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US 12,041,364 B2Granted
Imaging method with pulsed light
AssigneeFluoptics
InventorsAnthony Daures, Philippe Rizo
Life of this patent
Estimating the term…
Abstract
The invention relates to a method allowing the use of the information accessible by fluorescence imaging to be optimized. For this purpose, it implements the combination of a protocol for calibration and synchronization of a pulsed light for exciting a fluorescent marker, with the operation in “rolling shutter” mode of a fluorescence camera. An appropriate correction factor allows the complete signal integrated by all of the photodiodes of the camera to be used so that no image is lost.
Claims19
An imaging method comprising:
- using a recorder to record an electrical signal that defines brightness of a pixel on an image, the electrical signal having been generated by at least one photosensor from a matrix of photosensors, the matrix including first and second photosensor groups, each including at least one photosensor;
- using a first controller, carrying out closed-loop control of the recorder for sequentially recording a signal generated by the first photosensor group before recording a signal generated by the second photosensor group, wherein a set that comprises the groups of photosensors allows reconstruction of an image of a region-of-interest that, while being illuminated by a second light source, is periodically illuminated by a first light source;
- using a second controller, controlling activation and extinction of the first light source over respective first and second time-periods, the second time-period succeeding the first time-period;
- for each photosensor of a photosensor group, subtracting a second value from a first value, wherein the second value corresponds to a signal recorded during the second time-period for the photosensor and the first value corresponds to a signal recorded during the first time-period for the photo sensor;
- determining a correction factor based on calibration measurements;
- and applying the correction factor to at least one value selected from the group consisting of the first value, the second value, and the result of having subtracted the second value from the first value;
- wherein, during the calibration measurements, first and second images are formed, the first image being an image of a surface that is constantly reflecting light that is emitted by a calibration light source that emits in continuous mode throughout the exposure time of the matrix of photosensors, and the second image being an image of a surface that is constantly reflecting light that is emitted by the same calibration light source while the calibration light source emits light periodically over the first time-period with a period that is the sum of the first and second time periods.
4 more elements
An apparatus comprising:
- a matrix of photosensor groups, each of which comprises at least one photosensor that is sensitive to a range of wavelengths that extends between at least seven hundred nanometers and nine hundred nanometers, said matrix being configured to be exposed in a rolling-shutter mode having a refresh frequency;
- a pulsed light source configured to excite a fluorophore in a region-of-interest;
- a synchronizer that is configured for synchronizing the activation and the extinction of the pulsed light source with a sequence for integrating the signal extracted from the photosensor groups and at an on/off frequency that is equal to half of the refresh frequency;
- a processor that is configured, for each photosensor of the at least one group:
- to generate a third value by subtracting a second value from a first value and to apply a correction factor to a value selected from the group consisting of the first value, the second value, and the third value;
- wherein said first value corresponds to a signal recording during a first time-period for said photosensor and wherein said second value corresponds to a signal recorded during a second time-period for said photosensor.
3 more elements
Dependencies are inferred from the claim text.