Field of Invention

The present invention relates to a cuvette used for spectrophotometrical analyses, in which electromagnetic energy is passed through a biological sample such as blood, urine or the like contained therein.

Background Information

A cuvette is a small tube designed to hold samples for spectroscopic experiments which is of square or circular shape, sealed at the bottom end and the top end is open but it can be sealed with a cap to shut. Generally, cuvettes are made up of glass, plastic, or fused quartz. More preferable cuvettes are clear and transparent without impurities that might affect a spectroscopic reading. There are three different types of cuvettes are used depend upon the utility of the cuvettes.

Photometers function in a certain wavelength region, whose selection is effected by color or interference filters. With the spectral photometers on the other hand the light of the illumination means is spectrally disaggregated with a monochromator. With calorimeters the determination of the concentration is effected by color comparison with a standard solution of the same substance. The irradiation may in particular lie in the region of the visible light, in the IR or UV region. The selection may be dependent of the sample to be analyzed. The material selection of the cuvette is in turn directed to the spectral region for which this is to be used.

In order to determine the amount of hemoglobin in the blood, the hemoglobin must be released from the blood cells so that it is free in solution. The pigment is then measured using a spectrophotometer and the absorbance is compared to a series of standards that are used to draw a standard calibration curve.

Measurement of haemoglobin (Hb) concentration is very important to diagonise the presence and severity of anaemia. However, all the diagnostic centers and laboratories or clinics and hospitals with laboratories are expensive and also time consuming. Therefore, this study was undertaken to provide an apparatus for the determination of Hb which portable to evaluate the initial diagnosis of anaemia.

Therefore it is an object of the present invention to provide a cuvette which is more convenient to measure the haemoglobin instantly.

Summary

Accordingly, the present invention provides a cuvette for holding body fluid sample for analysis comprising: an inlet cavity (1) for allowing body fluid sample to be analyzed into the cuvette; a measurement cavity (2) provided with predetermined test reagent and liquid sample (8) contained therein through which the electromagnetic energy is passed comprising a first side (9) through which the electromagnetic energy enters and a second opposite side (10) through which the electromagnetic energy leaves; reception cavity (3) to receive the capillary tube (4) containing body fluid sample is a down-gradient towards the closing end (5) of the cuvette; closing means (6) to close the cuvette when the capillary tube (7) containing body fluid dropped into the cuvette for analysis need to be mixed thoroughly.

Brief Description of the Several Views of the Drawings

The accompanying drawings are intended to provide further understanding of invention and are incorporated in and constitute a part of invention. The drawings illustrate an embodiment of invention and together with the description illustrate principle of invention. The drawings should not be taken as implying any necessary limitation on the essential scope of invention. The drawings are given by way of non-limitative example to explain the nature of the invention. For a more complete understanding of the instant invention reference is now made to the following description taken in conjunction with accompanying drawings.

Figure 1, illustrates the prior art cuvette with capillary tube and cuvette with capillary tube of the present invention.

Figure 2 illustrates the perspective view of the cuvette.

Figure 3, shows a longitudinal cross section of the cuvette.

Figure 4,4(a), illustrates a perspective view and cross sectional view of the cap.

The foregoing description is outlined rather broadly preferred and alternative feature of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing and modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should realize such equivalent conception do not depart from the spirit and scope of the invention in its broadest form.

Detailed description:

The apparatus I-heme of the present invention works on the photometric principle of absorption. The light emitted by an LED (light emitting diode) is passed through the cuvette containing biological sample and then measured by the photo-detector.

The concentration of HGB (color of the sample) is directly proportional to the light energy absorbed by the photo-detector.
The apparatus is used for the quantitative determination of Hemoglobin concentrated in the human blood using capillary or Venous blood. It is an open system, Hb Analyser for Clinicians, Clinical laboratories, Blood Banks, Intensive Care limits and wherever instant Hb determination is required.

