CA2437249A1 - Methods of determining glucose concentration in whole blood samples - Google Patents
Methods of determining glucose concentration in whole blood samples Download PDFInfo
- Publication number
- CA2437249A1 CA2437249A1 CA002437249A CA2437249A CA2437249A1 CA 2437249 A1 CA2437249 A1 CA 2437249A1 CA 002437249 A CA002437249 A CA 002437249A CA 2437249 A CA2437249 A CA 2437249A CA 2437249 A1 CA2437249 A1 CA 2437249A1
- Authority
- CA
- Canada
- Prior art keywords
- whole blood
- hematocrit
- blood sample
- measuring
- concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 0 C1C2C*C1C2 Chemical compound C1C2C*C1C2 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/327—Biochemical electrodes, e.g. electrical or mechanical details for in vitro measurements
- G01N27/3271—Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood
- G01N27/3274—Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/66—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving blood sugars, e.g. galactose
Abstract
The glucose concentration in a whole blood sample may be determined by providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations. The hematocrit concentration of the whole blood sample is measured using the electrochemical sensor via electrochemical impedance spectroscopy. The initial glucose concentration of the whole blood sample is measured using the electrochemical sensor. The unbiased glucose concentration in the whole blood sample is calculated using the initial glucose concentration measurement and the hematocrit concentration.
Description
METHODS OF DETE INING GLUCOSE CONCENTRATION
IN'VVHOLE BLOOD SAMPLES
FIELD OF THE INVENTION
The present invention relates generally to methods of determining glucose con-centration in whole blood samples and, more specifically, methods of determining glu-cose concentration in whole blood samples using hematocrit concentration.
ACI~GROITND OF 'THE INVENTION
Individuals have attempted to determine glucose concentration in whole blood samples for a number of years. The determination of glucose concentration in whole blood samples is important in a variety of applications. F'or example, determining and monitoring glucose concentration are important for diabetics in reducing risks and im-proving quality of life. The results of such tests can be used to determine what, if any, insulin or other medication needs are to be administered.
Glucose concentration in whole blood samples can be difficult to determine be-cause of the biasing associated with the whole blood hematocrit concentration.
The he-matocrit concentration is the concentration of red blood cells in the whole blood sample.
Variations in the hematocrit concentration of whole blood samples result in bias to the glucose concentration measurements. The bias to the glucose concentrations can be sig-nificant such as, for example, a 1 °/~ bias per 1 % change in the hematocrit concentration.
Typical sensors used to measure the glucose concentration of a whole blood sam-ple are dependent upon the hematocrit concentration thereof. Attempts have been made to minimize or eliminate the bias in the glucose concentration of a whole blood sample by modifying the chemistry in the glucose sensor. Gne example of modifying the chem-istry is lysing the blood. Lysing the blood involves breaking up the red blood cells and exposing the contents of the cell. By breaking up the red blood cells, the chemical reac-tion in the sensor that measures the glucose concentration occurs faster.
These attempts have generally reduced the effect of the hematocrit concentration upon the measured glu-cose concentration, but they generally produce less than ideal results in determining the actual glucose concentrations. Another disadvantage of lysing the blood is the additional MSE #2658 time needed to perform the testing process. Additionally, lysing the blood may expose contents of cells that potentially interfere with measuring the glucose concentration.
~ther attempts have involved removing the red blood cells from the whole blood sample before measuring the glucose concentration. Such removal methods are more complicated than simply measuring the glucose concentration without removing the red blood cells. Additionally, such techniques are more difficult when using smaller amounts of whole blood such as those used in the disposable self testing market.
Other attempts to minimize or eliminate the bias in the glucose concentration readings have included separately measuring the he~natocrit concentration from the glu-cose concentration. The hematocrit measurements of the whole blood sample have been performed using a conductivity measurement. These attempts have various disadvan-tages such as requiring separate electrodes to measure the hematocrit and glucose con-centrations. Furthermore, while this approach may be suitable for at least some clinical analyzers, it is cost prohibitive for the disposable sel:~ testing market.
It would be desirable to have a method that obtains a more accurate glucose con-centration from a whole blood sample.
SLTMMAR'Y OF THE II'I~VEl~TTI~hT
The glucose concentration in a whole blood sample may be determined according to one method by providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations. The hematocrit concentration of the whole blood sample is measured using the electrochemical sensor via electrochemical impedance spectroscopy.
The initial glucose concentration of the whole blood sample is measured using the elec-trochemical sensor. The unbiased glucose concentration in the whole blood sample is calculated using the initial glucose concentration measurement and the hematocrit con-centration.
The glucose concentration in a whole blood sample may be determined according to one method by providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations. The hernatocrit concentration of the whole blood sample is measured using the electrochemical sensor via electrochemical impedance spectroscopy using an amperometric monitoring system. The initial glucose concentration of the MSE #2658 whole blood sample is measured using the electrochemical sensor. The unbiased glucose concentration in the whole blood sample is calculated using the initial glucose concen-tration measurement and the hematocrit concentration.
BRIEF DESCRIPTION OF TIDE DRAWINGS
FIG. 1 is a plot of phase shift versus frequency of whole blood samples with a single glucose concentration and varying hematocrit conceni:rations.
FIG. 2 is a plot of impedance versus frequency of whole blood samples with a single glucose concentration and varying hematocrit concentrations.
FIG. 3 is a plot of phase shift versus hematocrit concentration of whole blood samples at a single frequency with varying glucose concentrations.
FIG. 4 is a plot of impedance versus hematocrit concentration of whole blood samples at a single frequency with varying glucose concentrations.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
The present invention is directed to determining the glucose concentration in whole blood samples. The whole blood sample comprises plasma and red blood cells. In determining the glucose concentration, the hematocrit concentration (red blood cell con-centration) of the whole blood sample is also determined because the glucose concentra-tion varies based upon the hematocrit concentration. By compensating for the hematocrit concentration, a more accurate glucose concentration of the whole blood sample can be calculated.
The glucose concentration of the whole blood sample may be determined by us-ing an electrochemical sensor according to one embodiment of the present invention. It is important that the electrochemical sensor provides reliable and reproducible measure-ments. An example of an electrochemical sensor is a sensor that may be used in an am-perometric monitoring system. Examples of an electrochemical sensor that can be used to measure glucose concentrations are those used in Bayer Corporation's Glucometer DEX~ and ELITE~ systems.
MSE #2658 According to one embodiment, an electrochemical sensor comprises an insulating base plate having provided thereon an electrode system. The electrode system comprises at least an electrode for measurement and a counter electrode. On the electrode system, a reaction layer is included that contains a biosensing or reagent material, such as an en-zyme, and an electron acceptor. The enzyme of the reaction layer may be combined with a hydrophilic polymer. A, cover may be used to mate with the base plate to form a space including the reaction layer. A whole blood sample is introduced into the space via an introducing port. Gas is discharged from the space by the inflow of the whole blood sample via a discharge port. It is believed that the glucose in the whole blood sample reacts with the enzyme by the action of the glucose oxidase earned on the electrodes to produce hydrogen peroxide. A voltage is applied (e.g., 1 V ) between the electrodes and the electrode for measurement is polarized in the anode direction. By applying a voltage in the anode direction, an oxidizing current for the produced hydrogen peroxide is ob-tained. This current level corresponds to the concentration of glucose in the whole blood sample.
More details on such an electrochemical sensor may be found in U.S. Patent Nos.
IN'VVHOLE BLOOD SAMPLES
FIELD OF THE INVENTION
The present invention relates generally to methods of determining glucose con-centration in whole blood samples and, more specifically, methods of determining glu-cose concentration in whole blood samples using hematocrit concentration.
ACI~GROITND OF 'THE INVENTION
Individuals have attempted to determine glucose concentration in whole blood samples for a number of years. The determination of glucose concentration in whole blood samples is important in a variety of applications. F'or example, determining and monitoring glucose concentration are important for diabetics in reducing risks and im-proving quality of life. The results of such tests can be used to determine what, if any, insulin or other medication needs are to be administered.
Glucose concentration in whole blood samples can be difficult to determine be-cause of the biasing associated with the whole blood hematocrit concentration.
The he-matocrit concentration is the concentration of red blood cells in the whole blood sample.
Variations in the hematocrit concentration of whole blood samples result in bias to the glucose concentration measurements. The bias to the glucose concentrations can be sig-nificant such as, for example, a 1 °/~ bias per 1 % change in the hematocrit concentration.
Typical sensors used to measure the glucose concentration of a whole blood sam-ple are dependent upon the hematocrit concentration thereof. Attempts have been made to minimize or eliminate the bias in the glucose concentration of a whole blood sample by modifying the chemistry in the glucose sensor. Gne example of modifying the chem-istry is lysing the blood. Lysing the blood involves breaking up the red blood cells and exposing the contents of the cell. By breaking up the red blood cells, the chemical reac-tion in the sensor that measures the glucose concentration occurs faster.
These attempts have generally reduced the effect of the hematocrit concentration upon the measured glu-cose concentration, but they generally produce less than ideal results in determining the actual glucose concentrations. Another disadvantage of lysing the blood is the additional MSE #2658 time needed to perform the testing process. Additionally, lysing the blood may expose contents of cells that potentially interfere with measuring the glucose concentration.
~ther attempts have involved removing the red blood cells from the whole blood sample before measuring the glucose concentration. Such removal methods are more complicated than simply measuring the glucose concentration without removing the red blood cells. Additionally, such techniques are more difficult when using smaller amounts of whole blood such as those used in the disposable self testing market.
Other attempts to minimize or eliminate the bias in the glucose concentration readings have included separately measuring the he~natocrit concentration from the glu-cose concentration. The hematocrit measurements of the whole blood sample have been performed using a conductivity measurement. These attempts have various disadvan-tages such as requiring separate electrodes to measure the hematocrit and glucose con-centrations. Furthermore, while this approach may be suitable for at least some clinical analyzers, it is cost prohibitive for the disposable sel:~ testing market.
It would be desirable to have a method that obtains a more accurate glucose con-centration from a whole blood sample.
SLTMMAR'Y OF THE II'I~VEl~TTI~hT
The glucose concentration in a whole blood sample may be determined according to one method by providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations. The hematocrit concentration of the whole blood sample is measured using the electrochemical sensor via electrochemical impedance spectroscopy.
The initial glucose concentration of the whole blood sample is measured using the elec-trochemical sensor. The unbiased glucose concentration in the whole blood sample is calculated using the initial glucose concentration measurement and the hematocrit con-centration.
The glucose concentration in a whole blood sample may be determined according to one method by providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations. The hernatocrit concentration of the whole blood sample is measured using the electrochemical sensor via electrochemical impedance spectroscopy using an amperometric monitoring system. The initial glucose concentration of the MSE #2658 whole blood sample is measured using the electrochemical sensor. The unbiased glucose concentration in the whole blood sample is calculated using the initial glucose concen-tration measurement and the hematocrit concentration.
BRIEF DESCRIPTION OF TIDE DRAWINGS
FIG. 1 is a plot of phase shift versus frequency of whole blood samples with a single glucose concentration and varying hematocrit conceni:rations.
FIG. 2 is a plot of impedance versus frequency of whole blood samples with a single glucose concentration and varying hematocrit concentrations.
