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  • 1. HELWAN UNIVERSITY FACUILITY OF ENGINEERING BIOMEDICAL DEPARTMENT Presented By: FATMA KAMAL HEBA ABD ELSABOUR MAGAD AHMED NASHWA ADEL SUPERVISORS: DR.Mohamed Eldsoky Eng .Ahmed mostfa
  • 2. *Definitions *Types of measurements *Component *Technical specifications
  • 3. -Electrolytes are positively and negatively charged molecules called ions, that are found within the body's cells and extracellular fluids, including blood plasma. -Electrolytes play multiple roles in the maintenance of body functions: 1-They sustain osmotic pressure which related control fluids distribution in the body (related level). to sodium level
  • 4. 2-Maintain proper body Ph . 3-Regulate the function of the heart and other muscles. 4- Assist in electron transfer reactions. 5- Participate in enzymatic reactions . Some of the disorders associated with electrolyte imbalances include:
  • 5. 1-Congestive heart failure. 2-Respiratory alkalosis (occurs when occurs 35), blood pH falls above 7.35 and acidosis 35). occurs( when blood pH falls below 7.35 3-Diabetes insipidus (water loss by the water kidneys). kidneys 4-Gastrointestinal and kidney diseases. 5-overhydrationn and dehydration. (When water loss is greater than intake, or When versa). vice versa
  • 6. -Doctors refer to a low electrolyte level with the prefix “hypo_” and to a high level With the prefix “hyper_”. -Because abnormal electrolyte levels can result from or cause various disorders, their analysis is a key factor in patient diagnosis and treatment. -Electrolyte Analyzers measure these electrolytes in serum, plasma and urine.
  • 7. ELECTROLYTE PANEL Electrolyte analyzers measure electrolyte concentrations in body fluids - typically whole blood, plasma, serum, or urine specimens. Electrolytes typically measured by an Electrolyte Analyzer are called the “Electrolyte Panel” which consists of: - Sodium (Na+) - Potassium (K+) - Chloride (CL+) -Bicarbonate(HCO3+)
  • 8. -Calcium, the most abundant mineral in the body, is also measured by many electrolyte analyzers. The concentration of ionized calcium (Ca++), total calcium, or both can be measured in the same body fluids as electrolytes. -Sodium is the principal extracellular cation and potassium the principal intracellular cation. A cation is an ion with a positive charge. Anions have a negative charge.
  • 9. AlD(1) Micro_ DC processor motor Peristlatic pump Any LCD Electrolyte AlD(2) REF. Bubble Detector
  • 10. 1-what analyte you want to measure ? The external reference electrode and measuring electrode are exposed to the unknown sample solution, potential of the sample solution is measured relative to the external reference. 2- Buffering the voltage generated by ion selective electrode by operational amplifier. 3- Analong multiplexer selecting signal.
  • 11. 4- An (AlD 1) converter for converting the signal into digital domain . 5- Micro-processor based computer control mechanical functions of the analyzer. 6- Digital display for showing results and displaying messages and questions 7- The motor driver turns drives D.C motor. 8- D .C motor drives the Peristaltic Pump
  • 12. 9-Bubble detector verifies the presence of air or fluid in the sample tubing. 10-An (AlD 2) converts the bubble detector reading into digital form to the computer.
  • 13. METHODS OF ELECTROLYTIC ANALYSIS 1-Flame Emission Photometry(FEP) 2-Ion Selective Electrode(ISE)
  • 14. Flame Emission Photometry Flame photometry can be used to measure Na+, K+, and lithium Li+ .This method is based on the fact that some metallic elements absorb thermal energy, exciting their electrons to a higher energy state .As the electrons return to the stable ground state, they emit photons light at wavelengths characteristic of the particular element and at intensities proportional to the element’s concentration.
  • 15. The concentration of the test solution is determined by comparing its signal with that obtained for standard solutions.
  • 16. There is a different colored filter for - each analyte measured -The output of the photo-detector is directly proportional to the concentration of the analyte being measured. -The brighter the flame (in that in wavelength), wavelength the greater the concentration of the analyte
  • 17. -There is a different colored filter for each analyte measured. • Sodium is yellow with a wavelength of about 590 nm • Calcium is red with a wavelength of about 640 nm • Potassium is blue with a wavelength of about 490 nm
  • 18. • Lithium is dark red with a wavelength of about 710 nm The output of the photodetector is - directly proportional to the concentration of the analyte being measured -The brighter the flame in that wavelength, the greater the concentration of the analyte Each analyte emits a specific color when burned.
  • 19. Reported problems Flame photometry measurements can be compromised when insufficient attention is paid to maintenance procedures, optimal flame size, and aspiration rate .In addition, a warm-up period is usually required to stabilize the system .Because of the gas used to fuel the system, flame photometry systems should be used in a well-ventilated area.
  • 20. Problems can arise when results from methods using direct measurements undiluted specimens are compared with those from methods using indirect measurements diluted specimens .Flame photometry provides an indirect measurement of total concentration, particularly in Na +and K +analyses, while ISE methods provide direct measurements of activity .
  • 21. Because hyperproteinemic or hyperlipidemic specimens have decreased amounts of plasma water, indirect measurements can yield falsely lowered results. Direct methods are not subject to this type of error.
  • 22. Ion-Selective Electrodes (ISE)
  • 23. Principles of operation This method measures the voltage that develops between the inner and outer surfaces of an ion selective electrode. Most electrolyte analyzers use ISE methodology in which measurements of the ion activity in solution are made potentiometrically using an external reference electrode and an ISE containing an internal reference electrode .
  • 24. The external reference electrode and ISE are exposed to the unknown sample solution, and the potential of the sample solution is measured relative to the external reference As the specific ions under .electrode analysis are selectively bound to the ISE, the internal reference electrode detects the potential difference between an internal filling solution and the sample solution potential
  • 25. between the external reference electrode and the ISE, which is a function of the specific ion’s activity concentration, is amplified and liter L displayed in millimoles per liter The ISE system is calibrated with solutions containing known concentrations of analytes; the concentration of an unknown solution is derived by comparing its potential with that of a solution of known concentration .
  • 26. Samples can be diluted before analysis “indirect method” or analyzed without dilution “direct method.” Different types of ISEs provide measurements for specific analytes .The Na-+sensitive electrode is made of glass specially formulated to provide high selectivity for Na .+The K-+sensitive electrode consists of polyvinyl chloride PVC impregnated with valinomycin, an antibiotic that is selective for K .+The Cl-- sensitive
  • 27. electrode consists of a liquid membrane containing quaternary amines, which are selective for chloride ions, in a PVC support .A calcium ISE uses an ion selective calcium sensor that consists of either a neutral membrane PVC impregnated with uncharged calcium selective organic molecules dissolved in a plasticizer or a negatively charged membrane PVC impregnated with an organophosphate.
  • 28. Some errors observed when using ISEs occur because of proteins coating the membranes, lack of selectivity , or contamination with ions that compete with selected ion. Calibration standardization has been recommended to minimize deviations among different ISE analyzers.
  • 29. -Reagents -Electrode Module -Peristaltic Pump -Sample Probe -Waste Chamber
  • 30. ELECTROLYTE ANALYZER COMPONENTS 1 -Reagents • Refers to the Cal and Slope standards and the Wash solution. • Cal and Slope solutions are two calibration fluids of different concentrations used during a Two Point Calibration more on that later.
  • 31. • Wash solution may also be referred to as a flush or rinse solution and does just what it implies, it cleans and rinses the tubing after each analysis. 2 -Electrode Module • Also referred to as a Flow Cell or Electrode Train. • Houses the: -Air/fluid detector -Measuring electrodes -Reference electrode
  • 32. *Air Fluid Detector • Located at the entrance or exit of the Electrode Module. • Verifies the presence of air or fluid in the sample tubing. – A small light source shines through the tubing into a photodetector. –The photodetector is monitored by the μP which monitors the air/fluid detector so it knows when to start and stop.
  • 33. Reference Electrode • Supplies a continuous electrical potential that is used as a reference to measure the electrical potential produced by each ISE. • Constant 756 mV potential
  • 34. 3-Peristaltic Pump • Pushes the reagent fluids and patient sample through the tubing to the sample probe and Electrode Module out to the waste bottle. • Fluid is drawn into the analyzer as the flexible tubing is pressed by the rollers of the pump and drawn through the tubing via the squeezing action of the rollers on the tubing.