Measuring Procedure : Optical absorption photometer

Light Source : Green LED 565 tun

Detector : Photo diode 420 to 670 nm

Measuring Range : 2 to 27 g/dl

Specimen : Capillary blood/venous blood

Cuvette : Borosilicate Glass Cuvette.

Sample Volume : 10 l

Reagent Volume : 2.5 ml

Measuring Time : 2 sec

Power Supply : 230AC/50-60Hz

Power consumption : 5 VA

Dimensions : 2.55mm x 120mm x 80mm

Weight : 1.65 Kg.

The apparatus is designed to measure Hb from a blood sample of 10 µl using a Capillary which is calibrated to accurately aspirate l0µl. A capillary is packaged along with the instrument.

The Cuvette for the apparatus is provided for analysing the solution from a sample collected in a capillary. The capillary filled with biological sample, particularly blood has to be dropped into the cuvette containing 2.5ml of reagent and mixed by shaking. The user also needs to make sure that the Capillary settles down in the bottom shaft to avoid obstruction in the reading path. Each cuvette comes fitted with a rubber cap. The cap should remain on during mixing and reaction time.

ADJUSTABLE LANCING DEVICE
1. Depth Adjustment Cap,

2. Lancet Holder.

3. Cocking Control,

4. Release Button

Lancet Protective Cap.

LOADING THE LANCET DEVICE

a. Remove the Dept Adjustment Cap and load the lancet into the holder. Make sure it is fully seated.

b. Remove the protective cap of the Lancet twisting.

c. Replace the Depth Adjustment Cap and set it at the appropriate number (Higher the number, deeper the puncture)

d. Pull back the cocking mechanism till you hear a click. Press the release button for piercing.

DISPLAY AND KEYBOARD

i-heme has a 16 Channel, Single Line Back lit LCD display. The Keyboard of i-heme has two keys

1. Cal/Blank

2. Reset.

REAGENTS

The apparatus is an open system and is compatible with all commercially available Cyanmethaemoglobin reagents available in the market. The instrument needs to be calibrated for each reagent for the first run. i-heme has been successfully evaluated on several brands of Cyanmethaemoglobin reagents commercially available in the market with following specifications.

CALIBRATION

To re-calibrate the machine the user has to enter the new standard value and then read one blank tube followed by five runs of calibrators or standards. Step-by step procedures for calibration is as follows.

a. Ensure i-heme is Switched Off and no tube is present in the reading cell.
b. Keeping the BLANK/CAL key pressed, Switch On the i-heme.
c. Wait for the display message "STANDARD MODE" before releasing
the BLANK/CAL Key.
d. On releasing the BLANK/CAL Key, i-heme will request the user to
enter the standard value with the display showing "Enter The STD"
e. The cursor will be blinking on the left extreme digit.
f. Press BLANK/CAL Key for changing the digit from 0 to 9.
g. Use RESET Key to move the cursor to the next digit,
h. Pressing RESET on the last digit will store the value.

i. The machine will now ask the user to insert the blank tube by
displaying READ BLANK,
j. Once the user inserts the blank tube in the reading cell, the Blank value
is stored,
k. Once the tube is removed, the user will be asked to read the standard 5
times.
1. The user can choose to read standard prepared in 5 separate tubes or
reading same standard tube 5 times,
m. Each time the user insert the standard tube, the machine will display
READ STD (value entered by the user) #1-5
n. After the 5* standard is read and the tube removed, the display will
show "FACTOR STORED" followed by "Switch Off'
o. The user has to switch off the machine.

RESET CALIBRATION

a. Ensure machine is Switched Off.
b. Keeping the RESET key pressed. Switch On the i-heme.
c. The display will show "Resetting"
d. Release the RESET key at once.
e. Now the i-heme is reset to default (factory set) calibration.