FIG. 3 is a plot of phase shift versus hematocrit concentration of whole blood samples at a single frequency with varying glucose concentrations.
FIG. 4 is a plot of impedance versus hematocrit concentration of whole blood samples at a single frequency with varying glucose concentrations.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
The present invention is directed to determining the glucose concentration in whole blood samples. The whole blood sample comprises plasma and red blood cells. In determining the glucose concentration, the hematocrit concentration (red blood cell con-centration) of the whole blood sample is also determined because the glucose concentra-tion varies based upon the hematocrit concentration. By compensating for the hematocrit concentration, a more accurate glucose concentration of the whole blood sample can be calculated.
The glucose concentration of the whole blood sample may be determined by us-ing an electrochemical sensor according to one embodiment of the present invention. It is important that the electrochemical sensor provides reliable and reproducible measure-ments. An example of an electrochemical sensor is a sensor that may be used in an am-perometric monitoring system. Examples of an electrochemical sensor that can be used to measure glucose concentrations are those used in Bayer Corporation's Glucometer DEX~ and ELITE~ systems.
MSE #2658 According to one embodiment, an electrochemical sensor comprises an insulating base plate having provided thereon an electrode system. The electrode system comprises at least an electrode for measurement and a counter electrode. On the electrode system, a reaction layer is included that contains a biosensing or reagent material, such as an en-zyme, and an electron acceptor. The enzyme of the reaction layer may be combined with a hydrophilic polymer. A, cover may be used to mate with the base plate to form a space including the reaction layer. A whole blood sample is introduced into the space via an introducing port. Gas is discharged from the space by the inflow of the whole blood sample via a discharge port. It is believed that the glucose in the whole blood sample reacts with the enzyme by the action of the glucose oxidase earned on the electrodes to produce hydrogen peroxide. A voltage is applied (e.g., 1 V ) between the electrodes and the electrode for measurement is polarized in the anode direction. By applying a voltage in the anode direction, an oxidizing current for the produced hydrogen peroxide is ob-tained. This current level corresponds to the concentration of glucose in the whole blood sample.
More details on such an electrochemical sensor may be found in U.S. Patent Nos.
5,120,420 and 5,320,732 which are both incorporated by reference in their entirety. One or more electrochemical sensor may be purchased from Matsushita Electric Industrial Company. It is contemplated that other electrochemical sensors may be used in the pres-ent invention. For example, an electrochemical sensor is disclosed in U.S.
Patent No.
5,798,031, which is incorporated by reference in its entirety. A further example of an electrochemical sensor that may be used in an amperometric monitoring system is dis-closed in U.S. Patent No 5,429,735. It is contemplated that other sensors may be used in the present invention.
The electrochemical sensors may be located in a blood glucose sensor dispensing instrument that is adapted to have loaded therein a sensor pack that includes a plurality of sensors or testing elements. Each of the sensors is adapted to be ejected from the sensor pack. One example of a sensor pack loaded in a sensor dispensing instrument is dis-closed in U.S. Patent No. 5,660,791.
To reduce any bias of the initial glucose concentration resulting from variations in the hematocrit concentration of the whole blood sample, the hematocrit concentration is MSE #2658 preferably first measured. It is contemplated, however, that the hematocrit concentration may be measured before measuring the initial glucose concentration of the whole blood sample. The hematocrit concentration needs to be measured because the electrochemical sensors used to measure the initial glucose concentration are dependent upon the hemato-crit concentration of the whole blood sample. The greatest sensitivity in accurately measuring the glucose concentration of the whole blood sample occurs at higher glucose levels (e.g., 250 or 400 mg/dL). At such glucose levels, a lower or higher percentage of hematocrit (e.g., 20 vol.% or 70 vol.% hematocrit) causes substantial deviation between the initial glucose concentration measurement and the actual glucose concentration as compared to an average hematocrit concentration (e.g., 40 vol.% hematocrit).
It is believed that the impact of a whole blood sample's hematocrit concentration on the measured glucose concentration is consistent in electrochemical sensors in am-perometric monitoring systems. This consistency of the hematocrit concentration on the measured glucose concentration occurs in both disposable amperometric monitoring systems and clinical analyzers as well. Thus, the bias, if any, can be corrected by meas-uring the hematocrit concentration and subsequently adjusting the initial glucose meas-urement.
The hematocrit concentration is determined using the same electrochemical sen-sor that determines the initial glucose concentration of the whole blood sample. Ac-cording to one embodiment, the hernatocrit concentration is determined using electro-chemical impedance spectroscopy (EIS) that is integrated in the glucose monitoring sys-tem, such as the above described amperometric monitoring system. EIS is essentially a solution impedance measurement covering a single frequency or a plurality of frequen-cies. The higher the measured impedance of the whole blood sample, the higher the con-centration of hematocrit therein.
Electrochemical sensors may be used by applying AC waveforms from generally about 1 to about 10,000 Hz. It is contemplated that the AC waveforms may be higher than 10,000 Hz. The AC waveforms may vary in voltage but are generally from about 1 to about 100 mV and, more specifically, from about 3 to about 30 mV. The AC
wave-forms are either discrete frequencies or co-added waveforms that are subsequently de-convoluted using a Fourier Transform (FT) routine. The Fourier Transform approach is MSE #2658 desirable because it significantly reduces measurement time versus other techniques. It is contemplated that techniques other than the Fourier Transform may be used to assist in ultimately determining the hematocrit concentration.
Alternatively, or in addition to using one or more frequency measurements, a phase shift and/or magnitude of an impedance measurement may also be used to measure the hematocrit concentration. The resulting phase shift and/or magnitude of the imped-ance are measured at each frequency. The AC waveform is superimposed on a bias volt-age of, for example, lSOmV, the applied potential at which an electrochemical sensor may be operated. By comparing the phase shift and/or magnitude of an impedance measurement, the hematocrit concentration can be determined. It is desirable to use a frequency or frequencies in which the phase shift and/or magnitude of an impedance measurement can be easily differentiated between hematocrit concentrations.
Examples of frequencies that may be used with measuring the phase shift of an impedance measurement include those from about 800 to 900 Hz. It is contemplated that other frequency or frequencies may be used in measuring phase shift of an impedance measurement. Examples of frequencies that may be used v~rith measuring the magnitude of an impedance measurement include those from about 300 to about 10,000 Hz.
It is contemplated that other frequency or frequencies may be used in measuring the magni-tude of an impedance measurement.
After the hematocrit concentration is determined, it is used to correct the bias, if any, associated with the initial glucose concentration measurement in the whole blood sample. The relationship or bias, if any, between the hematocrit concentration and the initial glucose concentration measurement may be stored in a calibration table. The cali-bration table is typically generated using a number of hematocrit concentrations and ini-tial glucose concentration measurements. By correcting for any bias caused by the he-matocrit concentration on the initial glucose measurement, a more accurate whole blood glucose measurement is determined.
The method for more accurately determining glucose concentrations by reducing or eliminating any bias caused by hematocrit concentration may be performed in dispos-able self testing systems. The disposable self testing systems are often used by end con-sumers, especially those who are diabetic. Alternatively, the method for more accurately MSE #2658 determining glucose concentrations by reducing or eliminating any bias caused by the hematocrit concentration may be performed in clinical analyzers. Clinical analyzers are often used in hospitals or clinics.
The present invention is especially desirable with neonates (newborn children that are less than one month old). Neonates typically have fairly high blood hematocrit con-centrations (normal ranges from about 55 vol.% to 65 vol.%). ~ne of medical conditions that may occur in neonates, as well as adults, is hypoglycemia. tVith respect to hypogly-cemia, the decision point in neonates is Lower than that of adults (40 mg/dL
vs. 60 mg/dL). The combination of lower glucose concentrations with higher hematocrit con-centrations may lead to highly inaccurate initial glucose readings caused from the bias of the hematocrit concentrations. Thus, the present invention is desirable in determining the glucose concentration in the whole blood sample of neonates.
The testing end of the sensor is adapted to be placed into contact with the whole blood sample to be tested. The whole blood sample tnay be generated by a lancing device such as a microlet. The lancing device may obtain blood by, e.g., pricking a person's finger. According to one process, the whole blood sample may be prepared for testing by (a) removing the electrochemical sensor from packet, (b) placing the electrochemical sensor into a glucose concentration measuring instrument, (c) generating a whole blood sample and (d) bringing the sensor and the whole blood sample into contact wherein the blood is generally drawn into the sensor by capillary action.
Examples Several plots have been prepared to show the relationships between (a) hemato-Grit level and (b) phase shift, glucose concentration, frequency and impedance.
FIG. 1 is a plot of phase shift versus frequency of whole blood samples. The whole blood samples had a glucose concentration of 300 mg/dL and the hematocrit con-centration was either 20 vol.%, 40 vol.% or 60 vol.%. The tests were performed on Bayer Corporation's Glucometer DEX~ system with a three-pass reagent electrochemi-cal sensor. The electrochemical sensor was operated at an applied potential of 150mV.
The frequency (measured in Hertz) was plotted logarithmically along the x-axis versus the phase shift (measured in degrees) which was plotted along the y-axis. FIG.
1 shows MSE #2658 that there are many frequencies that result in distinct phase shifts between varying he-matocrit concentrations. It is desirable to chose a frequency in which the phase shift is more pronounced between varying levels of hematocrit concentrations.
FIG. 2 is a plot of impedance (Z) versus frequency of whole blood samples. The whole blood samples had a glucose concentration of 100 mg/dL and the hematocrit con-centration was either 20 vol.%, 40 vol.% or 60 vol.%. 'rhe tests were performed on Bayer Corporation's Glucometer DEX~ system with a three-pass reagent electrochemi-cal sensor. The electrochemical sensor was operated at an applied potential of 150mV.
The frequency (measured in Hertz) was plotted logarithmically along the x-axis versus the impedance (measured in ohms) which was plotted logarithmically along the y-axis.
FIG. 2 shows that there are many frequencies that result in distinct impedance measure-ments between varying hematocrit concentrations. It is desirable to chose a frequency, such as the higher frequencies, in which the impedance measurements are more pro-nounced between varying levels of hematocrit concentrations.
FIG. 3 is a plot of phase shift versus hematocrit concentration of whole blood samples. There were several glucose concentrations that were tested: 0 mg/dL, SOmg/dL, 100 mg/dL, 300 mg/dL and 600 mg/dL. Each of the glucose concentrations was plotted separately in FIG. 3. The individual data points that were used in forming the plot of FIG. 3 are listed in Table 1 below.
MSE #2658 '~ ~k~~~ '~
wo _ w;, . ,~ ~ : x ~ >, y .~,> ~ .
. ~ a r\ ~\. i.!, ~ , t a.: ~,, ~F:, f~,.,t "3 ~;a.
. ,3 ' ' ~~~ ~~ ~ , .'>__ , a ,.., ~ ,d:.! o , s 4 "M , ~'' ,.:
,.
t r 3 d .<, a ~ a =I°,' ~:3, ; 9 . :. ~ , 1 t.'; ", e... ,' r:3!F
Ii f3fi" , a s ' '~- 3 ..._ t , 3 . 3 b a . 3, a1i ,;
1 ., ~ ,.!, - ' ~ 0 1, . J. .' 3 ',.
