automation

• Automation


  Started with the ingenuity of the Coulters
• Wallace H. Coulter


  • 1913-1998
• Joseph R. Coulter, Jr


  • 1924-1995
• Coulter Principle


  Used to count and size the different blood cells
• One principle that hematology analyzers employ during the analysis of blood cells
• Automation in Hematology was developed
• Why do we employ analyzers in Hematology?

  • Cell counting
  • Diagnosis of hemoglobinopathies
  • Immunophenotyping
  • Diagnosis of Leukemias and Lymphomas
  • Coagulation abnormalities

  
• Paroxysmal nocturnal hemoglobinuria


  • Complement system
  • Anemia caused by a deficiency in CD55 and CD59
• How to detect paroxysmal nocturnal hemoglobinuria

  1. Perform phenotyping

  2. Detect the presence of CD55 and CD59

  3. If the results confirm there is deficiency of CD55 and CD59, the doctor can make a diagnosis then and there with that information

  4. No further tests needed to concretize the diagnosis

  5. One simple immunophenotyping - the doctor can already make a diagnosis

  
• Advantages of Automation


  • Speed and efficient handling of samples
  • Greater Accuracy and Precision
  • Multiple tests on single platform
  • More efficient workload and management
  • More timely diagnosis
• Speed and efficient handling of samples

  • With automated machines, what MedTechs do is to load the sample in the machine, press the enter button for the machine to start the analysis
  • Limited - the person who will receive the sample from the phlebotomist will be the same person who will label the sample and load the sample on the machine
  • Chain of custody will only be for one person - the sample was not passed from one person to another
  • In 1 minute, the machine is able to process the sample the was loaded
• Greater Accuracy and Precision

  • Perform quality control and assurance on the machine in order to maintain its accuracy
  • Errors are prevented with the use of automated machines
• More efficient workload and management


  • Since one machine does the job
  • Medical technologists will still have to monitor the machine and should not rely solely
  • If the machine gives a notification that something is wrong with the sample processed, there is a need for the MT to do a manual analysis of the sample
• More timely diagnosis


  Lesser turnaround time
• Disadvantages of Automation


  • Flagging of machine
  • RBC morphology limited
  • Erroneous results
  • Expensive
• Advantages outweigh the disadvantages
• Hematology labs employ automation
• There are a lot of possibilities
• Studies have shown that with automation machines, there is less error vs manual performance
• Semi-Automated Hematology Analyzers


  • Measures only few parameters
  • Some steps like dilution is carried out manually
• Fully Automated Hematology Analyzers

  • All of the steps during analysis are performed by the machine itself
  • Measures multiple parameters
  • Requires only anticoagulated blood samples
• Basic Components of Hematology Analyzer

  • Hydraulics
  • Pneumatics
  • Electricals
• Hydraulics


  • Mixing Chambers
  • Aperture baths/Flow cell
  • Hemoglobinometer
  • Aspirating unit
  • Dispensers
  • Diluters
• Pneumatics


  Vacuums and pressure for operating valves and also to move the samples among the hydraulics
• Electricals


  • Analyzers and computing circuitry
  • Responsible to do the analysis and then the calculation, and also the reflection of the sample of the result generated
  • Will be able to control the operational sequences of the total system
  • Has an algorithm on how to analyze and process the data during analysis of the blood samples/ blood cells
• Electrical Impedance


  • Makes use of the Coulter Principle
  • Detection and measurement of changes in electrical resistance produced by cells as they traverse a small aperture
• Aperture Bath


  • Where the sample is suspended
  • Solution is composed of electrically conductive diluent
  • There is a flow of electric current within the solution
  • 2 chambers filled with a conductive buffered electrolyte solutions separated by glass tube having a small aperture
  • Direct current is generated between the internal and external electrode
  • Aperture for RBC/platelet is smaller than the WBC aperture
• Aperture tube


  • Has the aperture where the cells pass through
  • Sensing zone detects/does the analysis of the blood cell that passes through here
  • Internal And external electrode
• Electrical Impedance


  • Our cells are poor conductors of electricity; they impede electrical current/ resist electrical current
  • As the cell passes through the sensing zone in the aperture, it resists/impedes the electrical current and the resistance / electrical current creates a voltage pulse
• Voltage pulse


  • The height of the pulse is equivalent to the volume of the cell
  • The higher the voltage pulse, the higher the volume of the cell
  • The number of pulses generated is equivalent to the number of cells being counted/analyzed by the machine
• Oscilloscope


  • The voltage pulses will be gathered by the Oscilloscope
  • The height of the pulse is equivalent to the volume of the cell
  • Higher pulse, higher volume
  • Number of pulses is equivalent to the number of cells analyzed in the machine
  • The pulses will be gathered and sorted out so they will be plotted into the histogram
• Histogram


  • X axis - volume of the cell
  • Y axis - number of the cell
  • Pulses gathered together according to their volume
  • The height of the histogram corresponds to the number of cells on that particular volume

  
• Threshold Discriminator


  • The machine is set to identify a particular cell based on a treshold volume
  • Any particles measured by the machine that has a volume of 2-30 fL will be discriminated by the machine as platelets
  • For other blood cell types, there will be threshold limits
• Hydrodynamic Focusing


  • Provides a sample stream surrounded by a sheath fluid as cells pass through the aperture
  • Allows the alignment of cells into a single-file passage through the sensing zone
  • Prevents coincident passage of cells
  • Prevents recirculation of cells back to the sensing zone
• Different Variables Measured by Electrical Impedance

  • RBCs: RBC Count, MCV, Size distribution histogram, RDW, Hematocrit, MCH, MCHC
  • WBC: Total Count, 3-part differential, Lymphocytes Mononuclear Cells, Granulocytes
  • Platelets: Platelet Count, Platelet histogram, Mean Platelet Volume, Platelet distribution Width
• Radio Frequency


  • Incorporated with another principle
  • Application of high voltage electromagnetic current flowing between electrodes
  • Application of another current that is in the form of Radiofrequency current
  • The RF signal's purpose is to analyze the Internal complexity of the cell
• Radio Frequency and Direct Current

  • The direct current/ electrical impedance is the one the analyzes the volume of the cell
  • The RF signal's purpose is to analyze the Internal complexity of the cell
  • With the incorporation of the RF, the internal structures of the cell are analyzed the same time with DC
• Optical Light Scatter


  Involves light scattering

  
• Electrical impedance


  The basis is the volume of the cell
• Mainly because of the volume


  But how are we sure?