WO2001094917A1 - System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content - Google Patents
System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content Download PDFInfo
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Classifications
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
- A61B5/0082—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes
- A61B5/0084—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes for introduction into the body, e.g. by catheters
- A61B5/0086—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence adapted for particular medical purposes for introduction into the body, e.g. by catheters using infrared radiation
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
- A61B5/14546—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue for measuring analytes not otherwise provided for, e.g. ions, cytochromes
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
- G01N21/359—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
- A61B5/0075—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy
Definitions
- This invention relates to systems and methods for noninvasively and/or continuously and quantitatively measuring spectrophotometrically a patient's blood urea nitrogen, blood osmolarity, plasma free hemoglobin, and tissue water content.
- BUN Blood urea nitrogen
- Phem plasma free hemoglobin
- tissue water content is important indications of a patient's condition.
- BUN which is the amount of urea or urea nitrogen per unit volume of blood expressed, typically, in milligram percent units (mg%) is typically a by-product of the catabolism of various body proteins principally found in muscle and liver tissues. It is present in extra (and intra) vascular spaces, but later processed and excreted through the kidneys into the urine.
- urea becomes a toxin to many other organ systems of the body including the brain, heart, skin, etc.
- Medical professionals routinely desire to know the BUN, or dialysate urea or dialysate urea nitrogen (DUN) value, of the patient, because of the above-mentioned deleterious and serious side effects.
- DUN dialysate urea or dialysate urea nitrogen
- tissue water or hydration status
- tissue water increases dramatically due to the inadequate elimination of water from the interstitial and intravascular spaces, since the kidney no longer correctly functions.
- the patients become edematous and their tissue water content increases dramatically.
- the goal of therapy is to remove all of the toxins of the blood and body. Some of these toxins are the urea, potassium, and even water which can become a significant toxin to the patient. Therefore, removal of water from the tissue is crucial because this water overloaded state requires excessive energy expenditure by the heart to function.
- tissue water content is conventionally measured by bioelectrical impedance; however, bioimpedance can be costly and requires the injection of small electrical currents into the patient.
- Another technique involves measuring the amount of water in the tissue spaces by injecting radio-isotopes into a patient. This is done principally on a research basis, however, because of the attendant radiation risks.
- PFH Pulsma Free Hemoglobin
- PFH is the amount of hemoglobin not contained inside a red blood cell, but rather free in plasma solution and is expressed, typically in milligram percent units (mg%).
- PFH is typically a result of red blood cell breakage or hemolysis, with spillage of the hemoglobin directly into the plasma.
- the PFH levels in the blood may elevate due to tubing lines kinking and pump rollers crushing the red blood cells during the course of the hemodialysis treatment. This can occur in cardio-pulmonary surgeries as well.
- PFH itself becomes a toxin to many other organ systems of the body.
- Medical professionals desire to know the PFH of the patient, because of the above mentioned deleterious and serious side effects associated with the presence of PFH.
- PFH is measured by drawing a sample of blood by veni-puncture. Then, using widely accepted techniques the sample of blood is subjected to biochemical reactions to determine the level of PFH in the plasma of the blood.
- Blood osmolarity is the osmolar content of blood per unit volume of blood expressed, typically, in milliosmolar units. The osmolar content of blood (and/or the sodium content) should have a narrow range of values due to the body's compensatory abilities.
- the blood osmolarity varies greatly.
- the present invention is directed to apparatus and methods for determining a biologic constituent value, such as BUN, PFH, tissue water and osmolarity, transcutaneously, continuously, and noninvasively.
- a biologic constituent value such as BUN, PFH, tissue water and osmolarity
- One aspect of the present invention provides a method and system for the noninvasive measurement of tissue water content in which an emitter and a detector are positioned outside of a patient (either remote from the patient or, preferably, mounted on the skin of a patient), light from the emitter passes through a portion of a patient's body and is received by the detector.
- the detector measures light of a selected wavelength that is absorbed by water.
- the intensity of light at an initial time is measured by a detector; then at a later time, typically after a period of dialysis, the intensity of detected light is compared with the initial intensity and the percent change in tissue water is calculated.
