WO2002099384A2

WO2002099384A2 - Multimode structure for current measurement, ultrasonic and near-ir spectrum collection and processing

Info

Publication number: WO2002099384A2
Application number: PCT/US2002/018091
Authority: WO
Inventors: Robert Andrew Lodder
Original assignee: University Of Kentucky Research Foundation
Priority date: 2001-06-06
Filing date: 2002-06-06
Publication date: 2002-12-12
Also published as: WO2002099384A3; AU2002314969A1

Abstract

A compact device and method for collecting and processing acoustic and near-IR spectra of a bio-sample. The device (10) has a spectrometric unit (12) and, in proximity to an outer surface of the spectrometric unit, is a unit (14) for processing spectral data collected by the spectrometric unit. The spectrometric unit outer surface has: an acoustic energy transmission port and a near-IR radiation port for applying, respectively, acoustic energy and near-IR radiation to the bio-sample in the presence of a magnetic field; and electrode-terminal for measuring an electrical signal; an acoustic wave receiving port; and a near-IR radiation receiving port. The processing unit is preferably adaptable for performing at least one numeric operation on at least a portion of the data collected. The method includes: positioning an outer surface of a spectrometric unit nearby a surface of the bio-sample in the presence of a magnetic field; receiving acoustic waves and near-IR radiation with, respectively, an acoustic wave receiving port and a near-IR radiation receiving port; measuring an electrical signal with at least one electrode-terminal on the outer surface; and processing spectral data collected by the spectrometric unit.

Description

University of Kentucky (Disclosurel028) Attorney Docket UKRF-lllPCT (as filed <?* June 2002) Inventors: Robert Andrew Lodder, Ph.D.

Multimode Structure for Current Measurement, Ultrasonic and Near-IR Spectrum Collection and Processing

Background of the Invention

The invention described herein was partially supported by the American Heart Association and further under National Science Foundation. This application claims priority to pending U.S. provisional patent application filed by the assignee hereof serial no. 60/296,421 filed 06 June 2001.

In general, the present invention relates to nondestructive and generally noninvasive techniques for identification and analysis of a specimen/sample/analyte of interest, including targeted, preselected samples containing electrolytes such as blood glucose, plaques, tissue specimens and constituent components thereof

(especially constituents of susceptible plaques— cholesterol and lipoproteins), unknown matter for which constituent identification is desired, and tissue samples where the state of inflammation, disease, or injury is desired (damage caused or that likely— such as, assaying the effects of oxidative stress or the inflammatory cascade in tissue) through spectral analysis. More particularly, the novel nondestructive sample analysis technique and associated compact unique multimode device of the invention described herein aids in collecting acoustic-resonance and near-IR spectra alone or in conjunction with a magnetic field, in vivo, as well as in other areas or cavities where space is limited or human contact with the sample is not preferred, such as where constituents are largely unknown (as in the area of astrobiology).

Through utilization of acoustic-resonance waves and near-IR radiation transmitted and received from a compact spectrometric unit preferably in the presence of a magnetic field according to the invention, a wide variety of sample/ specimens of bio-substances may be identified and analyzed for a wide range of analytical research and clinical purposes (including, among others, measurement of blood lipoprotein cholesterol levels for clinical prevention of atherosclerosis, ischemia, and related maladies, determining pH, analysis of lipid peroxidation, extract useful physiologic information from a bio-sample such as the state of or damage caused by injury, inflammation, and disease, study of an environmental toxicity effect on a mammal or organism, and so on). A chip-style device can be micro-sized for encapsulation, if required, by a tiny biocompatible casing, embedded within an ingestible tablet or pill, and so on, for in vivo positioning (to include implanting within a mammal, fish, bird, or other organism for a few minutes, a week, a month or more) near tissue of interest, preferably temporarily, e.g., stabilized within an artery for characterization and analysis of vulnerable plaque (i.e., plaque susceptible to either rupture or erosion) according to conventional surgical techniques (utilizing guidewires, stents, catheter tips and other probe ends, etc., threaded through tubular cavities of the subject). Alternatively, a device of the invention is accordingly sized for incorporation into wetsuits, spacesuits, military fatigues, and other attire as well as helmets, face masks, and other headgear for collecting and communicating spectral information of a subject. This is especially important where state of potential inflammation or disease is needed on-site while a subject is in action, as is the case for example, in monitoring heightened oxidative stress of brain tissue of a deep sea diver, miner, or patient undergoing therapy within a hyperbaric oxygen (HBO) chamber. Further, a device of the invention, or components thereof, may be mounted or secured to a probe end for contacting a bio-sample surface, such as skin, through which the acoustic and near-IR radiation can penetrate and from which spectra can be collected. A device of the invention can be used to collect and process spectra by performing several numeric operations: Fourier transform, multiplicative scatter correction to said near-IR spectrum and said electrical signal spectrum, singular value decomposition, principal component analysis, and principal curve analysis.

As is known, spectrometers are relatively bulky instruments, as is the apparatus in FIG. 3 of U.S. Patent 5,553,610 issued in 1996 to the applicant, hereof, Robert A. Lodder, Ph.D. that employs a tri-spectral technique coined as multi-component magnetohydrodynamic (MHD), acoustic-resonance, near-IR spectroscopy, or "MARNIR", to analyze, in vitro, one or more targeted analyte in a vial, V, containing a known or unknown sample/specimen undergoing clinical medical analysis (for example, may be from a subject undergoing medical diagnosis). Therefore, a compact more-flexible device is needed in order to utilize spectral collection techniques, including the tri-spectral MARNIR Lodder technique earlier developed. One aspect of the invention is directed to a chip-style structure utilizing an enhanced Fourier transform mangetohydrodynamic acoustic-resonance near-IR spectrometry (Ft-MAReNIR) process to collect spectra from a bio-sample and process the spectral data collected for wider use. The instant invention relates to a novel multifunctional compact chip-style structure for the collection of information about specific chemical interactions, bulk properties, interface properties, and ionic properties of a bio-sample/specimen. These novel structures emit radiation and/or receive all or a portion of the tri- spectra collected from an outer surface of a spectrometric unit utilizing the more- enhanced MAReNIR technique that employs additional processing as disclosed herein, and may be built as: a micro-sized device employing readily available MEMS (MicroElectroMechanical System) techniques or by employing known wafer or microchip fabrication techniques such that the device is comprised of MEMS devices or other micro-devices; or on a slightly larger scale on the order of a couple of centimeters to fit within apparel, headgear, at the end of a probe unit, etc. for handy on-site use.

Background Technology Discussion

I. Electromagnetic Fields and the Electromagnetic Spectrum

As is well known, electric and magnetic fields are fundamentally fields of force that originate from electric charges. Whether a force field may be termed electric, magnetic, or electromagnetic hinges on the motional state of the electric charges relative to the point at which field observations are made. Electric charges at rest relative to an observation point give rise to an electrostatic (time- independent) field there. The relative motion of the charges provides an additional force field called magnetic. That added field is magnetostatic if the charges are moving at constant velocities relative to the observation point. Accelerated motions, on the other hand, produce both time-varying electric and magnetic fields termed electromagnetic fields. The "electromagnetic spectrum" includes the full range of electromagnetic radiation, including the radio spectrum and visible light.

II. MEMS (MicroElectroMechanical Systems) Technology

MEMS, as used throughout, refers to a class of micro electro-mechanical devices that are physically small built to function as ultra-miniaturized sensors, actuators, communication systems, control systems, and so on. MEMS devices generally react to electronic, optoelectronic, or optoacoustic stimuli in a mechanical way. MEMS chips and VLSI (integrated circuit) chips are micro-fabricated using similar techniques. MEMS are laid out and packaged within a chip that looks similar to an electronic microchip. A primary difference is that MEMS chips incorporate small micro-machines of optoelectronic, optoacoustic, or mechanical devices built on or within the chip. Use of MEMS provides the advantage of small size, low-power, low-mass, low-cost and high-functionality to integrated electromechanical systems on a micro scale.

III. General Spectroscopy and the earlier MARINER Spectroscopy is a technique that uses the interaction of energy with a sample to perform an analysis. The data collected with a receiving unit of the spectrometer is called a spectrum. A spectrum is a plot of the intensity of energy detected versus some characteristic of interest of the radiating energy, such as wavelength, mass, momentum, frequency, induced current magnitude, magnitude of emission intensity, etc. A spectrum can be used to obtain information about atomic and molecular energy levels, molecular geometries, chemical bonds, interactions of molecules, and related processes. Spectra can be used to identify the components of a sample (qualitative analysis) or measure amount of material (quantitative analysis). Many energy types (spectroscopies) may be used to irradiate a sample. Basic components of a spectrometer are an energy source (laser, ion source or other source of radiation that isolates it into its component wavelengths) and a receiving or detection unit for detecting and recording the relative intensities of each of the component wavelengths of energy radiating from the sample. For example, in the case of absorbance spectroscopy light transmitted through a sample is analyzed, and in the case of emission spectroscopy light emitted from the sample is analyzed. The term spectrometry is often used instead of spectroscopy when the intensities of the signals at different wavelengths are measured electronically. Types of spectroscopy include: astronomical spectroscopy where energy from celestial objects is used to analyze their chemical composition, density, pressure, temperature, magnetic fields, velocity, and other characteristics; each of the several subtypes of electron spectroscopy are associated with measuring changes in electronic energy levels; Fourier transform spectroscopy includes a family of spectroscopic techniques in which the sample is irradiated by all, or most all, relevant wavelengths simultaneously for a short period of time and the absorption spectrum is obtained by applying a mathematical analysis to the resulting energy pattern; infrared spectroscopy is used to both identify a substance and quantify the number of adsorbing molecules— the infrared absorption spectrum of a substance or sample is a sort of 'molecular fingerprint'; and laser spectroscopies provide information about the interaction of coherent light with matter.

The earlier-developed MARNIR analytical technique employs source and receiving components shown therein to collect three spectra (a near-IR spectrum, an acoustic-resonance (AR) spectrum, and a magnetohydrodynamic (MHD) spectrum) simultaneously in an effort to provide additional selectivity and performance enhancement for targeted analytes in a sample undergoing analysis plus decrease, and preferably eliminate, near-IR spectral interference from water in a sample to determine concentration of a biological molecule or ion in an aqueous environment.

rv. Near-IR Spectrometry

Near-IR spectrometry is characterized by low molar absorptivities and scattering, which permit ready evaluation of pure materials and broad overlapping bands, diminishing the importance of using a large number of wavelengths in calibration and analysis. The near-IR region of the electromagnetic spectrum is usually considered to include wavelengths between 700 nm (near the red end of the visible spectrum) and 3000 nm (near the beginning of infrared stretches of organic compounds). Absorbance peaks in the near-IR region originate from overtones and combinations of the fundamental (mid-IR) bands and from electronic transitions in the heaviest atoms. For example, C-H, N-H, and O-H bonds are responsible for most major absorbances observed in the near-IR spectrum, and near-IR spectrometry is routinely used to identify or quantify molecules that include unique hydrogen atoms (i.e., the quantitative analyses of water, alcohols, amines, and any compounds comprising C-H, N-H, and/or O-H groups). Numerous other elementary bond combinations likely generate near-IR absorbance peaks. In addition to analyzing pharmaceutical products, analysis of patients is of particular interest, here. In vivo near-IR spectrometry has been plagued historically by problems with high water absorbance in tissue, light scattering, peak overlap, and peak shifting with temperature and sample-matrix composition. To analyze the increasingly complex biological and medical problems of patients, more intense and more stable light sources, as well as more efficient detectors and improved methods of obtaining rapid wavelength selectivity, are all needed; as is evident in the application of near-IR to atherosclerosis, heart attack, and stroke research.