OPERATION

Switching On and Blanking.

a. Make Sure there is no tube present in the reading cell. If i-heme is switched on with a cuvette in the reading cell "Remove Tube" message will be displayed.

b. Re-calibrate the machine if the reagent brand is changed.

c. Switch on the machine and ensure there are no error codes on display.

d. Allow the machine to read the "Air" and wait for the machine to get ready by prompting "READ BLANK TUBE"

e. Insert Blank tube (cuvette filled only with reagent), then instrument will store the absorbance of the blank reagent and will be automatically subtracted from the absorbance of subsequent sample tubes.

Re-blanking

While in run the samples for re-blanking the instrument, Press BLANK/CAL key. i-heme will prompt to "READ BLANK TUBE". Insert a new Blank tube (cuvette filled only with reagent) to set the new baseline absorbance for the blank reagent.

Sample Preparation

i-heme is designed to measure Hb using.
a. Capillary sample
b. Venous sample.

CAPILLARY SAMPLE

a. Make sure the finger of the patient is properly disinfected before pricking. Using the Lancet device and Lancet provided with the instrument, prick the finger of the patient. Press and wipe away
first drop of blood on the finger.

b. Take a capillary which was supplied along with the instrument, press gently once again and hold the tip of the capillary in the middle of the blood drop. Let the capillary fill in one step.
c. Using a tissue wipe any excess blood stuck outside the capillary outer wall to ensure accuracy of the sample volume of lOp.1.

Venous Sample

a. Collect the venous sample in an appropriate sample tube and allow it to mix with the anti-coagulant.

b. Pipette a drop of blood on a non-absorbent material like a glass slide or ceramic tile.

c. Take the capillary which was supplied with the instrument and hold the tip of the capillary in the middle of the blood drop. Let the capillary fill in one step.

d. Using a tissue wipe any excess blood stuck outside the capillary outer wall to ensure accuracy of the sample volume of 10µl.

PREPARATION OF SAMPLE TUBE AND READING

Dispense 2.5ml of reagent in to a clean cuvette using the Micropipette provided along with i-heme (please follow the enclosed instruction sheet from the Pipette manufacturer)
a. Drop the capillary into the prepared cuvette, cap the cuvette and mix by inverting 2 or 3 times.

b. Incubate the tube for 5 minutes at room temperature (20C To 30C)

c. Insert the cuvette into the reading cell of the i-heme and note the result from the display.

The cuvette is used for analysing a sample of any body fluid, such as whole blood, plasma, serum or urine. However, in the following description, reference will be made only to analysis of a sample of whole blood. A person skilled in the art would be able to implement analysis of other body fluids based on the description below.

The reagent for analyzing the biological fluid is selected depend upon the sample to be analyzed which already known in the prior art. The closing means is a cap madeup of any suitable material used in the art.

According to the present invention, a cuvette for holding body fluid sample for analysis comprising: an inlet cavity (1) for allowing body fluid sample to be analyzed into the cuvette; a measurement cavity (2) provided with predetermined test reagent and liquid sample (8) contained therein through which the electromagnetic energy is passed comprising a first side (9) through which the electromagnetic energy enters and a second opposite side (10) through which the electromagnetic energy leaves; reception cavity (3) to receive the capillary tube (4) containing body fluid sample is a down-gradient towards the closing end (5) from the measuring cavity (2) of the cuvette; closing means (6) to close the cuvette when the capillary tube (5) containing body fluid dropped into the cuvette for analysis need to be mixed thoroughly.

The diameter of the inlet cavity (1) for allowing body fluid sample to be analyzed into the cuvette is between 8mm and 13mm.

The diameter of the measurement cavity (2) is between 7mm and 15mm; length is between 30mm and 90mm.

The thickness of the first side (9) through which the electromagnetic energy enters and a second opposite side (10) through which the electromagnetic energy leaves of the cuvette is between 0.3mm and 1.5mm.

The diameter of the reception cavity (3) is between 2mm and 10mm; the length is between 15mm and 50mm.