9C5 ~' ~-:!
q". t L.a. >
F , . a' t .:
'"c _ 3 3, : .: ~ ~'~ '4" m ~ 3. ' t ,a ,°..
,......
3 ..s '. a ~ :. , ,3 ,1 -f ", ~ ~t t F
t ~ F .~-. 4 .k .. .I i _.~- ,.=~,~~c _ , S >-Z F';,.
i.~5 t ~ . 4 , ..~ t. ., w.,.
, . .~ v-~.'= _ - 'b ,~ _-~' W a . v ~. _ ,. m_ v~ _ ~ \_w v v v t. \
\~~._. . ;-~ -.\\ s -\
>.
~ ~ ate. ~ m \\\ - _~., e~w <,a-w : C \~ . _, w '~-~,.~.3. _\\.~ . \~~ >
\w,\
W- v,. v~-.« 6'a tw\ . >> =." . ~\ > ~\
v \ ~ . - . , r~ _,~\ _ 9.3 , d'td > :--~:
~\ .~ \ . C ~. \_- r v, ~ . ~'~ ,. Aw \ '->aF F
a_ "\-- ~ \ -,\
F: . _"\ ~.. .-- v .._ >~ \ v., a - _ \, v 9 . ~ 0 -'\ !
~w ,. .~~r 0 \ a \ _ v ... ° .a , W ~:.~ ~ _3 ~ _ . '~ .-_ t- . .% : ,~ _ ~\ .,~x1-= .. .' ~ r ,~ ~ ~ _ _\ ~ ~n_ - ~ . _\ .-ov\ ~..-'.
~. s\ >_ ~,'.c. ._.\., .-~ _'.~'a... , ~ ~\ ~._.. _ > ~- ~s.>.. . \\ ;~. ~-_ ~~~ ~.~:....\~., _ ~, ~ ,..
; '~ ~s a ~.. _ ~ .. -s .~..
.~:,,~., >..~..rz F
,..r.. o....t.c!., ;; ~ ~S. ,: I;:; .
3, 5 I d ' f ~... 3i~3:' , 1 ' f - h"'.
~i;~..: v $
i~ , ~ ~:v>' . ,.:~i" , ':;'7'. , ~.">.,.i~~" ... t1 t . = I a ~Jl$a. ,"~ ,R~~~n=~s.: '; ..~ , r, .::t~a",'~ ".
k . a .. ~ _ ~ ,r.!~
w.. ~ ~ ~pis~ ~ r _.t t .,,F'm f t ~ ~ fn f., .
~ .__...,-__-... _ ._ y ~s~J ~~~ ~7.1u ~aC _ ' 7.~a?
~ __.._. ~5.~3 -- ~_~.5~
~~_~'~C~ '~g~.~4 ...-_ __. ~~ ,." _;'_~.~~ -d ~ ~~1~ ~ ,~L~s ---t- ~~.~3~J
f ~~ a ~ ~ ~~ ~ '~1.~2 v'~ ~3 L~J 'a~J
~~t~3 ~ ~ ~~ ~ ~3.~3 ~C~ ~ ~~ _~~ E ~.~5 ! ~? ~~_~ ~~ ~~ 9 ~5.~2 -.--~ ~ ~. ~&
~G ~_ i~.~7 ~~3~ ~C~ ~'i.'~1 j 35 ~C~S ._~~~~_ >~.~~9 ~~~ ..._..___~ .~.' ...._ ..._._ ~
As s~c~~nrr~ :sue '~'~:~i: i, ai~s~ aii ~~~t~~~ ~°oeit~ci. ~:v~,~ae ~;~~~~rat~~~rio~: a~~ n~ernat~-grit ~~~.c~r~tr°atiora ~o~sxL.a~ti~~s ~,~°x~:; tes'~.~ t~i~~.
'p~~ t~~,tir~~~ t~~ =y~a,s~ si~i~t versus im~aa°~o~rit ~~r~oon~ratio~s r~port~U i=._~ ~'~~i~ i ~r3si p~o~a~~ in -~~~~~. s r gas ciori~ ~.t a ~°ro-~~a~ ~~~ o~ i i i~z. ~~~ tests w~r~ y~~rr'~or:~:~or; ~a~e~a ~ ~~~~~or~3~~~~'s ~:~~~~or.~~t~r ~:~G
systerrf v~r~th a t~~reo-pass r~aaer~t a=~,s~troo~drrioa~ se_~sor. ~~ze ~~octroc~~~~oai svr~sor was op~rU~~ed .at a~~ appti~p;~?~~~tia:~. ~~~~ i~~rx~.~l. '~~ ~~;~:~=.~~s~~tt ~c~~~entr~vi~~ ~a~i.%) wr~s plott~,~l aior~g the x-axis ~r°rs~as tl~~ p~as~; s~ii~ ~<r~eas~z~-~~
i~x degrees) ~>w~i~~°3 Haas pioi~~;
a'9~ri~'~f'.~2 ~'-axFS. _~'~'~. .~ s~'°~~~1VS i°~~s~s, i~lei'~
1S a ~!i~rl~.l:i~~, Irl t~l~ p~1~,5~ S~E~~~ w~t~l ~~'IIC~S~.
iali~~ ~~~Jc~
~. c ~~~~~.~,n~ra~i~r~s at a ire~~~v~~~ ~f ~~~ l~as~ ~ ~ ~ ~~~. ~~~. : ~.~.so slaQws ~ha~ ~1~3~~:m, :~u a v~.ria~~-c;r~.
in ~9'z~ p~"~~.5~ s~'li~: ~li~;l~ ~~~~~'~~,~ ~1'~~ ~?~r~':r~~~G.:~$:
~s~n~,E;:~~~-a_'s1~0~'1.
~~r. 4~ is ~ ply ~s :° i~ p~~~.a~~~~: ~~, verses ~~~7~ K ~~ ;rig nor>~~n~ra~i~r~ ~~~' ~rl~~~~~ bl~~d sar~les. There ~a~r~ s~~~aa ~:T..~~,~s~, ~~r~~,en~ra~;iQns r~~ ~ ~r~~ae ~:~ste~.: ~ ~r~~/d~,, ~Orr~g/dl~,, ~ ~~ ~ylid~.,, ~~3~ r~~~gl~af~ n~.rm. ~t~~ ra~~~ldL. ~ac:~~ ~~~~a~~ ~i~~~s~ ~~-~~a~~~~ca~i~n<~ gas pio~~,d s~pa~-atel~~ in ~T~. 4. '1'~.~~ ndjvrid~~l d~~a p~i~.~ts ~~,a.r v,v~r~:;
~a~;~,~ an ~°~r~;~~iv~a~ ~l~e pl~~ o~
~'~~. ~- are lisped >r° ~'a~l~ ~ ~~i~~.:~.
,.
Q
.. ~ , ~.
_~ ~,._..~\.
F._ \ :- -a ~o ~~ pearl ~'m $ ~a~ ~ ~t f . a t~. ,.~ r ;
~..N.:
a ,' ~: ,$:
F
~:a t ' f.~'I ~ . .. $' : r.~ $ ,', :. Y
, v$na,f __ f ,fit t '. ~. ..'f , 6 "a z~~. .~~,;
', r ' E~z $ t ,.., s . W
n f s s ..
.',4. . ' . 's w. ".: s , ' o .,. ~ ,. #
., fr ,. , r -.
z .°
\', :.~
__ y,\ .., .,~.~:, h \ .~ , Q d -~' '- \ \ _ ~ -<
~'~ ...\, . ~, a .-_3 . .. -~, ~, .. .$ ~ ~. ~ f:.. 3 ~,.~-_ ~ _-_: \
't~ . , a \ ~J~ _s . ~ v 3 ... v +.
ry~_ , 3 ;~ , s . ~# . a ~~ , a ., = ~, w a 7.F. , ., t:
1. ,~ F.. ,' .
r:3 ~ , ., ' a m.
'~ r ~_ d _.
1.Y .. , , . ~#
N .. f ",....
s1,.: 1 , _ ~ , ~E , , _z.. , , i. ~ .~, . ; ",,., :~..,: ;.e ~ 3 t .,., a .. ...; >dt a A , a.,.~:. ~-'a ' ,.#:
r r ., ~ -.. ". .
a ,'i' '. 't , 7 3. H
q . . ~. . ~ ~s 'N ., roR.° $ . , f a r j"'. , ~i ah t - .r .__x. , a F h=N
E , i. Y ' , n'.:ø. "~-' a , r ~,.
a as = d , . ,: ~P ~s~a . L .,, q.:. . _-~ s r ,.. E _ < 3,4 -' # ~ a. ,t, a _ ~ .. . "LU~~. _~._~ ~_s _, ~>~~~~ . ~~~ .._f . s-~ ._ _ ~4 _.H . ~C~.,~_~~ ,,~~\ _.~txz. ~ ~ ~~ ~~ -~ ,a~ 9~s~
16 ~~ ~811.g o __~~
~ _~_ ~~ ~i X169.6 _ ~~ ~ ~' ~8~~.9 ~6~5.2 ~8 ~ 65 E 8_1~7.Q
'?J ~~3 ~~ ~ °~~8~.6 i E) 2~ s~ 4~S -__~n ~ - ~ ~~~.~d ,_. - _.,.
6~~~ ~~ ~ ~a~1~6 f_ -i __ -' Su ~_.~ 6th 8'9 65.8 !2~ 1~~~~~ t ~.~ ~--_ _W ~~11.3~~
16~ ~.~~ ~~ -! _63_8_0.6 °~6~~ ~ ~~3 ~~~86.3 1~_._..~_ 6~ _____ _..._.~ 85~1.a °
1 ~~ a ~_~ 6~ __ ~ _8169.6 3_G~ j ~ 2~r ~ 665.9 _ ~$~~,' _ 4~ . _~ rCB9.8 27 ~ 6~~; '--.'~_'_._"__. 6~ __.~___.~# __ 8165.8 u5~ ~~y~ 6_. ~.~. 859.1 2 ~ 6t3~~ ;~~ _ ~~ __ . ~~ 8~81.~
65~= ' ~~ ~ ~a:~1.5 3U 6~~ ° E 6~~~ 8656. _.
i ~ 6~~ ~°.m~ 6_.___......_ X629.8 ~~~'. #2~~~
1 ~_ ~s s~~~~~r~. i~ ~'~.~~~ ~9 ~~r :~~° ~~°~~ :~~~m~~~ ~a~~~s~ ~~n~~
~~~~~~~>rP ~.~Pr~~r~P~~~~.~~~'~ ~~P~.c~rP~r~.~
,,.~Yt rpr~~.,,v~øf~~p~,~~~y 2,t~y~v~"y~sEp~e- °.yw = ,~~tq~.,6~
.~Y1!~~i ~ ~yyGg~-~s~ø,~~e Li~~ v~~P a~~P~~~ ~~te., ~.'urf~S,~ "vl""1n4,,~~ "~.~A~ ~~~F~rri~ ".~:v.3RY4., :.~~~a~'.~~~~~ ~'~Ey~c.,r~~~~ ~~~~~~..b'~'~
~'~'T'~CGIl~aa~I~r'aS P'~~7~~~C~ :.~?, s ~~i~ ~, ~.i'PF~ ~~~;~~ ~6~ ~«~~
d°~~. -fit- ~~~leaS ~~1'P~, ~d: "ca bf"~~~~.'1.~~~- ~~ ~~~.
a"-iii. r~Pf,''i~Sl;s ~%~,''_Y°~ ~r?ea ~~':~ ~-P.~ex~~~.~
i~~r~Syr'~4;~~~~,> ~'~.'~aP~~Lx'k'a~t~:,= ~~i~~ ~i~S~~S1'? ~!'1~
7eS'La~E,'°3~.sS r~2t~E.'r°a~, ~,'~~.~'~ 'v~'.CP~ri':3v'~'E
S~rns,~'rx. ~ ~~E J~(,',s°.,~~',~,3~i3'~iP11~C1 s~r~si~n' 'Y~r,s Oy°'_~~~6;C~ G.'l ~~ ~'"~(;~~I~~ 39~J~~P~.~P~~ ~a ~v~~. ~ '_,~ _~C:~~G~~P°.r3e:
~~r3_~~.~,ri''~F"~~It3fi ~~J~s.%~ a~J:~w ~'~''~~l'bC'~. ~t~at~~'1 v ~~3~ X-aXPS il~P°S~JS $~iC', ~tPy~:,~~is~:,~ ~~ 3v'~'~:~'t~P°~;u zip i3~3~°9su ~.~s~?a',~5 ~d°e'Vv Y'9~~ECC,~~ cl~6~w'P'~~ ~~ ~ ~
-~XPS.
E~ ~.~. ~<° S~~°v~,'s ~:~~$ '~'L?~P'~ i;~ ~. 1~C~~eau$~n s'E
arr~~~~,:z~. ~~, 47z6~' P'~;5~6..~': ~.~' '~~:~'_. "'P~%P'P~~~~,~,~~°P~
~~~r i,~~bi~l:~ri 2.~ ~~ li~G~-~~~9~,a! ;~L~~~: if',P~'°. ~~'~~ ~~~~. a ~~.
~" ~~~.',~.r'S ~:: 5~~~~1 ~,~~:~ :.i"I~ ~a~rPP~ll~!' ~~ ~~'z~ lri~~3~C~~~P~~ Ps Pa ~ ~~'~~~~'P~~~: ~..' ~~~~ ~~r~.~~~5~~ ~:,~r:4 ,:l~iY~e~:~3'P ~~~ c'~ tr~~s3 ~'~.~i~ t9:i c~,~ ~~~c~
~~~ i ~~.
~!~~~~ ~~~''~:I~~P~.c?:" ~Ii~~J"~C.~,~.~'P~tx~':e~::~C~.
''~~.~~3e~,~~.~~~~~Y'a:3 C~~ ~~'1~ ~~r~S~s~~ Pr.P~e,.r~~..rP~:R~'PP il~k'V-:
~f,~P'a a~~LIS'~r~.~~d at'~~ ~'~~~:~'~~'~9 1"6 .k~ c~ ic, ~8~~,rS~&~~3~
~~~~~~: f~~ll~ ~~zm~~T2~.iW<. F,s :'P~~ lrr~,i'~4;f~ ~a~
e~7~ ~3'~°~~iS~.' CJ~s'°~P"L~C~s_~°" 3 ~aP"P~:
°.6~.>~53~P63aS ~°ss ~~S~CL ~u=:,'s'~Ph asPGa i~~~ ',j~~~~l:~s r:'I,d'Jd~PiCsL-~P~IiS~ ~~I~.P'P~~Sy ~:~~ ~~~~°_~;;k~3Pl~, ai~~:~' ~~ ~a.,~"'~~"a,s't~
~r~ b'~ ~~'P~ ~C;P'~~!~PP~~ G~~'S~%rP~~;:C~2~PS '~TelP1'.~1~,°t.;~
~e°.,~9'~Ql"'viflg iP'f~Y~ 9.~~ s'ZS~~ ~.3iC~ 5~..~~w "~~ t.ct~
~,ri~l~~~~.P~7ha ~''s !''~~'.,a~"u_~3~i~'. Iia 3~~~ ~~i~ri~u"~.~
f°,i~l~"k2S.
Patent No.
5,798,031, which is incorporated by reference in its entirety. A further example of an electrochemical sensor that may be used in an amperometric monitoring system is dis-closed in U.S. Patent No 5,429,735. It is contemplated that other sensors may be used in the present invention.
The electrochemical sensors may be located in a blood glucose sensor dispensing instrument that is adapted to have loaded therein a sensor pack that includes a plurality of sensors or testing elements. Each of the sensors is adapted to be ejected from the sensor pack. One example of a sensor pack loaded in a sensor dispensing instrument is dis-closed in U.S. Patent No. 5,660,791.
To reduce any bias of the initial glucose concentration resulting from variations in the hematocrit concentration of the whole blood sample, the hematocrit concentration is MSE #2658 preferably first measured. It is contemplated, however, that the hematocrit concentration may be measured before measuring the initial glucose concentration of the whole blood sample. The hematocrit concentration needs to be measured because the electrochemical sensors used to measure the initial glucose concentration are dependent upon the hemato-crit concentration of the whole blood sample. The greatest sensitivity in accurately measuring the glucose concentration of the whole blood sample occurs at higher glucose levels (e.g., 250 or 400 mg/dL). At such glucose levels, a lower or higher percentage of hematocrit (e.g., 20 vol.% or 70 vol.% hematocrit) causes substantial deviation between the initial glucose concentration measurement and the actual glucose concentration as compared to an average hematocrit concentration (e.g., 40 vol.% hematocrit).
It is believed that the impact of a whole blood sample's hematocrit concentration on the measured glucose concentration is consistent in electrochemical sensors in am-perometric monitoring systems. This consistency of the hematocrit concentration on the measured glucose concentration occurs in both disposable amperometric monitoring systems and clinical analyzers as well. Thus, the bias, if any, can be corrected by meas-uring the hematocrit concentration and subsequently adjusting the initial glucose meas-urement.
The hematocrit concentration is determined using the same electrochemical sen-sor that determines the initial glucose concentration of the whole blood sample. Ac-cording to one embodiment, the hernatocrit concentration is determined using electro-chemical impedance spectroscopy (EIS) that is integrated in the glucose monitoring sys-tem, such as the above described amperometric monitoring system. EIS is essentially a solution impedance measurement covering a single frequency or a plurality of frequen-cies. The higher the measured impedance of the whole blood sample, the higher the con-centration of hematocrit therein.
Electrochemical sensors may be used by applying AC waveforms from generally about 1 to about 10,000 Hz. It is contemplated that the AC waveforms may be higher than 10,000 Hz. The AC waveforms may vary in voltage but are generally from about 1 to about 100 mV and, more specifically, from about 3 to about 30 mV. The AC
wave-forms are either discrete frequencies or co-added waveforms that are subsequently de-convoluted using a Fourier Transform (FT) routine. The Fourier Transform approach is MSE #2658 desirable because it significantly reduces measurement time versus other techniques. It is contemplated that techniques other than the Fourier Transform may be used to assist in ultimately determining the hematocrit concentration.
Alternatively, or in addition to using one or more frequency measurements, a phase shift and/or magnitude of an impedance measurement may also be used to measure the hematocrit concentration. The resulting phase shift and/or magnitude of the imped-ance are measured at each frequency. The AC waveform is superimposed on a bias volt-age of, for example, lSOmV, the applied potential at which an electrochemical sensor may be operated. By comparing the phase shift and/or magnitude of an impedance measurement, the hematocrit concentration can be determined. It is desirable to use a frequency or frequencies in which the phase shift and/or magnitude of an impedance measurement can be easily differentiated between hematocrit concentrations.
Examples of frequencies that may be used with measuring the phase shift of an impedance measurement include those from about 800 to 900 Hz. It is contemplated that other frequency or frequencies may be used in measuring phase shift of an impedance measurement. Examples of frequencies that may be used v~rith measuring the magnitude of an impedance measurement include those from about 300 to about 10,000 Hz.
It is contemplated that other frequency or frequencies may be used in measuring the magni-tude of an impedance measurement.
After the hematocrit concentration is determined, it is used to correct the bias, if any, associated with the initial glucose concentration measurement in the whole blood sample. The relationship or bias, if any, between the hematocrit concentration and the initial glucose concentration measurement may be stored in a calibration table. The cali-bration table is typically generated using a number of hematocrit concentrations and ini-tial glucose concentration measurements. By correcting for any bias caused by the he-matocrit concentration on the initial glucose measurement, a more accurate whole blood glucose measurement is determined.
The method for more accurately determining glucose concentrations by reducing or eliminating any bias caused by hematocrit concentration may be performed in dispos-able self testing systems. The disposable self testing systems are often used by end con-sumers, especially those who are diabetic. Alternatively, the method for more accurately MSE #2658 determining glucose concentrations by reducing or eliminating any bias caused by the hematocrit concentration may be performed in clinical analyzers. Clinical analyzers are often used in hospitals or clinics.
The present invention is especially desirable with neonates (newborn children that are less than one month old). Neonates typically have fairly high blood hematocrit con-centrations (normal ranges from about 55 vol.% to 65 vol.%). ~ne of medical conditions that may occur in neonates, as well as adults, is hypoglycemia. tVith respect to hypogly-cemia, the decision point in neonates is Lower than that of adults (40 mg/dL
vs. 60 mg/dL). The combination of lower glucose concentrations with higher hematocrit con-centrations may lead to highly inaccurate initial glucose readings caused from the bias of the hematocrit concentrations. Thus, the present invention is desirable in determining the glucose concentration in the whole blood sample of neonates.
The testing end of the sensor is adapted to be placed into contact with the whole blood sample to be tested. The whole blood sample tnay be generated by a lancing device such as a microlet. The lancing device may obtain blood by, e.g., pricking a person's finger. According to one process, the whole blood sample may be prepared for testing by (a) removing the electrochemical sensor from packet, (b) placing the electrochemical sensor into a glucose concentration measuring instrument, (c) generating a whole blood sample and (d) bringing the sensor and the whole blood sample into contact wherein the blood is generally drawn into the sensor by capillary action.
Examples Several plots have been prepared to show the relationships between (a) hemato-Grit level and (b) phase shift, glucose concentration, frequency and impedance.
FIG. 1 is a plot of phase shift versus frequency of whole blood samples. The whole blood samples had a glucose concentration of 300 mg/dL and the hematocrit con-centration was either 20 vol.%, 40 vol.% or 60 vol.%. The tests were performed on Bayer Corporation's Glucometer DEX~ system with a three-pass reagent electrochemi-cal sensor. The electrochemical sensor was operated at an applied potential of 150mV.
The frequency (measured in Hertz) was plotted logarithmically along the x-axis versus the phase shift (measured in degrees) which was plotted along the y-axis. FIG.
1 shows MSE #2658 that there are many frequencies that result in distinct phase shifts between varying he-matocrit concentrations. It is desirable to chose a frequency in which the phase shift is more pronounced between varying levels of hematocrit concentrations.
FIG. 2 is a plot of impedance (Z) versus frequency of whole blood samples. The whole blood samples had a glucose concentration of 100 mg/dL and the hematocrit con-centration was either 20 vol.%, 40 vol.% or 60 vol.%. 'rhe tests were performed on Bayer Corporation's Glucometer DEX~ system with a three-pass reagent electrochemi-cal sensor. The electrochemical sensor was operated at an applied potential of 150mV.
