Imaging method with pulsed light

A method that comprises using an apparatus to carry out imaging, wherein the apparatus comprises a sensor, a recorder, a first controller, first and second light sources, and a second controller, wherein the sensor comprises a matrix of photodiodes, wherein the first and second light sources illuminate a region-of-interest, wherein the method comprises using the recorder to record an electrical signal generated by at least one of the photodiodes, wherein the signal is used to define the brightness of a pixel on an image, using the first controller to carry out closed-loop control of the recorder for sequentially recording a signal generated by a group of photodiodes of the matrix before recording a signal generated by another group of photodiodes of the matrix, each of the groups of photodiodes comprising at least one photodiode, wherein a set that comprises the groups of photodiodes allows an image of the region-of-interest to be reconstructed, using the second controller to control activation of the first light source over a first time-period and extinction of the first light source over a second time-period, the second time-period succeeding the first time-period, for each photodiode of at least one group of photodiodes from the matrix, subtracting a second value from a first value, wherein the second value corresponds to a signal recorded during the second time-period for the photodiode and the first value corresponds to a signal recorded during the first time-period for the photodiode, 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, wherein the first image is an image of a surface that is constantly reflecting light emitted by a calibration light source that emits in continuous mode throughout the sensor's exposure time, wherein the second image is an image of a surface that is constantly reflecting light emitted by the same calibration light source while the calibration light source emits light periodically over the first time-period, and wherein the period with which the calibration light source emits light periodically is the sum of the first and of the second time-period.

An apparatus comprising a fluorescence imaging device specially designed for the implementation of the method of claim 1, wherein said device comprises a camera, a light source, a synchronizer, and a processor, wherein said camera operates in a rolling-shutter mode of operation having a refresh frequency, wherein said camera comprises a sensor comprising groups arranged in a matrix, each group comprising at least one photodiode, wherein said photodiodes are sensitive to a range of wavelengths, wherein said light source is a pulsed light source configured to excite a fluorophore in a region-of-interest, wherein said synchronizer is configured for synchronizing the activation and the extinction of the pulsed light source with a sequence for integrating the signal extracted from the groups, wherein, for each photodiode of at least one group, said processor is configured 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 photodiode, wherein said second value corresponds to a signal recorded during a second time-period for said photodiode, wherein said synchronizer is configured to synchronize the activation and the extinction of the light source with an on/off frequency equal to half of the refresh frequency, and wherein the range of wavelengths extends at least between 700 nanometer and 900 nanometers.