Erythrocyte sedimentation rate (ESR) test measurement instrument of unitary design and method of using the same
An erythrocyte sedimentation rate (ESR) measurement instrument having a Blood Collection Configuration and an ESR Measurement Configuration. The ESR measurement instrument comprises a sedimentation measurement tube having an hollow interior volume containing a predetermined quantity of blood sample diluting agent therewithin and being air/fluid sealed with respect to the ambient environment; and a blood collection tube having a hollow interior volume containing a predetermined quantity of anti-coagulant and being vacuum-sealed with respect to the ambient environment, and physically coupled to the air-sealed sedimentation measurement tube, by at least a portion of the sedimentation measurement tube being inserted within a portion of the hollow interior volume of the blood collection tube. The sedimentation measurement tube and the blood collection tube are maintained stationarily fixed relative to each other as a unitary assembly having a syringe-like form factor when the ESR measurement instrument is arranged in the Blood Collection Configuration. During this configuration, a needle-supporting connector can be connected to the blood collection tube and a sample of whole blood from a patient vacuum-drawn and injected into the blood collection tube. After the sample of anti-coagulated blood has been collected in the blood collection tube and the needle-supporting connector is disconnected therefrom, the air/fluid seal of the sedimentation measurement tube can be broken and then the sedimentation measurement tube can be manually plunged into and to the bottom of the hollow interior volume of said blood collection tube, using a single-handed operation to rearrange the ESR measurement instrument into the ESR Measurement Configuration. The anti-coagulated sample of blood fills up a substantially portion of the sedimentation measurement tube and mixes with the blood sample diluting agent to enable the blood plasma/erythrocyte cell (P/E) interface level within the sedimentation measurement tube to settle downwards toward the blood collection tube during a predetermined time period when said ESR measurement instrument is oriented in a gravity vertical position. By virtue of the present invention, the erythrocyte sedimentation rate (ESR) of the collected blood sample can be measured by determining how far the P/E interface level has moved against graduation markings formed along the length of the sedimentation measurement tube during the predetermined time period.
1. Field of Invention
The present invention relates to an improved method of, and a disposable test measurement instrument for, determining the Erythrocyte (or red blood cell) Sedimentation Rate (ERS) of a sample of anti-coagulated whole blood, in a safe, effective and inexpensive manner within diverse clinical settings.
2. Brief Description of the State of Knowledge in the Art in the Field of Invention
In 1894, Edmund Biernacki (1866-1912), a Polish physician, first noted the increased sedimentation rate of blood from ill individuals and realized that this increase was due to the presence of fibrinogen in the individual's blood sample.
In 1918, Robin Fahraeus (1888-1968) furthered Biernacki's work. His initial motivation to study the ESR of blood was as a pregnancy test, but his interest expanded to the study of the ESR test in disease states of his patients.
In 1921, Alf Westergren (1881-1968) refined the technique of performing the ESR test and reported its usefulness in determining the prognosis of patients with tuberculosis.
In 1935, Maxwell M. Wintrobe (1901-1986) published a variation of the ESR methodology and, at one time, this method was in wide use.
In 1977, the International Committee for Standardization in Hematology (ICSH) recommended the adoption of the Westergren method as the worldwide standard of ESR testing.
In 1997, the NCCLS published the ICSH's most recent recommendations on ESR Testing in the NCCLS Publication No. H2-A4 entitled “Reference and Selected Procedure For The Erythrocyte Sedimentation Rate (ESR) Test; Approved Standard (Fourth Edition), incorporated herein by reference in its entirety.
Also, NCCLS has recently published a number of other important documents setting forth standards and guidelines in relation to ESR testing, namely: No. C28-A2 entitled “How to Define and Determine Reference Intervals in the Clinical Laboratory” which sets forth standard guidelines for determining reference values and reference intervals for quantitative clinical laboratory tests; No. H1-A4 entitled “Evacuated Tubes and Additives for Blood Specimen Collection” which sets forth standard requirements for blood collection tubes and additives including heparin, EDTA, and sodium citrate; No. H3-A4 entitled “Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture” which sets forth standard procedures for the collection of diagnostic specimens by venipuncture, including line draws, blood culture collection, and venipuncture in children, and also includes recommendations on order of draw; No. H7-A3 entitled “Procedure for Determining Packed Cell Volume by the Microhematocrit Method” which sets forth the standard microhematocrit method for determining packed-cell volume, and addresses recommended materials and potential sources of error; No. H18-A2 entitled “Procedures for the Handling and Processing of Blood Specimens” which addresses the multiple factors associated with handling and processing specimens, as well as factors that can introduce imprecision or systematic bias into results; and also No. M29-A entitled “Protection of Laboratory Workers from Instrument Biohazards and Infectious Disease Transmitted by Blood, Body Fluids and Tissue” which sets forth guidance on the risk of transmission of hepatitis viruses and human immunodeficiency viruses in any laboratory setting, specific precautions for preventing the laboratory transmission of blood-borne infection from laboratory instruments and materials, and recommendations for the management of blood-borne exposure. Each of these NCCLS documents helps to indicate the state of knowledge in the art in this field, and is incorporated herein by reference in its entirety.
