Blood Gas Analyzer

A short description and narrative on the blood gas analyzer machine made by undergraduates for a college assignment

1. Presentation By: Amr Ahmad Ahmed Abdelkarim Sodfa Ayman Ahmed Sadeq Khaled Essayed Blood Gas Analyzer

2. CONTENTS I. Introduction. II. The working principle. III. Components of the device (diagrams and explanation). Components of the device (in detail). Circuit Diagram for a device model. Comparison between device manufacturers. Service manual. Common faults and how to fix them. IX. References.

3. Blood gas analysis, also called arterial blood gas (ABG) analysis, and refers to the measurement of pH and the partial pressures of oxygen (O2) and carbon dioxide (CO2) in arterial blood.     Introduction I.

4. Introduction This device can be found in many departments around the hospital including, Respiratory department, Intensive care units, emergency rooms, operating rooms, and blood chemistry lab.   It is a very important tool in the diagnosis of many horrifying disease with high mortality for example: kidney failure: Estimates are that 2 million people worldwide suffer from kidney failure, and the number of patients diagnosed with the disease continues to increase at a rate of 5-7% per year. Mortality rates vary depending on the kidney failure treatment. After one year of treatment, those on dialysis have a 15-20% mortality rate, with a 5-year survival rate of under 50%. heart failure: An estimated 64.3 million people are living with heart failure worldwide. 17.9 million people die each year from CVDs, an estimated 32% of all deaths worldwide.

5. The ABG device has many sectors, each perform a different task than the other, to study how it works, we need to dive fairly deep into each one of these sectors.     The Working Principle II. Electrodes are used in blood gas/pH analyzers to determine the pH, partial pressure of carbon dioxide, and partial pressure of oxygen in the blood. A dry reagent pad system is used in chemistry analyzers, in which a filter pad impregnated with all chemicals necessary for a specific reaction is put on a thin plastic strip.

6. i . Power of Hydrogen (pH):

7. ii. Partial Pressure of Carbon Dioxide (CO2): The Severinghaus Electrode is the mainstay of carbon dioxide measurement from the arterial blood gas. It is essentially a pH electrode but contains the pH and reference electrodes within one device. The result takes a long time to determine (1 – 3 minutes) due to the prolonged equilibration, and calibration. (PaCO2 α [H+]).   𝐶𝑂 2 + 𝐻 2 𝑂 ⇌ 𝐻 2 𝐶𝑂 3 ⇌ 𝐻 2 𝐶𝑂 3 − + [ 𝐻 +]

8. ii. Partial Pressure of Carbon Dioxide (CO2):

9. iii. Partial pressure of oxygen (PaO2): The partial pressure of oxygen in blood is measured using an electrode. The principle is that a certain number of O2 molecules within a salt solution will produce a current. Ohm’s Law is the governing principle: V = IR BUT, R (resistance) is constant, and thus: V α I Thus increasing [O2] results in a higher current produced.

10. ii. Partial Pressure of Oxygen (O2):

11. Calculated Values: As for the main calculated values that are deduced from these three parameters and the entered data: 1. Bicarbonate Value (HCO3-): HCO3-(P) includes ions of hydrogen carbonate, carbonate and carbamate in the plasma. It is calculated from the Henderson Hasselbalch equation which is shown in the next slide. The ABG machine rearranges this equation in order to derive an actual bicarbonate concentration from the pCO2 and pH measurements. The reference manual for the local unit does not elaborate on how the constants were selected uses a slightly simpler equation:   HCO 3 -  = 0.03 × pCO 2 × 10 (pH- 6.1)

12. Bicarbonate Value:

13. Calculated Values: 2. Partial Alveolar Oxygen (PAO 2 ): The alveolar gas equation is of great help in calculating and closely estimating the partial pressure of oxygen inside the alveoli. The alveolar gas equation is used to calculate alveolar oxygen partial pressure:   P a O 2 = ( P atm - PH 2 O) FiO 2 - pCO 2 / RQ The value of inspired oxygen fraction concentration (FiO2) needs to be fed into the machine. And RQ is the amount of CO2 liberated per minute divided by amount of O2 utilized per minute. Normal values are 200 ml/250 ml =0.8. 3. O2 sat: Proportion/percentage of hemoglobin which is saturated with oxygen. To calculate this parameter, the hemoglobin value must be either entered to the device or calculated by a separate internal module.

14. Calculated Values: 4. Base Excess (BE), Base Buffer (BB): BE refers to actual base excess in variance from (above or below) total buffer base (BB). Normal BB is 48-49 mmol/L. If BB is 40, it means buffer base is reduced by nearly 8 Deorari , AIIMS 2008 12 mmol/L, or BE is –8 (also called base deficit). If BB is 60, it means buffer base is increased by nearly 12 mmol/L, or BE is +12. BB is dependent on hemoglobin, as 25% of BB is constituted by hemoglobin buffer. Fifty percent of BB is contributed by bicarbonate and 25% by other buffers (proteins, phosphate, sulphate).