V. Microelectronics: Chip-style Structures and Devices

Microelectronics is that area of electronics technology associated with the fabrication of electronic systems or subsystems using extremely small (microcircuit- level) components. Since semiconductor fabrication and processing is driven by the computer-electronics industry, the demands for greater capability and faster data collection and processing of smaller-sized computerized units result in a demand for smaller-and-smaller integrated circuit (IC) microcircuits. "Chip-style" or "chip" as used throughout in connection with the novel structures includes not only the traditional use of 'chip' or 'microchip' (including any one or set of microminiaturized, electronic circuits, or microdevices that have been designed for use as electrical components, processors, computer memory, as well as countless special purpose uses in connection with consumer goods and industrial products), but also larger sized similarly-styled structures on the order of 1 cm to perhaps up to 10⁺cm. The terms chip, integrated circuit (IC), and microchip are often used interchangeably within the electronics industry.

By way of reference: the smaller microchips can hold from a handful to tens-of-thousands of transistors— they look like tiny chips of no more than 1/16" square by 1/30" thick; whereas larger-sized microchips of more than Vi-inch square, hold millions of transistors. It is generally the top one-thousandth of an inch of a chip's surface that holds the microcircuits, the substrate below provides mechanical strength and stability. Precision processing remains ever-more important in chip fabrication. Microcircuit wafer fabrication generally starts with a substrate to which layers, films, and coatings (such as photoresist) can be added or created (e.g., when fabricating a MOS monolithic IC, a silicon oxide layer is created on top of the silicon wafer), and from which these added or created materials can be subtractively etched (e.g., as in dry etching).

VI. Atherosclerosis and Lipoprotein Analysis

Epidemiological studies performed over a period of years have indicated that reduction of blood lipoprotein cholesterol levels significantly reduces the risk of atherosclerosis, ischemia, and death. However, in the clinical prevention of such maladies, identification and quantitative analysis of the variety of lipoproteins and apolipoproteins poses a problem in analyzing makeup thereof. About 2/3 of the total cholesterol in plasma is carried in low-density lipoprotein (LDL) and intermediate- density lipoprotein (IDL) particles from 21-35 nm in diameter. The LDL particles have a surface layer that is about 8% cholesterol while the core is about 42% cholesterol esters. The remainder of the LDL particles is 6% triglycerides (found in the core), 22% phospholipids (found at the surface), and 22% protein (also found at the surface). The principal LDL apolipoprotein is apoB (95% of apolipoprotein content, and 90% of apoB in plasma is carried in LDL), but traces of at least 7 other apoproteins can be found. The effect of in vivo oxidative processes on all of these apoproteins remains uncertain. As one can better appreciate, the subject matter of interest for identification and analysis according to the invention, is complex: Serum LDL is known to be a heterogenous substance by ultracentrifugation and by nondenaturing gel electrophoresis. There are as many as 7 LDL subclasses with particles ranging in size from 20-40 nm, and molecular weights from 2 million to 3.5 million daltons. The distribution of serum LDL across these classes varies, and it has been proposed that two distinct LDL subclass phenotypes exist, A and B. Environmental influences such as drug treatments and oxidation have also been shown to affect the distribution of serum LDL across the subclasses. Elevated levels of serum LDL have been shown to increase the risk of cardiovascular disease. Oxidation of serum LDL (forming oxLDL) has also been shown to promote lesion formation and growth in animal models of atherosclerosis.

Tests currently available for cholesterol have several disadvantages: they are invasive and cause patient discomfort, resulting in decreased willingness to submit to regular cholesterol screening. Many of these tests are very expensive, and certain tests for mass screening have been shown to be quite inaccurate. Although samples in vials can readily be analyzed in vitro, for example, there is currently no accurate non-destructive in vivo reference assay for HDL, LDL, or apolipoproteins immobilized in the walls of living arteries to provide generally 'real-time' data.

The true life cycle of atherosclerotic plaques remains a mystery from a chemical standpoint because chemical assays currently require interrupting the life cycle by microsurgically removing the plaque, dissecting it down to the smooth muscle cell layer of the blood vessel wall, and perhaps freezing in liquid nitrogen for in vitro near-IR scanning and any further validation of lipoprotein composition. Though fiber-optic catheters have been used to locate atherosclerotic lesions, current fiber-optic techniques can do little beyond distinguishing lesions from healthy arterial tissue (a detailed breakdown of constituent proteins is simply not possible). Accurate chemical analysis of lesions in vivo would permit a kinetic study of atherogenesis, contributing to better understanding lesion formation and growth.

VII. Need exists for Non-destructive Near-IR Cholesterol Assay and Device

Near-IR spectroscopy has been used in the past to determine cholesterol in serum samples acquired from patients and a near-IR technique has been developed to create false-color images of cholesterol in developing atheromas in rats. The determination of cholesterol by conventional near-IR spectrometry presents several problems, however, the most important arising from the fact that the near-IR spectrum of an analyte is dependent on the environment of the analyte. In tests performed, although the levels of albumin, protein, glucose, and triglycerides differ among the cholesterol residual groups, varying sodium ion concentration constitutes a major source of error in conventional near-IR determination of cholesterol.

