Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre

Area of Science:

• Biomedical Engineering
• Materials Science

Background:

• Developing artificial myocardium to support natural contractile function is crucial for circulatory assistance.
• Previous designs using shape memory alloy fibers lacked blood compatibility.
• The need for sensorless integrative mechanical elements for effective myocardial functional reproduction.

Purpose of the Study:

• To develop an artificial myocardium using sophisticated shape memory alloy fibers.
• To achieve myocardial functional reproduction using integrative small mechanical elements without sensors.
• To accomplish effective circulatory support through artificial myocardium.

Main Methods:

• Fabrication of a prototype artificial myocardial assist unit using 100-micron diameter shape memory alloy fibers (Biometal).
• Examination of mechanical response using pulse width modulation (PWM) control.
• Characterization of the relationship between strain and electric resistance, and initial unit response.
• Design of a PWM control component with a RISC microcomputer for regulating myocardial contractile function.

Main Results:

• Optimal PWM parameters were confirmed for controlling the artificial myocardium.
• Fibrous displacement was successfully regulated under simulated body temperature and bias tensile loading conditions.
• Demonstrated the potential for precise control of myocardial contractile function.

Conclusions:

• The developed artificial myocardium shows promise for effective circulatory support.
• The PWM control theory can be applied to sophisticated ventricular restraint systems.
• This technology offers a potential solution for assisting impaired cardiac function.