1. A rail-to-rail (R-R) input stage circuit operating over a rail-to-rail input common mode voltage range, comprising:
a differential pair circuit, having a first input common mode voltage range, coupled to a level shifted differential pair, having a second input common mode voltage range to enable operation of the R-R input stage circuit over an input common mode voltage that extends from a negative power supply to a positive power supply; and
a first bias control circuit, coupled to the level shifted differential pair, to dynamically control the bias current of the level shifted differential pair when the input common mode voltage of the R-R input stage circuit is outside the second input common voltage range.
2. The R-R input stage circuit of claim 1, where the first bias control circuit gradually turns off the level shifted differential pair in response to the input common mode voltage of the R-R input stage circuit.
3. The R-R input stage circuit of claim 1, where the first bias control circuit further comprises a voltage sensor circuit for generating a tracking current inversely proportional to a sensed input common mode voltage of the R-R input stage, when the input common mode voltage of the R-R input stage circuit is outside the second input common voltage range.
4. The R-R input stage circuit of claim 3, further comprising a current mirror circuit having one terminal coupled to the voltage sensor circuit and a second terminal coupled to the current source of the level shifted differential pair to control the bias current of the level shifted differential pair in response to the tracking current.
5. The R-R input stage circuit of claim 3, where the voltage sensor circuit is a MOS device, and where the input common mode voltage of the R-R input stage circuit controls the gate of the MOS device.
6. The R-R input stage circuit of claim 4, where the current mirror comprises a MOS device, having its gate and drain coupled to the voltage sensor circuit and to the current source of the level shifted differential pair.
7. The R-R input stage circuit of claim 1, where the differential pair circuit comprises a pair of matched MOS transistors and a current source.
8. The R-R input stage circuit of claim 1, where the level shifted differential pair comprises a source follower and a differential pair circuit, where the differential pair circuit comprises a pair of matched MOS transistors and a current source.
9. The source follower of claim 8, comprising a pair of matched MOS transistors of type complementary to that of the MOS transistors of the differential pair circuit.
10. The R-R input stage circuit of claim 3, further comprising a second bias control circuit, coupled to the differential pair circuit, to dynamically control the bias current of the differential pair circuit when the input common mode voltage of the R-R input stage circuit is outside the first input common mode voltage range.
11. The R-R input stage circuit of claim 10, where the second bias control circuit gradually turns off the differential pair circuit in response to the input common mode voltage of the R-R input stage circuit.
12. The R-R input stage circuit of claim 10, further comprising a first gm control circuit having a first terminal coupled to the first bias control circuit and a second terminal coupled to the current source of the differential pair circuit, where the first gm control circuit adjusts the current through the differential pair circuit to maintain the transconductance of the R-R input stage circuit substantially constant when the input common mode voltage of the R-R input stage circuit is outside the first input common mode voltage range.
13. The R-R input stage circuit of claim 12, where the first gm control circuit adjusts the current through the differential pair circuit in response to the tracking current generated by the first bias control circuit.
14. The R-R input stage circuit of claim 13, further comprising a second gm control circuit having a first terminal coupled to the second bias control circuit and a second terminal coupled to the current source of the level shifted differential pair, where the second gm control circuit adjusts the current through the level-shifted differential pair to maintain substantially constant the transconductance of the R-R input stage circuit when the input common mode voltage of the R-R input stage circuit is outside the first input common mode voltage range.
15. The R-R input stage circuit of claim 14, where the second gm control circuit adjusts the current through the level shifted differential pair in response to the tracking current generated by the second bias control circuit.
16. A rail-to-rail (R-R) input stage circuit operating over a rail-to-rail input common mode voltage range, comprising:
a differential pair circuit, having a first input common mode voltage range, coupled to a level shifted differential pair, having a second input common mode voltage range to enable operation of the R-R input stage circuit over an input common mode voltage that extends from negative power supply to positive power supply; and
first means, coupled to the level shifted differential pair, for dynamically controlling the bias current of the level shifted differential pair when the input common mode voltage of the R-R input stage circuit is outside of the second input common mode voltage range.
17. The R-R input stage circuit of claim 16, where the first means gradually turns off the level shifted differential pair in response to the input common mode voltage of the R-R input stage circuit.
18. The R-R input stage circuit of claim 16, where the first means includes means for sensing the input common mode voltage of the R-R input stage circuit.
19. The R-R input stage circuit of claim 18, where the means for sensing also generate a tracking current inversely proportional to the sensed input common mode voltage, when the input common mode voltage of the R-R input stage circuit is outside the second input common mode voltage range.
20. The R-R input stage circuit of claim 19, where the first means further comprises means for mirroring the tracking current to the current source of the level shifted differential pair to control the bias current of the level shifted differential pair.
21. The R-R input stage circuit of claim 19, further comprising second means coupled to the differential pair circuit, to dynamically control the bias current of the differential pair circuit when the input common mode voltage of the R-R input stage circuit is outside the first input common mode voltage range.
22. The R-R input stage circuit of claim 21, where the second means gradually turns off the differential pair circuit in response to the input common mode voltage of the R-R input stage circuit.
23. The R-R input stage circuit of claim 22, where the second means includes means for sensing the input common mode voltage of the R-R input stage circuit.
24. The R-R input stage circuit of claim 23, where the means for sensing also generate a tracking current inversely proportional to the sensed input common mode voltage, when the input common mode voltage of the R-R input stage circuit is outside the first input common mode voltage range.
25. The R-R input stage circuit of claim 19, further comprising first gm control means having a first terminal coupled to the first means and a second terminal coupled to the differential pair circuit, where the first gm control means adjusts the current through the differential pair circuit in response to the tracking current generated by the first means, to maintain the transconductance of the R-R input stage circuit substantially constant when the input common mode voltage of the R-R input stage circuit is outside the first input common mode voltage range.
26. The R-R input stage circuit of claim 25, further comprising second gm control means having a first terminal coupled to the second means and a second terminal coupled to the level shifted differential pair, where the second gm control means adjust the current through the level shifted differential pair in response to the tracking current generated by the second means, to maintain the transconductance of the R-R input stage circuit substantially constant when the input common mode voltage of the R-R input stage circuit is outside the second input common mode voltage range.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-11. (canceled)
12. A kit for performing a blood sedimentation rate analysis, comprising:
a) a substantially optically clear glass tube having an overall length of about 100 to about 300 mm and a wall thickness of about 0.5 to about 1.5 mm, and having a plastic containment barrier with a thickness of less than about 1 mm and a closed end, and containing an additive including a surfactant that is free of clouding under the conditions to which it will be exposed prior to and during sedimentation rate testing and at least one additional additive selected from the group consisting of an anti-microbial, and anti-coagulant, a preservative, or any combination thereof; and
b) at least two components for performing a blood sedimentation rate analysis selected from an alcohol swab, gauze, a tube holder, a tube rack for performing a blood sedimentation rate analysis, a tourniquet, a glove, another cell collection tube, needle, lancet, adhesive strip, syringe, test strip, glass or plastic strip containing reagents for cell analysis, packaging to store the desired components, packaging to transport the blood sample stored in the tube after collection, a timer, a worksheet, or any combination thereof.
13. The kit of claim 12, wherein the surfactant is present in sufficient amount that it is capable of providing reproducible sedimentation rate tests in a consistent and reproducible manner that approximates that of a fresh blood sample after a delay of more than about 6 hours.
14. The kit of claim 13, wherein the surfactant is a nonionic surfactant of the form CxEy, where x is the number of carbons in the alkyl chain (C) and y is the number of ethylene oxide units in the polyoxyethylene chain (E).
15. The kit of claim 14, wherein x is from about 6 to about 18 and y is from about 4 to about 40.
16. A blood collection tube for sedimentation rate analysis, comprising:
an evacuated and sealed elongated glass tube with an open first end for receiving a venipuncture blood sample of at least 1 ml, formed with a closed end opposite the first end;
a plastic containment barrier that is substantially transparent and substantially encapsulates the elongated glass tube so that following a fracture of the tube, blood is contained within the tube;
and a surfactant, based upon polyoxyethylene alcohols, polyoxyethylene alkylphenols, or a combination thereof, being present in sufficient amount that it is capable of providing reproducible sedimentation rate tests in a consistent and reproducible manner that approximates that of a fresh blood sample after a delay of more than about 6 hours, and that is free of clouding under the conditions to which it will be exposed Prior to and during sedimentation rate testing.
17. The blood collection tube of claim 16, wherein the surfactant is a nonionic surfactant of the form CxEy, where x is the number of carbons in the alkyl chain (C) and y is the number of ethylene oxide units in the polyoxyethylene chain (E).
18. The blood collection tube of claim 17, wherein x is from about 6 to about 18 and y is from about 4 to about 40.
19. The blood collection tube of claim 18, wherein the surfactant is present in a concentration of about 0.1 gl to about 5 gl, the surfactant is selected to have an average monomer molecular weight in the range of about 500 to about 2000, and the surfactant will have an aggregation number that ranges from about 20 to about 120; and further comprising at least one additional additive selected from the group consisting of an anti-microbial, and anti-coagulant, a preservative, or any combination thereof.
20. The blood collection tube of claim 19, wherein the surfactant is present such that a sedimentation rate test approximating that of fresh blood is obtained after a period of at least 4 days between the time of the blood draw and sedimentation rate testing.
21. A method for performing an erythrocyte sedimentation rate analysis, comprising:
drawing a venipuncture blood sample into an evacuated and sealed elongated glass tube with an open first end and a closed end opposite the first end, the elongated glass tube including a containment barrier that is substantially transparent and substantially encapsulates the elongated glass tube so that following a fracture of the tube, the blood sample is contained within the tube;
contacting the blood sample with a surfactant in the glass tube, the surfactant being free of clouding under the conditions to which it will be exposed prior to and during sedimentation rate testing; and
performing the erythrocyte sedimentation rate analysis while the blood sample is contained within the tube.
22. The method of claim 21, wherein the surfactant is a nonionic surfactant of the form CxEy, where x is the number of carbons in the alkyl chain (C) and y is the number of ethylene oxide units in the polyoxyethylene chain (E).
23. The method of claim 22, wherein x is from about 6 to about 18 and y is from about 4 to about 40.
24. The method of claim 23, wherein the surfactant is present in a concentration of about 0.1 gl to about 5 gl, the surfactant is selected to have an average monomer molecular weight in the range of about 500 to about 2000, and the surfactant will have an aggregation number that ranges from about 20 to about 120;
25. The method of claim 21, wherein the surfactant is selected from polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (23) lauryl ether, polyoxyethylene (9) mono(octylphenyl)ether, polyoxyethylene octylphenyl ether, or any combination thereof.
26. The method of claim 21, wherein the surfactant is selected from organosilicone surfactants, alcohols, esters of fatty acids, mercaptans, and alkylamines; nonionic surfactants containing an amide group; polyol ester surfactants or any combination thereof
27. The method of claim 22, further comprising contacting the blood sample in the tube with at least one additional additive selected from the group consisting of an anti-microbial, and anti-coagulant, a preservative, or any combination thereof.