If the levels of all background constituents were known, a far more accurate near-IR determination of cholesterol could be made. It is possible to determine sodium, protein, triglycerides, albumin, and glucose through invasive and time consuming procedures, but the goal is a rapid noninvasive analysis. While the development of the prior MARNIR spectrometer was an important step in the direction of noninvasive near-IR imaging and analysis, the multimode, compact chip-style structure of the invention aids in the collection of acoustic and near-IR spectra, as well as an electrical signal response or 'spectrum', which in combination give information about specific chemical interactions, bulk properties, and ionic properties of a sample, allowing a nearly real-time determination of cholesterol and its background constituents that cause errors in the near-IR calibration curve. Unlike the very bulky systems currently available, the compact multimode chip-style structure of the invention is both useful in vitro as describe above, and in vivo for positioning near a sample of interest, e.g., stabilized within an artery for characterizing/analysis of vulnerable plaque (i.e., plaque susceptible to either rupture or erosion) according to conventional surgical techniques (utilizing guidewires, stents, catheter tips, etc.).

Summary of the Invention

It is a primary object of the invention to provide a compact device having a spectrometric unit and, in proximity to an outer surface of the spectrometric unit, a unit for processing spectral data collected by the spectrometric unit.

As can be appreciated, the innovative device and associated method of the invention— as contemplated and described herein— can accommodate a variety of bio-samples for monitoring and analysis according to the technique of the invention, including features claimed herein, all within the spirit and scope of this disclosure. Advantages include, without limitation: (a) Versatility— The compact design of the multimode structure of the invention is useful for analytical research purposes and for clinical medical applications (e.g. routine cholesterol screening of patients, monitoring of patients undergoing therapy in a HBO chamber, emergency testing at the site of an accident for electrolyte concentration, as a routine blood glucose test, and where other types of physiologic information is desired, to identify and analyze tissue and constituent components thereof, electrolytes, and so on, requiring a proportionately smaller amount of energy to transmit emissions and receive spectral information in a wide range of environments (for example, in vitro, the structure may be incorporated into a self-powered handheld unit for on-site emergency use or positioned nearby a sample of interest to detect spectra thereof within a spacesuit or military fatigues, inside a face mask or other headgear, within a HBO chamber or other closed system; and, in vivo, a micro-sized structure can be encapsulated or embedded, secured atop a catheter end, guidewire tip, a stent, and so on, for analysis). (b) Simplicity of Design and Operation— The compact, simplified structural design of the invention lends itself to incorporation with different types of suitable medical instruments, for use to complement or replace current methodologies. The design allows for ready incorporation of a device of the invention into self- diagnostic kits for on-site monitoring or tracking changes. (c) Data capacity and Speed of results— The speed with which large data files can be accessed for use permits on-site communication of results even where complex processing has been necessary to perform desired mathematical operations on the spectra collected; for example, the multispectral (2- to 3-dimensional) and hyperspectral (4-, or more, dimensional, with dimensions of wavelength by wavelength, and time and space) data files can get large (up to 1-Gb or more, in size) per patient imaged, yet in many cases the results must be preserved. Equipment within which a novel device of the invention has been incorporated, may be interconnected to existing off-site computer systems whether ranning UNIX- or LINUX-, WINDOWS™- or MACINTOSH™-based operating systems for data acquisition, storage, and later retrieval/comparison, and use.

(d) Design Flexibility —The multimode structure of the invention is capable of carrying out, or assisting substantially with collecting MARNIR, FT- MAReNIR, and other multi-spectral techniques, allows for fabrication of many different structures into a variety of chip-style shapes using many different suitable compatible materials for the different environments in which the structure is intended to operate. Briefly described, once again, the invention includes a compact device for collecting and processing acoustic and near-IR spectra of a bio-sample. The device has a spectrometric unit and, in proximity to an outer surface of the spectrometric unit, is a unit for processing spectral data collected by the spectrometric unit. The spectrometric unit outer surface has: an acoustic energy transmission port and a near-IR radiation port for applying, respectively, acoustic energy and near-IR radiation to the bio-sample in the presence of a magnetic field; an electrode-terminal for measuring an electrical signal; an acoustic wave receiving port; and a near-IR radiation receiving port. The processing unit is preferably adaptable for performing at least one numeric operation on at least a portion of the data collected.

Associated with the device disclosed hereby, is a method for collecting and processing acoustic and near-IR spectra of a bio-sample. The method includes: positioning an outer surface of a spectrometric unit nearby a surface of the bio- sample for analysis; applying acoustic energy and near-IR radiation to the bio- sample in the presence of a magnetic field with, respectively, an acoustic energy transmission port and a near-IR radiation port; receiving acoustic waves and near-IR radiation with, respectively, an acoustic wave receiving port and a near-IR radiation receiving port; measuring an electrical signal with at least one electrode-terminal on the outer surface; and processing spectral data collected by the spectrometric unit with a unit in proximity to the outer surface. The spectral data collected can include a near-IR spectrum, an acoustic spectrum, and an electrical signal spectrum.

Further distinguishing features of both the device and method are numerous. The processing preferably includes performing at least one numeric operation on at least a portion of the data collected to aid in producing useful information from the spectral data collected. The several options include, without limitation: applying a Fourier transform operation on the spectral data collected; performing multiplicative scatter correction to a near-IR and electric signal spectra of the spectral data collected; performing singular value decomposition on the spectral data collected; performing principal component analysis on the spectral data collected; and performing principal curve analysis on the spectral data collected. Information about a physical parameter of the bio-sample can be communicated to a subject, or an individual monitoring the data collection, information of interest may include state of oxidative stress, tissue pH, electrolyte identify (such as glucose, plaques and their constituents— cholesterol and lipoproteins), electrolyte concentration, state of inflammation, injury, and disease, and other physiologic information. The spectral data collected may be stored for analysis once the spectrometric unit (whether mounted to a support member, secured directly to a catheter or other probe, etc.) has been removed from a vessel or other in vivo cavity. The step of measuring an electrical signal can include contacting the bio-sample with the outer surface. The spectral data collected may also be stored for subsequent generation of an electrolyte response profile for the bio-sample (for example, a concentration or reaction within the bio-sample may be targeted for ongoing or periodic monitoring and later comparison); the response profile may be generated once the outer surface has been removed from its placement or positioning.

In further characterizations, the invention may include any of the following. The outer surface may have a second electrode-terminal and may be operatively arranged for contact with a surface of the bio-sample undergoing examination, such as a skin. The magnetic field may be produced by at least one magnetically hard element on the outer surface. A support member may be included to which the spectrometric and processing units are mounted; for example, the support member may be a substrate into which one or more unit is etched and encapsulated. The spectrometric and processing units may be secured (whether by way of a support member) at a catheter, or other probe, end. The device may be encapsulated, encased, or embedded within a suitably biocompatible material. The acoustic energy transmission port and acoustic wave receiving port may each comprise a respective piezoelectric transducer deposited on the substrate; the near-IR radiation port may comprise a semiconductor laser, with the near-IR radiation receiving port comprising a laser detector. The outer surface may be curvilinear for surrounding at least a portion of the bio-sample. A thermistor may be included, plus a power source may be added in proximity to the outer surface to power the acoustic energy transmission, the near-IR radiation, and the processing unit. The device may be micro-sized for operative arrangement in vivo (e.g., threaded through a vessel or other tubular cavity), the processing unit to comprise a micro-chip mounted to the support member substrate, the outer surface may be that of a second substrate mounted to the support member substrate. The device may be sized for operative arrangement within a face mask. Brief Description of the Drawings

For purposes of illustrating the innovative nature plus the flexibility of design and versatility of the preferred device and method disclosed hereby, the invention will be better appreciated by reviewing accompanying drawings (in which like numerals, if included, designate like parts). One can appreciate the many features that distinguish the instant invention from known devices and techniques. The have been included to communicate the features of the innovative structure and method of the invention by way of example, only, and are in no way intended to unduly limit the disclosure hereof.

FIG. 1 depicts, in isometric fashion not to scale, components of a device 10 and method of the invention for collecting and processing acoustic and near-IR spectra of a bio-sample. The spectrometric unit 12, a processing unit 14 as well as storage 15, indicator 19, and thermistor 13 are shown secured or mounted to a support depicted at 11 (such as a substrate, catheter or other probe end, guidewire end, stent support, or other support member suitably sized to accommodate an in vitro or in vivo use).

FIGs. 2, 3, and 4A-4B each depict, in isometric fashion not to scale, an embodiment of the layout of an outer surface (respectively, 28a, 38a, 48a) of a spectrometric unit (respectively, 22, 32, and 42) of the invention.

FIGs. 4A (top plan view) and 4B (isometric) schematically depict a spectrometric unit 42 featuring an open-ended fluid channel (optical pathway 49) through which a bio-sample fluid specimen containing a target analyte(s) may be passed.

FIG. 5 schematically depicts features of a spectrometric unit 52 embodiment of the invention illustrating relationship of features of to unit.

FIG. 6 depicts, in isometric fashion not to scale, an embodiment of a device 60 of the invention featuring a probe-style support 61 which can optionally provide support for a 'local' micro-sized power source 66m or a unit comprising a more traditionally-sized remote source of power 66r (in communication 63 with the probe) for generating energy for transmission of the acoustic and near-IR radiation as well as powering the micro-processing unit 64.

FIG. 7 A is a partial cross-sectional view of an in vivo tubular cavity 81 of a vessel (or artery) 80 illustrating a probe-style support 71 positioned, by way of example, near a bio-sample of interest, here, plaque having been ruptured at 85. FIG. 7B is an end view looking into the tubular cavity 81 of FIG. 7A. Detailed Description of the Preferred Embodiments

FIG. 1 depicts components of a device 10 and method of the invention for collecting and processing acoustic and near-IR spectra of a bio-sample. The spectrometric unit 12, a processing unit 14 as well as storage 15, indicator 19, and thermistor 13 for aiding in localized temperature regulation (may be controlled in connection with processing unit functionality to help compensate for bio-sample surface temp, and any convection cooling/heating from nearby fluids such as blood flowing behind animal skin) are shown secured or mounted to support 11. Support represented at 11 is intended to cover number of various support structures such as a substrate, catheter or other probe end, guidewire end, stent support, or other support member suitably sized to accommodate an in vitro or in vivo use. A 'local' power source 16 is shown coupled to support 11, by way of example, for providing a source of energy or powering any one of the energy forms for the spectroscopies collected according to the invention.

FIGs. 2 - 4 depict alternative layouts of an outer surface (respectively, 28a, 38a, 48a) of a spectrometric unit (respectively, 22, 32, and 42) of the invention. Outer surface 28a of FIG. 2 includes a port 20b for transmitting an acoustic wave, the acoustic transmitter is not shown for simplicity, but may be a suitable piezoelectric (PZT) transducer for generating ultrasound waves that will pass through port 20b. Port 20a is available for receiving acoustic energy once it has interacted with the bio-sample (not shown for simplicity) in order to collect the acoustic spectrum. Two ports 24a, 24b (Di, laser diode input) allow near-IR radiation to pass for interaction with the bio-sample and detection/receipt through two near-IR ports 24c, 24d (Do, light detector output). At 26 between acoustic transducer ports 20a and 20b is the location of a magnet for generating a suitable static magnetic field. Electrode terminals (such as platinum electrodes) ending at 23a - 23d are utilized for measuring an electrical signal to produce a voltage- frequency response curve, or electrical signal spectrum, for use according to the invention. Transducers are devices capable of converting an input signal into an output signal of a different form— a piezoelectric crystal of an electric circuit converts mechanical or acoustical signals to electric signals and vise versa. Piezoelectric transducers may be supplied with AC or pulsed DC, and laser diodes may be powered with DC. The circuitry for generating the AC or pulsed DC can include a VCO, voltage controlled oscillator; a variable voltage regulator can be employed for powering the laser diode(s). Outer surface layout 38a of FIG. 3 includes port 30b for transmitting an acoustic wave, once again the acoustic transmitter is not shown for simplicity, but may be a suitable piezoelectric transducer for generating ultrasound waves that will pass through port 30b. Port 30a is available for receiving acoustic energy once it has interacted with the bio-sample (also not shown for simplicity) in order to collect the acoustic spectrum. Here, one port 34a (Di, laser diode input) allows near-IR radiation to pass for interaction with the bio-sample and detection/receipt through near-IR port 34b (Do, light detector output). At 36 between acoustic transducer ports 30a and 30b, and between electrodes 33a and 33b for measuring current, is the location of the magnet for generating a suitable static magnetic field; here, magnet details include a soft iron plate-like element 36 having north (N) 37 and south (S) 38 magnetic elements made of, for example, samarium cobalt.

FIGs. 4 A and 4B schematically depict a spectrometric unit 42 featuring an open-ended fluid channel 49 through which a bio-sample such as a fluid specimen containing a target analyte(s) may be passed. Fluid channel/optical path 49, by way of example, is shown sandwiched between two disk-shaped magnetized elements, one at 47 in contact with substrate 48b such as by mounting to surface 48a, and one above in-phantom at 41 (in exploded view) to generate the necessary magnetic bias field to aid in collecting what has been coined by the applicant as magneto- hydrodynamic (MHD) spectra, by way of measuring current at electrodes 43a, 43b for determining ion concentration of the sample. Additional alternative structures are contemplated. The bias magnet element can be made of samarium cobalt. The substrate used in part for support and labeled 48a can be made of generally- nonconductive materials including quartz, glass, diamond, sapphire, or other materials transparent in the near-IR electromagnetic spectral region used. In applications where preferably the structure is encapsulated (such as for in vivo use) the specimen channel could be sealed or remain open. Acoustic transducer transmitter T (40b) and acoustic transducer receiver R (40a) are suitably mounted to the spectrometric unit. Near-IR source transmits radiation to the sample of interest, through port 44a (Di) and light is received by a suitable near-IR detector through port 44b (laser diode). The magnetohydrodynamic effect is the generation of a current as ions move in a magnetic field. The magnitude of the MHD electrical signal is proportional to the ion concentration. The acoustic wave causes the ions in the solution to oscillate at the frequency of the acoustic wave. The movement of the ions in a magnetic field causes current flow through the leads of electrodes in proximity to the sample. The MHD effect is used to find the ionic strength of the sample, which is valuable because ions in solution perturb the water bands of the near-IR spectrum through their effect on hydrogen bonding.

FIG. 5 schematically depicts features of a spectrometric unit 52 embodiment of the invention illustrating relationship of features of to unit. An acoustic energy source (PZT transducer) 50a transmits acoustic energy directed through waveguide

59 and through port at surface 58a of a spectrometric unit (not shown for simplicity). Acoustic waves are received through a port and then detected by suitable detection transducer 50b. Near-IR radiation is generated by suitable source such as a laser diode 54a and transmitted through port to the bio-sample at or near surface 58a. Light is received from optic channel 59 by Si/PbS laser detector 54b. Coincidentally, as shown here, light is transmitted through an optic channel that serves also as a waveguide for acoustic energy (at 59). The pick up electrodes each have a terminal 53a, 53b for measuring an electrical signal from or around.

FIG. 6 depicts, in isometric fashion not to scale, an embodiment of a device

60 of the invention featuring a probe-style support 61 which can optionally provide support for a 'local' micro-sized power source 66m or a unit comprising a more traditionally-sized remote source of power 66r (in communication 63 with the probe) for generating energy for transmission of the acoustic and near-IR radiation as well as powering the micro-processing unit 64. An indicator mechanism 69 shown by way of example, only, as a display is also remote from the probe 61 for communicating the spectral data collected as useful information to a diagnostic technician.

FIG. 7A is a partial cross-sectional view of an in vivo tubular cavity 81 of a vessel (or artery) 80 illustrating a probe-style support 71 positioned, by way of example, near a bio-sample of interest, here, plaque having been ruptured at 85. FIG. 7B is an end view looking into the tubular cavity 81 of FIG. 7A along 7B-7B. For reference in both FIGs. 7 A and 7B is a spectrometric unit 72 having an outer surface 78a in proximity to the bio-sample of interest 84, including any of its constituents, or the thrombus having emerged through (and just above) a rupture 85 in the plaque wall. The micro-probe or catheter end at 71 is, here, shown connected by way of optical fiber cabling 73 to either a remote power source or to a remote computer storage facility for data compilation and comparison. The chip-style structure 10, 60 can be micro-sized for encapsulation by a tiny biocompatible casing, embedding within an ingestible tablet or pill, securing/positioning atop a catheter tip, etc. for in vivo use. In the spirit of contemplated design goals, the structure of the invention can be fabricated as a larger multimode structure for use where micro-sizing is not critical, choosing a support with sufficient structural integrity and corrosive-resistance can be done, and the design lends itself to fabrication for cost-effective large-scale production.

A principal component analysis of typical near-IR spectra shows that only the first 15 to 20 factors contain useful information. Beyond 20 factors a Wald-

Wolfowitz runs test applied to the loading vectors shows that the components usually model merely random noise. The 20 useful factors correspond to the 20 largest sources of spectral variation in the sample, which often arise from the 20 components of the sample present in highest concentration. Most of the important/interesting constituents of biological materials (including cholesterol and lipoproteins) are not in the list of the 20 constituents present in tissue in the highest concentration. According to the ingenious technique and structural design of the instant invention, the more-enhanced MAReNIR analysis is used to remove some large sources of near-IR spectral variation from the samples, allowing different calibration models to be created for different levels of a major sample constituent, such as aqueous sodium ion.

