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Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Histotripsy cardiac therapy system integrated with real-time motion correction
Ryan M Miller1, Yohan Kim, Kuang-Wei Lin
1Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.
Ultrasound in Medicine & Biology
|September 26, 2013
Summary
This study presents a novel histotripsy system with real-time motion tracking for non-invasive cardiac therapy. The system accurately compensates for cardiac and respiratory motion, enabling effective treatment in beating hearts.
Area of Science:
- Medical physics
- Biomedical engineering
- Cardiovascular interventions
Background:
- Histotripsy offers non-invasive cardiac therapy potential, particularly for neonatal and fetal applications.
- Cardiac and respiratory motion pose challenges to treatment accuracy and efficacy in adult cardiac histotripsy.
- Real-time motion tracking and adaptive therapy delivery are crucial for overcoming these challenges.
Purpose of the Study:
- To develop and validate a histotripsy-mediated cardiac therapy system integrated with fast motion tracking and ultrasound monitoring.
- To assess the system's accuracy and efficacy in compensating for cardiac motion during therapy.
- To demonstrate the feasibility of motion-corrected histotripsy in a live beating heart model.
Main Methods:
- A histotripsy system was integrated with a diamond search block matching algorithm and Kalman filtering for real-time motion tracking.
- The system electronically adjusted the focus of a 1-MHz annular therapy array to correct for axial motion.
- Feasibility was tested using tissue phantoms and validated in an open-chest canine model with a live beating heart.
Main Results:
- The motion tracking system achieved sub-millimeter accuracy for displacements up to 15 mm and velocities up to 80 mm/s, with a maximum error under 3 mm.
- Tissue phantom tests showed comparable treatment efficiency and lesion size to stationary targets, even with motion up to 42 mm/s.
- In vivo validation successfully delivered 24 minutes of motion-corrected histotripsy therapy in a canine model, creating a lesion on the atrial septum.
Conclusions:
- The integrated motion tracking system effectively corrects for cardiac motion during histotripsy therapy.
- This technology demonstrates feasibility for non-invasive cardiac treatments in live beating hearts.
- Further development towards a full 3D motion correction system is anticipated to significantly benefit non-invasive cardiac therapy.
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