Related Experiment Videos
Effect of External Ultrasound Frequency on Thrombus Disruption In Vitro.
1Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California.
Journal of Thrombosis and Thrombolysis
|January 1, 1996
Summary
Lower ultrasound frequencies significantly enhance the disruption of human blood clots. This study found that frequencies as low as 25 kHz achieved 99% thrombus disruption, offering a promising therapeutic approach.
Area of Science:
- Biomedical Engineering
- Acoustics
- Hematology
Background:
- Ultrasound energy is known to disrupt human thrombi in vitro.
- Previous research has not explored the impact of varying ultrasound frequencies on thrombus disruption rates and extent.
Purpose of the Study:
- To investigate the effect of different external ultrasound frequencies on human thrombus disruption.
- To determine the optimal frequency range for efficient thrombus breakdown.
Main Methods:
- In vitro exposure of 56 human blood clots (1-3 hours old) to continuous wave ultrasound at 2.9 W/cm² for 3 minutes.
- Testing of seven distinct frequencies, ranging from 243 kHz down to 25 kHz.
Main Results:
- A progressive increase in thrombus weight reduction and percent disruption was observed with decreasing ultrasound frequencies.
- Frequencies of 25 kHz and 39 kHz resulted in 99% and 86% thrombus disruption, respectively, compared to 25% at 243 kHz.
- The average particle size of disrupted thrombi was 3.26 µm.
Conclusions:
- Lower ultrasound frequencies (25-39 kHz) are more effective for thrombus disruption than higher frequencies (243 kHz) at a consistent power intensity.
- The enhanced mechanical energy from larger acoustic bubbles induced by lower frequencies likely contributes to greater thrombus disruption.
- These findings suggest that frequency modulation of ultrasound could optimize therapeutic thrombolysis.