Today, the Erythrocyte Sedimentation Rate (ESR or Sed Rate) test is one of the most widely performed laboratory tests throughout the world, used to help screen for general illness by determining if a patient has a condition which is causing acute or chronic inflammation, indicated by elevated levels of fibrinogen in the patent's blood. While the ESR test is non-specific, it is still very helpful in following the course of some inflammatory diseases.
The Westergren ESR test method, which is the “Gold Standard” reference method for the ESR test, is performed by placing a diluted sample of anti-coagulated blood in a tall, perfectly vertical tube of 2.5 mm diameter and 200 mm length, and measuring how far in [mm/hr] the blood plasma/erythrocyte cell (P/E) interface level has settled under the influence of gravitational forces after the lapse of sixty (60) minutes (i.e one hour). The collected whole blood sample is prevented from coagulation by the addition of K3EDTA, and the anti-coagulated blood sample is then diluted by adding four parts of whole anti-coagulated blood to one part dilutent (such as physiologic saline or trisodium citrate at a concentration of between 0.10 to 0.136 mol/litre). The test works because the proteins associated with inflammation, particularly fibrinogen, counteract the zeta potential of red blood cells, which is created by a negative surface charge on the erythrocytes. This negative charge on the erythrocytes serve to repel the individual erythrocytes from each other and thus prolong erythrocyte sedimentation. When systemic inflammation is present, the fibrinogen content of the blood increases, and the erythrocytes tend to aggregate, thereby decreasing their surface-to-mass ratio, and thus increasing their rate of sedimentation.
The Wintrobe ESR test method employs a shorter tube (100 mm) than that used in the Westergren ESR method, and also a different anti-coagulant (i.e. ammonium oxide and potassium oxalate) in smaller amounts so as to not function as a diluting agent. It is generally accepted that the Wintrobe method is more sensitive for mild elevations, but also has a higher false positive rate than the Westergren method. On the other hand the Westergren method is more sensitive for changes at the elevated levels and more useful where the ESR test is being used to evaluate the response to therapy, i.e. in diseases such as temporal arteritis.
Various types of prior art apparatus have been proposed for performing the ESR test using manual principles of operation. The following Patents describe such form of apparatus: U.S. Pat. No. 5,914,272; U.S. Pat. No. 5,779,983; U.S. Pat. No. 5,745,227; U.S. Pat. No. 5,244,637; U.S. Pat. No. 5,065,768; U.S. Pat. No. 4,701,305; U.S. Pat. No. 4,622,847; U.S. Pat. No. 4,434,802; U.S. Pat. No. 4,353,246; U.S. Pat. No. 4,187,719; U.S. Pat. No. 3,938,370; U.S. Pat. No. 3,910,103; U.S. Pat. No. 3,660,037; U.S. Pat. No. 3,373,601; UK Application No. GB 2 116 319 A; and UK Application No. GB 2 048 836 A, each patent being incorporated herein by reference.
However, the ESR test instrumentation disclosed in the above prior art references generally involves the handling of blood in less than satisfactory manner, creates unnecessary risks to those performing the measurements and to those disposing of the collected blood samples, and requires the lab technician to possess a relatively high degree of skill and dexterity if the test results are to be measured accurately.
Various approaches to automating the ESR test have been attempted, notably using electronic and optical means for tracking the sedimentation of the erythrocytes and providing a result in less than the usual sixty minutes. Such techniques are illustrated in U.S. Pat. Nos. No. 5,914,272; No. 5,575,977; No. 5,316,729; No. 4,801,428; No. 4,744,056; No. 4,187,462; and No. 4,041,502, each being incorporated herein by reference.
