Sensor system using fluorometric decay measurements

Claim 2

A measurement system for analysis of fluid components inside a body, comprising: pulse generator means for generating a number of time related pulses; a fiber-optic equipped catheter having at least its distal portion located in an organ or a body in which a fluid component concentration is to be measured; said catheter having at least one fluorometric sensor deployed to sense fluid concentration in communication with one or more fiber optic light pipes within said catheter, said fluorometric sensor producing a fluorescent output in response to a light input, said fluroescent output having a lifetime indicative of said fluid con­centration in the environment of said fluorometric sensor; light source means responsive to one or more of said pulses to generate pulses of output light, and for directing a portion of said light into an input of said fiber-optic light pipe-equipped catheter; a photosensor positioned outside the body for sensing the fluorescent output of said fluorometric sensor conveyed by one of said fiber optic light pipes; and analysis means for analysing said fluorescent output with respect to time to obtain a lifetime signal related to the lifetime of the fluorometric sensor.

Claim 3

The measurement system of Claim 1 further comprising processing means for converting said lifetime signal to a fluid concentration and presenting a visual display of said concentration.

Claim 4

The apparatus according to Claim 1, wherein said analysis means for analyzing the fluorescent output performs an analysis technique wherein at least a portion of a fluorescent decay curve is integrated over time to provide a decay curve integral functionally related to the lifetime of the fluorometric sensor.

Claim 5

The apparatus according to Claim 3, wherein said decay curve is integrated over a predetermined time interval.

Claim 6

The apparatus according to Claim 3, wherein the analysis means begins decay curve integration at a predetermined time after light output from the light source means begins.

Claim 7

The apparatus according to Claim 3, wherein a baseline output of the fluorometric sensor is also integrated and subtracted from said decay curve integral to develop a signal which is functionally related to the lifetime of the fluorometric sensor.

Claim 8

The apparatus according to Claim 1, wherein said means for analyzing the fluorescent output performs an analysis technique wherein a fluorescent decay curve is measured to provide samples at predetermined times after initiation of light output from said light source means, said samples being compared to develop a signal indicative of the lifetime of the fluorometric sensor.

Claim 9

The apparatus according to Claim 7, wherein at least one of the samples represents a baseline output of the photosensor in the absence of a light signal.

Claim 10

The apparatus of Claim 2, wherein said pro­cessing means modifies said lifetime signal with a temperature signal indicative of the temperature of changes in the temperature in the environment of the fluorometric sensor.

Claim 11

The apparatus according to Claim 9, wherein said processing means analyzes the lifetime signal according to the Stern-Volmer relationship.

Claim 12

The apparatus according to Claim 10, wherein one or more of a group of parameters of the fluorometric sensor are modified according to changes in said tempera­ture signal, said group comprising a diffusion coefficient, a linearizing coefficient, and an unquenched lifetime.

Claim 13

The apparatus according to Claim 1, wherein said fluid component is an oxygen or a hydrogen ion.

Claim 14

The apparatus according to Claim 12, wherein said fluorometric sensor is a fluophor/polymer matrix.

Claim 15

The apparatus of Claim 13, wherein said matrix comprises a luminescent organometallic compound which is copolymerrized, dissolved, or diffused into a polymer plastic or mixture of polymer plastics.

Claim 16

The apparatus of Claim 14, wherein said luminescent organometallic compound is tris (4,7 diphenyl 1,10 phenthroline) Ruthenium II complex ion, or fluroesceinamine.

Claim 17

The apparatus of Claim 15, wherein said polymer is chosen from the group: silicon rubber, a copolymer of silicon and polycarbonate, a copolymer of silicon and polystyrene, or an ion exchange resin.

Claim 18

The apparatus of Claim 1, wherein said lifetime signal comprises a time-weighted average of the lifetime signals analyzed from each decay curve.

Claim 19

A measurement system for analysis of temperature inside a body, comprising: pulse generator means for generating a number of time-related pulses; a light source which is responsive to one or more of said pulses and capable of generating pulses of output light, and of directing a portion of said light into a fiber-optic light pipe-equipped catheter; a fiber-optic equipped catheter having at least its distal portion located in an organ or a body in which temperature is to be measured; said catheter having at least one fluorometric sensor deployed to sense temperature, said fluorometric sensor being in communication with one or more of said fiber optic light pipes within said catheter, said fluorometric sensor producing a fluorescent output that decays with time in response to said pulses from said light source, the average lifetime of said fluorescent output decay being indicative of said temperature in the environment of said fluorometric sensor; photosensor means in communication with said catheter for providing an output indicative of said fluorescent output decay; and means for analysis and display of a fluorescent decay curve wherein at least a portion of the decay curve is integrated over time, said integration beginning at a predetermined time after light output from the light source begins, said integral being functionally related to the temperature in the environment of the sensor.