15. III. Components of the device (diagrams and explanation): Size, power consumption, pricing, and convenience of use are all key factors to consider when entering atypical markets, the instruments must be Small enough to fit on benchtops. They must be tuned for battery operation if they are portable. They should also be affordable to allow point-of-care providers to get them, as well as adaptable enough to do various tests for greater cost efficiency.

16. Design Testing adaptability improves the device's cost-effectiveness. - and Most blood gas analyzers feature many sensors that are sent to an analogue-to-digital converter (ADC). through an amplifier multiplexer. The data is processed in the microcontroller, which is linked to a PC or other instruments through RS-232, USB, or Ethernet. A digital-to-analogue converter (DAC) is often used to calibrate sensor amplifiers to enhance electrode sensitivity.  

17. Main Block Diagram for The Device:

18. Block Diagram

19. IV. Components of the device (in detail):

20. Sensors

21. Electronic Unit and Vacuum Pump Electronic Unit Vacuum Pump

22. V. Circuit Diagram for a Device Model:

23. Micropower Electrochemical Gas Sensor Amplifier Reference Design

24. Low Power Fully Differential Programmable Gain Amplifier Reference Design:

25. Miniaturized Pulse Oximeter Reference Design:

26. VI. Comparison Between Device Manufacturers as a table .

27. Comparison Between Device Manufacturers Manufacturer Flagship Model Features Measured Parameters Siemens (German) RapidLab1200 (Benchtop). Testing panels can be customized to meet specific needs Capable of running the full test menu on short-sample patient draws (microsamples). Extensive test menu includes full CO-oximetry and neonatal total bilirubin Ready Sensor® electrode technology for industry-proven reliability Cost-effective, cartridge-based system Simplified operation with biosafe sampling Automatic quality control and documentation Seamless integration with your LIS/HIS Dedicated technical support and on-site service Ultra-fast sample processing enables immediate physician intervention Clinical accuracy reduces the need to repeat tests Microsample capability enables testing of very small sample volumes without compromising accuracy Full test menu from a single sample Get a complete picture in just 1 minute. Blood Gas (pH, pCO2, pO2). Electrolytes (Na+, K+, Ca++, Cl-). Metabolites (Glucose, Lactate, Neonatal Total Bilirubin). CO-oximetry ( tHb , HHb , O2Hb, sO2, COHb , MetHb ). Abbott Laboratories (American) i -Stat Alinity (Handheld). A robust, award-winning, user-friendly design. High-resolution color touchscreen and large touchscreen enables simple, intuitive navigation. Ergonomic design makes use balanced, comfortable, and secure. Audio, color & light cues signal to operator completion of test results. Robust construction for fast-paced environments; built with materials that can resist damage. High-resolution camera captures 2-D barcodes with picture ID Rechargeable battery designed to be easy to attach and remove. acid-base, blood gas, electrolyte, chemistry, and hematology.

28. F Hoffman La Roche (Swiss) Cobas b221 (Benchtop). Results in less than 2 minutes to support timely clinical decision making. Comprehensive parameter menu to meet varying department needs. Long-life, maintenance-free electrodes and minimal preventative maintenance Control reagents consumption Blood gases (pH, pO2, pCO2, pH) / Co-oximetry Electrolytes (Na+, K+, Ca2+-) / Hematocrit Metabolites (Glu / Lac) Metabolites (Glu / Lac / Urea (BUN)) Bilirubin Medica Corporation (American) EasyBloodGas Medica’s EasyBloodGas is designed to meet the laboratory’s need to deliver sample results economically. Compact electrode design and precise control of calibrator volumes ensure economical operation and a low cost per sample. pH, PCO2, and PO2 and calculates 11 additional parameters. Patient parameters, including FIO2 and Hb, can be entered using the digital keypad. Danaher Corporation (Radiometer) (American) ABL90 Flex Plus (Portable) The ABL90 FLEX PLUS analyzer gives you reliable results in only 35 seconds on 17 parameters – blood gas, electrolytes, metabolites, and co-oximetry – from a syringe, capillary tube, or test tube. All on one blood sample of only 45 µL. Blood gases: pH, pCO2, pO2 Metabolites: cGlu , cLac Electrolytes: cCa2+, cCl -, cK +, cNa + Oximetry: FCOHb , ctBil , ctHb , FHbF , FHHb , FMetHb , sO2, FO2Hb Comparison Between Device Manufacturers:

29. Instrumentation Laboratory (American) Gem Premier 5000 (Portable) potential errors are detected not only before and after, but also during sample analysis, along with real-time correction and documentation. Plus, it’s simple—just change the all-in-one GEM PAK once a month. So regardless of testing location or point-of-care operator, quality results and compliance are assured with every sample on the portable GEM Premier 5000 system. pH, pCO2, pO2, Na+, K+, Cl-, Ca++, Glu, Lac, tHb, O2Hb, COHb, MetHb, HHb, sO2, tBili or any combination of Electrochemical* analytes and CO-Oximetry** and/or tBili tHb, O2Hb, COHb, MetHb, HHb, sO2, tBili and/or tBili Nova Biomedical (American) Stat Profile pHOx ultra 20 critical care tests from one small, 210-microliter sample in only 2 minutes. Other partial test panels are available in less than one minute pHOx Ultra can be custom configured with as few as 5 tests to as many as 20 tests to satisfy the exact test menu requirements of each department Measured SO2%, Hb, and Hct on Each Sample Without CO-Oximetry Optional On-Board CO-Oximeter pH, PCO2, PO2, SO2% Na, K, ,iCa , iMg, Cl, Glucose, BUN/Urea, Creatinine, Lactate, Hct, Hb, O2Hb, HHb, COHb, MetHb, and tBil. Erba Mannheim (German) EBG Stat 820/1020 Simple 3 step operation Results in 60 seconds Zero maintenance True liquid quality control Controls run automatically at by the user selected intervals. Low running costs Lithium heparinized whole blood (arterial, venous, or capillary blood) 100 µl of whole blood for full menu Up to 10 measured parameters (pH, pO2, pCO2, Hct , Na, K, Cl, iCa , Glu, Lac)   20 calculated parameters (SO2%, HCO3- , TCO2, BE- ecf , BE-b, SBC, O2Ct, O2Cap, A, AaDO2, a/A, RI, P50, PO2/FIO2, Hb, anion gap, nCa , temperature corrected pH, PO2, pCO2) Comparison Between Device Manufacturers:

30. Comparison (Market Share):

31. VII. Service Manual: The calibration is performed using high precision standard solutions and gravimetrically prepared gas mixtures to determine the cassette’s measurement characteristics at multiple points within the analyte’s measurable range. Every cassette package is then labeled with a bar code containing this calibration information During the calibration and measurement processes, diagnostic tests are automatically performed to assure correct operation measurement of the cassette.

32. Types of Blood Gas Analysis calibration: Calibration before analyzing the sample:   calibration is a possible source of analytical error. Blood gas instruments must be periodically calibrated using known value samples. A one-point calibration is required at least every 30 minutes and a two-point calibration is required at least every 8 hours A test of linearity also is required at least twice a year. Failure to assure proper calibration within the required time of running a sample can result in inaccurate results being produced and reported    2. Calibration after corrective maintenance: after corrective maintenance we found an error in the results of blood gas analyzer to adjustment the error verifying the value of potentiometer and measure the volt on it to calibrate the blood gas analyzer.

33. Types of Calibration 3. Calibration for electrodes   Calibration of an electrode involves contacting the electrode with at least two standard solutions or gases having known concentrations of the substance being analyzed the electrode provides an electrical response that is used to generate a calibration slope. The electrode then is contacted with the blood sample, generating electrical respons , Electrodes in blood gas analyzers are calibrated periodically because the response provided by an electrode for a particular sample tends to drift (vary) with the passage of time.  

34. Maintenance of the analyzer Care and Maintenance The system needs little care and maintenance. Clean and maintain it periodically to ensure its optimum performance. Cleaning and Disinfecting the Exterior Surfaces Clean and disinfect the exterior surfaces to remove dust, splatters, blood, etc. Policies regarding the cleaning and disinfecting intervals are at the discretion of your individual institution.   Following the procedures below to clean and disinfect the exterior surfaces: 1. Turn off the analyzer. 2. Disconnect the power cord and the power adaptor. Disconnect the connecting cables if the system is connected to other pieces of equipment. Dampen a lint-free cloth with 0.5% sodium hypochlorite solution.

35. Preventive Maintenance The following safety checks should be performed at least once every 24 months by a qualified person who has training, knowledge, and practical experience to perform these tests. Inspect the analyzer and accessories for mechanical and functional damage. Inspect the safety related labels for legibility. Verify the analyzer functions properly as described in the instructions for use. If the analyzer is not functioning properly or fails any of the above tests, it has to be repaired. It is recommended by the manufacturer to perform the preventive maintenance every 4 months

36. VII I . Common Faults and How to fix them: 1-Out-of-date buffer solutions. 2-No calibration gas. 3- Bad electrode. 4- Poor Flushing 5-blood clotting in the sample tube

37. How to fix the faults The analyzer is easy to maintain, with up to 30 days (about 4 and a half weeks) in- use lifetime of consumables. You can customize pre-warnings, and easily reuse tests from one consumable. (2) We describe a new instrument that performs on-site mixing of oxygen (O2), carbon dioxide (CO2), and nitrogen (N2) to create compositions that can replace gases from standard premixed cylinders. (3) Switch with a new electrode . (4) Sterilization is done after each test procedure. (5) adding Heparin or water to sample tube

38. Cartlidge of the device A picture of Cartlidge of the device which contains gases and prop which takes the sample and blood pass through the small tube in the photo, and the roller in the photo is responsible for the prop mechanical movement

39. THANK YOU