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Updated: May 28, 2026
10:26
Fabrication and Characterization of Superconducting Resonators
Published on: May 21, 2016
Non-invasive temperature measurement by using phase changes in electromagnetic waves in a cavity resonator
Yasutoshi Ishihara1, Hiroshi Ohwada
1School of Science and Technology, Meiji University, Kawasaki, Japan.
Summary
A novel method uses electromagnetic wave phase changes to non-invasively measure body temperature changes during hyperthermia cancer treatment. This technique allows for accurate temperature monitoring, improving treatment efficacy.
Area of Science:
- Electromagnetic wave physics
- Medical imaging
- Biomedical engineering
Background:
- Hyperthermia treatment efficacy can be limited by inaccurate temperature monitoring.
- Non-invasive methods are needed to assess temperature distribution during treatment.
Purpose of the Study:
- To develop and validate a novel non-invasive method for measuring body temperature changes during hyperthermia treatment.
- To reconstruct internal body temperature images using electromagnetic wave properties.
Main Methods:
- Utilized phase changes of electromagnetic waves in a cavity resonator, dependent on temperature and dielectric constant.
- Employed a prototype system with a rotating aluminum cavity resonator and an optical electric field sensor.
- Reconstructed phase change distribution from 4-projection data using a back-projection algorithm.
Main Results:
- Demonstrated successful reconstruction of phase change distribution.
- Achieved approximately 20% difference between experimental and numerical phase change data, attributed to signal detection sensitivity.
Conclusions:
- Internal body temperature changes can be reconstructed from measured phase changes within a cavity resonator.
- This method shows potential for effective cancer treatment with non-invasive heating effect monitoring.
Related Concept Videos
01:13Equipments Used to Measure Body Temperature
Body temperature can be assessed using various devices and measured in Celsius or Fahrenheit.
Glass-bulb Thermometer:
Glass-bulb thermometers are hollow glass tubes with a bulb tip containing liquid such as ethanol or mercury. Historically, glass bulb mercury thermometers were the standard device to measure body temperature. Today, mercury thermometers are prohibited in many countries due to the hazardous effects of mercury and the risk of exposure if the glass bulb breaks. In general,...
Glass-bulb Thermometer:
Glass-bulb thermometers are hollow glass tubes with a bulb tip containing liquid such as ethanol or mercury. Historically, glass bulb mercury thermometers were the standard device to measure body temperature. Today, mercury thermometers are prohibited in many countries due to the hazardous effects of mercury and the risk of exposure if the glass bulb breaks. In general,...
01:14Temperature Measurement Sites
A thermometer measures body temperature. The common sites for measuring body temperature are the oral cavity, axillary region, temporal artery, and skin surface, such as the forehead, abdomen, and axilla. True core body temperature is assessed in the rectum, tympanic membrane, pulmonary artery, esophagus, and urinary bladder.
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
Oral: When assessing oral temperature, the thermometer tip should be placed under the tongue in the posterior sublingual pocket. It offers accurate readings and can be...
01:14Assessing Body Temperature - Tympanic membrane
Assessing tympanic membrane temperature involves using a tympanic membrane thermometer (TMT). Here is a step-by-step guide:
Step 1: Begin by practicing good hand hygiene to prevent the transmission of microorganisms.
Step 2: Turn on the thermometer and wait until the ready sign appears on the screen to ensure accurate measurement.
Step 3: Slide the probe cover in place to prevent cross-contamination.
Step 4: Instruct the patient to tilt their head to the side for comfort and check for cerumen...
Step 1: Begin by practicing good hand hygiene to prevent the transmission of microorganisms.
Step 2: Turn on the thermometer and wait until the ready sign appears on the screen to ensure accurate measurement.
Step 3: Slide the probe cover in place to prevent cross-contamination.
Step 4: Instruct the patient to tilt their head to the side for comfort and check for cerumen...
01:28Standing Waves in a Cavity
A household microwave and lasers are examples of standing electromagnetic waves in a cavity. When two conducting metal plates are placed parallel at the nodal planes, it creates a cavity where standing waves are formed. The cavity between the two planes is analogous to a stretched string held at the points x = 0 and x = L. Here, the distance 'L' between the two planes must be an integer multiple of half of the wavelength. The wavelengths that satisfy this condition are given by:
01:19Assessing Body Temperature - Temporal Artery
Here is a stepwise guide to assessing the body temperature at the temporal artery using a temporal artery thermometer
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's forehead...
Step 1: Perform hand hygiene and don a fresh pair of gloves to prevent cross-infection and ensure patient safety.
Step 2: Explain the procedure to the patient to establish trust. Clear communication establishes trust with the patient, ensures they understand what to expect, promotes cooperation, and enhances comfort during the procedure.
Step 3: Assess the patient's forehead...
01:27Assessing Body Temperature - Rectal
Rectal temperature measurement is considered the most precise method for assessing core body temperature and typically registers higher than oral temperature. For adults, the rectal thermometer should be inserted 1 to 1.5 inches into the rectum to obtain the most accurate reading.
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...
Follow these steps for rectal temperature assessment:
Step 1: Perform hand hygiene and don clean gloves to prevent cross-infection.
Step 2: Position the patient in a side-lying position to better visualize the rectal...