measured pattern of discriminator codes based on measured code values associated with each of the detected events, the amounts of time that elapsed between successive ones of the detected events, and a known basis pulse shape. ### Claim 2 (depends on 1) The method of claim 1, wherein the reconstructing is performed using an arithmetic equation. ### Claim 3 (depends on 1) The method of claim 1, wherein the reconstructing is performed using a lookup table. ### Claim 4 (depends on 1) The method of claim 1, wherein the reconstructing is performed using a synchronous digital state machine. ### Claim 5 (depends on 1) The method of claim 1, wherein the reconstructing is performed using timers and an event-driven state machine. ### Claim 6 A method of deconvolving overlapping first and second pulses in a photon-counting CT scanning system, the method comprising: detecting a first pulse event having a first detected level; detecting a second pulse event having a second detected level; determining an amount of time that elapses between the detected first pulse event and the detected second pulse event; and reconstructing the first pulse and the second pulse using the first and second detected levels, the duration of time between the first and second pulse events, and a known basis pulse shape. ### Claim 7 (depends on 6) The method of claim 6, wherein the detecting the first pulse event is performed using one of a time-over-threshold (TOT) event detection technique and a tick-down event detection technique. ### Claim 8 (depends on 6) The method of claim 6, wherein the detecting the second pulse event is performed using one of a time-over-threshold (TOT) event detection technique and a tick-down event technique. ### Claim 9 (depends on 6) The method of claim 6, further comprising incrementing a counter corresponding to the reconstructed first pulse. ### Claim 10 (depends on 6) The method of claim 6, further comprising incrementing a counter corresponding to the reconstructed second pulse. ### Claim 11 (depends on 6) The method of claim 6, wherein the reconstructing comprises performing an amplitude correction technique on the first and second pulses. ### Claim 12 (depends on 6) The method of claim 6, wherein the determining an amount of time that elapses between the detected first pulse event and the detected second pulse event comprises tracking a number of level changes that occur between the detection of the first pulse event and the detection of the second pulse event. ### Claim 13 (depends on 12) The method of claim 12, wherein the determining an amount of time that elapses between the detected first pulse event and the detected second pulse event further comprises, if a (TOT) event does not occur, approximating each of the level changes as an elapse of a threshold amount of time T ns divided by 2. ### Claim 14 (depends on 12) The method of claim 12, wherein the determining an amount of time that elapses between the detected first pulse event and the detected second pulse event further comprises, if a (TOT) event occurs, approximating each of the level changes as an elapse of a threshold amount of time T ns. ### Claim 15 (depends on 6) The method of claim 6, wherein the reconstructing is performed using one of an arithmetic equation, a lookup table, a synchronous digital state machine or timers and an event-driven state machine. ### Claim 16 A method for amplitude correction in a photon counting computed tomography (PCCT) scanning system, the method including: detecting a pulse at a pixel of the PCCT scanning system; for each change of voltage level detected in connection with the pulse, incrementing a counter; for each voltage level detected in connection with the pulse, determining whether an amount of time the pulse remains at the voltage level exceeds a threshold amount of time corresponding to a time-over-threshold (TOT) event; tracking the number of voltage level changes encountered between detection of the first pulse and detection of a second pulse; in response to a (TOT) event in connection with a voltage level, approximating the voltage level as a T ns time elapse; otherwise, approximating the voltage level change as a T/2 ns time elapse, where T is a threshold amount of time; and upon detection of the second pulse, using the approximated time elapse from the first pulse to compensate for contributions to the second pulse from the first pulse and resetting the counter to zero. ### Claim 17 (depends on 16) The method of claim 16, further comprising estimating an amplitude of the first pulse. ### Claim 18 (depends on 17) The method of claim 17, further comprising incrementing a counter corresponding to the estimated amplitude of the first pulse. ### Claim 19 (depends on 16) The method of claim 16, further comprising estimating an amplitude of the second pulse. ### Claim 20 (depends on 19) The method of claim 19, further comprising incrementing a counter corresponding to the estimated amplitude of the second pulse.