The frequency (measured in Hertz) was plotted logarithmically along the x-axis versus the impedance (measured in ohms) which was plotted logarithmically along the y-axis.
FIG. 2 shows that there are many frequencies that result in distinct impedance measure-ments between varying hematocrit concentrations. It is desirable to chose a frequency, such as the higher frequencies, in which the impedance measurements are more pro-nounced between varying levels of hematocrit concentrations.
FIG. 3 is a plot of phase shift versus hematocrit concentration of whole blood samples. There were several glucose concentrations that were tested: 0 mg/dL, SOmg/dL, 100 mg/dL, 300 mg/dL and 600 mg/dL. Each of the glucose concentrations was plotted separately in FIG. 3. The individual data points that were used in forming the plot of FIG. 3 are listed in Table 1 below.
MSE #2658 '~ ~k~~~ '~
wo _ w;, . ,~ ~ : x ~ >, y .~,> ~ .
. ~ a r\ ~\. i.!, ~ , t a.: ~,, ~F:, f~,.,t "3 ~;a.
. ,3 ' ' ~~~ ~~ ~ , .'>__ , a ,.., ~ ,d:.! o , s 4 "M , ~'' ,.:
,.
t r 3 d .<, a ~ a =I°,' ~:3, ; 9 . :. ~ , 1 t.'; ", e... ,' r:3!F
Ii f3fi" , a s ' '~- 3 ..._ t , 3 . 3 b a . 3, a1i ,;
1 ., ~ ,.!, - ' ~ 0 1, . J. .' 3 ',.
9C5 ~' ~-:!
q". t L.a. >
F , . a' t .:
'"c _ 3 3, : .: ~ ~'~ '4" m ~ 3. ' t ,a ,°..
,......
3 ..s '. a ~ :. , ,3 ,1 -f ", ~ ~t t F
t ~ F .~-. 4 .k .. .I i _.~- ,.=~,~~c _ , S >-Z F';,.
i.~5 t ~ . 4 , ..~ t. ., w.,.
, . .~ v-~.'= _ - 'b ,~ _-~' W a . v ~. _ ,. m_ v~ _ ~ \_w v v v t. \
\~~._. . ;-~ -.\\ s -\
>.
~ ~ ate. ~ m \\\ - _~., e~w <,a-w : C \~ . _, w '~-~,.~.3. _\\.~ . \~~ >
\w,\
W- v,. v~-.« 6'a tw\ . >> =." . ~\ > ~\
v \ ~ . - . , r~ _,~\ _ 9.3 , d'td > :--~:
~\ .~ \ . C ~. \_- r v, ~ . ~'~ ,. Aw \ '->aF F
a_ "\-- ~ \ -,\
F: . _"\ ~.. .-- v .._ >~ \ v., a - _ \, v 9 . ~ 0 -'\ !
~w ,. .~~r 0 \ a \ _ v ... ° .a , W ~:.~ ~ _3 ~ _ . '~ .-_ t- . .% : ,~ _ ~\ .,~x1-= .. .' ~ r ,~ ~ ~ _ _\ ~ ~n_ - ~ . _\ .-ov\ ~..-'.
~. s\ >_ ~,'.c. ._.\., .-~ _'.~'a... , ~ ~\ ~._.. _ > ~- ~s.>.. . \\ ;~. ~-_ ~~~ ~.~:....\~., _ ~, ~ ,..
; '~ ~s a ~.. _ ~ .. -s .~..
.~:,,~., >..~..rz F
,..r.. o....t.c!., ;; ~ ~S. ,: I;:; .
3, 5 I d ' f ~... 3i~3:' , 1 ' f - h"'.
~i;~..: v $
i~ , ~ ~:v>' . ,.:~i" , ':;'7'. , ~.">.,.i~~" ... t1 t . = I a ~Jl$a. ,"~ ,R~~~n=~s.: '; ..~ , r, .::t~a",'~ ".
k . a .. ~ _ ~ ,r.!~
w.. ~ ~ ~pis~ ~ r _.t t .,,F'm f t ~ ~ fn f., .
~ .__...,-__-... _ ._ y ~s~J ~~~ ~7.1u ~aC _ ' 7.~a?
~ __.._. ~5.~3 -- ~_~.5~
~~_~'~C~ '~g~.~4 ...-_ __. ~~ ,." _;'_~.~~ -d ~ ~~1~ ~ ,~L~s ---t- ~~.~3~J
f ~~ a ~ ~ ~~ ~ '~1.~2 v'~ ~3 L~J 'a~J
~~t~3 ~ ~ ~~ ~ ~3.~3 ~C~ ~ ~~ _~~ E ~.~5 ! ~? ~~_~ ~~ ~~ 9 ~5.~2 -.--~ ~ ~. ~&
~G ~_ i~.~7 ~~3~ ~C~ ~'i.'~1 j 35 ~C~S ._~~~~_ >~.~~9 ~~~ ..._..___~ .~.' ...._ ..._._ ~
As s~c~~nrr~ :sue '~'~:~i: i, ai~s~ aii ~~~t~~~ ~°oeit~ci. ~:v~,~ae ~;~~~~rat~~~rio~: a~~ n~ernat~-grit ~~~.c~r~tr°atiora ~o~sxL.a~ti~~s ~,~°x~:; tes'~.~ t~i~~.
'p~~ t~~,tir~~~ t~~ =y~a,s~ si~i~t versus im~aa°~o~rit ~~r~oon~ratio~s r~port~U i=._~ ~'~~i~ i ~r3si p~o~a~~ in -~~~~~. s r gas ciori~ ~.t a ~°ro-~~a~ ~~~ o~ i i i~z. ~~~ tests w~r~ y~~rr'~or:~:~or; ~a~e~a ~ ~~~~~or~3~~~~'s ~:~~~~or.~~t~r ~:~G
systerrf v~r~th a t~~reo-pass r~aaer~t a=~,s~troo~drrioa~ se_~sor. ~~ze ~~octroc~~~~oai svr~sor was op~rU~~ed .at a~~ appti~p;~?~~~tia:~. ~~~~ i~~rx~.~l. '~~ ~~;~:~=.~~s~~tt ~c~~~entr~vi~~ ~a~i.%) wr~s plott~,~l aior~g the x-axis ~r°rs~as tl~~ p~as~; s~ii~ ~<r~eas~z~-~~
i~x degrees) ~>w~i~~°3 Haas pioi~~;
a'9~ri~'~f'.~2 ~'-axFS. _~'~'~. .~ s~'°~~~1VS i°~~s~s, i~lei'~
1S a ~!i~rl~.l:i~~, Irl t~l~ p~1~,5~ S~E~~~ w~t~l ~~'IIC~S~.
iali~~ ~~~Jc~
~. c ~~~~~.~,n~ra~i~r~s at a ire~~~v~~~ ~f ~~~ l~as~ ~ ~ ~ ~~~. ~~~. : ~.~.so slaQws ~ha~ ~1~3~~:m, :~u a v~.ria~~-c;r~.
in ~9'z~ p~"~~.5~ s~'li~: ~li~;l~ ~~~~~'~~,~ ~1'~~ ~?~r~':r~~~G.:~$:
~s~n~,E;:~~~-a_'s1~0~'1.
~~r. 4~ is ~ ply ~s :° i~ p~~~.a~~~~: ~~, verses ~~~7~ K ~~ ;rig nor>~~n~ra~i~r~ ~~~' ~rl~~~~~ bl~~d sar~les. There ~a~r~ s~~~aa ~:T..~~,~s~, ~~r~~,en~ra~;iQns r~~ ~ ~r~~ae ~:~ste~.: ~ ~r~~/d~,, ~Orr~g/dl~,, ~ ~~ ~ylid~.,, ~~3~ r~~~gl~af~ n~.rm. ~t~~ ra~~~ldL. ~ac:~~ ~~~~a~~ ~i~~~s~ ~~-~~a~~~~ca~i~n<~ gas pio~~,d s~pa~-atel~~ in ~T~. 4. '1'~.~~ ndjvrid~~l d~~a p~i~.~ts ~~,a.r v,v~r~:;
~a~;~,~ an ~°~r~;~~iv~a~ ~l~e pl~~ o~
~'~~. ~- are lisped >r° ~'a~l~ ~ ~~i~~.:~.
,.
Q
.. ~ , ~.
_~ ~,._..~\.
F._ \ :- -a ~o ~~ pearl ~'m $ ~a~ ~ ~t f . a t~. ,.~ r ;
~..N.:
a ,' ~: ,$:
F
~:a t ' f.~'I ~ . .. $' : r.~ $ ,', :. Y
, v$na,f __ f ,fit t '. ~. ..'f , 6 "a z~~. .~~,;
', r ' E~z $ t ,.., s . W
n f s s ..
.',4. . ' . 's w. ".: s , ' o .,. ~ ,. #
., fr ,. , r -.
z .°
\', :.~
__ y,\ .., .,~.~:, h \ .~ , Q d -~' '- \ \ _ ~ -<
~'~ ...\, . ~, a .-_3 . .. -~, ~, .. .$ ~ ~. ~ f:.. 3 ~,.~-_ ~ _-_: \
't~ . , a \ ~J~ _s . ~ v 3 ... v +.
ry~_ , 3 ;~ , s . ~# . a ~~ , a ., = ~, w a 7.F. , ., t:
1. ,~ F.. ,' .
r:3 ~ , ., ' a m.
'~ r ~_ d _.
1.Y .. , , . ~#
N .. f ",....
s1,.: 1 , _ ~ , ~E , , _z.. , , i. ~ .~, . ; ",,., :~..,: ;.e ~ 3 t .,., a .. ...; >dt a A , a.,.~:. ~-'a ' ,.#:
r r ., ~ -.. ". .
a ,'i' '. 't , 7 3. H
q . . ~. . ~ ~s 'N ., roR.° $ . , f a r j"'. , ~i ah t - .r .__x. , a F h=N
E , i. Y ' , n'.:ø. "~-' a , r ~,.
a as = d , . ,: ~P ~s~a . L .,, q.:. . _-~ s r ,.. E _ < 3,4 -' # ~ a. ,t, a _ ~ .. . "LU~~. _~._~ ~_s _, ~>~~~~ . ~~~ .._f . s-~ ._ _ ~4 _.H . ~C~.,~_~~ ,,~~\ _.~txz. ~ ~ ~~ ~~ -~ ,a~ 9~s~
16 ~~ ~811.g o __~~
~ _~_ ~~ ~i X169.6 _ ~~ ~ ~' ~8~~.9 ~6~5.2 ~8 ~ 65 E 8_1~7.Q
'?J ~~3 ~~ ~ °~~8~.6 i E) 2~ s~ 4~S -__~n ~ - ~ ~~~.~d ,_. - _.,.
