A probe to measure pulse-based differences in light absorbence by the vascularized tissue of the septum of the nose of a patient in need thereof, comprising: a. housing from which emanates two extensions (54, 56), each of said extensions being sized and spaced to enter one nares of the nose, and each of said extensions being flexible so as to deflect from the wall of the septum; b. at least two light-generating components (62, 64) that emit light at at least two different wavelength bands, positioned on the inside face of one of the two extensions (54, 56); c. at least one light-detecting component that detects light transmitted from said at least two light-generating components (62, 64), positioned on the inside face of the other of the two extensions (54, 56); and d. first individual conductors for energizing said at least two light-generating components (62, 64), connecting said components to a monitoring system for light signal production and modulation, and second individual conductors connecting said at least one light-detecting component to said monitoring system to convey signals of light detected by said at least one light-detecting component, said first and said second individual conductors passing within said housing and thereafter through a cable for carrying said first and said second individual conductors to said monitoring system, wherein said probe is apt to provide data used to provide pulse oximetry results, other plethysmophotometric results, or both, characterized in that each of said extensions (54, 56) provides a non-contiguous fit with regard to said septum, wherein said two extensions (54, 56) are sized and spaced such that when placed in the nasal cavity of a patient, they do not simultaneously contact the respective areas of mucosal tissue of the nasal septum where are positioned said at least two light generating components (62, 64) and said at least one light-detecting component, and wherein the blood flow is not dampened by simultaneous pressing of said tissue from both sides at the point of data measurement. a. housing from which emanates two extensions (54, 56), each of said extensions being sized and spaced to enter one nares of the nose, and each of said extensions being flexible so as to deflect from the wall of the septum; b. at least two light-generating components (62, 64) that emit light at at least two different wavelength bands, positioned on the inside face of one of the two extensions (54, 56); c. at least one light-detecting component that detects light transmitted from said at least two light-generating components (62, 64), positioned on the inside face of the other of the two extensions (54, 56); and d. first individual conductors for energizing said at least two light-generating components (62, 64), connecting said components to a monitoring system for light signal production and modulation, and second individual conductors connecting said at least one light-detecting component to said monitoring system to convey signals of light detected by said at least one light-detecting component, said first and said second individual conductors passing within said housing and thereafter through a cable for carrying said first and said second individual conductors to said monitoring system, wherein said probe is apt to provide data used to provide pulse oximetry results, other plethysmophotometric results, or both, characterized in that each of said extensions (54, 56) provides a non-contiguous fit with regard to said septum, wherein said two extensions (54, 56) are sized and spaced such that when placed in the nasal cavity of a patient, they do not simultaneously contact the respective areas of mucosal tissue of the nasal septum where are positioned said at least two light generating components (62, 64) and said at least one light-detecting component, and wherein the blood flow is not dampened by simultaneous pressing of said tissue from both sides at the point of data measurement.