Patent ID: 11877828
Assignee: SUNNYBROOK RESEARCH INSTITUTE
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A method of performing differential photoacoustic radar imaging, the method comprising:
generating first modulated optical energy within a first wavelength band and second modulated optical energy a second wavelength band, wherein the first modulated optical energy and the second modulated optical energy are respectively modulated, out of phase, based on a reference waveform having a chirped temporal profile;
performing a first calibration to reduce radio frequency noise by:
processing first signals obtained from an ultrasound transducer to generate first calibration image data, wherein the first signals are processed by performing, in the frequency domain, cross-correlation between the first signals and the reference waveform; and
controlling a relative modulation amplitude and a relative modulation phase of electrical signals employed for modulation of the first modulated optical energy and the second modulated optical energy to reduce radio frequency noise in the first calibration image data; and

performing a second calibration to facilitate differential photoacoustic detection by:
directing the first modulated optical energy and the second modulated optical energy onto a region of a subject;
detecting photoacoustic energy responsively generated due to absorption of the first modulated optical energy and the second modulated optical energy, thereby obtaining photoacoustic signals, and processing the photoacoustic signals to generate second calibration image data, wherein the photoacoustic signals are processed by performing, in the frequency domain, cross-correlation between the photoacoustic signals and the reference waveform; and
tuning a relative intensity of the first modulated optical energy and the second modulated optical energy, in the absence of varying the relative modulation amplitude and relative modulation phase of the electrical signals employed for modulation of the first modulated optical energy and the second modulated optical energy, to reduce photoacoustic image artefacts in the second calibration image data, wherein the photoacoustic image artefacts are associated with a material intended to be suppressed via differential optical excitation; and

after having performed the first calibration and the second calibration to obtain a calibrated differential photoacoustic radar imaging system, employing the calibrated differential photoacoustic radar imaging system to perform differential photoacoustic radar imaging.