6~~~ ~~ ~ ~a~1~6 f_ -i __ -' Su ~_.~ 6th 8'9 65.8 !2~ 1~~~~~ t ~.~ ~--_ _W ~~11.3~~
16~ ~.~~ ~~ -! _63_8_0.6 °~6~~ ~ ~~3 ~~~86.3 1~_._..~_ 6~ _____ _..._.~ 85~1.a °
1 ~~ a ~_~ 6~ __ ~ _8169.6 3_G~ j ~ 2~r ~ 665.9 _ ~$~~,' _ 4~ . _~ rCB9.8 27 ~ 6~~; '--.'~_'_._"__. 6~ __.~___.~# __ 8165.8 u5~ ~~y~ 6_. ~.~. 859.1 2 ~ 6t3~~ ;~~ _ ~~ __ . ~~ 8~81.~
65~= ' ~~ ~ ~a:~1.5 3U 6~~ ° E 6~~~ 8656. _.
i ~ 6~~ ~°.m~ 6_.___......_ X629.8 ~~~'. #2~~~
1 ~_ ~s s~~~~~r~. i~ ~'~.~~~ ~9 ~~r :~~° ~~°~~ :~~~m~~~ ~a~~~s~ ~~n~~
~~~~~~~>rP ~.~Pr~~r~P~~~~.~~~'~ ~~P~.c~rP~r~.~
,,.~Yt rpr~~.,,v~øf~~p~,~~~y 2,t~y~v~"y~sEp~e- °.yw = ,~~tq~.,6~
.~Y1!~~i ~ ~yyGg~-~s~ø,~~e Li~~ v~~P a~~P~~~ ~~te., ~.'urf~S,~ "vl""1n4,,~~ "~.~A~ ~~~F~rri~ ".~:v.3RY4., :.~~~a~'.~~~~~ ~'~Ey~c.,r~~~~ ~~~~~~..b'~'~
~'~'T'~CGIl~aa~I~r'aS P'~~7~~~C~ :.~?, s ~~i~ ~, ~.i'PF~ ~~~;~~ ~6~ ~«~~
d°~~. -fit- ~~~leaS ~~1'P~, ~d: "ca bf"~~~~.'1.~~~- ~~ ~~~.
a"-iii. r~Pf,''i~Sl;s ~%~,''_Y°~ ~r?ea ~~':~ ~-P.~ex~~~.~
i~~r~Syr'~4;~~~~,> ~'~.'~aP~~Lx'k'a~t~:,= ~~i~~ ~i~S~~S1'? ~!'1~
7eS'La~E,'°3~.sS r~2t~E.'r°a~, ~,'~~.~'~ 'v~'.CP~ri':3v'~'E
S~rns,~'rx. ~ ~~E J~(,',s°.,~~',~,3~i3'~iP11~C1 s~r~si~n' 'Y~r,s Oy°'_~~~6;C~ G.'l ~~ ~'"~(;~~I~~ 39~J~~P~.~P~~ ~a ~v~~. ~ '_,~ _~C:~~G~~P°.r3e:
~~r3_~~.~,ri''~F"~~It3fi ~~J~s.%~ a~J:~w ~'~''~~l'bC'~. ~t~at~~'1 v ~~3~ X-aXPS il~P°S~JS $~iC', ~tPy~:,~~is~:,~ ~~ 3v'~'~:~'t~P°~;u zip i3~3~°9su ~.~s~?a',~5 ~d°e'Vv Y'9~~ECC,~~ cl~6~w'P'~~ ~~ ~ ~
-~XPS.
E~ ~.~. ~<° S~~°v~,'s ~:~~$ '~'L?~P'~ i;~ ~. 1~C~~eau$~n s'E
arr~~~~,:z~. ~~, 47z6~' P'~;5~6..~': ~.~' '~~:~'_. "'P~%P'P~~~~,~,~~°P~
~~~r i,~~bi~l:~ri 2.~ ~~ li~G~-~~~9~,a! ;~L~~~: if',P~'°. ~~'~~ ~~~~. a ~~.
~" ~~~.',~.r'S ~:: 5~~~~1 ~,~~:~ :.i"I~ ~a~rPP~ll~!' ~~ ~~'z~ lri~~3~C~~~P~~ Ps Pa ~ ~~'~~~~'P~~~: ~..' ~~~~ ~~r~.~~~5~~ ~:,~r:4 ,:l~iY~e~:~3'P ~~~ c'~ tr~~s3 ~'~.~i~ t9:i c~,~ ~~~c~
~~~ i ~~.
~!~~~~ ~~~''~:I~~P~.c?:" ~Ii~~J"~C.~,~.~'P~tx~':e~::~C~.
''~~.~~3e~,~~.~~~~~Y'a:3 C~~ ~~'1~ ~~r~S~s~~ Pr.P~e,.r~~..rP~:R~'PP il~k'V-:
~f,~P'a a~~LIS'~r~.~~d at'~~ ~'~~~:~'~~'~9 1"6 .k~ c~ ic, ~8~~,rS~&~~3~
~~~~~~: f~~ll~ ~~zm~~T2~.iW<. F,s :'P~~ lrr~,i'~4;f~ ~a~
e~7~ ~3'~°~~iS~.' CJ~s'°~P"L~C~s_~°" 3 ~aP"P~:
°.6~.>~53~P63aS ~°ss ~~S~CL ~u=:,'s'~Ph asPGa i~~~ ',j~~~~l:~s r:'I,d'Jd~PiCsL-~P~IiS~ ~~I~.P'P~~Sy ~:~~ ~~~~°_~;;k~3Pl~, ai~~:~' ~~ ~a.,~"'~~"a,s't~
~r~ b'~ ~~'P~ ~C;P'~~!~PP~~ G~~'S~%rP~~;:C~2~PS '~TelP1'.~1~,°t.;~
~e°.,~9'~Ql"'viflg iP'f~Y~ 9.~~ s'ZS~~ ~.3iC~ 5~..~~w "~~ t.ct~
~,ri~l~~~~.P~7ha ~''s !''~~'.,a~"u_~3~i~'. Iia 3~~~ ~~i~ri~u"~.~
f°,i~l~"k2S.
Claims (28)
1. A method of determining glucose concentration in a whole blood sample comprising:
providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations;
measuring the hematocrit concentration of the whole blood sample using the electrochemical sensor via electrochemical impedance spectroscopy;
measuring the initial glucose concentration of the whole blood sample using the electrochemical sensor; and calculating the unbiased glucose concentration in the whole blood sample using the initial glucose concentration measurement and the hematocrit concentration.
providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations;
measuring the hematocrit concentration of the whole blood sample using the electrochemical sensor via electrochemical impedance spectroscopy;
measuring the initial glucose concentration of the whole blood sample using the electrochemical sensor; and calculating the unbiased glucose concentration in the whole blood sample using the initial glucose concentration measurement and the hematocrit concentration.
2. The method of claim 1, wherein the glucose concentration of the whole blood sample is determined using an amperometric monitoring system.
3. The method of claim 1, wherein the electrochemical sensor includes an insulating base plate, an electrode system on the base plate and a cover adapted to mate with the base plate to form a space in which the electrode layer is available to contact the whole blood sample.
4. The method of claim 3 further including a reaction layer comprising an enzyme that reacts with the glucose in the whole blood sample.
5. The method of claim 4, wherein the enzyme in the reaction layer is com-bined with a hydrophilic polymer.
6. The method of claim 1, wherein the method of determining glucose con-centration in a whole blood sample occurs in disposable self-testing systems.
7. The method of claim 1, wherein the method of determining glucose con-centration in a whole blood sample occurs in a clinical analyzer.
8. The method of claim 1, wherein the measuring of the hematocrit concen-tration in the whole blood sample is performed before measuring the initial glucose con-centration.
9. The method of claim 1, wherein the measuring of the hematocrit concen-tration of the whole bloodsample is performed using a single frequency measurement.
10. The method of claim 1, wherein the measuring of the hematocrit concen-tration of the whole blood sample is performed using a plurality of frequency measure-ments.
11. The method of claim 1, wherein the measuring of the hematocrit concen-tration is performed using a phase shift of an impedance measurement.
12. The method of claim 11, wherein the measuring of the hematocrit con-centration is performed with at least one frequency between about 800 and about 900 Hz.
13. The method of claim 1, wherein the measuring of the hematocrit concen-tration is performed using magnitude components of an impedance measurement.
14. The method of claim 13, wherein the measuring of the hematocrit is per-formed with at least one frequency between about 300 and about 10,000 Hz.
15. The method of claim 1 further including applying AC waveforms from about 1 to about 10,000 Hz to the electrochemical sensor.
16. The method of claim 1 further including applying AC waveforms from about 1 to about 100mV to the electrochemical sensor.
17. The method of claim 1 further applying AC waveforms that are subse-quently deconvoluted using a Fourier transform.
18. A method of determining glucose concentration in a whole blood sample comprising:
providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations;
measuring the hematocrit concentration of the whole blood sample using the electrochemical sensor via electrochemical impedance spectroscopy using an am-perometric monitoring system;
measuring the initial glucose concentration of the whole blood sample using the electrochemical sensor; and calculating the unbiased glucose concentration in the whole blood sample using the initial glucose concentration measurement and the hematocrit concentration.
providing an electrochemical sensor adapted to measure glucose and hematocrit concentrations;
measuring the hematocrit concentration of the whole blood sample using the electrochemical sensor via electrochemical impedance spectroscopy using an am-perometric monitoring system;
measuring the initial glucose concentration of the whole blood sample using the electrochemical sensor; and calculating the unbiased glucose concentration in the whole blood sample using the initial glucose concentration measurement and the hematocrit concentration.
19. The method of claim 18, wherein the method of determining glucose con-centration in a whole blood sample occurs in disposable self-testing systems.
20. The method of claim 19, wherein the measuring of the hematocrit con-centration of the whole blood sample is performed using a single frequency measure-ment.
21. The method of claim 19, wherein the measuring of the hematocrit con-centration of the whole blood sample is performed using a plurality of frequency meas-urements.
22. The method of claim 19, wherein the measuring of the hematocrit con-centration is performed using a phase shift of an impedance measurement.
23. The method of claim 22, wherein the measuring of the hematocrit con-centration is performed with at least one frequency between about 800 and about 900 Hz.
24. The method of claim 19, wherein the measuring of the hematocrit con-centration is performed using magnitude components of an impedance measurement.
25. The method of claim 24, wherein the measuring of the hematocrit is per-formed with at least one frequency between about 300 and about 10,000 Hz.
26. The method of claim 19 further including applying AC waveforms from about 1 to about 10,000 Hz to the electrochemical sensor.
27. The method of claim 19 further including applying AC waveforms from about 1 to about 100mV to the electrochemical sensor.
