Research ArticleMEDICAL ROBOTS

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

See allHide authors and affiliations

Science Robotics  22 Nov 2017:
Vol. 2, Issue 12, eaan6736
DOI: 10.1126/scirobotics.aan6736
  • Fig. 1 Soft robotic VAD concept.

    (A) Section view illustration showing the soft robotic device principle of operation on the right side of the heart in diastole (left) and systole (right; outermost central actuator is removed here for illustrative purposes). (B) Photograph of the soft robotic device during in vivo operation on the RV in diastole (the red object is the standard surgical tourniquet used to tension the purse string suture that retains the sealing ring in the ventricle wall). (C) Photograph of the device on the RV in systole. (D) Annotated photograph of the device implementation for the RV.

  • Fig. 2 Soft robotic VAD implementations, control schemes, and HF models.

    (A) Soft robotic device as applied to the RV with pacing for control and as a HF model. (B) Device applied to the RV with pressure-triggering control and a pressure overload RHF model. (C) Soft robotic device applied to the LV with coronary ligation LHF model. (D) Soft robotic device applied to the LV with a coronary microvasculature occlusion LHF model.

  • Fig. 3 Deployment of the septal anchoring system.

    (A) Insertion of needle and guidewire under ultrasound guidance. (B) Insertion of a 20-French introducer sheath and deployment of a collapsible septal anchor. (C) Removal of the introducer sheath and retraction of the deployed septal anchor. (D) Introduction of a delivery tube and coupling of a tip-mounted septal disc to a collapsible anchor. (E) Coupling of a bracing bar and removal of the delivery tube. (F) Insertion of the ventricle wall sealing ring. Implanted components are shown in green.

  • Fig. 4 Ex vivo testing of the soft robotic devices.

    (A) Experimental setup with instrumented heart (photograph shows device implementation for the LV). (B and C) Plots showing average volumetric ejection and peak pressures on the LV at a range of afterloads. NS, not significant. (D to G) Plots showing the pressure, flow rate, average volumetric ejections, and peak pressures for the device as applied to the RV. Error bars denote ±SD. ***P < 0.001.

  • Fig. 5 In vivo characterization of the soft robotic device concept applied to the RV.

    (A) Brace force profiles for different systolic timings (as a percentage of total cardiac cycle) at an actuator inflation pressure of 10 psi. (B) Peak brace forces observed for different systolic actuation periods at an inflation pressure of 10 psi. (C) Photograph showing in vivo deployment of the device with integrated force sensors. (D) Characterization of pulmonary flow output for actuation of the device at different systolic actuation and delay periods. (E) Plot showing the contribution of actuator pairings on pulmonary flow rate. Error bars denote ±SD.

  • Fig. 6 Soft robotic device applied to the RV in a pressure overload model of RHF.

    (A to C) Plots showing pulmonary flow rate, aortic flow rate, and peak RV pressure versus time at baseline, at HF, and with the device actuating after 50 min of continuous operation. (D to G) Plots showing pulmonary flow rate, aortic flow rate, peak RV pressure, and end diastolic RV pressure at baseline, at HF, and with the device actuating after 50 min of continuous operation, for 15 consecutive cycles. Error bars denote ±SD. ***P < 0.001.

  • Fig. 7 Soft robotic device applied to the left side in a coronary ligation HF model.

    Photographs of the device in diastole (A) and in systole (B). Ultrasound images of the septal anchor and brace bar assembly in vivo: (C) the device in diastole and (D) the device in systole. (E to G) Aortic flow, LV, and LA pressure profiles of the LV device at baseline, at HF, and with the device actuating after 5 min of continuous operation.

  • Fig. 8 Steady-state performance of the soft robotic device in LHF models.

    (A to C) Plots showing aortic flow rate, peak LV pressure, and end diastolic LV pressure at baseline, at HF, and with the device actuating after 5 min of continuous operation in a coronary artery ligation model of LHF. (D to F) Plots showing aortic flow rate, peak LV pressure, and end diastolic LV pressure at baseline, at HF, and with the device actuating after 50 min of continuous operation in a coronary microvasculature occlusion model of LHF. Data are based on 15 consecutive cycles. Error bars denote ±SD. ***P < 0.001.

Supplementary Materials

  • robotics.sciencemag.org/cgi/content/full/2/12/eaan6736/DC1

    Materials and Methods

    Fig. S1. Pressure-displacement characteristics of the actuators.

    Fig. S2. Soft actuator contraction response times.

    Fig. S3. Force characterization of a soft actuator at varying inflation pressure.

    Fig. S4. Ex vivo testing on the RV.

    Fig. S5. Plots showing forces applied to the RV in vivo and corresponding pulmonary flow rates.

    Fig. S6. Characterization of the soft robotic device actuator on the RV in a pacing-induced HF after 5 min of continuous operation.

    Movie S1. Device concept and ex vivo and in vivo footage.

    Movie S2. Deployment procedure of the septal bracing system.

    Movie S3. Demonstration of septal motion.

  • Supplementary Materials

    Supplementary Material for:

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

    Christopher J. Payne, Isaac Wamala, Daniel Bautista-Salinas, Mossab Saeed, David Van Story, Thomas Thalhofer, Markus A. Horvath, Colette Abah, Pedro J. del Nido, Conor J. Walsh,* Nikolay V. Vasilyev*

    *Corresponding author. Email: nikolay.vasilyev{at}childrens.harvard.edu (N.V.V.); walsh{at}seas.harvard.edu (C.J.W.)

    Published 22 November 2017, Sci. Robot. 2, eaan6736 (2017)
    DOI: 10.1126/scirobotics.aan6736

    This PDF file includes:

    • Materials and Methods
    • Fig. S1. Pressure-displacement characteristics of the actuators.
    • Fig. S2. Soft actuator contraction response times.
    • Fig. S3. Force characterization of a soft actuator at varying inflation pressure.
    • Fig. S4. Ex vivo testing on the RV.
    • Fig. S5. Plots showing forces applied to the RV in vivo and corresponding pulmonary flow rates.
    • Fig. S6. Characterization of the soft robotic device actuator on the RV in a pacing-induced HF after 5 min of continuous operation.
    • Legends for movies S1 to S3

    Download PDF

    Other Supplementary Material for this manuscript includes the following:

    • Movie S1 (.mp4 format). Device concept and ex vivo and in vivo footage.
    • Movie S2 (.mp4 format). Deployment procedure of the septal bracing system.
    • Movie S3 (.mp4 format). Demonstration of septal motion.

    Files in this Data Supplement:

Stay Connected to Science Robotics

Navigate This Article