- a measurement of intensity transmitted (i.e. detected) versus intensity emitted at a wavelength selected for absorption by water allows calculation of the volume percent of water in a patient's tissue.
- Another aspect of the present invention also provides a method and system for the measurement of urea concentration in the blood of a patient by measuring the quantities of light at two wavelengths where the function of the extinction coefficient versus urea concentration at each given wavelength holds BUN information that is different in at least one of curvature, offset, linearity or sign from the other wavelength.
- a further aspect of the present invention provides a method and system for measuring osmolarity (or sodium content) of a patient's blood.
- Yet another aspect of the present invention provides a method and system for measuring plasma free hemoglobin through an optical technique.
- FIG. 1 shows a typical hemodialysis tubing circuit and connections.
- FIG. 2 shows a perspective view of apparatus used to noninvasively measure tissue water content.
- FIG. 2A shows an enlarged cross-sectional view of a patient's finger in the apparatus of Fig. 2, configured in a transmission mode.
- FIG. 3 shows absorption coefficient values for oxyhemoglobin, reduced hemoglobin and water.
- FIG. 4 shows a plot of Log (Io/I) at 1300 nm wavelength versus hematocrit of a blood sample as it is diluted with saline to show that intensity of light has slight dependence on Hematocrit.
- FIG. 5 shows an absorption spectrum of 14% urea at room temperature.
- FIG. 6 represents a hypothetical plot of log light intensity vs. urea concentration (milligram percentage , g % ) .
- FIG. 7 shows plots of the % change in absorbance of a beam of light at 810 nm and 810 nm 1300 nm v. sodium.
- FIG. 8 shows plots of hematocrit (HCT) as measured by three techniques vs. mean cell volume (MCV).
- FIG. 9 shows plots of hematocrit (HCT) as measured by three techniques vs. mean cell volume (MCV).
- FIG. 10 shows plots of the % change in absorbance of light at 810 nm and 810 nm/1300 nm vs. PFH.
- the present invention is directed to apparatus and methods for determining a biologic constituent value transcutaneously, continuously, and noninvasively. This is achieved by passing at least one wavelength of light onto or through body tissues such as the finger, earlobe, or scalp, etc., see FIG. 2 and 2A, and then compensating for the effects of the other non-water, body tissues using a modified Beer Lambert Law as a theoretical basis.
- body tissues such as the finger, earlobe, or scalp, etc.
- body part is intended to include skin, earlobe, fingertip, lip, etc., but also "extracorporeal conduit", see FIG. 1, may refer to a disposable blood chamber or in- vitro blood containers such as tubes and cuvettes.
- measurements are conducted using the apparatus (or modified versions thereof) described in U.S. Patent Nos. 5,456,253 (column 1, line 18 through column 14, line 67; Figures 1-13) and 5,372,136 (column 1, line 12 through column 14, line 39; Figures 1-16), and U.S. Patent Application Ser. No. 08/479,352 which are incorporated herein as if reproduced in full below.
- kidneys are located on either side of the spine. In a healthy patient, kidneys function to stimulate ⁇ d blood cell production and regulate the content of the blood. Kidneys also produce hormones that affect other organs and control growth. When functioning properly, kidneys serve as a means for cleaning the blood by removing excess fluids and toxins.
- the filtering task in each kidney is performed in part by the some one million nephrons in the kidney.
- the nephrons are filtering units made up of tiny blood vessels. Each such blood vessel is called a glomerulus. Every day, roughly 200 quarts of blood and fluids will be processed by the kidney. The kidney removes about two quarts of water and toxic chemicals which are sent to the bladder as urine for subsequent voiding thereof by urination.
- FIG. 1 is now referred to. While FIG. 1 incorporates a view of a presently preferred embodiment of the present invention, it also incorporates a view of some common components which are typical in a general hemodialysis environment. The general environment of hemodialysis and typical components therein will now be discussed.
- blood is taken put of a patient 200 by an intake catheter means, one example of which is shown in FIG. 1 as an input catheter 122.
- Input catheter 122 is intravenously ' inserted into patient 200 at a site 180 and is used for defining a blood passageway upstream of a blood filter used to filter the impurities out of the blood.
- the blood filter is also called a dialyzer 130.