While these prior art methods and apparatus have reduced ESR test times substantially below the standard 60 minute test time period, the results produced by such prior art methods and apparatus do not correlate well with the “reference” Westergren ESR method, and involve the use of expensive equipment.
Thus, there is a great need in the art for an improved method of and apparatus for measuring the rate of erythrocyte sedimentation in a sample of whole blood, while avoiding the shortcomings and drawbacks of prior art apparatus and methodologies.
SUMMARY AND OBJECTS OF INVENTIONAccordingly, it is an object of the present invention to provide an improved method of and apparatus for measuring the Erythrocyte Sedimentation Rate (ESR) in a sample of whole blood, while avoiding the shortcomings and drawbacks of prior art apparatus and methodologies.
It is a further object of the present invention to provide such apparatus in the form of an improved disposable ESR test measurement instrument having a syringe-like form factor, and unitary construction.
It is a further object of the present invention to provide such an ESR measurement instrument having a Blood Collection Configuration and an ESR measurement configuration.
It is another object of the present invention to provide such an ESR measurement instrument, wherein, during its Blood Collection Configuration, an air/fluid sealed sedimentation measurement tube containing a blood diluting agent (i.e. dilutent) is coupled to a vacuum-sealed blood collection tube containing an anti-coagulating agent (i.e. anti-coagulant), so that such sealed tubes are stationarily fixed relative to each other as a unitary assembly. While the ESR measurement instrument is arranged in its Blood Collection Configuration, a Leur® type connector is then connected to the vacuum-sealed blood collection tube and a sample of whole blood from a patient is drawn and injected into the blood collection tube of the ESR measurement instrument.
It is another object of the present invention to provide such an ESR measurement instrument, wherein after the sample of anti-coagulated blood has been collected in the sealed blood collection container and the Leur® type connector is disconnected therefrom, the air-seal of the sedimentation measurement tube is broken and then the sedimentation measurement tube is manually plunged into and to the bottom of the blood collection tube, using a single-handed operation, so as to rearrange the ESR measurement instrument into its ESR Measurement Configuration. This causes the liquid seal between the two tubes to be broken and the anti-coagulated sample of collected blood to mix with the physiologic (0.145 mol/L; 8.5 g/L; “0.85%) NaCl solution contained in the sedimentation measurement tube, thereby filling up a substantial portion thereof with the diluted blood sample and permitting the blood plasma/erythrocyte cell (P/E) interface level of the diluted anti-coagulated blood sample to settle downwards toward the blood collection tube by a measurable distance during a predetermined test time period (e.g. 60 minutes) when the ESR measurement instrument is oriented in a gravity vertical position. Using this ESR measurement instrument, the ESR of the colleted blood sample can be determined by measuring the distance that the P/E interface level travels against graduation markings on the sedimentation measurement tube, during the 60 minute test period.
Another object of the present invention is to provide such an ESR measurement instrument, wherein the blood collection tube has (i) a hollow interior cylindrical volume of a predetermined internal diameter for receiving the sample of whole human blood during blood collection operations, (ii) a pair of low-relief flanges projecting about the outer end surface of the blood collection tube for gripping a rubber needle-pierceable cap with a thick self-sealing end portion and thinner wall portions that snap fit over the low-relief flanges and the outer end portion of the blood collection tube during assembly, and (iii) a large annular flange projecting from the outer end of the blood collection tube at its opposite end, for engagement with the fingers of a person pushing the sedimentation measurement tube within the blood collection tube with his or her thumb.
Another object of the present invention is to provide such an ESR measurement instrument, wherein the sedimentation measurement tube has (i) a hollow central bore of a predetermined diameter and an outer diameter slightly smaller than the interior diameter of the hollow interior volume of the blood collection tube, (ii) a series of graduation marks formed along the exterior surface of the sedimentation measurement tube for indicating the ESR of a whole blood sample in accordance with the ESR measurement method of the present invention, (iii) a plurality of low-relief plunger gripping flanges projecting from the opposite end of the sedimentation measurement tube for retaining a rubber plunger having a hollow inner volume bounded on its closed end by a thin, rupturable wall membrane, and having outer wall surfaces which slide over the free end of the sedimentation measurement tube and engage the flanges projecting therefrom.
