Soft robotic ventricular assist device with septal bracing for therapy of heart failure

Abstract

Previous soft robotic ventricular assist devices have generally targeted biventricular heart failure and have not engaged the interventricular septum that plays a critical role in blood ejection from the ventricle. We propose implantable soft robotic devices to augment cardiac function in isolated left or right heart failure by applying rhythmic loading to either ventricle. Our devices anchor to the interventricular septum and apply forces to the free wall of the ventricle to cause approximation of the septum and free wall in systole and assist with recoil in diastole. Physiological sensing of the native hemodynamics enables organ-in-the-loop control of these robotic implants for fully autonomous augmentation of heart function. The devices are implanted on the beating heart under echocardiography guidance. We demonstrate the concept on both the right and the left ventricles through in vivo studies in a porcine model. Different heart failure models were used to demonstrate device function across a spectrum of hemodynamic conditions associated with right and left heart failure. These acute in vivo studies demonstrate recovery of blood flow and pressure from the baseline heart failure conditions. Significant reductions in diastolic ventricle pressure were also observed, demonstrating improved filling of the ventricles during diastole, which enables sustainable cardiac output.

Wearable and Implantable Devices for Cardiovascular Healthcare: from Monitoring to Therapy Based on Flexible and Stretchable Electronics

“…j) Schematic of a univentricular‐pacing soft robotic device, composed of a semilunar frame, soft actuators, a brace bar, and a septal anchor, placed on the right ventricle (RV) during the diastolic (left) and systolic phases (right) (LV: left ventricle; IVS: interventricular septum). Reproduced with permission . Copyright 2017, AAAS.…”

“…Different actuator pairings were activated (distal and/or central pairs). Reproduced with permission . Copyright 2017, AAAS.…”

“…With left‐sided heart failure, congestion can increase the pressure of the diseased LV and thereby shift the movement of the interventricular septum toward the normal right ventricle, increasing the risk of right‐sided heart failure . A soft robotic device anchored into the ventricular wall and an interventricular septum was proposed to augment heart function for one‐sided heart failure (Figure j) . Two McKibben soft actuators are oriented to be centrally adjacent to a semilunar bracing frame, and the other two actuators are oriented distally on either side of the bracing frame.…”

Using Soft Robotic Technology to Fabricate a Proof‐of‐Concept Transcatheter Tricuspid Valve Replacement (TTVR) Device

“…These types of soft robots have been shown in the form factor of a gripper, tentacle, and rehabilitation glove . These soft fluid actuators are of particular interest for biomedical applications because they are lightweight, inexpensive, easily fabricated, distribute forces easily, and can provide non‐linear motion with simple inputs . Thus, this technology provides a simple method for conforming devices to the variable anatomy of patients.…”

Variable Contraction Timing for a Soft Robotic Cardiac Assist Device

“…Ventricular Assist Devices (VADs) are medical implants designed to augment cardiac output for patients with heart failure. We recently proposed a soft robotic VAD (SRVAD) that adopts pneumatic soft actuators to rhythmically massage the heart left ventricle (LV) via septal bracing [1]. The performance of SRVADs is highly dependent on effective temporal synchronization between the device and the native heart contraction [1,2].…”