- the unclean blood flows from an artery in patient 200 to a pump means, an example of which is pump 140. From pump 140, the blood flows to dialyzer 130.
- Dialyzer 130 has an input port 230 and an output port 240.
- the pump 140 performs the function of moving the unclean blood from patient 200 into input port 230 through dialyzer 130, and out of dialyzer 130 at output port 240.
- unclean blood in input catheter 122 is transported to input port 230 of dialyzer 130. After passing through and being cleansed by dialyzer 130, the blood may receive further processing, such a heparin drip, in hemodialysis related component 300.
- the now clean blood is returned to patient 200 after the dialyzing process by means of an output catheter means, an example of which is output catheter 124.
- Output catheter 124 which is also intravenously inserted into patient 200 at site 180, defines a blood passageway which is downstream from dialyzer 130, taking the blood output by dialyzer 130 back to patient 200.
- the hemodialysis process uses a blood filter or dialyzer 130 to clean the blood of patient 200.
- dialyzer 130 As blood passes through dialyzer 130, it travels in straw-like tubes (not shown) within dialyzer 130 which serve as membrane passageways for the unclean blood.
- the straw-like tubes remove poisons and excess fluids through a process of diffusion.
- An example of excess fluid in unclean blood is water and an example of poisons in unclean blood are blood urea nitrogen (BUN) and potassium.
- BUN blood urea nitrogen
- the excess fluids and poisons are removed by a clean dialysate liquid fluid, which is a solution of chemicals and water.
- Clean dialysate enters dialyzer 130 at an input tube 210 from a combined controller and tank 170.
- the dialysate surrounds the straw-like tubes in dialyzer 130 as the dialysate flows down through dialyzer 130.
- the clean dialysate picks up the excess fluids and poisons passing through the straw-like tubes, by diffusion, and then returns the excess fluids and poisons with the dialysate out of dialyzer 130 via an output tube 220, thus cleansing the blood.
- Dialysate exiting at output tube 220 after cleansing the blood may be discarded.
- the general hemodialysis process and environment is seen in FIG. 1 and has been described above. A summary of this process is that patient 200, whose kidneys are performing
- ⁇ substandardly is dialyzed.
- the unclean blood flows from an artery in patient 200 to the pump 140 and then to dialyzer 130.
- Unclean blood flows into dialyzer 130 from input catheter 122, and then clean blood flows out of dialyzer 130 via output catheter 124 back to patient 200.
- the pump 140 causes the blood flowing into, through, and out of dialyzer 130 to flow in a pulsatile fashion.
- a spectrophotometry means for defining a blood flow path, for emitting radiation into the blood in the flow path, and for detecting radiation passing through both the blood and the flow path.
- the spectrophotometry means includes a cuvette means 10 for defining the blood flow path, and an emitter/detector means 100 for directing and detecting radiation. Within the emitter/detector means is both an emission means for directing radiation and a detector means for detecting radiation.
- Emitter/detector apparatus 100 enables the detection by a photodetector (not shown) of the portion of radiation which is directed by a photoemitter (not shown) to cuvette 10 and passes through both the blood therein and the cuvette 10.
- the cuvette 10 is installed at either end of dialyzer 130.
- Each cuvette 10 has a photoemitter and a photodetector thereon.
- the emitter/detector means is electrically connected to a calculation means.
- a calculation means In a preferred embodiment of the system, an example of the calculator means is depicted in FIG. 1 as computer 150 which is electrically connected to the photoemitter and the photodetector on emitter/detector apparatus 100 by means of cable 120.
- Intake catheter 122 takes blood to cuvette 10 situated before input port 230 of dialyzer 130.
- Emitter/detector apparatus 100 at input port 230 of dialyzer 130 subjects the blood therein to at least two radiation wavelengths of electromagnetic radiation for the purposes of analysis, via spectrophotometry, so that the concentration of a desired biological constituent can be derived.
- Each photodetector, at both input port 230 and output port 240 of the dialyzer 130 communicates the detected radiation at least a first and a second wavelength via cable 120 to computer 150.
- Computer 150 calculates both before dialysis and after dialysis concentrations of the sought-after or desired biological constituent. Computer 150 then displays, respectively, at a first display 152 and a second display 154, the derived concentration of the biological constituent in their analogue or digital representations.