28. The method of claim 19 further applying AC waveforms that are subse-quently deconvoluted using a Fourier transform.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US40606602P | 2002-08-27 | 2002-08-27 | |
| US60/406,066 | 2002-08-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2437249A1 true CA2437249A1 (en) | 2004-02-27 |
Family
ID=31496009
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002437249A Abandoned CA2437249A1 (en) | 2002-08-27 | 2003-08-14 | Methods of determining glucose concentration in whole blood samples |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US20040079652A1 (en) |
| EP (1) | EP1394545A1 (en) |
| JP (1) | JP2004163411A (en) |
| AU (1) | AU2003234944A1 (en) |
| CA (1) | CA2437249A1 (en) |
Families Citing this family (68)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8148164B2 (en) | 2003-06-20 | 2012-04-03 | Roche Diagnostics Operations, Inc. | System and method for determining the concentration of an analyte in a sample fluid |
| US20070264721A1 (en) * | 2003-10-17 | 2007-11-15 | Buck Harvey B | System and method for analyte measurement using a nonlinear sample response |
| JP4458802B2 (en) * | 2003-10-02 | 2010-04-28 | パナソニック株式会社 | Method for measuring glucose in blood and sensor used therefor |
| CN100432663C (en) * | 2003-12-04 | 2008-11-12 | 松下电器产业株式会社 | Hematocrit(hct) measuring method, sensor used for same, and measuring instrument |
| US8535497B2 (en) * | 2003-12-04 | 2013-09-17 | Panasonic Corporation | Method of measuring blood component, sensor used in the method, and measuring device |
| NZ550825A (en) * | 2004-03-31 | 2009-01-31 | Bayer Healthcare Llc | Method and apparatus for implementing threshold based correction functions for biosensors |
| KR101108381B1 (en) * | 2004-04-19 | 2012-01-30 | 파나소닉 주식회사 | Method for measuring blood components and biosensor and measuring instrument for use therein |
| BRPI0510779A (en) * | 2004-05-14 | 2007-11-20 | Bayer Healthcare Llc | methods for performing hematocrit adjustment in assays and devices for same |
| EP1813937A1 (en) * | 2006-01-25 | 2007-08-01 | Roche Diagnostics GmbH | Electrochemical biosensor analysis system |
| US8529751B2 (en) | 2006-03-31 | 2013-09-10 | Lifescan, Inc. | Systems and methods for discriminating control solution from a physiological sample |
| US20070235346A1 (en) * | 2006-04-11 | 2007-10-11 | Popovich Natasha D | System and methods for providing corrected analyte concentration measurements |
| US7909983B2 (en) * | 2006-05-04 | 2011-03-22 | Nipro Diagnostics, Inc. | System and methods for automatically recognizing a control solution |
| US7822557B2 (en) * | 2006-10-31 | 2010-10-26 | Abbott Diabetes Care Inc. | Analyte sensors and methods |
| US7751864B2 (en) * | 2007-03-01 | 2010-07-06 | Roche Diagnostics Operations, Inc. | System and method for operating an electrochemical analyte sensor |
| US9121806B1 (en) | 2007-07-26 | 2015-09-01 | University Of South Florida | Impedance spectroscopy-based cellular analysis device |
| US8778168B2 (en) | 2007-09-28 | 2014-07-15 | Lifescan, Inc. | Systems and methods of discriminating control solution from a physiological sample |
| US8517941B1 (en) * | 2007-10-23 | 2013-08-27 | Pacesetter, Inc. | Implantable cardiac device and method for monitoring blood-glucose concentration |
| US8325329B2 (en) | 2007-10-26 | 2012-12-04 | Arkray, Inc. | Sample detector and measurement device equipped with the same |
| WO2009108239A2 (en) * | 2007-12-10 | 2009-09-03 | Bayer Healthcare Llc | Slope-based compensation |
| US8603768B2 (en) | 2008-01-17 | 2013-12-10 | Lifescan, Inc. | System and method for measuring an analyte in a sample |
| WO2009114115A1 (en) * | 2008-03-10 | 2009-09-17 | S.E.A. Medical Systems, Inc. | Intravenous fluid monitoring |
| US8551320B2 (en) | 2008-06-09 | 2013-10-08 | Lifescan, Inc. | System and method for measuring an analyte in a sample |
| MX2011005864A (en) | 2008-12-08 | 2011-06-20 | Bayer Healthcare Llc | Biosensor system with signal adjustment. |
| US8480581B2 (en) | 2009-03-24 | 2013-07-09 | Cardiac Pacemakers, Inc. | Systems and methods for anemia detection, monitoring, and treatment |
| DE102009002497B4 (en) | 2009-04-20 | 2011-06-16 | Leibniz-Institut Für Festkörper- Und Werkstoffforschung Dresden E.V. | Method for determining electrical and mechanical material properties |
| SG176600A1 (en) * | 2009-06-08 | 2012-01-30 | S E A Medical Systems Inc | Systems and methods for the identification of compounds in medical fluids using admittance spectroscopy |
| US9052276B2 (en) | 2009-06-08 | 2015-06-09 | S.E.A. Medical Systems, Inc. | Systems and methods for the identification of compounds using admittance spectroscopy |
| US8760178B2 (en) | 2009-09-30 | 2014-06-24 | Arkray, Inc. | Method for measuring target component in erythrocyte-containing specimen |
| JP5350960B2 (en) | 2009-09-30 | 2013-11-27 | アークレイ株式会社 | Method for measuring target components in erythrocyte-containing samples |
| CN102753965B (en) * | 2009-12-09 | 2016-01-13 | Iti苏格兰有限公司 | Detect analytes |
| US8877034B2 (en) | 2009-12-30 | 2014-11-04 | Lifescan, Inc. | Systems, devices, and methods for measuring whole blood hematocrit based on initial fill velocity |
| US8101065B2 (en) * | 2009-12-30 | 2012-01-24 | Lifescan, Inc. | Systems, devices, and methods for improving accuracy of biosensors using fill time |
| US20110168575A1 (en) * | 2010-01-08 | 2011-07-14 | Roche Diaagnostics Operations, Inc. | Sample characterization based on ac measurement methods |
| MX2012010860A (en) * | 2010-03-22 | 2013-03-05 | Bayer Healthcare Llc | Residual compensation for a biosensor. |
| WO2011156152A1 (en) | 2010-06-07 | 2011-12-15 | Bayer Healthcare Llc | Slope-based compensation including secondary output signals |
| WO2012003223A1 (en) * | 2010-06-30 | 2012-01-05 | Edwards Lifesciences Corporation | Analyte sensor |
| BR112013005720A2 (en) | 2010-09-09 | 2019-09-24 | S E A Medical Systems Inc | sensor for immittance spectroscopy, immittance spectroscopy systems and for accumulating and identifying drug residues, methods of determining the identity and / or concentration of a drug, for accumulating and identifying drug residue, for determining the identity and concentration of a drug and to precisely and automatically supply a drug, and a fully automated medical system |
| US8617370B2 (en) | 2010-09-30 | 2013-12-31 | Cilag Gmbh International | Systems and methods of discriminating between a control sample and a test fluid using capacitance |
| US8932445B2 (en) | 2010-09-30 | 2015-01-13 | Cilag Gmbh International | Systems and methods for improved stability of electrochemical sensors |
| AU2012300836B2 (en) * | 2011-09-02 | 2015-02-12 | Lifescan Scotland Limited | Hematocrit corrected glucose measurements using phase angles and impedance for electrochemical test strip |
| US9261477B2 (en) | 2011-09-02 | 2016-02-16 | Lifescan Scotland Limited | Hematocrit corrected glucose measurements for electrochemical test strip using time differential of the signals |
| ES2663097T3 (en) | 2011-09-21 | 2018-04-11 | Ascensia Diabetes Care Holdings Ag | Biosensor with error compensation |
| US20130084591A1 (en) * | 2011-09-30 | 2013-04-04 | Lifescan Scotland Ltd. | Analytical test strip with isolated bodily fluid phase-shift and analyte determination sample chambers |
| US8623660B2 (en) | 2011-09-30 | 2014-01-07 | Lifescan Scotland Limited | Hand-held test meter with phase-shift-based hematocrit measurement circuit |
| US9903830B2 (en) * | 2011-12-29 | 2018-02-27 | Lifescan Scotland Limited | Accurate analyte measurements for electrochemical test strip based on sensed physical characteristic(s) of the sample containing the analyte |
| GB2548295B (en) * | 2012-04-13 | 2017-11-29 | Tape Specialities Ltd | Sampling apparatus and method for sampling |
| GB2551943B (en) | 2012-04-13 | 2018-08-01 | Smartcare Tech Limited | Improvements in and relating to sample measurement |
| GB201207583D0 (en) * | 2012-05-01 | 2012-06-13 | Isis Innovation | Electrochemical detection method and related aspects |
| US9645111B2 (en) * | 2012-06-08 | 2017-05-09 | Medtronic Minimed, Inc. | Application of electrochemical impedance spectroscopy in sensor systems, devices, and related methods |
| CN105164523B (en) | 2013-03-15 | 2017-09-12 | 豪夫迈·罗氏有限公司 | Scale the method for the data for constructing biology sensor algorithm and merge the unit and system of methods described |
| US9395319B2 (en) | 2013-05-02 | 2016-07-19 | Lifescan Scotland Limited | Analytical test meter |
| US20140353176A1 (en) * | 2013-06-04 | 2014-12-04 | Lifescan Scotland Limited | Hand-held test meter with time-multiplexed phase detection |
| JP6521948B2 (en) * | 2013-06-10 | 2019-05-29 | エフ．ホフマン−ラ ロシュ アーゲーＦ． Ｈｏｆｆｍａｎｎ−Ｌａ Ｒｏｃｈｅ Ａｋｔｉｅｎｇｅｓｅｌｌｓｃｈａｆｔ | Method and system for detecting an analyte in body fluid |
| US9435764B2 (en) | 2013-06-27 | 2016-09-06 | Lifescan Scotland Limited | Transient signal error trap for an analyte measurement determined from a specified sampling time derived from a sensed physical characteristic of the sample containing the analyte |
| US9435762B2 (en) | 2013-06-27 | 2016-09-06 | Lifescan Scotland Limited | Fill error trap for an analyte measurement determined from a specified sampling time derived from a sensed physical characteristic of the sample containing the analyte |
| US9835578B2 (en) | 2013-06-27 | 2017-12-05 | Lifescan Scotland Limited | Temperature compensation for an analyte measurement determined from a specified sampling time derived from a sensed physical characteristic of the sample containing the analyte |
| US9459231B2 (en) | 2013-08-29 | 2016-10-04 | Lifescan Scotland Limited | Method and system to determine erroneous measurement signals during a test measurement sequence |
| US9243276B2 (en) | 2013-08-29 | 2016-01-26 | Lifescan Scotland Limited | Method and system to determine hematocrit-insensitive glucose values in a fluid sample |
| US20150073718A1 (en) * | 2013-09-10 | 2015-03-12 | Lifescan Scotland Limited | Phase-difference determination using test meter |
| US9828621B2 (en) | 2013-09-10 | 2017-11-28 | Lifescan Scotland Limited | Anomalous signal error trap for an analyte measurement determined from a specified sampling time derived from a sensed physical characteristic of the sample containing the analyte |
| US10945630B2 (en) | 2013-12-16 | 2021-03-16 | Medtronic Minimed, Inc. | Use of Electrochemical Impedance Spectroscopy (EIS) in gross failure analysis |
| US9470649B2 (en) * | 2014-06-10 | 2016-10-18 | Lifescan Scotland Limited | Hand-held test mester with low-distortion signal generation circuit |
| KR101666978B1 (en) | 2014-09-17 | 2016-10-24 | 주식회사 아이센스 | Apparatus and Method for measuring concentration of Whole Blood Samples Using the same |