Another object of the present invention is to provide such an ESR measurement instrument, wherein the sedimentation measurement tube has a large annular flange projecting from its outer end at the end opposite the rubber plunger, for engagement with the thumb of the person pushing the sedimentation measurement tube within the blood collection tube when rearranging the ESR measurement instrument into its ESR Measurement Configuration.
Another object of the present invention is to provide such an ESR measurement instrument, wherein an air/fluid flow restriction plug is insertable into the top end portion of the sedimentation measurement tube so as to restrict or occlude the flow of blood diluting agent out of the sedimentation measurement tube while the ESR measurement instrument is arranged in its Blood Collection Configuration.
Another object of the present invention is to provide such an ESR measurement instrument, wherein a rubber washer, slidable over the plunger gripping flanges, before the rubber plunger is attached to the end of the sedimentation measurement tube, for creating a liquid seal between outer walls of the sedimentation measurement tube and the inner walls of blood collection tube.
Another object of the present invention is to provide such an ESR measurement tube, wherein a tube holder and restraint assembly is provided for holding the plunger portion of the sedimentation measurement tube is inserted within the upper portion of the blood collection tube, and maintaining these tubes in a stationary position with respect to each other while the small quantity of anti-coagulant (e.g. K3EDTA) is contained within the vacuum-sealed blood collection tube while the ESR measurement instrument is arranged in its Blood Collection Configuration.
Another object of the present invention is to provide a novel method of ESR measurement using an ESR measurement instrument having a unitary construction, with a syringe-like form factor.
Another object of the present invention is to provide such an ESR measurement method, wherein the needle of blood collecting apparatus is injected through a rubber cap associated with a blood collection tube that is vacuum-sealed and contains a predetermined quantity of anti-coagulant within the hollow interior volume of said blood collection tube and which is further integrated with a sedimentation measurement tube that is air/fluid-sealed and contains a predetermined quantity of blood sample diluting agent (e.g. physiologic NaCl solution or sodium citrate solution), wherein a liquid seal is disposed between the interior volume of said blood collection tube and the interior volume of said sedimentation measurement tube.
Another object of the present invention is to provide such an ESR measurement method, wherein a sample of whole blood is drawn from a patient's body under vacuum pressure and the blood sample collected through the needle and into the blood collection tube, wherein the collected sample of whole blood mixes with the predetermined quantity of anti-coagulant within the blood collection tube.
Another object of the present invention is to provide such an ESR measurement method, wherein the needle is withdrawn from the blood collecting device, and then the air/fluid seal of sedimentation measurement device is broken.
Another object of the present invention is to provide such an ESR measurement method, wherein liquid seal between the sedimentation measurement tube and the blood collection tube is broken by manually pushing the sedimentation measurement tube into the hollow interior volume of the blood collection tube, thereby causing the sample of anti-coagulated blood to fill up a substantial portion of the sedimentation measurement tube, and mix with the predetermined quantity of blood sample diluting agent (e.g. physiologic NaCl solution or sodium citrate solution), whereby the P/E interface (of the erythrocyte sediment) is permitted to settle down towards the blood collection tube over a predetermined time period when the ESR instrument is supported in a gravity vertical direction during the predetermined time period, so that the erythrocyte sedimentation rate (ESR) of the collected blood sample can be measured by determining the distance that the P/E interface level moved against graduation markings of the sedimentation measurement tube during the predetermined test period.
Yet another object of the present invention is to provide an improved erythrocyte sedimentation rate (ESR) measurement instrument having a syringe-like form factor, wherein an empty sedimentation measurement tube is coupled to a vacuum-sealed blood collection tube containing both an anti-coagulating agent (i.e. anti-coagulant) and a blood diluting agent (i.e. dilutent), so that such sealed tubes are stationarily fixed relative to each other as a unitary assembly during Blood Collection Operations, but are intercoupled into each other and arranged in fluid communication when the ESR measurement instrument is manually configured into its ESR Measurement Configuration. This embodiment of the present invention is most suitable for practicing the Westergren ESR method, wherein blood sample dilution is employed.
Yet another object of the present invention is to provide an improved erythrocyte sedimentation rate (ESR) measurement instrument having a syringe-like form factor, wherein an empty sedimentation measurement tube is coupled to a vacuum-sealed blood collection tube containing only an anti-coagulating agent (i.e. anti-coagulant), so that such sealed tubes are stationarily fixed relative to each other as a unitary assembly during Blood Collection Operations, but are intercoupled into each other and are arranged in fluid communication when the ESR measurement instrument is manually configured into its ESR Measurement Configuration. This embodiment of the present invention is most suitable for practicing the Wintrobe ESR method, wherein blood sample dilution is not employed.
