Integrated sensing system approach for handheld spectral measurements

• US 20070084990A1
• Filed: 11/29/2006
• Published: 04/19/2007
• Est. Priority Date: 08/14/2003
• Status: Active Grant

• Current Assignee: George N. Appell
• Original Assignee: MicroSpectral Sensing, LLC
• Inventors: Coates, John
• Granted Patent: US 7,459,713 B2
• Time in Patent Office: Days
• US Class Current: 250/226
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0259 Monolithic
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/0267 Sample holders for colorimetry
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01N 2021/6417 Spectrofluorimetric devices
• CPC Class Codes: G01N 2035/1062 for testing the liquid while it is in the transfer device
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/4738 Diffuse reflection precedence is given to G01N21/55 - G01N21/57 if specular component is taken into consideration, e.g. also for testing fluids, fibrous materials
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids

Abstract

An integrated spectral sensing engine featuring energy sources and detectors within a single package that includes sample interfacing optics and acquisition and processing electronics. The miniaturized sensor is optimized for specific laboratory and field-based measurements by integration into a handheld format. Design and fabrication components support high volume manufacturing. Spectral selectivity is provided by either continuous variable optical filters or filter matrix devices. The sensor'"'"'s response covers the range from 200 nm to 25 μm based on various solid-state detectors. The wavelength range can be extended by the use of filter-matrix devices. Measurement modes include transmittance/absorbance, turbidity (light scattering) and fluorescence (emission). On board data processing includes raw data acquisition, data massaging and the output of computed results. Sensor applications include water and environmental, food and beverage, chemical and petroleum, and medical analyses. These can be expanded into various field and consumer-based applications.

Claims

1. An optical spectral sensing device, for determining properties of a sample, said device comprising:

an integrated energy source and an integrated spectral sensing detector package having a spectral sensing detector;

an optimized sample chamber or cell dimensionally designed to match the active area of the spectral detection device without the aid of additional interfacing optics;

integrated electronics for providing energy for said source and for receiving a signal generated by said spectral sensing detector in response to energy coupled to said detector by said sample chamber or cell, said integrated electronics providing direct output of sample properties of said sample;

on-board computer processing with a microcomputer or digital signal processor, which includes memory storage for data, calibration coefficients, methods and results;

on-board data communications including output to a visual display, communications of results to a process monitoring computer, and the option for wireless communications to an optimized network; and

apparatus for disposable sample handling for ease of use, and to minimize sample contamination.

2. The device of claim 1, having an optical structure formed in a configuration that allow for at least one of transflectance, or transmittance/absorption, or fluorescence or light scattering measurements.

3. The device of claim 1, wherein said optical structure is fabricated from at least one of glass, plastic, metal and similar materials that can be machined or molded to provide a sample interface with a cross-section that has optimal coupling between the energy source and spectral detection package.

4. The device of claim 1, further comprising an integrated spectral measurement system either based on the use of a continuous linear variable filter (LVF) or discrete optical components that comprise a matrix or mosaic-based filter-detector measurement system.

5. The device of claim 1, further comprising a disposable sample handing system.

6. The device of claim 5, having an optical transmission/absorption mode where energy passes into the sample, traverses the sample into a retro-reflective optical structure and re-enters the sample interface, and is imaged on to the spectral sensing detector.

8. The device of claim 5, having an optional optical scattering mode or fluorescence/emission mode, wherein energy propagates orthogonally with respect to normal passage of energy through the sample.

9. The device of claim 1, having a sample interface component that is renewable and disposable.

10. The device of claim 1, further comprising a disposable sample handing system configured as one of a sampling device in a pipette form, as a stirring device, in a dip or insertion form, or as a surface measurement device for solids.

11. An integrated sensing module having a detector comprising a solid-state device either matched directly in spectral response to a source, or capable of responding to wavelengths over a broad spectral range from one or more sources, sensitive in spectral regions of UV (230 nm to 400 nm), UV-visible wavelengths (350 nm to 700 nm) near infrared (600 nm to 2500 nm) and mid-infrared (2.5 μ

m to 25 μ

m, 2500 nm to 25000 nm).

12. The sensing module of claim 11, further comprising:

system optics;

one or more on-board processors;

a memory for storing reference spectral data recorded in the absence of analyte material, said reference spectral data being used to provide a ratio of energy detected by a sample measurement and energy obtained from the reference data, thereby providing a direct measure of the energy absorbed by the sample and system optics.

13. The sensing module of claim 11, wherein the spectral data recorded represents optical interaction of multiple analytes, thereby enabling more than one analysis to be performed, or where a more complex analysis is performed in the event that a condition being monitored provides different independent responses at different wavelengths, said sensor module providing an output for either multiple components or measurement of a complex condition by use of modeling techniques.

14. The sensing module of claim 11, further comprising:

a processor for processing the signal produced from the detector or detectors;

an on-board memory for storing calibration coefficient data for simple and complex calibrations, including simple linear response calibrations, second order and higher response calibrations, multivariate models for complex calibrations and/or multicomponent analyses, and storage of methods linked to said calibration coefficient data.

15. The sensing module of claim 11, further comprising;

a processor for processing the signal produced by the detector;

an on-board memory for storing multiple spectra, multiple calibrations, and multiple methods using said calibrations.

16. The sensing module of claim 11, further comprising;

a processor for processing the signal produced by the detector;

an on-board memory for storing pre-loaded or downloaded calibration coefficients for defined methods, the methods being fully defined to include data acquisition parameters, data pre- and post processing, numerical calculations and data transfer and/or display.

17. The sensing module of claim 16, wherein downloading is carried out directly via a built-in serial interface, or over an optional wireless communications interface.

18. The sensing module of claim 11, comprising a processor having at least one of:

a computation means for performing computations including concentration calculations;

means for processing of intelligent sensor outputs;

support for standard data formats, standard protocols and standard forms of communications, including serial and bus-oriented communications formats; and

support of hardware based and wireless based communications protocols

19. The sensing module of claim 11, in combination with and integrated into a fully self-contained handheld device

20. The handheld device of claim 19, configured to measure liquids or solids, and useful as a sampling device in a pipette form, as a smart stirring device, in a dip or insertion form, or as a surface measurement device for solids.

21. The handheld device of claim 19, configured to operates with disposable tips and/or samplers, selected based on application and method required for measurement.

22. The handheld device of claim 21 wherein the disposable components are in the form of tips or samplers, where specific reagents are integrated into the body of the tips or within the measurement cavity of the sampler.

23. The handheld device of claim 22, wherein the tips and samplers are visibly or electrically encoded to designate the intended application.