Apparatus and method for non-invasive and minimally-invasive sensing of parameters relating to blood

Abstract

Medical diagnostic system, apparatus and methods are disclosed. Optical transmitters generate radiation-containing photons having a specific interaction with at least one target chromophore in a target structure, preferably a blood vessel such as the interior jugular vein. The optical transmitters transmit the radiation into at least a first area including a substantial portion of the target structure and into a second area not including a substantial portion of the target structure. Optical receivers detect a portion radiation scattered from at least the first area and the second area. A processor estimates oxygenation, pH or cardiac output based on the scattered radiation detected from the first area, and the scattered radiation from the second area.

1 . A system for monitoring one or more parameters relating to blood of a patient comprising: one or more optical transmitters configured to generate pulsed radiation containing photons having a specific interaction with at least one target chromophore in a target structure within the patient, said one or more optical transmitters configured and positioned to transmit the pulsed radiation from the optical transmitter into at least a first area including a substantial portion of the target structure and into a second area not including a substantial portion of the target structure; one or more optical receivers configured and positioned to detect a portion of the pulsed radiation scattered from at least the first area and the second area; and a processor adapted to estimate the one or more parameters relating to the patient's blood, the estimation based in part on the scattered pulsed radiation detected from the first area, and the scattered pulsed radiation from the second area. 
     
     
         2 . A system according to  claim 1  wherein the target structure is a blood vessel. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . A system according to  claim 1  wherein said one or more optical transmitters is adapted to transmit the pulsed radiation into the first and second areas simultaneously. 
     
     
         6 . A system according to  claim 1  wherein the processor comprises a central processing unit and a memory device and said one or more optical receivers are configured and adapted to measure optical properties associated with the second area. 
     
     
         7 . (canceled) 
     
     
         8 . A system according to  claim 6  wherein said processor is further adapted to calculate a probability for the pulsed radiation to pass through the first area and the second area. 
     
     
         9 . (canceled) 
     
     
         10 . A system according to  claim 1  wherein said processor estimates the one or more parameters in part by relating probabilities for the pulsed radiation to pass through the first and second areas. 
     
     
         11 . (canceled) 
     
     
         12 . A system according to  claim 1  wherein the pulsed radiation comprises photons having a first wavelength and photons having a second wavelength, the first wavelength selected to have the specific interaction with a first target chromophore, and the second wavelength selected to have a specific interaction with a second target chromophore. 
     
     
         13 .- 20 . (canceled) 
     
     
         21 . A system according to  claim 1  wherein said one or more optical transmitters comprise an optical source and one or more launch optics coupled to the optical source via one or more optical fibers. 
     
     
         22 . A system according to  claim 21  wherein said one or more optical receivers comprise one or more optical detectors and one or more collecting optics coupled to the one or more optical detectors via one or more optical fibers. 
     
     
         23 .- 44 . (canceled) 
     
     
         45 . An apparatus for monitoring one or more parameters relating to blood of a patient comprising: a pad of pliable material adapted to be engaged with the skin of a patient; one or more launch optics in communication with at least one optical source via optical fiber, said one or more launch optics being mounted on the pad and positioned so as to enable pulsed transmission of photons generated by the at least one optical source through the patient's skin into at least a first area including a substantial portion of a target blood vessel and into a second area not including a substantial portion of the target blood vessel; and one or more collecting optics in communication with at least one optical detector via optical fiber, said one or more collecting optics being mounted on the pad and positioned so as to enable detection of the photons having been scattered within the first area and the second area, wherein the photons have a specific interaction with at least one target chromophore in the target blood vessel. 
     
     
         46 . An apparatus according to  claim 45  further comprising two or more transmitter-receiver pairs each pair comprising one launch optic and one collecting optic, including a first pair having a spacing and being positioned such that the launch optic and collecting optic associated with the first pair transmits photons into and detects scattered photons from the first area, and a second pair having a spacing and being positioned such that the launch optic and collecting optic associated with the second 
     
     
         47 .- 50 . (canceled) 
     
     
         51 . An apparatus according to  claim 45  wherein some of the photons have a first wavelength and some of the photons have a second wavelength, the first wavelength selected to have the specific interaction with a first target chromophore within the target blood vessel, and the second wavelength selected to have a specific interaction with a second target chromophore within the target blood vessel. 
     
     
         52 .- 55 . (canceled) 
     
     
         56 . An apparatus according to  claim 45  wherein said at least one optical source and said at least one optical detector are housed in a portable box being dimensioned and sized such the patient can carry the portable box for extended periods, and said portable box further housing a battery and a wireless transmitter for data communication to a station box located at a hospital or clinic. 
     
     
         57 .- 64 . (canceled) 
     
     
         65 . A method for monitoring one or more parameters relating to blood of a patient comprising the steps of: engaging one or more optical transmitters and one or more optical receivers on a tissue boundary of the patient; generating pulsed radiation containing photons having a specific interaction with at least one target chromophore in a target structure within the patient; transmitting said pulsed radiation through the optical transmitters into a first area including a substantial portion of a target blood vessel and into a second area not including a substantial portion of the target structure; detecting with the one or more optical receivers a portion of the pulsed radiation scattered from at least the first area and the second area; and estimating the one or more parameters relating to a patient's blood based in part on the detected scattered pulsed radiation from the first area, and the scattered pulsed radiation from the second area. 
     
     
         66 .- 68 . (canceled) 
     
     
         69 . A method according to  claim 65  further comprising the step of calculating optical properties associated with the second area, wherein said step of estimating is based in part on the measured optical properties associated with the second area. 
     
     
         70 . A method according to  claim 69  wherein said optical properties associated with the second area includes average tissue scattering and absorption properties for the pulsed radiation associated with the second area. 
     
     
         71 . A method according to  claim 69  wherein said step of estimating the one or more parameters includes calculating a probability for the pulsed radiation to pass through the first area and the second area. 
     
     
         72 . A method according to  claim 71  wherein said probabilities are calculated using a photon diffusion equation. 
     
     
         73 .- 81 . (canceled) 
     
     
         82 . A method according to  claim 65  wherein the step of transmitting said pulsed radiation includes transmitting the pulsed radiation through the optical transmitters into a third area including a substantial portion of a second target structure, and said step of detecting comprises detecting pulsed radiation scattered from the third area. 
     
     
         83 .- 84 . (canceled) 
     
     
         85 . A method according to  claim 65  wherein said step of generating pulsed radiation uses at least one optical source, said step of transmitting uses one or more launch optics coupled to the at least one optical source via one or more optical fibers, said one or more optical receivers comprise one or more optical detectors and one or more collecting optics coupled to the one or more optical detectors via one or more optical fibers. 
     
     
         86 .- 96 . (canceled)