A soft robotic sleeve mimicking the haemodynamics and biomechanics of left ventricular pressure overload and aortic stenosis

Abstract

Existing models of aortic stenosis (AS) are limited to inducing left ventricular pressure overload. As they have reduced control over the severity of aortic constriction, the clinical relevance of these models is largely hindered by their inability to mimic AS hemodynamics and recapitulate ow patterns associated with congenital valve defects, responsible for the accelerated onset and progression of AS. Here we report the development of a highly tunable bio-inspired soft robotic tool that enables the recapitulation of AS in a porcine model, in which customization of actuation patterns allows hemodynamic mimicry of AS and congenital aortic valve defects. In vitro and computational tools including lumped-parameter, nite element, and computational uid dynamics platforms were developed to predict the hemodynamics induced by the bio-inspired soft robotic sleeve. The controllability of our in vivo model and its ability to replicate ow patterns of AS and congenital defects were demonstrated in swine through echocardiography, left ventricular catheterization, and magnetic resonance imaging. This work supports the use of soft robotics to simulate human physiology and disease, while paving the way towards the development of patient-speci c models of AS and congenital defects that can guide clinical decisions to improve the management and treatment of these patients.

Soft robotic patient-specific hydrodynamic model of aortic stenosis and ventricular remodeling

“…Biomechanical mimicry of the AS lesion is paramount to accurately recreate local flow hemodynamics in a high-fidelity platform. In this work, calculation of the DSC between the model and CT images demonstrated that the patient-specific aortic sleeve can achieve enhanced mimicry (DSC = 0.88 ± 0.05) compared with commercial aortic banding techniques (DSC = 0.47) and nonspecific aortic sleeves (DSC = 0.72) ( 30 ). Furthermore, our platform recapitulates the hemodynamics of AS (Fig.…”

“…The controllability of molding or MM3DP-based hydrodynamic models is further limited by differences between the mechanical properties of the manufactured valve material and those of the native leaflet tissue. Although the investigation of valve kinetics was beyond the scope of this work, the dynamics of the aortic sleeve in this model could be controlled to mimic the motion of stenotic valve leaflets, as previously demonstrated (30). Unlike other models, our platform was also able to recreate the anatomies of congenital valvular defects, such as BAV (patients 12 to 15 in Figs.…”

“…Leveraging our previous work, in which we demonstrated the ability of a non-patient-specific aortic sleeve to recreate the hemodynamics of AS in a porcine model (30), we propose a soft roboticsenabled 3D-printed anatomical hydrodynamic system that is capable of recreating the hemodynamics of AS and congenital defects in a patient-specific fashion. In addition, using an analogous design workflow, we developed a patient-specific soft robotic LV sleeve that allows us to mimic changes in cardiac function observed in these patients, simulating longitudinal disease progression.…”

“…Analogously to the manufacturing technique previously described by our group (30,54), for each of the four LV molds and three aortic molds (or two for bicuspid valve anatomies) per patient, two sheets of thermoplastic polyurethane (TPU; HTM 8001-M 80A shore polyether film, 0.012 inches in thickness; American Polyfilm Inc., Branford, CT) were vacuum-formed (Dental Vacuum Former, Yescom, City of Industry, CA) into the shape of the molds. Each pair of TPU sheets was then heat-sealed at 320°F for 8 s on a heat press transfer machine using negative acrylic molds to create enclosed and inflatable geometries.…”

Scalable multi-dimensional topological deformation actuators for active object identification

“…Actuators have been widely used in biomedicine and other fields. 33,34 However, in complicated and unknowable environments, identifying the type and size of the object the actuator is in contact with is a huge challenge. Tactile feedback is made possible in uncharted surroundings by combining TDAs with deformability and TENGs that produce various electrical signals when in touch with different materials.…”