- I ⁇ is the intensity of the incident source radiation
- I is the transmitted intensity of the source radiation through the sample
- E is the extinction coefficient of the sought for constituent
- x is the concentration of the sample constituent in the tissue (or blood conduit)
- d is the optical path length (distance).
- K b absorbance due to blood '
- K w absorbance due to water
- X b volume of blood per volume of tissue
- the absolute value of the tissue water may be desired.
- the following indicate the mathematical operations required to determine the absolute value of tissue water, see FIG. 6. The following operations indicate the need for additional
- one aspect of the present invention is directed to apparatus and methods for determining the biologic constituent value, the tissue water value, transcutaneously and noninvasively. This is achieved by passing at least one wavelength of light onto or through body tissues such as the finger, earlobe, scalp, etc. and then compensating for the effects of other body tissues not related to water.
- the light can also be passed directly through blood in a conduit.
- the wavelength of light is selected to be near 1300 nanometers (nm). At that particular wavelength, blood is almost independent of the hematocrit value but the water absorption coefficient at 1300 nm is very large compared to that of blood. Hence, the measurement at 1300 nm is independent of the hemoglobin content of the tissue per se.
- Another significant advantage of the present invention is the capability of monitoring multiple wavelengths simultaneously other than 1300 nm, where water absorption is even greater than that at 1300 run. However, at those wavelengths (1480 nm, 1550 nm, 1800 nm and 1900 nm) the simultaneous compensation for the hemoglobin value is required.
- a modified Beer-Lambert equation can also utilized for the determination of urea in the blood as follows:
- B (d,Ex)) is an optical pathlengthening function
- lo is the intensity of the incident source radiation
- I is the transmitted intensity of the source radiation through the sample
- E is the extinction coefficient of the sought for constituent
- x is the concentration of the sample constituent in the tissue (or disposable blood conduit)
- d is the optical separation distance
- a measuring wavelength (M) and a reference wavelength (R) must be selected. These wavelengths may be selected close enough to one another such that the pathlengthening factors are approximately the same for each wavelength (longer wavelengths are preferred since they exhibit less sensitivity to scattering). For example, the selection of a measuring wavelength at 2190 nm and a reference wavelength at 1900 nm may be appropriate since the scattering functions (pathlengthening factors) are approximately the same at these wavelengths, and the difference between the peak BUN absorption at 2190 nm and the minimal urea absorption at 1900 nm holds significant BUN information, as seen in FIG. 5.
- the pulsatile characteristics of the bipod require the utilization of the form and mathematical operations presented in U.S. Patent No. 5,372,136, and using the described ⁇ I/I technique in order to eliminate certain intrinsic tissue and extrinsic light source effects.
- [BUN] corrected [E ⁇ /E ooMF [log (I/I 0 ) 8 /log (I/I 0 ) 13 ]] (14) where F[(log 8 /log 13 )J is a function of the hematocrit. It is likely that other competing substances will be detected at 2190 nm, those can also be compensated with similar functional operators.
- the electronic structure and memory components for a BUN measuring system are similar to that described in U.S. Patent No. 5,372,136.
- the wavelengths 1300 nm, 1800 nm, 1900 nm, and 2190 nm are selected. Telcom Device Corp. of Camarillo, California manufactures the corresponding LEDs with product numbers: 1300 nm LED, 1.8 LED, 1.9 LED and 2.2 LED.
- a preferred source for the detector may be photodiode, PD24-04, manufactured by JJBSG, St. Russia.
- BUN dialysate urea nitrogen
- one wavelength of light is selected to be at or near the peak absorption level of urea and another wavelength (the reference) selected at an absorption minimum of urea (or urea nitrogen) with respect to water.
- One such peak wavelength for urea (or urea nitrogen) is at 2190 nanometers (nm) and one such reference wavelength with respect to water may be 1300 nm wavelength of light.
- Other wavelengths of significant absorption due to water (the reference) and minimal absorption due to urea or urea nitrogen are also present at 1480 nm, 1550 nm, 1800 nm, 1900 nm, etc.
- the proposed method takes advantage of the fact that the log (8)/log (13) ratio is insensitive to [Na + ] changes, whereas the log (8) alone, see FIGs. 7, 8 and 9, is very sensitive to Na + or MCV changes.
