Systems and methods for correcting optical reflectance measurements

Abstract

We disclose measurement systems and methods for measuring analytes in target regions of samples that also include features overlying the target regions. The systems include: (a) a light source; (b) a detection system; (c) a set of at least first, second, and third light ports which transmit light from the light source to a sample and receive and direct light reflected from the sample to the detection system, generating a first set of data including information corresponding to both an internal target within the sample and features overlying the internal target, and a second set of data including information corresponding to features overlying the internal target; and (d) a processor configured to remove information characteristic of the overlying features from the first set of data using the first and second sets of data to produce corrected information representing the internal target.

1 . A measurement system, comprising:
 (a) a light source;   (b) a detection system;   (c) a set of at least first, second, and third light ports, which set transmits light from the light source to a sample and receives and directs light reflected from the sample to the detection system, wherein a distance between the first port and the third port comprises a first detection distance and a distance between the second port and the third port comprises a second detection distance; wherein the first detection distance is larger than the second detection distance; and wherein either (i) the first and second ports are transmitting ports and the third port is a receiving port, or (ii) the first and second ports are receiving ports and the third port is a transmitting port; and   wherein the detection system generates a first set of data corresponding to the first detection distance and comprising information corresponding to both an internal target within the sample and features overlying the internal target, and a second set of data corresponding to the second detection distance and comprising information corresponding to features overlying the internal target; and   (d) a processor configured to remove information characteristic of the overlying features from the first set of data using the first and second sets of data to produce corrected information representing the internal target.