These and other objects of the present invention will become apparent hereinafter and in the Claims to Invention appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
The Detailed Description of the Illustrative Embodiments will now be described in detail with reference to the accompanying Drawings, wherein like structures and elements shown throughout the figures thereof shall be indicated with like reference numerals.
The Detailed Description set forth below discloses a detailed specification of two illustrative embodiments of the ESR measurement instrument of the present invention. In general, these ESR measurement instruments are both portable and disposable in nature, and are designed for quickly performing precise ESR measurements in diverse environments including, for example, doctor offices, laboratories, hospitals, medical clinics, battlefields, and the like.
First Illustrative Embodiment of the ESR Measurement Instrument of the Present Invention As shown in
In
As shown in
As shown in
In the illustrative embodiment, the sedimentation measurement tube 9, the blood collection tube 2 and the air/fluid flow restriction plug 18 can be injection-molded using high-quality medical-grade plastics as currently used to manufacturer plastic blood collection tubes and the like. Rubber cap 5, rubber plunger 13 and washer seal 19 can be made from medical-grade rubber materials in a manner well known in the art.
Referring to
As indicated at Block A of
As indicated at Block B in
As indicated at Block C in
As indicated at Block D of
As indicated at Block E in
Thereafter, the cover halves 22D and 22B1, 22B2 of assembly 22 are reattached about the top and bottom flanges 17 and 8, respectively, as shown in
After the ESR measurement is taken, and recorded in the patient's medical record, the locked ESR measurement instrument can be discarded as medical waste according to government regulations and/or safety standards.
As the collected blood sample is always contained within the instrument during the ESR measurement method of the present invention, there is little if any risk to the technician performing the ESR test measurement using the ESR measurement instrument of the present invention. Also, as the instrument is essentially locked, the risk of leakage or environmental contamination is substantially minimized.
Second Illustrative Embodiment of the ESR Measurement Instrument of the Present Invention As shown in
However, in this second illustrative embodiment, its tube holder and restraint assembly 45 is realized in a markedly simpler construction than the tube holder and restraint assembly 22 used in the first illustrative embodiment. This tube holder and restraint assembly 45 will be described in detail below.
In
As shown in
In the illustrative embodiment, the sedimentation measurement tube, the blood collection tube and the air/fluid flow restriction plug can be injection-molded using high-quality medical-grade plastics as currently used to manufacturer plastic blood collection tubes and the like. Rubber cap 5, rubber plunger 13 and washer seal 19 can be made from medical-grade rubbers in a manner well known in the art.
Referring to Blocks A and B in
As indicated at Block A of
As indicated at Block B in
As indicated at Block C in
As indicated at Block D of
As indicated at Block E in
Thereafter, the cover halves 45, 45 are reattached about the bottom flange 8, as shown in
After the ESR measurement is taken (i.e. by reading the P/E interface level location) against the calibrated graduations 11 along the sedimentation measurement tube, and recorded in the patient's medical record, the locked ESR measurement instrument can be safely discarded as medical waste according to government regulations and/or safety standards.
As the collected blood sample is always contained within the instrument during the ESR measurement method of the present invention, this is little if any risk to the technician performing the ESR measurement using the ESR measurement instrument of the present invention. Also, as the instrument is essentially locked, the risk of leakage or environmental contamination is substantially minimized.
Third Illustrative Embodiment of the ESR Measurement Instrument of the Present Invention In
In
When designing and implementing any of the illustrative embodiments of the ESR test measurement instrument of the present invention described above, it is understood that the actual physical dimensions of the blood collection tube and the sedimentation measurement tube will depend on several factors, including: (1) the actual amount of the whole blood sample to be collected and treated by the instrument during ESR testing; and (2) the particular type and variation of the ESR testing method (e.g. Westergren, Wintrobe, etc.) to be carried out using the ESR measurement instrument.