| US20160091450A1 (en) | 2014-09-25 | 2016-03-31 | Lifescan Scotland Limited | Accurate analyte measurements for electrochemical test strip to determine analyte measurement time based on measured temperature, physical characteristic and estimated analyte value and their temperature compensated values |
| US20160091451A1 (en) | 2014-09-25 | 2016-03-31 | Lifescan Scotland Limited | Accurate analyte measurements for electrochemical test strip to determine analyte measurement time based on measured temperature, physical characteristic and estimated analyte value |
| US9423374B2 (en) | 2015-01-26 | 2016-08-23 | Lifescan Scotland Limited | Reference electrode error trap determined from a specified sampling time and a pre-determined sampling time |
| CN111448452B (en) * | 2017-12-14 | 2023-05-23 | 豪夫迈·罗氏有限公司 | Method and device for determining information about equivalent series resistance |
| MX2021009620A (en) * | 2019-02-11 | 2021-09-08 | Trividia Health Inc | Systems and methods for hematocrit impedance measurement using switched capacitor accumulator. |
Family Cites Families (52)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE758318A (en) * | 1969-12-01 | 1971-04-30 | Technicon Instr | METHOD AND APPARATUS FOR THE AUTOMATIC HIGH PRECISION DETERMINATION OF THE HEMATOCRITIS OF TOTAL BLOOD SAMPLES |
| US4301412A (en) * | 1979-10-29 | 1981-11-17 | United States Surgical Corporation | Liquid conductivity measuring system and sample cards therefor |
| US4301414A (en) * | 1979-10-29 | 1981-11-17 | United States Surgical Corporation | Disposable sample card and method of making same |
| US4303887A (en) * | 1979-10-29 | 1981-12-01 | United States Surgical Corporation | Electrical liquid conductivity measuring system |
| US4407290A (en) * | 1981-04-01 | 1983-10-04 | Biox Technology, Inc. | Blood constituent measuring device and method |
| JPS5829450A (en) * | 1981-08-18 | 1983-02-21 | 株式会社豊田中央研究所 | Hematocrit measuring apparatus |
| DE3202067C2 (en) * | 1982-01-23 | 1984-06-20 | Holger Dr. 5100 Aachen Kiesewetter | Device for determining the hematocrit value |
| US4605628A (en) * | 1984-10-04 | 1986-08-12 | E. I. Du Pont De Nemours And Company, Inc. | Electrochemical determination of hematocrit |
| US4699887A (en) * | 1984-10-04 | 1987-10-13 | E. I. Du Pont De Nemours And Company | Electrochemical determination of hematocrit |
| US4686479A (en) * | 1985-07-22 | 1987-08-11 | Young Chung C | Apparatus and control kit for analyzing blood sample values including hematocrit |
| US4864229A (en) * | 1986-05-03 | 1989-09-05 | Integrated Ionics, Inc. | Method and apparatus for testing chemical and ionic sensors |
| DE3627814A1 (en) * | 1986-08-16 | 1988-02-25 | Fresenius Ag | DEVICE FOR DETERMINING THE HAEMATOCRIT |
| US5854209A (en) * | 1995-03-23 | 1998-12-29 | Biopure Corporation | Method for oxygenating tissue having reduced red blood cell flow |
| US4933048A (en) * | 1988-02-16 | 1990-06-12 | I-Stat Corporation | Reference electrode, method of making and method of using same |
| USRE36268E (en) * | 1988-03-15 | 1999-08-17 | Boehringer Mannheim Corporation | Method and apparatus for amperometric diagnostic analysis |
| US5108564A (en) * | 1988-03-15 | 1992-04-28 | Tall Oak Ventures | Method and apparatus for amperometric diagnostic analysis |
| DE68924026T3 (en) * | 1988-03-31 | 2008-01-10 | Matsushita Electric Industrial Co., Ltd., Kadoma | BIOSENSOR AND ITS MANUFACTURE. |
| US5096669A (en) * | 1988-09-15 | 1992-03-17 | I-Stat Corporation | Disposable sensing device for real time fluid analysis |
| US5212050A (en) * | 1988-11-14 | 1993-05-18 | Mier Randall M | Method of forming a permselective layer |
| US5200051A (en) * | 1988-11-14 | 1993-04-06 | I-Stat Corporation | Wholly microfabricated biosensors and process for the manufacture and use thereof |
| US5053199A (en) * | 1989-02-21 | 1991-10-01 | Boehringer Mannheim Corporation | Electronically readable information carrier |
| DE69029556T2 (en) * | 1989-10-18 | 1997-05-15 | Fuji Photo Film Co Ltd | Dry analytical element for the quantitative analysis of analytes contained in whole blood |
| US5008616A (en) * | 1989-11-09 | 1991-04-16 | I-Stat Corporation | Fluidics head for testing chemical and ionic sensors |
| WO1991009139A1 (en) * | 1989-12-15 | 1991-06-27 | Boehringer Mannheim Corporation | Redox mediator reagent and biosensor |
| US5508171A (en) * | 1989-12-15 | 1996-04-16 | Boehringer Mannheim Corporation | Assay method with enzyme electrode system |
| US5320732A (en) * | 1990-07-20 | 1994-06-14 | Matsushita Electric Industrial Co., Ltd. | Biosensor and measuring apparatus using the same |
| US6128518A (en) * | 1990-10-04 | 2000-10-03 | Microcor, Inc. | System and method for in-vivo hematocrit measurement using impedance and pressure plethysmography |
| US5642734A (en) * | 1990-10-04 | 1997-07-01 | Microcor, Inc. | Method and apparatus for noninvasively determining hematocrit |
| US5526808A (en) * | 1990-10-04 | 1996-06-18 | Microcor, Inc. | Method and apparatus for noninvasively determining hematocrit |
| US5194909A (en) * | 1990-12-04 | 1993-03-16 | Tycko Daniel H | Apparatus and method for measuring volume and hemoglobin concentration of red blood cells |
| US6471872B2 (en) * | 1991-10-11 | 2002-10-29 | Children's Hospital Medical Center | Hemofiltration system and method based on monitored patient parameters |
| US5264103A (en) * | 1991-10-18 | 1993-11-23 | Matsushita Electric Industrial Co., Ltd. | Biosensor and a method for measuring a concentration of a substrate in a sample |
| US5334706A (en) * | 1992-01-30 | 1994-08-02 | Baxter International | Administration of low dose hemoglobin to increase perfusion |
| US5352351A (en) * | 1993-06-08 | 1994-10-04 | Boehringer Mannheim Corporation | Biosensing meter with fail/safe procedures to prevent erroneous indications |
| US5366609A (en) * | 1993-06-08 | 1994-11-22 | Boehringer Mannheim Corporation | Biosensing meter with pluggable memory key |
| DE69427911T2 (en) * | 1993-06-21 | 2002-04-04 | Roche Diagnostics Corp | STABILIZER FOR DIAGNOSTIC REAGENTS |
| US5947892A (en) * | 1993-11-10 | 1999-09-07 | Micromed Technology, Inc. | Rotary blood pump |
| US5437999A (en) * | 1994-02-22 | 1995-08-01 | Boehringer Mannheim Corporation | Electrochemical sensor |
| US5429735A (en) * | 1994-06-27 | 1995-07-04 | Miles Inc. | Method of making and amperometric electrodes |
| JPH10501823A (en) * | 1995-04-10 | 1998-02-17 | バクスター、インターナショナル、インコーポレイテッド | Use of cross-linked hemoglobin in the treatment of subarachnoid hemorrhage |
| US5759160A (en) * | 1995-11-20 | 1998-06-02 | Utah Medical Products, Inc. | Blood sampling system |
| US5869971A (en) * | 1996-05-17 | 1999-02-09 | Sendx Medical, Inc. | Method and apparatus for ratiometric measurement of hematocrit |
| US5660791A (en) * | 1996-06-06 | 1997-08-26 | Bayer Corporation | Fluid testing sensor for use in dispensing instrument |
| DE69807042T2 (en) * | 1997-01-17 | 2003-02-06 | Metracor Technologies Inc | METHOD FOR CALIBRATING SENSORS IN DIAGNOSTIC TEST METHODS |
| US5987353A (en) * | 1997-04-10 | 1999-11-16 | Khatchatrian; Robert G. | Diagnostic complex for measurement of the condition of biological tissues and liquids |
| US5798031A (en) * | 1997-05-12 | 1998-08-25 | Bayer Corporation | Electrochemical biosensor |
| US6046051A (en) * | 1997-06-27 | 2000-04-04 | Hemosense, Inc. | Method and device for measuring blood coagulation or lysis by viscosity changes |
| US5997817A (en) * | 1997-12-05 | 1999-12-07 | Roche Diagnostics Corporation | Electrochemical biosensor test strip |
| US6645368B1 (en) * | 1997-12-22 | 2003-11-11 | Roche Diagnostics Corporation | Meter and method of using the meter for determining the concentration of a component of a fluid |
| US6064898A (en) * | 1998-09-21 | 2000-05-16 | Essential Medical Devices | Non-invasive blood component analyzer |
| US6475372B1 (en) * | 2000-02-02 | 2002-11-05 | Lifescan, Inc. | Electrochemical methods and devices for use in the determination of hematocrit corrected analyte concentrations |
| JP2000262298A (en) * | 1999-03-15 | 2000-09-26 | Fuji Photo Film Co Ltd | Determination of glucose or cholesterol concentration in whole blood |
-
2003
- 2003-08-13 AU AU2003234944A patent/AU2003234944A1/en not_active Abandoned
- 2003-08-14 CA CA002437249A patent/CA2437249A1/en not_active Abandoned
- 2003-08-21 EP EP03018656A patent/EP1394545A1/en not_active Withdrawn
- 2003-08-22 US US10/645,785 patent/US20040079652A1/en not_active Abandoned
- 2003-08-26 JP JP2003300826A patent/JP2004163411A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP1394545A1 (en) | 2004-03-03 |
| US20040079652A1 (en) | 2004-04-29 |
| AU2003234944A1 (en) | 2004-03-18 |
| JP2004163411A (en) | 2004-06-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2437249A1 (en) | Methods of determining glucose concentration in whole blood samples | |
| JP6306557B2 (en) | System and method for measuring analyte concentration in a sample | |
| AU2003252777B2 (en) | Analyte Test Instrument Having Improved Versatility | |
| KR101289757B1 (en) | Determination of partial fill in electrochemical strips | |
| Feldman et al. | FreeStyle™: a small-volume electrochemical glucose sensor for home blood glucose testing | |
| AU2008221593B2 (en) | Systems and methods of discriminating control solution from a physiological sample | |
| US8815076B2 (en) | Systems and methods for determining a substantially hematocrit independent analyte concentration | |
| US8083925B2 (en) | Analyte determination methods and devices | |
| JP3260739B2 (en) | Apparatus and method for determining the concentration of a medically significant component of a biological fluid | |
| ES2758478T3 (en) | Method for determining low fill level in an electrochemical biosensor and low fill level detection system | |
| EP1443322A1 (en) | Concentration measuring method and concentration measuring device | |
| CZ20023332A3 (en) | Method of determining concentration in a liquid sample and apparatus for making the same | |
| TW200914820A (en) | System and methods for determination of analyte concentration using time resolved amperometry | |
| TW201037299A (en) | System and methods for determination of analyte concentration using time resolved amperometry | |
| EP3220137B1 (en) | Method for detecting an interferent contribution in a biosensor | |
| JP2013539035A (en) | System and method for identifying control sample and test fluid using capacitance | |
| WO2008029110A2 (en) | Electrochemical device with 3 detection areas | |
| CN108132284B (en) | A kind of test method of electrochemical sensor | |
| WO2008050145A1 (en) | Measurement device | |
| TW201610427A (en) | Examination method for detecting abnormal electrochemical test strip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20090814 |