Capturing multi-spectral images

A method for performing a colorectal cancer (CRC) screening, the method comprising:

• determining a position of a system relative to a sample, wherein the system comprises a phone or a tablet with a front side having a screen and a camera located above the screen, and wherein the sample comprises stool, saliva, sweat, blood, urine, skin, or a combination thereof;
• instructing a user holding the phone or tablet to move the phone or tablet into a predetermined position in response to the determined position, wherein moving the phone or tablet varies a distance between the front side and the sample, varies an angle between the front side and the sample, or both;
• illuminating the sample with the light from the screen at a first wavelength while the phone or tablet is at the predetermined position;
• capturing a first image of the sample using the camera while the phone or tablet is at the predetermined position and the sample is illuminated with the light at the first wavelength;
• illuminating the sample with the light from the screen at a second wavelength while the phone or tablet is at the predetermined position, wherein the sample is illuminated with the light at the second wavelength after the first image has been captured, and wherein the first and second wavelengths are different;
• capturing a second image of the sample using the camera while the phone or tablet is at the predetermined position and the sample is illuminated with the light at the second wavelength;
• combining the first and second images to produce a multispectral image;
• measuring a spectral feature at each pixel in the multispectral image using a spectral processing algorithm running on the system;
• determining a concentration of a biomarker in the sample based at least partially upon the spectral feature, wherein the biomarker comprises hemoglobin, bilirubin, calprotectin, albumin, fatty acid, hydrogen sulfide, or a combination thereof, and
• determining that a person from whom the sample was taken is at increased risk for a condition based at least partially upon the concentration of the biomarker.

A system for performing a screening, the system comprising:

• a screen configured to emit light to illuminate a sample, wherein the screen is configured to vary a wavelength of the light between a first wavelength and a second wavelength, wherein the first and second wavelengths are different;
• a camera configured to capture a first image of the sample while the sample is illuminated with the light at the first wavelength and to capture a second image of the sample while the sample is illuminated with the light at the second wavelength;
• and
• a computing system configured to:
• combine the first and second images to produce a multispectral image;
• measure a spectral feature in the multispectral image;
• and
• determine that a person from whom the sample was taken is at increased risk for a condition based at least partially upon the spectral feature.