Exam II

Benefit of MRI over CT

Does not expose patients to radiation.

Limitation of MRI

Exposes patients to radiation is not a limitation.

Acoustic Impedance

The property of a medium that makes the propagation of sound waves more difficult.

Classification of Biosensors

Not classified as mechanical.

Biopotential Measurement

Can be measured both noninvasively and invasively.

Copper Half-Cell Potential

0.340 V.

Aluminum Half-Cell Potential

-1.706 V.

Calculation of Current Rate

Current rate can be calculated using V=IR formula.

Thermistor Material Constant

A thermistor material constant indicates temperature sensitivity.

Electrode Types for Biopotential Measurements

Include noble metals to minimize tissue toxicity.

Microbial Biosensors

Composed of immobilized microorganisms used as recognition elements.

Optical Biosensors

Based on changes in optical properties of biological or physical mediums.

Index of Refraction

The ratio of light velocity in free space to its velocity in a specific material.

Transducer in Biosensors

Converts a biochemical reaction into a signal.

Advantages of Ultrasound

Low cost, portability, safe to use, non-invasive.

Limitations of Ultrasound

Requires high skill for good image acquisition.

Computed Tomography (CT)

A noninvasive imaging technique using cross-sectional x-rays.

MRI Resolution

Typically 1 mm, determined by the gradient of the magnetic field.

Function of Glucose Oxidase

Enzyme used to detect blood glucose levels.

Echolocation

The use of sound waves by bats to navigate.

Electromagnet in MRI

Powerful device used for scanning within MRI machines.

Medical Imaging

Techniques used to visualize the interior of the body.

Ultrasound Wavelengths

Limit detail detection capability.

Biochemical Signal

Proportional to the concentration of a specific chemical in biosensors.

Aluminum and Copper Electrode Calculation

Results in a potential difference of 2.046 V.

Noble Metals in Implants

Minimize tissue toxicity and react minimally with electrolytes.

Transducer Types

Include optical, electrical, or physical devices.

Impacts of ionizing radiation from CT

Increased risk of cancer.

Electrode Selection for ECG

Must consider biocompatibility and stability.

Ultrasound Applications

Used for monitoring fetal health and diagnosing diseases.

Medical Imaging Techniques

Include MRI, CT, and ultrasound.

Sensor Mechanism in Microbial Sensors

Transport and measure product reaction through membranes.

Radiation Exposure in Imaging Techniques

CT exposes patients to higher radiation than X-rays.

Interference in Bioanalytical Sensors

Prevent accurate detection due to environmental factors.

Properties of Ultrasound Waves

Ultrasound waves are affected by acoustic impedance.

Substrate in Microbial Biosensors

Transported to the sensor for reaction and measurement.

Signal Generation in Biosensors

Based on the biochemical reaction's proportional signal.

External Comparison of Sensors

Address different biopotential measurements issues.

Transducer Used for Airflow Measurement

Airflow transducers measure airflow in ventilators.

Temperature-Sensitive Transducers

Thermistors change resistance with temperature variation.

Half-Cell Potential Calculation Example

Demonstrates potential difference in electrodes.

Noninvasive vs. Invasive Measurements

Describes electrode usage in biopotential recordings.

Biochemical Reaction in Biosensors

Essential for transducing signals.

Design Considerations for Biosensors

Involves selecting appropriate biological recognition elements.

Safety in Medical Imaging

Ultrasound is non-invasive and safe for patients.

Limitations of CT Scans

High radiation exposure and precision issues.

Ultrasound Technical Skills

Expertise required for accurate interpretation and diagnosis.