Related Experiment Video
Updated: Jan 5, 2026
07:36
Studying Cavitation Enhanced Therapy
Published on: April 9, 2021
5.7K
Circulation Cooling in Continuous Skin Sonoporation at Constant Coupling Fluid Temperatures
Jeremy Robertson1, Marie Squire2, Sid Becker1
1Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand.
Ultrasound in Medicine & Biology
|October 22, 2019
Summary
Continuous ultrasound enhances skin permeability for molecular transport. Maintaining constant coupling fluid temperature reduces heating issues and cavitation, potentially improving drug delivery efficiency.
Area of Science:
- Biomedical Engineering
- Dermal Transport
- Acoustic Cavitation
Background:
- Low-frequency ultrasound increases skin permeability for molecular transport.
- Heating of coupling fluid necessitates duty cycles, extending experimental time.
- A novel method is needed for continuous ultrasound application with controlled temperature.
Purpose of the Study:
- To develop and evaluate a method for continuous low-frequency ultrasound application in a modified Franz diffusion cell.
- To investigate the effect of coupling fluid temperature on ultrasound-induced cavitation and skin permeability.
Main Methods:
- A modified Franz diffusion cell with a heat exchanger circulated coupling fluid.
- Porcine skin was exposed to continuous 20 kHz ultrasound (55 W/cm²) at controlled temperatures (13°C, 33°C, 46°C).
- Inertial cavitation activity was assessed using foil pitting and passive cavitation detection. Molecular transport was measured using calcein concentration.
Main Results:
- Inertial cavitation activity decreased as coupling fluid temperature increased.
- Higher coupling fluid temperatures correlated with increased mean donor calcein concentration, though not statistically significant.
- Stratum corneum lipid structure weakening at higher temperatures may enhance cavitation-induced defects.
Conclusions:
- Continuous ultrasound application with temperature control is feasible.
- Higher temperatures reduce cavitation but may increase permeability due to lipid structure changes.
- This method offers potential for optimized ultrasound-mediated transdermal delivery.
More Related Videos
Related Concept Videos
01:21Joule-Thomson Effect
8.8K
The Joule-Thomson effect, also known as the Joule-Kelvin effect, describes the temperature change of a fluid when it is forced through a valve or porous plug while keeping it in a thermally insulated environment. This experiment is called a throttling process. This is an important effect widely used in refrigeration and the liquefaction of gases.
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
This experiment forces high-pressure gas through a throttle valve or a porous plug to a lower-pressure region. The gas expands as it passes through to...
8.8K
01:19Mechanism of heat transfer
1.8K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.8K
01:25Body Temperature
3.9K
The body's temperature, measured in degrees, is determined by the balance between heat production and dissipation to the surrounding environment. For instance, if exercising vigorously, the body will produce more heat, causing sweat and dissipating that heat. Despite extreme environmental conditions and physical exertion, the human temperature-control system maintains a constant core body temperature (the temperature of deep tissues, which are the tissues located beneath the skin and other...
3.9K
01:20Mechanisms of Heat Transfer II
4.1K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
4.1K
01:14Mechanisms of Heat Transfer I
5.8K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
5.8K
01:14Mechanisms of Heat Transfer
1.5K
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
1.5K