Artificial Hearts 2

What are the main application types of extracorporeal heart assist devices

univentricular devices (LVAD, RVAD) and biventricular devices (BiVAD)

What are the application distribution shown for extracorporeal heart assist devices

41% LVAD, 48% BiBAD, 11% RVAD

Extracorporeal

medical procedures or devices that function outside the body

What is the Berlin Heart EXCOR?

An extracorporeal VAD system available in different pump sizes.

How does the Berlin Heart EXCOR reduce thrombogenesis?

By heparin coating of all blood-contacting surfaces

What two valve systems are used in Berlin Heart EXCOR blood pumps?

Titanium tilting-disc valves and polyurethane velum valves.

What is notable about CardioBerlin’s moving parts?

It creates pulsatile flow with only one moving part

How is pulsatile flow created in the pusher-plate pump?

A pusher plate moves via an eccentric drive lever powered by a brushless DC motor and Harmonic Drive gear

Why can a continuously running motor still create pulsatile flow in a pusher-plate pump?

Because the motor drives a mechanism that cyclically moves the pusher plate

How are VADs evaluated according to the lecture?

By CFD flow simulation, flow visualization, endurance testing in vitro, and acute animal testing.

What does TET stand for in the Accor concept?

Transcutaneous Energy Transmission

What are the four main ACcor concept components shown?

Pump unit, compliance and buffer battery, transcutaneous energy transmission, and external energy supply

How have TAH controllers changed over time?

They have become smaller and more portable.

What improvements are listed for VAD electromechanical actuators?

New ball-screw materials, new surface treatment, long-lasting lubricants, infinite-life design, and long prototype testing

What haemocompatibility features are used for VAD cannulae?

e-PTFE reinforced graft base, steel spring reinforcement, polyurethane inner and outer coating, valve mounting, and a Dacron apical tip outside. Blood sees polyurethane only

What power supply options are listed for VAD development?

Wearable batteries, an emergency implantable battery, a recharging and maintenance unit, and line power supply

How is blood sac durability assessed in VAD development?

FEM analysis, design criteria, accelerated prototype testing, new ventricle design, and manufacturing/QC

What does IABP stand for?

Intra-Aortic Balloon Pump

What is IABP based on?

Counterpulsation

Why is IABP widely used?

It is cheaper, easier to implant, and widely established clinically

When can IABP be used around surgery?

Pre-operatively, intra-operatively, and post-operatively

What are the two main actions of the IABP balloon?

Inflation in diastole and deflation before systole

What is the main benefit of balloon inflation?

It increases aortic diastolic pressure and can improve coronary perfusion

What is the main benefit of balloon deflation?

It decreases aortic end-diastolic pressure and reduces LV afterload.

What is the dicrotic notch?

The notch on the aortic pressure waveform associated with aortic valve closure, used as a timing landmark. The lecture highlights it on the waveform slide

What is diastolic augmentation?

The rise in diastolic aortic pressure caused by IABP inflation, which helps coronary perfusion

How does IABP affect myocardial oxygen demand?

It reduces myocardial oxygen demand by lowering afterload and assisted end-diastolic pressure

What physiological effects of IABP are listed?

Reduced systolic pressure, reduced afterload, increased coronary blood flow, reduced LV volume and preload, increased cardiac output, increased renal blood flow, reduced stroke work, and reduced wall tension

What happened to peak LAD diastolic flow velocity with IABP?

It increased significantly compared with pump off

What are the main indications for IABP?

Refractory ventricular failure, cardiogenic shock, unstable refractory angina, mechanical complications after acute MI, intra-operative cardiac support for high-risk patients, and weaning from cardiopulmonary bypass

What are the main contraindications for IABP?

Severe aortic insufficiency, abdominal or aortic aneurysm, severe calcific aorto-iliac or peripheral vascular disease, and severe obesity or groin scarring for sheathless insertion

What factors affect diastolic augmentation in IABP?

Timing and balloon position

Why is correct triggering time important in IABP?

Because incorrect inflation or deflation reduces benefit and can worsen haemodynamics. The lecture shows correct, early, and late timing examples

In the acute MI with cardiogenic shock study, what three groups were compared?

Thrombolytics only, IABP only, and thrombolytics plus IABP

What developmental issue is highlighted when the IABP operates at an angle?

The two ends of the balloon experience different hydrostatic pressures

What two effects occur when the IABP balloon is angled?

Inflation starts from tip to base, and the volume displaced toward the coronary arteries is reduced

What is the TID inflation mechanism?

It begins inflating from the tip with the largest diameter and deflates from the base with the smallest diameter

What is the TDD inflation/deflation mechanism?

It begins inflating from the tip with the smallest diameter and deflates from the base with the largest diameter

Why can balloon shape matter in IABP performance?

Because upstream and downstream resistance during inflation and deflation affect how effectively blood is displaced. The final slide compares resistance values for tapered and cylindrical balloons