In applications where large whole blood samples can be collected (e.g. as with adult patients), the blood collection tube can be designed to contain a standard volume (e.g. 1.0 ml) of collected whole blood and a negligible amount of K3EDTA anti-coagulating agent, whereas the sedimentation measurement tube can be designed to contain this same amount of anti-coagulated blood in addition to a blood diluting agent (e.g. physiologic NaCl solution or sodium citrate solution) mixed in the standard ratio of 1 part blood dilutent to 4 parts of anti-coagulated blood. Preferably, the final form factor of the disposable ESR test measurement instrument design will resemble a slightly-elongated syringe-like instrument. The final ESR measurement instrument design should be calibrated against the standard Westergren ESR test method and apparatus kit, as published by NCCLS, in the document entitled “Reference and Selected Procedure For The Erythrocyte Sedimentation Rate (ESR) Test; Approved Standard—Fourth Edition”, (NCCLA Publication No. H2-A4), supra.
In applications where only small whole blood samples can be collected (e.g. as with infants and younger children), the blood collection tube can be designed to contain a smaller volume (e.g. 0.5 ml) of collected whole blood and a negligible amount of K3EDTA anti-coagulating agent, whereas the sedimentation measurement tube can be designed to contain this same amount of anti-coagulated blood in addition to a blood diluting agent (e.g. physiologic NaCl solution or sodium citrate solution) mixed in the standard ratio of 1 part blood dilutent to 4 parts of anti-coagulated blood. Preferably, the final form factor of the disposable ESR measurement instrument design will resemble a slightly-elongated syringe instrument. The final ESR measurement instrument design should be calibrated against the standard Westergren ESR test method and apparatus kit, as published in “Reference and Selected Procedure For The Erythrocyte Sedimentation Rate (ESR) Test; Approved Standard—Fourth Edition”, supra, so that test results from the ESR test measurement instrument of the present invention are strong correlated with test results obtained from the standard Westergren ESR test method.
Modifications Which Come to MindWhile each embodiment of the disposable ESR test measurement instrument disclosed hereinabove has employed a rubber plunger element having a rupturable membrane, it is understood that in other embodiments of the present invention, the rupturable membrane may be realized using a blow-out type of plug or element which, in response to sufficient blood sample pressure, blows out permitting the blood sample to fill up the sedimentation measurement tube as the instrument is arranged in its ESR Measurement Configuration. Preferably, this blow-out type plug or element is hingedly connected to the walls of the rubber plunger so as to not interfere with the ESR test measurement. Clearly, other ways and means can be used to create this pressure-sensitive blood flow valve structure arranged between the hollow interior volume of the sedimentation measurement tube and the hollow interior volume of the blood collection tube of the instrument, in accordance with the general spirit of the present invention.
It is understood that the ESR instruments of the illustrative embodiments may be modified in a variety of ways which will become readily apparent to those skilled in the art, and having the benefit of the novel teachings disclosed herein. All such modifications and variations of the illustrative embodiments thereof shall be deemed to be within the scope and spirit of the present invention as defined by the accompanying Claims to Invention.
Claims
1-25. (canceled)
26. An erythrocyte sedimentation rate (ESR) measurement instrument having a Blood Collection Configuration and an ESR Measurement Configuration, said ESR measurement instrument comprising:
- a sedimentation measurement tube having an hollow interior volume containing a predetermined quantity of blood sample diluting agent therewithin and being air/fluid sealed with respect to the ambient environment; and
- a blood collection tube having a hollow interior volume containing a predetermined quantity of anti-coagulant, and being physically coupled to said air-sealed sedimentation measurement tube, by at least a portion of said sedimentation measurement tube being inserted within a portion of the hollow interior volume of said blood collection tube;
- wherein said sedimentation measurement tube and said blood collection tube are maintained stationarily fixed relative to each other as a unitary assembly when said ESR measurement instrument is arranged in said Blood Collection Configuration, during which a needle-supporting connector can be connected to said blood collection tube and a sample of whole blood from a patient drawn and injected into said blood collection tube; and
- wherein after the sample of anti-coagulated blood has been collected in said blood collection tube and the needle-supporting connector is disconnected therefrom, the air/fluid seal of said sedimentation measurement tube can be broken and then said sedimentation measurement tube can be manually plunged into and to the bottom of the hollow interior volume of said blood collection tube, so as to rearrange said ESR measurement instrument into said ESR Measurement Configuration,
- whereby the anti-coagulated sample of blood fills up a substantially portion of said sedimentation measurement tube and mixes with said blood sample diluting agent to enable the blood plasma/erythrocyte cell (P/E) interface level within said sedimentation measurement tube to settle downwards toward said blood collection tube during a predetermined time period when said ESR measurement instrument is oriented in a gravity vertical position, so that the erythrocyte sedimentation rate (ESR) of said collected blood sample can be measured by determining how far said P/E interface level has moved against graduation markings formed along the length of said sedimentation measurement tube during said predetermined time period.