- Log (8) is equal to log (I/I 0 ) at the 810 nm wavelength and log (13) is equal to log (I/L) at the 1300 nm wavelength.
- the actual function of E versus the OSM or Na + concentration at each given wavelength must hold OSM (or Na + ) information that is different in at least one of curvature, offset, linearity, or sign from the other wavelength, see FIG. 7.
- FIG. 7 shows the direct affect of Na + on the optical absorbance (% change in absorbance), for a single wavelength (log (8)) and a dual wavelength device
- FIGs. 8 and 9 show that either Na + or osmolar changes in blood affect the mean cell volume of a red blood cell.
- a difference will be measured as a function, of mean cell value and thus of Na + or osmolarity.
- the lines plotted in FIGs. 8 and 9 should be linear. They are not because the graphs represent actual experimental data measured with the present invention.
- wavelengths of 810 nm and 1300 nm are preferred wavelengths, the wavelengths may be selected further apart from one another such that the pathlengthening factors are exaggerated for each wavelength. Therefore, a shorter and longer wavelength are preferred since they exhibit even more sensitivity to scattering.
- the selection of the measuring wavelength at 585 nm and the reference wavelength at 1550 nm may be more appropriate since the scattering functions (pathlengthening factors) are exaggerated at these two selected wavelengths.
- OSM g [Na + ] + b (16) where OSM is a function of Na + and g [Na + ] is a function of Na + . Further, g. is slope and b is offset. Both g and b are empirically determined using known methods that employ a look-up table. 5 MEASURING PLASMA FREE HEMOGLOBIN
- the modified Beer-Lambert equation (2) can also be utilized to determine PFH.
- PFH is determined by using an optical technique that does not distinguish between hemoglobin in red blood cells and hemoglobin in plasma. Rather, when light at 800nm is shined through blood, each of the elements (red blood cells, plasma and hemoglobin)
- K ⁇ 0. Otherwise, K Hgb adds to the total hemoglobin in plasma and red blood cells. 35 As an example, at 800 nm wavelength:
- FIG. 10 shows plots of the % change in absorbance of light at 810nm and 810nm/1300nm versus PFH. In this way, FIG. 10 illustrates that using only a single wavelength (800nm)
- PFH and hematocrit information that is different in curvature, or offset, or linearity, or sign from the other wavelength, see FIG. 10. If the functions of E versus PFH are not sufficiently different, then the ratio E1/E2 for the two wavelengths will not hold PFH information. It will be appreciated that other wavelengths such as 585 nm and 1550 nm would also satisfy the condition of having adequate PFH detected with respect to water. B. Further, the wavelengths may be selected further apart from one another such that the path-lengthening factors are exaggerated for each wavelength. Therefore, a shorter and longer wavelength are preferred since they exhibit more sensitivity to absorption and scattering. The selection of the measuring wavelength at 585 nm and the reference wavelength at 1900 nm may be more appropriate since the scattering functions (path- lengthening factors) are exaggerated at those two selected wavelengths.
- FIG. 10 shows that as PFH varies the log (8)/log (13) ratio is unaffected.
- log (8) varies greatly.
- the absorption effects due to hemoglobin, whether inside the red blood cell or in the plasma itself are seen by the detector as a bulk absorbance.
