Apparatus for non-invasive analyses of biological compounds

An apparatus for a non-invasive, in vivo analysis of constituents carried in blood of a living mammal, said blood including red blood cells having hemoglobin therein, said apparatus comprising:

• a first light source for generating a pump beam having a wavelength which is preferentially absorbed in the hemoglobin of red blood cells;
• means for intensity modulating said pump beam at a predetermined frequency;
• means for directing the pump beam through a skin of the mammal and into the blood so that the energy of the pump beam is absorbed in the red blood cells in a manner to generate thermal waves emanating therefrom;
• a second light source for generating a probe beam;
• means for directing the probe beam through the skin of the animal and into the blood;
• a phase synchronous detector for monitoring the periodic changes in the probe beam caused by the thermal waves in the blood and generating an output signal;
• and
• processor means for analyzing the constituents in the blood based on the output signal generated by said detector and with the modulation frequency of the pump beam and the phase of the output signal of the detector with respect to the periodic heating being selected to target the analysis to selected constituents in the sample.

An apparatus for non-invasive, in vivo analysis of glucose carried in a blood stream of a living mammal, said blood stream also carrying red blood cells having hemoglobin therein, said apparatus comprising:

• a first light source for generating a pump beam having a wavelength which is preferentially absorbed in the hemoglobin of red blood cells;
• means for intensity modulating said pump beam at a predetermined frequency;
• means for directing the pump beam through a skin of the mammal and into the blood stream so that the energy of the pump beam is absorbed in the red blood cells in a manner to generate thermal waves emanating therefrom, with the modulation frequency of the pump beam being selected so that the thermal waves extend beyond the hemoglobin and interact with the glucose in the blood stream;
• a second light source for generating a probe beam;
• means for directing the probe beam through the skin of the mammal and into the blood stream;
• a phase synchronous detector for monitoring periodic changes in the probe beam caused by the thermal waves interacting with the glucose in the blood stream and generating an output signal responsive thereto, said detector for monitoring the periodic changes in the probe beam that are approximately ninety degrees out of phase with respect to the thermal waves;
• and
• processor means for analyzing a concentration of glucose in the blood stream based on the output signal generated by said detector.

A method for analyzing properties of a sample, said sample being non-homogenous and including at least first and second constituents, said method comprising the steps of:

• generating a pump beam having a wavelength which is preferentially absorbed in the first constituents, said pump beam being intensity modulated with a predetermined frequency;
• directing the pump beam to interact with the sample to selectively induce a periodic heating in the first constituents in a manner to generate thermal waves emanating therefrom, and wherein the modulation frequency of the pump beam is selected so that the thermal waves extend beyond the first constituents and interact with the second constituents;
• generating a probe beam;
• directing the probe beam to interact with the sample;
• monitoring periodic changes in the probe beam caused by the thermal waves interacting with the second constituents and generating an output signal responsive thereto, and with the monitored periodic changes being approximately ninety degrees out of phase with the periodicity of the thermal waves;
• and
• analyzing the second constituents in the sample based on the output signal.

A method for a non-invasive, in vivo analysis of glucose carried in a blood stream of a living mammal, said blood stream also carrying red blood cells having hemoglobin therein, said method comprising the steps of:

• generating a pump beam having a wavelength which is preferentially absorbed in the hemoglobin of red blood cells;
• intensity modulating said pump beam at a predetermined frequency;
• directing the pump beam through a skin of the mammal and into the blood stream so that the energy of the pump beam is absorbed in the red blood cells in a manner to generate thermal waves emanating therefrom, with the modulation frequency of the pump beam being selected so that the thermal waves extend beyond the hemoglobin and interact with the glucose in the blood stream;
• generating a probe beam;
• directing the probe beam through the skin of the mammal and into the blood stream;
• monitoring periodic changes in the probe beam caused by the thermal waves interacting with the glucose in the blood stream and generating an output signal responsive thereto, and with the monitored periodic changes in the probe beam being approximately ninety degrees out of phase with the periodicity of the thermal waves;
• and
• analyzing a concentration of glucose in the blood stream based on the output signal generated by said detector.

An apparatus for analyzing properties of a sample, said sample being non-homogenous and including at least first and second constituents, said apparatus comprising:

• a first light source for generating a pump beam having a wavelength which is preferentially absorbed in the first constituents, said pump beam being intensity modulated with a predetermined frequency;
• means for directing the pump beam to interact with the sample to selectively induce a periodic heating in the first constituents in a manner to generate thermal waves emanating therefrom, and wherein the modulation frequency of the pump beam is selected so that the thermal waves extend beyond the first constituents and interact with the second constituents;
• a second light source for generating a probe beam;
• means for directing the probe beam to interact with the sample;
• a phase synchronous detector for monitoring periodic changes in the probe beam caused by the thermal waves interacting with the second constituents and generating an output signal responsive thereto, and with the monitored periodic changes being approximately ninety degrees out of phase with respect to the thermal waves;
• and
• a processor for analyzing the second constituents in the sample based on the output signal from the detector.

A method for analyzing properties of a sample, said sample being non-homogeneous and including at least first and second constituents, said apparatus comprising:

• selectively inducing a periodic heating at a predetermined frequency in said first constituents in the sample in a manner to create thermal waves therein and wherein said predetermined frequency is selected to substantially confine the thermal waves to the first constituents when the properties of said first constituent are to be analyzed, and wherein the predetermined frequency is selected so that the thermal waves will spread out to reach the second constituents when the properties of the second constituents are to be analyzed;
• monitoring periodic effects of the thermal waves on the sample and generating an output signal, and wherein the portion of the output signal which is in phase with respect to the periodic heating will be primarily from the first constituents while the portion of the output signal which is ninety degrees out of phase with the periodic heating will be primarily from the second constituents when the predetermined frequency has been selected so that the thermal waves spread out to reach the second constituents;
• and
• analyzing the sample based on the output signal and with the frequency of the periodic heating and the phase of the output signal with respect to the periodic heating being selected to target the analysis to one of the first or second constituents in the sample.