27. The ESR measurement instrument of claim 26, wherein said blood collection tube is vacuum sealed.
28. The ESR measurement instrument of claim 26, wherein said unitary assembly has a syringe-like form factor.
29. The ESR measurement instrument of claim 28, wherein said blood collection tube has (i) a hollow interior cylindrical volume of a predetermined internal diameter for receiving the sample of whole human blood during blood collection operations, (ii) a pair of low-relief flanges projecting about the outer end surface of the blood collection tube for gripping a rubber needle-pierceable cap with a thick self-sealing end portion and thinner wall portions that snap fit over the low-relief flanges and the outer end portion of the blood collection tube during assembly, and (iii) a large annular flange projecting from the outer end of the blood collection tube at its opposite end, for engagement with the fingers of a person pushing said sedimentation measurement tube within the blood collection tube with his or her thumb.
30. The ESR measurement instrument of claim 26, wherein said sedimentation measurement tube has (i) a hollow central bore of a predetermined diameter and an outer diameter slightly smaller than the interior diameter of the hollow interior volume of the blood collection tube, (ii) a series of graduation marks formed along the exterior surface of the sedimentation measurement tube for indicating the ESR of a whole blood sample in accordance with the ESR measurement method of the present invention, (iii) a plurality of low-relief plunger gripping flanges projecting from the opposite end of the sedimentation measurement tube for retaining a rubber plunger having a hollow inner volume bounded on its closed end by a thin, rupturable wall membrane, and having outer wall surfaces which slide over the free end of said sedimentation measurement tube and engage the flanges projecting therefrom.
31. The ESR measurement instrument of claim 30, wherein said sedimentation measurement tube has a large annular flange projecting from its outer end at the end opposite the rubber plunger, for engagement with the thumb of the person pushing the sedimentation measurement tube within the blood collection tube when rearranging the ESR measurement instrument into said ESR Measurement Configuration.
32. The ESR measurement instrument of claim 30, wherein an air/fluid flow restriction plug is insertable into the top end portion of said sedimentation measurement tube so as to restrict or occlude the flow of air from the ambient environment and the interior of the hollow central bore while the ESR measurement instrument is arranged in said Blood Collection Configuration.
33. The ESR measurement instrument of claim 30, wherein a rubber washer, slidable over the plunger gripping flanges, before the rubber plunger is attached to the end of the sedimentation measurement tube, for creating a liquid seal between outer walls of said sedimentation measurement tube and the inner walls of said blood collection tube.
34. The ESR measurement instrument of claim 26, wherein means is provided for maintaining the plunger portion of the sedimentation measurement tube within the upper portion of the blood collection tube in a stationary position with respect to each other while the predetermined quantity of anti-coagulant is contained within the vacuum-sealed blood collection tube while the ESR measurement instrument is arranged in said Blood Collection Configuration.
35. A method of ESR measurement using an ESR measurement instrument having a unitary construction, said method comprising the steps of:
- (a) injecting the needle of blood collecting apparatus through a rubber cap associated with a blood collection tube that contains a predetermined quantity of anti-coagulant within the hollow interior volume of said blood collection tube and which is further integrated with a sedimentation measurement tube that is air/fluid-sealed and contains a predetermined quantity of blood sample diluting agent, wherein a liquid seal is disposed between the interior volume of said blood collection tube and said sedimentation measurement tube;
- (b) drawing a sample of whole blood from a patient's body and collecting said sample through said needle and into said blood collection tube, wherein the collected sample of whole blood mixes with said predetermined quantity of anti-coagulant within said blood collection tube;
- (c) withdrawing said needle from said blood collecting device;
- (d) breaking the air/fluid seal of said sedimentation measurement device; and
- (e) breaking the liquid seal between said sedimentation measurement tube and said blood collection tube by manually pushing said sedimentation measurement tube into the hollow interior volume of said blood collection tube,
- thereby causing the sample of anti-coagulated blood to fill up a substantial portion of said sedimentation measurement tube, and mix with said predetermined quantity of blood sample diluting agent, and
- whereby the blood plasma/erythrocyte cell (P/E) interface level within said sedimentation measurement tube is permitted to flow down towards said blood collection tube over a predetermined time period when said ESR measurement instrument is supported in a gravity vertical direction during said predetermined time period, so that the erythrocyte sedimentation rate (ESR) of said collected blood sample can be measured by determining how far said P/E interface level has moved against graduation markings formed along the length of said sedimentation measurement tube during said predetermined time period.