- each wavelength will carry, individually, bulk absorbance values.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
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CA002411049A CA2411049A1 (en) | 2000-06-02 | 2000-06-02 | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content |
AU2000254395A AU2000254395A1 (en) | 2000-06-02 | 2000-06-02 | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content |
PCT/US2000/011866 WO2001094917A1 (en) | 2000-06-02 | 2000-06-02 | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content |
JP2002502418A JP2003535630A (en) | 2000-06-02 | 2000-06-02 | System and method for measuring serum urea nitrogen, osmolality, plasma free hemoglobin, and tissue water content |
EP00939286A EP1299709A1 (en) | 2000-06-02 | 2000-06-02 | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content |
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PCT/US2000/011866 WO2001094917A1 (en) | 2000-06-02 | 2000-06-02 | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content |
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PCT/US2000/011866 WO2001094917A1 (en) | 2000-06-02 | 2000-06-02 | System and method for measuring blood urea nitrogen, blood osmolarity, plasma free haemoglobin and tissue water content |
Country Status (5)
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EP (1) | EP1299709A1 (en) |
JP (1) | JP2003535630A (en) |
AU (1) | AU2000254395A1 (en) |
CA (1) | CA2411049A1 (en) |
WO (1) | WO2001094917A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9091660B2 (en) | 2009-01-13 | 2015-07-28 | Smart Medical Solutions Gmbh | Device for measuring at least one parameter of an arterial blood sample |
JP2017205204A (en) * | 2016-05-17 | 2017-11-24 | 日本電信電話株式会社 | Hematocrit value measuring device and method |
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JP2008264217A (en) * | 2007-04-20 | 2008-11-06 | Sekisui Chem Co Ltd | Hemodialysis evaluation method and apparatus |
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DE4339067A1 (en) * | 1993-11-16 | 1995-05-18 | Jenoptik Jena Gmbh | Method and arrangement for the non-invasive, transcutaneous determination of substance concentrations in body fluid or human tissue |
US5747806A (en) * | 1996-02-02 | 1998-05-05 | Instrumentation Metrics, Inc | Method and apparatus for multi-spectral analysis in noninvasive nir spectroscopy |
WO1998019592A1 (en) * | 1996-11-01 | 1998-05-14 | Rio Grande Medical Technologies, Inc. | Dialysis monitoring method and apparatus |
WO1999039631A1 (en) * | 1998-02-05 | 1999-08-12 | In-Line Diagnostics Corporation | Method and apparatus for non-invasive blood constituent monitoring |
US6040578A (en) * | 1996-02-02 | 2000-03-21 | Instrumentation Metrics, Inc. | Method and apparatus for multi-spectral analysis of organic blood analytes in noninvasive infrared spectroscopy |
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US5351686A (en) * | 1990-10-06 | 1994-10-04 | In-Line Diagnostics Corporation | Disposable extracorporeal conduit for blood constituent monitoring |
US5331958A (en) * | 1992-03-31 | 1994-07-26 | University Of Manitoba | Spectrophotometric blood analysis |
-
2000
- 2000-06-02 CA CA002411049A patent/CA2411049A1/en not_active Abandoned
- 2000-06-02 EP EP00939286A patent/EP1299709A1/en not_active Withdrawn
- 2000-06-02 JP JP2002502418A patent/JP2003535630A/en active Pending
- 2000-06-02 WO PCT/US2000/011866 patent/WO2001094917A1/en active Application Filing
- 2000-06-02 AU AU2000254395A patent/AU2000254395A1/en not_active Abandoned
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4339067A1 (en) * | 1993-11-16 | 1995-05-18 | Jenoptik Jena Gmbh | Method and arrangement for the non-invasive, transcutaneous determination of substance concentrations in body fluid or human tissue |
US5747806A (en) * | 1996-02-02 | 1998-05-05 | Instrumentation Metrics, Inc | Method and apparatus for multi-spectral analysis in noninvasive nir spectroscopy |
US6040578A (en) * | 1996-02-02 | 2000-03-21 | Instrumentation Metrics, Inc. | Method and apparatus for multi-spectral analysis of organic blood analytes in noninvasive infrared spectroscopy |
WO1998019592A1 (en) * | 1996-11-01 | 1998-05-14 | Rio Grande Medical Technologies, Inc. | Dialysis monitoring method and apparatus |
WO1999039631A1 (en) * | 1998-02-05 | 1999-08-12 | In-Line Diagnostics Corporation | Method and apparatus for non-invasive blood constituent monitoring |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US9091660B2 (en) | 2009-01-13 | 2015-07-28 | Smart Medical Solutions Gmbh | Device for measuring at least one parameter of an arterial blood sample |
JP2017205204A (en) * | 2016-05-17 | 2017-11-24 | 日本電信電話株式会社 | Hematocrit value measuring device and method |
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EP1299709A1 (en) | 2003-04-09 |
JP2003535630A (en) | 2003-12-02 |
AU2000254395A1 (en) | 2001-12-17 |
CA2411049A1 (en) | 2001-12-13 |
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