I.s.s. (usa), Inc.

University of Illinois

Beniamino Barbieri

Enrico Gratton

Sergio Fantini

Maria Angela Franceschini

William Mantulin

Martin VandeVen

A fluorescence spectrometer comprises a laser and at least one beam splitter positioned to receive a light beam from the laser and to divide it into several first light beam portions. Dichroic mirrors are positioned to separately receive the first light beam portions and to reflect the beam portions at an angle to the first light beam portions. Transparent chambers are provided for holding the samples. Objective lens systems are respectively positioned in the path of the reflected beam portions to respectively focus each reflected beam portion to a point within one of the separate transparent chambers. Lenses are positioned to receive fluorescence from a sample for testing within the transparent chambers and to respectively focus the fluorescence at pin holes in opaque partitions. The lenses are positioned to receive the fluorescence, which passes back through the objective lens system and the dichroic mirror. Light detectors are each respectively positioned adjacent to one of the partitions, with one of the partitions respectively positioned between each of the lens and the light detectors to permit each light detector to sense fluorescence through the pin hole. Electronics are provided to receive and process signals from each light detector. Structure is provided to permit high speed data collection from a large number of samples in separate, transparent chambers.

Rapid high throughput spectrometer and method

The quantitative determination of various materials in highly scattering media such as living tissue may be determined in an external, photometric manner by the use of a plurality of light sources positioned at differing distances from a sensor. The light from said sources is amplitude modulated, and, in accordance with conventional frequency domain fluorometry or phosphorimetry techniques, the gain of the sensor is modulated at a frequency different from the frequency of the light modulation. Data may be acquired from each of the light sources at differing distances at a frequency which is the difference between the two frequencies described above. From these sets of data from each individual light source, curves may be constructed, and the slopes used to quantitatively determine the amount of certain materials present, for example glucose, oxyhemoglobin and deoxyhemoglobin in living tissue.

Photosensor with multiple light sources

The quantitative determination of various materials in highly scattering media such as living tissue may be determined in an external, photometric manner by the use of a plurality of light sources positioned at differing distances from a sensor. The light from said sources is amplitude modulated, and, in accordance with conventional frequency domain fluorometry or phosphorimetry techniques, the gain of the sensor is modulated at a frequency different from the frequency of the light modulation. Data may be acquired from each of the light sources at differing distances at a frequency which is the difference between the two frequencies described above. From these sets of data from each individual light source, curves may be constructed, and the slopes used to quantitatively determine the amount of certain materials present, for example oxyhemoglobin and deoxyhemoglobin in living tissue.

An apparatus for cross-correlation frequency domain fluorometry-phosphorimetry comprises a source of electromatic radiation and means for amplitude modulating the radiation at the first frequency. The amplitude modulated radiation is directed at a sample, while an optical array detector measures the resulting luminescence of the sample. A signal is provided coherent with the amplitude modulated electromagnetic radiation signals, at a second frequency which is different from the first frequency. The apparatus has the capability for shutting off and turning on the coherent signal at the second frequency in a cycle which is at a third frequency that is different from the difference between the first and second frequencies. This produces a resultant signal at a frequency derived from the difference and the third frequency. The resultant signal, when turned on, modulates the gain of the detecting means or multiplies its output, depending upon the nature of the detecting means. The amount of luminescence measured by the optical array detector is read when the coherent signal is off in its cycle of the third frequency. A signal from the reader described above is then detected at a frequency of the resultant signal to determine phase shift and modulation changes of the luminescence.

Time resolved optical array detectors and CCD cameras for frequency

Apparatus for cross-correlation frequency domain fluorometry and/or phosphorimetry in which means are provided for sequentially performing runs of the cross correlation frequency domain fluorometry and/or phosphorimetry at sequentially differing first and second frequencies. The intensities of signal responses of the runs are detected at the respective cross-correlation frequency in each run. The detection of the signal response is prolonged in each run until an integrated signal with a specified standard deviation has been acquired at each of the differing runs. Preferably the sequential runs are automatically executed by a program. Also, the waveforms sensed by deriving the resultant signal response in each run are folded. That is: corresponding segments of the waveforms are superimposed to obtain an average waveform value for each run having an increased signal to noise ratio over the individual waveform segments. Also, preferably, a software-created variable frequency digital filter is used to filter signal responses at the cross-correlation frequency.

Growing community of inventors

Champaign, IL, United States of America

Beniamino Barbieri