SU-E-J-211: Development of Respiratory Training System Using Individual Characteristic Guiding Waveform

Area of Science:

• Medical Physics
• Biomedical Engineering
• Radiation Oncology

Background:

• Respiratory motion is a significant source of artifact in radiation therapy, impacting treatment accuracy.
• Accurate patient immobilization and motion management are crucial for effective radiation therapy.
• Existing methods for managing respiratory motion may have limitations in real-time adaptation and patient guidance.

Purpose of the Study:

• To develop an adaptive respiratory training system utilizing individual characteristic guiding waveforms.
• To reduce artifacts in radiation therapy caused by respiratory motion.
• To enhance the accuracy and efficiency of 4D radiation therapy (4D-RT) and 4D computed tomography (4D-CT).

Main Methods:

• A respiratory training system was developed using LabView, incorporating an in-house belt-type sensor for signal acquisition and a head-mounted display (HMD) for visual guidance.
• The system comprises respiratory signal reading, peak detection, individual characteristic guiding waveform generation (based on Fourier series), and real-time acquisition with visual feedback.
• Feasibility was assessed in 5 volunteers, comparing free breathing with guided breathing using the system, with root mean square error (RMSE) used to quantify respiratory regularity improvements.

Main Results:

• The developed respiratory training system significantly improved respiratory regularity.
• Root Mean Square Error (RMSE) for guided breathing showed a decrease of up to 40% in displacement and 76% in period compared to free breathing.
• Average RMSE decreased from 0.012V to 0.008V in displacement and from 0.432 sec to 0.192 sec in period.

Conclusions:

• The in-house developed respiratory training system effectively improved respiratory regularity.
• The guiding waveform was easily followed by volunteers, leading to significant improvements in breathing control.
• This system holds promise for enhancing the accuracy and efficiency of 4D radiation therapy and 4D-CT procedures.