  • 35. • Peristaltic Action Flexible Rubber Tubing 4-Sample Probe • Aspirates fluids into the analyzer via the peristaltic pump. • The probe accepts fluids in the STAT position up or Automatic position down.
  • 36. -Performed with the probe in the up position -The probe accepts a handheld sample for a single analysis.
  • 37. - Performed with the probe in the down position. -The probe automatically accepts samples from a test tube or a cuvette in a tray or carousel. -This is the position of the probe during normal operation.
  • 38. TWO POINT CALIBRATION -A ‘Two Point Cal’ is a full calibration usually run on a daily basis that establishes the calibration and slope for each electrode. -Two standards of known analyte concentrations are analyzed. -Each electrode measures the analyte concentration in both standards in order to obtain the electrode’s slope curve.
  • 39. ONE POINT CALIBRATION -Used to monitor and correct the instrument for electrode drift. • Electrode drift is a gradual change in electrode potential that can adversely affect electrode performance. -Normally performed prior to every analysis and involves just running the cal standard through the instrument.
  • 40. Very important The electrolyte analyzer must match the facility’s present and future testing requirements and performance needs Several performance features can be used to assess accuracy and reliability, including the following:
  • 41. • Analytical range. The concentration range over which an instrument can measure a particular Analyte. Purchasers should check these values carefully under conditions in their own laboratories because actual ranges may vary significantly from those stated by the manufacturer
  • 42. • Linearity. The linearity of an analyzer determines how accurately the unit can measure analyte concentration over a certain concentration range as determined against a given control or standard. Instruments with large linear ranges can analyze samples with awide range of analyte concentrations without diluting or manipulating them in any way. This feature provides a faster turnaround of results and may save operator time if dilutions must be manually performed.
  • 43. • Specificity. This is the ability of an instrument to measure only the analyte selected. In electrochemical analyzers, this is a function of electrode design and construction • Precision .A high degree of precision, which is a measure of how closely a test result can be reproduced, not only provides a more sensitive determination of changes in the patient’s condition,
  • 44. but also reduces the need for duplicate testing to verify the accuracy of initial test results .Precision is expressed numerically in terms of the coefficient of variation CV, with a small CV indicating a highly precise instrument. • Stability. Analyzers that give readings with a high degree of precision for extended periods of use have very stable calibration curves. These units may be less costly to operate than analyzers with more labile curves because.
  • 45. they do not require recalibration as often; the unit thus uses less buffer and control and runs fewer non patient analytical tests • Carryover .Residue left over on an ISE from a previous sample is called carryover .This results from incomplete cleaning of the electrode with the wash solution .Carryover can cause erroneously higher or lower readings in samples and result in unnecessary duplicate testing.
  • 46. • Downtime .Downtime occurs when the analyzer is undergoing routine maintenance or is shut down for troubleshooting and repairs .A unit that requires frequent maintenance or has a poor reliability record cannot consistently handle a normal workload and will cost the laboratory money to service (even with a good service contract )and to compensate for lost testing revenue .Under these circumstances, a reliable backup analyzer is a necessity.
  • 47. Technical features • Equipment Interface 4 line, 128 × 64 dots LCD display with backlight and three keys. • Analysis principle Direct “Flow Thru” Ion selective electrodes (ISE). • Sample volume 100μl . • Sample type Whole Blood, Serum, Plasma, Urine. • Sample Application From Syringe, Sample Cup, Capillary or Collection Tube.
  • 48. • Throughput 60 samples/hour without printout, 50 samples/hour with printout. • Calibration Automatic two-point calibration with additional option for carrying out one-point and two-point calibration manually.
  • 49. • Normal Reference Range Users can adjust reference range for all parameters according to their requirements. Flagging of abnormal samples provides easier analysis. • Display 128 × 64 Dot LCD display with backlight. • Printer Built in Stationary Head Graphical Thermal Printer.
  • 50. • Storage Capacity Patient Result: 250 samples. • Interface port RS 232 Interface. • Power Voltage: 165-250 V, 50 Hz; Power < 35VA. • Dimensions 300(H) × 350(W) × 230(D) mm. • Weight 6 Kg approx. • Operating environment. • Temperature 15° to 40°C. • Relative humidity 20%~ 80%.