By way of example only, in experimental work done using a system having a pulsed, tunable near-IR light with a wavelength from 1.4 to 4.1 micrometers with an effective power of 3.3 million watts, the aorta of a small animal was scanned with the laser and catheter in vivo. One can produce moving graphics, digital video, etc. with such a catheter and combine the real-time motional graphics with the enhanced MAReNIR spectra collected according to the invention. The lipoproteins in a lesion identified were then extracted and analyzed by ultracentrifugation and SDS-PAGE. The catheter used included a small near-IR fiber-optic probe connected to the tunable laser and a detector, fast A/D converter, and computer. The catheter was inserted into the artery of the animal, and advanced to the aortic arch. Spectra were collected as the catheter was slowly withdrawn. A near-IR laser was used to provide enough light to obtain usable spectra through the animal's blood and tissue.

Analytes of interest, both clinically and for research purposes, include: cholesterol and cholesterol esters, lipoproteins, collagens, elastin, albumin, progesterone, estrogen, sodium, potassium and glucose. These analytes are physiologically relevant in lung, uterine, and breast cancers and cardiovascular disease, heart attack, and stroke. The multimode chip-style structure of the invention can be used to analyze complex mixtures of biological materials through the simultaneous application of a plurality of spectrometric techniques on a single structure will allow for nearly-simultaneous determination of 20 or more analytes within a complex specimen/sample, isolating the spectra of a select one or two for analysis thereof. There is a branch of astrobiology focused on duplicating conditions on planets and moons (like Mars and Europa) on earth. Earth analogs (identified to simulate conditions) for Mars can be found in the deserts of Antarctica and beneath glaciers, while analogs for Europa are found around deep ocean hydrothermal vents. A device of the invention can be incorporated onto planetary probes, and results compared with those obtained from analogous experiments on earth. Analysis of lipid peroxidation in brain tissue of deep ocean divers is of interest since, at high pressures, enough oxygen can be driven into tissue to cause brain seizures, lung, and retinal damage to divers. Once the target analyte data has been collected from the multimode device, it can be stored for retrieval and comparison in later studies.

As one can appreciate, feature details of a method for collecting and processing acoustic and near-IR spectra of a bio-sample according to the invention, are readily ascertainable by reviewing the accompanying figures and supporting text such that further visual depiction is unnecessary.

While certain representative embodiments and details have been shown merely for the purpose of illustrating the invention, those skilled in the art will readily appreciate that various modifications may be made to these representative embodiments without departing from the novel teachings or scope of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in any illustrative-claim included below. Although the commonly employed preamble phrase "comprising the steps of" may be used herein, or hereafter, in a method claim, the Applicants in no way intend to invoke 35 U.S.C. Section 112 §6. Furthermore, in any claim that is filed hereafter (as well as any claim included herewith for illustrative purposes), any means-plus-function clauses used, or later found to be present, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.

Claims

What is claimed is:

1. A device for collecting and processing acoustic and near-IR spectra of a bio- sample, the device comprising: a spectrometric unit comprising an outer surface having: an acoustic energy transmission port and a near-IR radiation port for applying, respectively, acoustic energy and near-IR radiation to the bio-sample in the presence of a magnetic field; an electrode-terminal for measuring current; an acoustic wave receiving port; and a near-IR radiation receiving port; and a unit in proximity to said outer surface for processing spectral data collected by said spectrometric unit, said unit adaptable for performing at least one numeric operation on at least a portion of said data collected.

2. The device of Claim 1 wherein: said outer surface has a second electrode- terminal; said outer surface has been operatively arranged for contact with a surface of the bio-sample undergoing examination; said magnetic field is produced by at least one magnetically hard element on said outer surface; and said spectral data collected comprises a near-IR spectrum, an acoustic spectrum, and an electrical signal spectrum.

3. The device of Claim 2 wherein said outer surface is curvilinear for surrounding at least a portion of the bio-sample, and said at least one numeric operation is selected from the group consisting of: Fourier transform; multiplicative scatter correction to said near-IR spectrum and said electrical signal spectrum; singular value decomposition; principal component analysis; and principal curve analysis; the device further comprising a power source in proximity to said outer surface to power said acoustic energy transmission and said near-IR radiation.

4. The device of Claim 1 micro-sized for operative arrangement in vivo; the device further comprising a power source in proximity to said outer surface to power said acoustic energy transmission and said near-IR radiation of the bio- sample, and a support member to which said spectrometric and processing units are mounted.

5. The micro-sized device of Claim 4 wherein: said support member is a substrate into which said processing unit is etched; said support member and said mounted spectrometric and processing units are encapsulated; said acoustic energy transmission port and said acoustic wave receiving port each comprises a respective piezoelectric transducer deposited on said substrate; and said near-IR radiation port comprises a semiconductor laser.

6. The micro-sized device of Claim 4 wherein: said processing unit comprises a micro-chip; said outer surface is that of a second substrate mounted to said support member substrate; said micro-chip is mounted to said support member substrate; and said acoustic energy transmission port and said acoustic wave receiving port each comprises a respective piezoelectric transducer deposited on said outer surface.

7. The device of Claim 1 micro-sized for operative arrangement within a blood vessel, the micro-sized device further comprising a power source in proximity to said outer surface to power said acoustic energy transmission and said near-IR radiation of the bio-sample comprising a wall of said vessel; and wherein said spectrometric and processing units are secured at a catheter end and encapsulated.

8. The micro-sized device of Claim 7 wherein: said acoustic energy transmission port and said acoustic wave receiving port each comprises a respective electro-acoustic transducer for operation over a range of frequencies from 1 KHz to 100 MHz; said near-IR radiation port comprises a laser; said near-IR radiation receiving port comprises a laser detector; and said magnetic field is produced by at least one magnetically hard element on said outer surface.

9. The micro-sized device of Claim 7 wherein said spectral data collected comprises a near-IR spectrum, an acoustic spectrum, and an electrical signal spectrum; and said at least one numeric operation is selected from the group consisting of Fourier transform, multiplicative scatter correction to said near-IR spectrum and said electrical signal spectrum, singular value decomposition, principal component analysis, and principal curve analysis; and further comprising, in communication with said processing unit, a storage device and an indicator having a display for communicating information about said spectral data collected.

10. The device of Claim 1 sized for operative arrangement within a face mask; the device further comprising: a power source in proximity to said outer surface to power said acoustic energy transmission and said near-IR radiation of the bio- sample comprising a skin surface, at least one magnetically hard element on said outer surface, and a support member to which said spectrometric and processing units are mounted.

11. The device of Claim 10 wherein said support member is secured at a probe end, said outer surface of said spectrometric unit is adapted for contact with said skin surface, and said at least one numeric operation is selected from the group consisting of: Fourier transform; multiplicative scatter correction; singular value decomposition; principal component analysis; and principal curve analysis; the device further comprising an indicator having a display in communication with said processing unit for communicating information about said spectral data collected.

12. The device of Claim 10 so operatively arranged wherein said support member is secured within said mask, said skin surface is that of a subject on whom said face mask has been placed; the device further comprising an indicator for communicating to said subject, information from said spectral data collected about a physical parameter of said bio-sample selected from the group consisting of a state of oxidative stress, tissue pH, electrolyte identity, electrolyte concentration, a state of inflammation, a state of injury, and a state of disease.

13. The device of Claim 1 further comprising a power source in proximity to said outer surface to power said acoustic energy transmission and said near-IR radiation of the bio-sample comprising unknown matter, at least one magnetically hard element on said outer surface, and a support member to which said spectrometric and processing units are mounted; and wherein said support member is secured at a probe end.

14. The device of Claim 1 micro-sized for operative arrangement in vivo, the micro-sized device further comprising: a power source in proximity to said outer surface to power said acoustic energy transmission, said near-IR radiation, and said processing unit; and a support member to which said spectrometric and processing units are mounted as micro-electromechanical devices and encapsulated.

15. The micro-sized device of Claim 14 further comprising a thermistor on said outer surface; and an indicator for communicating information from said spectral data collected about a physical parameter of said bio-sample selected from the group consisting of a state of oxidative stress, tissue pH, electrolyte identity, electrolyte concentration, a state of inflammation, a state of injury, and a state of disease.

16. A method for collecting and processing acoustic and near-IR spectra of a bio-sample, comprising the steps of: positioning an outer surface of a spectrometric unit nearby a surface of the bio-sample for analysis; applying acoustic energy and near-IR radiation to the bio-sample in the presence of a magnetic field with, respectively, an acoustic energy transmission port and a near-IR radiation port of said outer surface; receiving acoustic waves and near-IR radiation with, respectively, an acoustic wave receiving port and a near-IR radiation receiving port of said outer surface; measuring an electrical signal with at least one electrode-terminal on said outer surface; and processing spectral data collected by said spectrometric unit with a unit in proximity to said outer surface.

17. The method of Claim 16 wherein: said spectral data collected comprises a near-IR spectrum, an acoustic spectrum, and an electrical signal spectrum; said step of processing comprises performing at least one numeric operation on at least a portion of said data collected; and further comprising the step of communicating information about said spectral data collected to a subject.

18. The method of Claim 16 wherein said step of processing comprises performing at least one numeric operation and is selected from the group consisting of: applying a Fourier transform operation on said spectral data collected; performing multiplicative scatter correction to a near-IR and electric signal spectra of said spectral data collected; perfoπriing singular value decomposition on said spectral data collected; performing principal component analysis on said spectral data collected; and performing principal curve analysis on said spectral data collected; and further comprising the step of communicating information about a physical parameter of said bio-sample selected from the group consisting of a state of oxidative stress, tissue pH, electrolyte identity, electrolyte concentration, a state of inflammation, a state of injury, and a state of disease.

19. The method of Claim 16 wherein said step of positioning further comprises threading, through a blood vessel, a micro-sized support member to which said spectrometric and processing units are mounted, and said surface of the bio-sample comprises a wall of said vessel; and further comprising the step of storing said spectral data collected for analysis once said micro-sized support member has been removed from said blood vessel.

20. The method of Claim 16 wherein the bio-sample comprises tissue and said step of positioning further comprises using a catheter to thread, in vivo, into a tubular cavity, a micro-sized support member to which said spectrometric and processing units, and a power source, are mounted and encapsulated; and further comprising the step of commumcating information about a physical parameter of said bio-sample selected from the group consisting of a state of oxidative stress, tissue pH, electrolyte identity, electrolyte concentration, a state of inflammation, a state of injury, and a state of disease.

21. The method of Claim 16 wherein said step of positioning further comprises operatively arranging, within a face mask, a support member to which said spectrometric and processing units are mounted, said surface of the bio-sample comprises a skin surface, and said step of measuring an electrical signal comprises contacting the bio-sample with said outer surface; said step of processing comprises performing at least one numeric operation on at least a portion of said data collected; and further comprising the step of communicating information about said spectral data collected to a subject on whom said face mask has been placed.

22. The method of Claim 16 wherein said step of positioning further comprises operatively arranging a probe end to which said spectrometric and processing units are mounted; said magnetic field is generated by at least one magnetically hard element on said outer surface of said spectrometric unit; and further comprising the step of storing said spectral data collected and generating an electrolyte response profile for the bio-sample.

23. The method of Claim 22 wherein said step of positioning further comprises contacting the bio-sample with said outer surface, said response profile being generated once said outer surface is removed; and further comprising the step of powering said acoustic energy transmission, said near-IR radiation, and said processing unit with a power source in proximity to said outer surface.