36. The method of ESR measurement of claim 35, wherein said blood collection tube is vacuum-sealed.
37. An erythrocyte sedimentation rate (ESR) measurement instrument having a Blood Collection Configuration and an ESR Measurement Configuration, said ESR measurement instrument comprising:
- a sedimentation measurement tube having an hollow interior volume; and
- a blood collection tube having a hollow interior volume containing a predetermined quantity of anti-coagulant and a predetermined quantity of blood sample diluting agent therewithin, and physically coupled to said sedimentation measurement tube by at least a portion of said sedimentation measurement tube being inserted within a portion of the hollow interior volume of said blood collection tube;
- wherein said sedimentation measurement tube and said blood collection tube are maintained stationarily fixed relative to each other as a unitary assembly when said ESR measurement instrument is arranged in said Blood Collection Configuration, during which a needle-supporting connector can be connected to said blood collection tube and a sample of whole blood from a patient drawn and injected into said blood collection tube; and
- wherein after the sample of whole blood has been collected in said blood collection tube and mixes with said anti-coagulating agent and said predetermined quantity of blood sample diluting agent, the needle-supporting connector is disconnected therefrom, and said sedimentation measurement tube can be manually plunged into and to the bottom of the hollow interior volume of said blood collection container, so as to rearrange said ESR measurement instrument into said ESR Measurement Configuration,
- whereby the anti-coagulated sample of blood fills up a substantially portion of said sedimentation measurement tube and the blood plasma/erythrocyte cell (P/E) interface level within said sedimentation measurement tube settles downwards toward said blood collection tube during a predetermined time period when said ESR measurement instrument is oriented in a gravity vertical position, so that the erythrocyte sedimentation rate (ESR) of said collected blood sample can be measured by determining how far said P/E interface level has moved against graduation markings formed along the length of said sedimentation measurement tube during said predetermined time period.
38. The ESR measurement instrument of claim 37, wherein said blood collection tube is vacuum sealed, and said unitary assembly has a syringe-like form factor.
39. The ESR measurement instrument of claim 37, wherein said sedimentation measurement tube can be manually plunged into and to the bottom of the hollow interior volume of said blood collection container, using a single handed operation, so as to rearrange said ESR measurement instrument into said ESR Measurement Configuration.
40. The ESR measurement instrument of claim 37, wherein said blood collection tube has (i) a hollow interior cylindrical volume of a predetermined internal diameter for receiving the sample of whole human blood during blood collection operations, (ii) a pair of low-relief flanges projecting about the outer end surface of the blood collection tube for gripping a rubber needle-pierceable cap with a thick self-sealing end portion and thinner wall portions that snap fit over the low-relief flanges and the outer end portion of the blood collection tube during assembly, and (iii) a large annular flange projecting from the outer end of the blood collection tube at its opposite end, for engagement with the fingers of a person pushing said sedimentation measurement tube within the blood collection tube with his or her thumb.
41. The ESR measurement instrument of claim 40, wherein said sedimentation measurement tube has (i) a hollow central bore of a predetermined diameter and an outer diameter slightly smaller than the interior diameter of the hollow interior volume of the blood collection tube, (ii) a series of graduation marks formed along the exterior surface of the sedimentation measurement tube for indicating the ESR of a whole blood sample in accordance with the ESR measurement method of the present invention, (iii) a plurality of low-relief plunger gripping flanges projecting from the opposite end of the sedimentation measurement tube for retaining a rubber plunger having a hollow inner volume bounded on its closed end by a thin, rupturable wall membrane, and having outer wall surfaces which slide over the free end of said sedimentation measurement tube and engage the flanges projecting therefrom.
Type: Application
Filed: Jul 29, 2005
Publication Date: Feb 9, 2006
Inventor: Denis Bouboulis (Darien, CT)
Application Number: 11/194,056
International Classification: G01N 33/86 (20060101);