Biosignals Overview Quiz
32 Questions
2 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What defines a biosignal?

  • An electrical disturbance in a circuit.
  • A measurement taken by passive sensors.
  • A sound generated by mechanical devices.
  • A description of a physiological phenomenon. (correct)

    • Which of the following is NOT a classification of biosignals based on their origin?

  • Mechanical signals.
  • Electrical signals.
  • Thermal signals. (correct)
  • Chemical signals.

    • Which statement best describes deterministic signals?

  • They can be described by explicit mathematical relationships. (correct)
  • They generate predominantly aperiodic waveforms.
  • They are always periodic in nature.
  • They cannot be predicted and are random.

    • What is the main purpose of noise reduction in biosignal analysis?

    <p>To extract the biosignal of interest from background noise.</p> Signup and view all the answers

    Which type of biosignal is defined only at discrete points in time?

    <p>Discrete signals.</p> Signup and view all the answers

    How can biological processes that are repetitive affect the biosignals generated?

    <p>They generate signals with a more deterministic waveform.</p> Signup and view all the answers

    What is the term for the process of reducing a continuous signal to a discrete signal?

    <p>Sampling.</p> Signup and view all the answers

    Which aspect is not typically significant for medical decision making when analyzing biosignals?

    <p>Noise characteristics of unrelated processes.</p> Signup and view all the answers

    What method uses the difference between two input voltages to help reduce noise in recording signals?

    <p>Differential amplifier</p> Signup and view all the answers

    Which method relies on the physical property of capacitance to reduce noise effects?

    <p>Grounding</p> Signup and view all the answers

    How does electrostatic shielding reduce the influence of noise?

    <p>By creating a zero electric field inside a conductor</p> Signup and view all the answers

    Which statement accurately describes quasiperiodic signals in living organisms?

    <p>They represent repetitive biological signals.</p> Signup and view all the answers

    Which of the following is NOT a method mentioned for reducing noise in recording systems?

    <p>FFC filtering</p> Signup and view all the answers

    What characterizes random signals in biological processes?

    <p>They are generated by cells depolarizing randomly.</p> Signup and view all the answers

    In the context of noise reduction, what is the role of the differential amplifier when noise sources are distant?

    <p>It produces equal potentials at both electrodes</p> Signup and view all the answers

    What aspect of the Earth's capacitance is leveraged in grounding to combat noise interference?

    <p>Its constant electric potential</p> Signup and view all the answers

    Which of the following is a defining characteristic of a stationary signal?

    <p>The signal's properties remain constant over time.</p> Signup and view all the answers

    Which of the following statements is true about grounded systems in noise reduction?

    <p>They offer a different system with high capacitance.</p> Signup and view all the answers

    How can signals be mathematically expressed?

    <p>By expressing them as a function of time.</p> Signup and view all the answers

    Which statement regarding biosignals is correct?

    <p>Biosignals are often complex and depend on various biological processes.</p> Signup and view all the answers

    What is a key feature of a conductor or mesh used in electrostatic shielding?

    <p>It creates zero electric field inside the surrounding space.</p> Signup and view all the answers

    What are the three parameters needed to fully describe a sine wave signal?

    <p>Amplitude, frequency, and phase.</p> Signup and view all the answers

    Which biosignal reflects the electrical activity of neurons?

    <p>Electroencephalogram (EEG).</p> Signup and view all the answers

    What differentiates transient signals from quasiperiodic signals?

    <p>Transient signals occur for a limited duration.</p> Signup and view all the answers

    What is the range of frequencies for blood pressure curves?

    <p>0.3-200 Hz</p> Signup and view all the answers

    Which of the following describes the role of sensors in biosignal acquisition?

    <p>They detect and convert nonelectric signals to electric signals.</p> Signup and view all the answers

    Which type of sensor is designed to generate electric current directly?

    <p>Active sensors</p> Signup and view all the answers

    What is one characteristic of microelectrodes used in biomedical applications?

