Dynamic Augmentation of Left Ventricle and Mitral Valve Function With an Implantable Soft Robotic Device

Figures

• 

  Figure 1. Soft Robotic Ventricular Assist Device With Septal Bracing (A) Annotated photograph of the device used for left ventricular (LV) support. (B) Optimum device position from the LV free wall to the interventricular septum and the geometric differences between end-diastole (left) and end-systole (right) of the LV cavity and mitral valve annulus and coaptation height with device actuation. RV = right ventricle.

• 

  Figure 2. Deployment of Intracardiac Component of Soft Robotic LV Assist Device With Septal Bracing Under Echocardiographic Guidance Ex vivo demonstrations are shown in the left columns and in vivo 2- and 3-dimensional echocardiography images are shown in the right columns. (A) Insertion of needle. (B) Introduction of the guidewire. (C) Dilator passed over the guidewire. (D) Insertion of a 20-F introducer sheath. (E) Deployment of a collapsible septal anchor. (F) Removal of the introducer sheath and retraction of the deployed septal anchor. (G) Introduction of a delivery tube and coupling of a tip-mounted septal disc on the right-side to left-side septal anchor. (H) Coupling of a bracing bar to the right-side septal disc and removal of the delivery tube. (I) Implanted brace with the covering sleeve shown in green. IVS = interventricular septum; LV = left ventricle; RV = right ventricle.

• 

  Figure 3. Mechanical Effect of Soft Robotic Ventricular Assist Device With Septal Bracing on LV Geometry Fractional shortening (FS) proportion of the left ventricle (LV) at (A) the LV basal level, (B) the mid-LV level, and (C) the LV apex. Level of FS measurement are marked with dashed lines: LV basal level with blue, the mid-LV level with red, and LV apex with green. (D) Echocardiographic view of the LV showing the distance changes between the LV free wall and the interventricular septum (IVS) at normal baseline (BL), induction of LV systolic dysfunction (LVSD), and during device actuation. *p = 0.031. NS = not significant.

• 

  Figure 4. Soft Robotic Device Effect on Mitral Valve Geometry (A) Delta change among the anterior to posterior points of the mitral valve annulus at end-diastole and end-systole at BL, after induction of LVSD, and after device actuation. (B) Change in mitral valve coaptation height at BL, after induction of LVSD, and after device actuation. *p = 0.031. Abbreviations as in Figure 3.

• 

  Supplemental Video 1 Echocardiography demonstration of dynamic augmentation of mitral valve geometry and function by soft robotic ventricular assist device. 2D and 3D long and short axes echocardiography views showing the location of soft actuators in relation to mitral valve, demonstrating the change in anterior to posterior mitral valve diameter during cardiac cycle and also the increase in leaflets coaptation height.

• 

  Supplemental Video 2 Echocardiography demonstration of dynamic augmentation of native left ventricular contractions by soft robotic ventricular assist device. 2D and 3D long and short axes echocardiography views showing the location of soft actuators in relation to left ventricle (LV) free wall and the location of brace bar inside the left ventricle. Also demonstrating the dynamic approximation of LV free wall toward interventricular septum to augment the native LV contractions.

• 

  Figure 7. Effect of Soft Robotic Device on Hemodynamics Boxplots of (A) mean arterial pressure, (B) aortic flow rate, and (C) pulmonary flow rate at BL, after induction of LVSD, and after continuous device actuation for 5 and 30 min. (D, E) Plots showing aortic pressure versus time and aortic flow rate at BL, after induction of LVSD, and with the device actuated at 5 and 30 min. ***p < 0.001. Abbreviations as in Figure 3.

• 

  Figure 8. Soft Robotic Device Provides Pulsatile Flow (A) Boxplots of pulse pressure at BL, after induction of LVSD, and after continuous device actuation for 5 and 30 min. (B) Boxplots of surplus hemodynamic energy (SHE), which represents the change in pulsatility, at BL, after induction of LVSD, and with the device actuated at 5 and 30 min. *p = 0.028, **p = 0.007, ***p < 0.001. Abbreviations as in Figure 3.