New interventions must undergo rigorous testing in heart simulators and animal subjects before reaching humans. However, current heart simulators fail to completely capture the complexity of a heart and have a short shelf-life of two to four hours. Also, animal studies can be expensive and time-consuming, with findings not always translating to humans. Now, scientists have achieved a significant milestone by creating a biorobotic heart, which accurately simulates the beating of a real human heart, marking a huge step forward in the field of cardiac surgery training and practice.

This advancement by scientists at Massachusetts Institute of Technology (MIT, Cambridge, MA, USA) primarily targets mitral regurgitation, a condition where the heart's left chamber valve doesn't close effectively, leading to reverse blood flow. This ailment affects approximately 24.2 million people worldwide and can result in symptoms like breathlessness, limb swelling, and heart failure. The complexity of the valve's structure makes surgical interventions to correct this issue highly sophisticated, creating the need for accurate technology and surgical techniques. The biorobotic heart, developed by the MIT team, is based on a pig heart model. The researchers replaced the left chamber's heart muscle with a silicone robotic pump system operated by air. This innovative system mimics real heart muscle actions by twisting and squeezing, thus pumping artificial blood through a simulated circulation system and replicating the beating of a biological heart.

When the team intentionally damaged the mitral valve of the biorobotic heart, it exhibited characteristics of a leaky heart valve. Cardiac surgeons then successfully repaired the damage using three different methods: anchoring the damaged valve leaflet tissue with artificial chords, replacing the valve with a prosthetic one, and implanting a device to assist in valve leaflet closure. These procedures restore the heart's normal function, pressure, and flow. The system also enabled the research team to collect real-time data during the surgeries and is compatible with existing clinical imaging technologies. The use of clear artificial blood in the system allows for direct visualization of the procedures. This novel heart model is seen as a significant step forward in the field of cardiac surgery training and practice. The research team is now focused on further improving the biorobotic heart system by reducing the production time and extending its shelf life. They are also exploring the use of 3D printing technology to create a synthetic human heart for the system, which could enhance its capabilities and applications.

“The simulator has a huge benefit as a research tool for those who study different heart valve conditions and interventions,” says senior author and biomedical engineer Ellen Roche of the MIT. “It can serve as a surgical training platform for clinicians, medical students, and trainees, allow device engineers to study their new designs, and even help patients better understand their own disease and potential treatments.” 

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