Medical Physics Concepts

Terminology

• Terminology is the science of terms.

Physics

• Physics is the science of nature.

Medical Physics

• Medical physics is a term that overlaps two fields: medicine and physics.
• It involves the study of physical parameters in the body, such as:
  • Pressure
  • Force
  • Energy
  • Power
  • Electricity
• It also involves the study of physics in body organs and systems, including:
  • Vision
  • Hearing
  • Skeletal system
  • Pulmonary system
  • Cardiovascular system
  • Nervous system

Applications of Physics in Medicine

• Laser in medicine
• Sound and ultrasound in medicine
• X-rays
• Computed tomography (CT) scanner
• Magnetic resonance imaging (MRI)
• Electrocardiography (ECG)
• Electroencephalography (EEG)
• Electroretinography (ERG)
• Radioisotopes
• Positron emission camera (PEC)
• Gamma (γ) and camera in nuclear medicine and radiotherapy

Biomaterials in Medicine

• Artificial bones
• Lenses
• Lasik used in ophthalmology
• Pacemakers and stents used in cardiovascular diseases
• Grafting materials and nerve conduits

Units in Medicine

• Standard units: some quantities are measured in the same units as in physics, such as:
  • Force in newtons
  • Work in joules
  • Power in watts
• Non-standard units: some quantities are measured in special units, such as:
  • Pressure in mmHg or cmHg
  • Energy in kilocalories (Kcal) or calories (Cal)

Measurement in Medicine

• Repetitive measurements: involve the number of repetitions per second, minute, and hour, e.g. pulse rate, breathing rate, and frequencies of electrical signals from the brain
• Non-repetitive measurements: involve one-time events, such as:
  • Time of kidney function to remove waste from the blood
  • Food digestion in the body
  • Time intervals of nerve signals
  • Eye movement
• Accuracy of measurement: important to minimize errors, otherwise diagnosis or treatment may lead to risky results
• Errors can occur due to:
  • Measuring instruments
  • Psychological reasons

Reducing Diagnostic Errors and Measurement Uncertainties

• Ways to reduce errors and uncertainties include:
  • Researching causes of misleading laboratory test values
  • Repeating measurements
  • Care in taking measurements
  • Developing new clinical tests
  • Better instrumentation
  • Using reliable instruments
  • Calibrating instruments relative to standard or already calibrated instruments

Medical Measurements

• Medical measurements that a physician should take before deciding on treatment include:
  • Routine measurements: body temperature, pulse rate, blood pressure, and body weight
  • Other required tests according to the patient's case, such as:
    • Laboratory investigation
    • Body signals investigations
    • Machinery measuring instruments

Terminology

• Terminology is the science of terms.

Physics

• Physics is the science of nature.

Medical Physics

• Medical physics is a term that overlaps two fields: medicine and physics.
• It involves the study of physical parameters in the body, such as:
  • Pressure
  • Force
  • Energy
  • Power
  • Electricity
• It also involves the study of physics in body organs and systems, including:
  • Vision
  • Hearing
  • Skeletal system
  • Pulmonary system
  • Cardiovascular system
  • Nervous system

Applications of Physics in Medicine

• Laser in medicine
• Sound and ultrasound in medicine
• X-rays
• Computed tomography (CT) scanner
• Magnetic resonance imaging (MRI)
• Electrocardiography (ECG)
• Electroencephalography (EEG)
• Electroretinography (ERG)
• Radioisotopes
• Positron emission camera (PEC)
• Gamma (γ) and camera in nuclear medicine and radiotherapy

Biomaterials in Medicine

• Artificial bones
• Lenses
• Lasik used in ophthalmology
• Pacemakers and stents used in cardiovascular diseases
• Grafting materials and nerve conduits

Units in Medicine

• Standard units: some quantities are measured in the same units as in physics, such as:
  • Force in newtons
  • Work in joules
  • Power in watts
• Non-standard units: some quantities are measured in special units, such as:
  • Pressure in mmHg or cmHg
  • Energy in kilocalories (Kcal) or calories (Cal)

Measurement in Medicine

• Repetitive measurements: involve the number of repetitions per second, minute, and hour, e.g. pulse rate, breathing rate, and frequencies of electrical signals from the brain
• Non-repetitive measurements: involve one-time events, such as:
  • Time of kidney function to remove waste from the blood
  • Food digestion in the body
  • Time intervals of nerve signals
  • Eye movement
• Accuracy of measurement: important to minimize errors, otherwise diagnosis or treatment may lead to risky results
• Errors can occur due to:
  • Measuring instruments
  • Psychological reasons

Reducing Diagnostic Errors and Measurement Uncertainties

• Ways to reduce errors and uncertainties include:
  • Researching causes of misleading laboratory test values
  • Repeating measurements
  • Care in taking measurements
  • Developing new clinical tests
  • Better instrumentation
  • Using reliable instruments
  • Calibrating instruments relative to standard or already calibrated instruments

Medical Measurements

• Medical measurements that a physician should take before deciding on treatment include:
  • Routine measurements: body temperature, pulse rate, blood pressure, and body weight
  • Other required tests according to the patient's case, such as:
    • Laboratory investigation
    • Body signals investigations
    • Machinery measuring instruments