    <p>They are inside a glass pipette filled with electrolyte solution.</p> Signup and view all the answers

    What is the primary function of electrodes in biosignal detection?

    <p>To convert ionic currents to electronic currents.</p> Signup and view all the answers

    Which characteristic best defines passive sensors?

    <p>They can detect signals when measuring associated parameters.</p> Signup and view all the answers

    What are signals that interfere with your biosignal of interest called?

    <p>Noise</p> Signup and view all the answers

    Which statement is true regarding the function of electronic signal processing in biosignal acquisition?

    <p>It requires the conversion of signals to digital format for storage.</p> Signup and view all the answers

    Study Notes

    Biosignals

    • Biosignals are descriptions of physiological phenomena.
    • Biosignals can be electric, mechanical, or chemical.
    • Continuous biosignals are defined at any moment in time, while discrete signals are only defined at discrete points in time.
    • Deterministic signals can be described by explicit mathematical relationships, while random signals cannot be exactly expressed.
    • Repetitive biosignals may have a more or less deterministic waveform.
    • Nonperiodic signals can be quasiperiodic or transient.
    • Random signals are generated by random processes.
    • Stationary signals have properties that do not change over time, while nonstationary signals have properties that change over time.
    • Biosignals are usually functions of time, expressed as s(t), where 's' is the signal and 't' is time.
    • Some signals can be described by a few parameters only.
    • Complex biosignals could be a composition of several signals with different amplitudes and frequencies.
    • The frequency spectrum of a signal is the collection of its frequencies and corresponding amplitudes or magnitudes.

    Examples of Biosignals

    • Electroencephalogram (EEG) reflects electrical activity of neurons.
      • Amplitudes less than 0.1mV
      • Frequency spectrum 3-200 Hz
    • Electrocardiogram (ECG) reflects electric activity of the heart.
      • Amplitudes less than 5mV
      • Frequency spectrum 0.3-200 Hz
    • Blood pressure curves are low-frequency biosignals of mechanical origin.
    • Phonocardiogram (PCG) represents heart sounds.
      • Biosignal of mechanical origin
      • Frequency range 30-2000Hz

    Biosignal Acquisition

    • A sensor detects and converts biosignals to electrical signals.
    • Sensors can be active or passive.
    • Active sensors convert energy to electric power.
    • Passive sensors detect biosignals directly or indirectly.
    • Electrodes are a type of direct sensor used for detecting electric currents or voltages.
    • Types of electrodes include:
      • Microelectrodes: Small wires inserted into electrolyte-filled glass pipettes, used for recording potential inside a single cell.
      • Small wire electrodes: Record potentials from many cells (around 100 from cardiac tissue).
      • Large metal electrodes: Used for ECG recordings.

    Noise during Biosignal Recordings

    • Signals other than the signal of interest are called noise.
    • Noise originates from internal and external sources.
    • Noise reduction methods include:
      • Differential amplifier: An electronic device with two inputs and one output, that amplifies the difference between input voltages to reduce noise from distant sources.
      • Grounding: Connecting the recording object to the Earth to reduce noise from external electric fields.
      • Electrostatic shield: Using a conductor to surround the recording space to reduce noise.
      • Filtering: Removing unwanted frequency components from the signal.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Biosignals Lecture Notes PDF

    Description

    Test your understanding of biosignals, including their types, properties, and distinctions between various signal categories. This quiz covers the fundamental concepts related to electric, mechanical, and chemical biosignals, as well as their classification based on determinism and periodicity. Explore how these signals are represented mathematically and their significance in physiological phenomena.

    More Like This

    Biosignals Overview Quiz
    32 questions

    Biosignals Overview Quiz

    WellKnownConstellation avatar
    WellKnownConstellation
    Biosignals and Their Applications
    120 questions

    Biosignals and Their Applications

    WellKnownConstellation avatar
    WellKnownConstellation
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser