Imaging system for combine full-color reflectance and near-infrared imaging
An imaging system for acquisition of NIR and full-color images includes a light source providing visible light and NIR light to an area under observation, such as living tissue, a camera having one or more image sensors configured to separately detect blue reflectance light, green reflectance light, and combined red reflectance light/detected NIR light returned from the area under observation. A controller in signal communication with the light source and the camera is configured to control the light source to continuously illuminate area under observation with temporally continuous blue/green illumination light and with red illumination light and NIR excitation light. At least one of the red illumination light and NIR excitation light are switched on and off periodically in synchronism with the acquisition of red and NIR light images in the camera.
1. A medical imaging system for acquisition of NIR images and full-color images comprising:
a light source configured to provide visible light and NIR excitation light to a sample area; and
a camera having an image sensor, the image sensor comprising:
a barrier filter to block NIR excitation light, and
sensor pixels arranged in a stacked array, the sensor pixels including:
first sensor pixels located at a first depth in the image sensor, the first sensor pixels configured to detect blue reflectance light,
second sensor pixels located at a second depth in the image sensor that is different from the first depth, the second sensor pixels configured to detect green reflectance light,
third sensor pixels located at a third depth in the image sensor that is different from the first and second depths, the third sensor pixels configured to detect red reflectance light, and
fourth sensor pixels located at a fourth depth in the image sensor that is different from the first, second, and third depths, the fourth sensor pixels configured to detect NIR fluorescence light received from the sample area.
2. The imaging system of claim 1 , wherein the image sensor is a CMOS sensor.
3. The imaging system of claim 1 , wherein the system is configured to generate NIR images and full-color images of the sample area.
4. The imaging system of claim 1 , wherein the visible light provided by the light source comprises blue illumination light, green illumination light, and red illumination light, the blue illumination light being reflected from the tissue as blue reflectance light, the green illumination light being reflected from the tissue as green reflectance light, and the red illumination light being reflected from the tissue as red reflectance light.
5. The imaging system of claim 4 , comprising a controller in signal communication with the light source and the camera, the controller being configured to:
control the light source to illuminate the area under observation with the blue illumination light continuously and illuminate the area under observation with the red illumination light and the NIR illumination light, wherein at least one of the red illumination light and NIR illumination light is switched on and off periodically according to a predetermined timing scheme;
simultaneously acquire a first image signal corresponding to the blue illumination light, and a second image signal corresponding to the red illumination light and the NIR illumination light; and
determine the red reflectance light and detected NIR light from the second image signal, based on the predetermined timing scheme.
6. The imaging system of claim 5 , wherein the predetermined timing scheme includes alternating the red illumination light and NIR illumination light.
7. The imaging system of claim 1 , wherein the light source comprises an illuminator configured to emit a substantially constant intensity of visible light and NIR light over a continuous spectral range, and a plurality of filters disposed between the illuminator and the area under observation for transmitting temporally continuous blue light and temporally discontinuous red light and discontinuous NIR light.
8. The imaging system of claim 1 , wherein the light source comprises one or more solid state sources.
9. The imaging system of claim 1 , wherein the blue, green, and red illumination light are produced by blue, green, and red LEDs, respectively.
10. The imaging system of claim 1 , wherein the imaging system is configured as an endoscope.
11. The imaging system of claim 1 , wherein the NIR light detected by the camera is fluorescent light.