Claim 20

A measurement system for analysis of temperature inside a body, comprising: pulse generator means for generating a number of time-related pulses; a light source which is responsive to one or more of said pulses and capable of generating pulses of output light, and of directing a portion of said light into a fiber-optic light pipe-equipped catheter; a fiber-optic equipped catheter having at least its distal portion located in an organ or a body in which temperature is to be measured; said catheter having at least one fluorometric sensor deployed to sense temperature, said fluorometric sensor being in communication with one or more of said fiber optic light pipes within said catheter, said fluorometric sensor producing a fluorescent output that decays with time in response to said pulses from said light source, the average lifetime of said fluorescent output decay being indicative of said temperature in the environment of said fluorometric sensor; photosensor means in communication with said catheter for providing an output indicative of said fluorescent output decay; and means for analysis and display of a fluorescent decay curve wherein at least a portion of the decay curve is integrated over time, said integration beginning at a predetermined time after light output from the light source begins, said integral being functionally related to the temperature in the environment of the sensor.

Claim 21

The apparatus of Claim 17, wherein said decay curve is integrated over a predetermined time interval.

Claim 22

The apparatus of Claim 17, wherein a baseline output of the sensor is also integrated, said baseline integral to deelop a signal which is functionally related to the lifetime of the fluorometric sensor.

Claim 23

A measurement system for analysis of temperature inside a body, comprising: a pulse generator means for generating a number of time-related pulses; a light source which is responsive to one or more of said pulses and capable of generating pulses of output light, and of directing a portion of said light into a fiber-optic light pipe-equipped catheter; a fiber-optic equipped catheter having at least it's distal portion located in an organ or a body in which temperature is to be measured, said catheter having at least one fluorometric sensor deployed to sense temperature, said fluorometric sensor being in communication with one or more of said fiber optic light pipes within said catheter, said fluorometric sensor producing a fluorescent decay curve in response to said pulses from said light source, the average lifetime of said fluorescent decay curve being indicative of said temperature in the environment of said fluorometric sensor, and a portion of said fluorescent decay being directed to a photosensor apparatus, the output of said photosensor being indicative of said fluorescent decay curve, and a means for analysis and display of said fluorescent decay curve output wherein the fluorescent decay curve is sampled at predetermined times after the initiation of light output from said light source, said samples being compared to develop a signal which is functionally related to the temperature in the environment of the fluorometric sensor.

Claim 24

A measurement system for analysis of temperature inside a body, comprising: a pulse generator means for generating a number of time-related pulses; a light source which is responsive to one or more of said pulses and capable of generating pulses of output light, and of directing a portion of said light into a fiber-optic light pipe-equipped catheter; a fiber-optic equipped catheter having at least it's distal portion located in an organ or a body in which temperature is to be measured, said catheter having at least one fluorometric sensor deployed to sense temperature, said fluorometric sensor being in communication with one or more of said fiber optic light pipes within said catheter, said fluorometric sensor producing a fluorescent decay curve in response to said pulses from said light source, the average lifetime of said fluorescent decay curve being indicative of said temperature in the environment of said fluorometric sensor, and a portion of said fluorescent decay being directed to a photosensor apparatus, the output of said photosensor being indicative of said fluorescent decay curve, and a means for analysis and display of said fluorescent decay curve output wherein the fluorescent decay curve is sampled at predetermined times after the initiation of light output from said light source, said samples being compared to develop a signal which is functionally related to the temperature in the environment of the fluorometric sensor.

Claim 25

The apparatus of Claim 20, wherein at least one of the samples represents the baseline output of the photosensor apparatus in the absence of a light signal.

Claim 26

The apparatus of Claim 20, wherein said fluorometric sensor is a natural or synthetic ruby.

Claim 27

The apparatus of Claim 20, wherein said fluoro­metric sensor is a fluophor/polymer matrix.

Claim 28

The apparatus of Claim 17, wherein the ratio of two integrals is functionally related to lifetime.

Claim 29

The apparatus of Claim 20, wherein the ratio of two samples is functionally related to temperature.

Claim 30

The apparatus of Claim 17 wherein the light source is chosen from the group: a light emitting diode, a laser diode, a diode-pumped solid state laser, or a flashlamp.