A method of performing an analysis using the cuvette will now be described. A sample of whole blood is drawn into the cuvette. The sample may be acquired directly from a pricked finger. Thus, the blood sample may be acquired very easily causing practically no pain to a patient with the help of the l0µ micropipette. The blood containing l0µl micropipette is dropped into the cuvette filled with reagent and the inlet cavity is closed with closing means. The cuvette is mixed thoroughly and kept aside in the room temperature for about 5 minutes. The cuvette is then placed in the spectrophotometer or colorimeter for taking the reading.

Figure 1, illustrates the prior art cuvette with capillary tube and cuvette with capillary tube of the present invention. The 10 µl micropipette used for drawing sample from the patient is accommodated within the reception cavity (3) of the cuvette so that the sample to be analyzed is measure through the measuring cavity (2) without any problem. The result obtained is consistent. It is very clear from the prior art cuvette and the cuvette of the present invention which is superior and gives accurate results.

Figure 3, shows a longitudinal cross section of the cuvette. The diameter of the inlet cavity (1) for allowing body fluid sample to be analyzed into the cuvette is between 8mm and 13mm. The diameter of the measurement cavity (2) is between 7mm and 15mm; length is between 30mm and 90mm. The thickness of the first side (9) through which the electromagnetic energy enters and a second opposite side (10) through which the electromagnetic energy leaves of the cuvette is between 0.3mm and l.5mm. The diameter of the reception cavity (3) is between 2mm and 10mm; the length is between 15mm and 50mm.

Figure 4, illustrates a perspective view and cross sectional view of the cap. The cap is made up of any suitable material which is used for glasswares. The inlet cavity is closed with closing means when the blood containing 10µl micropipette is dropped into the cuvette filled with reagent. The cuvette is mixed thoroughly and kept aside in the room temperature for about 5 minutes. The cuvette is then placed in the spectrophotometer or colorimeter for taking the reading with or without cap.

claim:

1. A cuvette for holding body fluid sample for analysis comprising: an inlet cavity (1) for allowing body fluid sample to be analyzed into the cuvette; a measurement cavity (2) provided with predetermined test reagent and liquid sample (8) contained therein through which the electromagnetic energy is passed comprising a first side (9) through which the electromagnetic energy enters and a second opposite side (10) through which the electromagnetic energy leaves; reception cavity (3) to receive the capillary tube (4) containing body fluid sample is a down-gradient towards the closing end (5) from the measuring cavity (2) of the cuvette; closing means (6) to close the cuvette when the capillary tube (5) containing body fluid dropped into the cuvette for analysis need to be mixed thoroughly.

2. A cuvette as claim in claim 1, wherein the diameter of the inlet cavity (1) for allowing body fluid sample to be analyzed into the cuvette is between 8mm and 13mm.

3. A cuvette as claim in claim 1, wherein the diameter of the measurement cavity (2) is between 7mm and 15mm; length is between 30mm and 90mm.

4. A cuvette as claim in claim 1, wherein the thickness of the first side (9) through which the electromagnetic energy enters and a second opposite side (10) through which the electromagnetic energy leaves of the cuvette is between 0.3mm and 1.5mm.

5. A cuvette as claim in claim 1, wherein the diameter of the reception cavity (3) is between 2mm and 10mm; the length is between 15mm and 50mm.

6. A cuvette as claim in claim 1, wherein body fluid are such as whole blood, plasma, serum or urine.

7. A method of performing an analysis for the body fluid using the cuvette comprising;

(i). drawing sample of whole blood using 10µl micropipette from a pricked finger;

(ii). placing the blood containing 10 micropipette into the cuvette filled with reagent (iii). Closing the inlet cavity with closing means; (iv). mixing the cuvette thoroughly for complete mixing of the sample and reagent and
kept aside in the room temperature for about 5 minutes; (v). placing the cuvette in the spectrophotometer or colorimeter for taking the reading.

8. A cuvette for holding body fluid sample for analysis such as herein described and exemplified.

9. A method of performing an analysis for the body fluid using the cuvette such as herein described and exemplified.