Artificial Heart 1

What are the 4 stages of the New York Functional

• Stage 1: Cardiac/ventricular disease no symptoms, normal daily physical activities

• Stage 2: Augmented symptoms- weak observation of physical limitations of physical activities

• Stage 3: Physical Activities cause discomfort and activities limitations become significant

• Stage 4: Limitations are severe, limiting movement and symptoms are even at rest

What is Class D of the American College of Cardiology Classification?

Class D is a heart disease not responding to medications/treatments

Write a paragraph on artificial hearts, what are they, what are they used for, who needs them?

Artificial hearts are a mechanical device that replaces a failing biological heart, primarily used as a temporary “bridge to transplant” for patients awaiting a donor heart.

They are used for patients who cannot have a biological transplant and are in end-state heart failure.

The people who need them usually do not have another options.

They are used as it is very difficult to find a transplantable heart e.g. the average wait time in the UK is 18-24 months.

What is the size of the problem regarding artificial hearts?

In the UK 350,000 new cases are diagnosed with heart failure.

1 in 5 people in the world will die of a cardiovascular disease.

It is a billion dollar industry

Can you discuss solutions and challenges of producing artificial hearts?

People need an artificial heart for a multitude of reasons.

This includes diet with the increase of fast-food delivery and lack of balanced diet this blocks arteries which causes the heart to work harder.

Socio-economical patterns are another reason with global obesity rates increasing.

There is also a lack of body exercise as it has been increasingly easier to do less exercise due to cars or even technology making it less apparent.

You can also gain heart-related diseases such as coronary heart disease or ventricular disease.

What are the current available solutions for heart disease?

One available solution is an LVAD which is a pump which is attached with conjunction with part of the heart to help it to pump

Can you discuss solutions and challenges of producing artificial hearts?

One problem with producing artificial hearts is the weight this is due to placement and it can’t be to heavy or else this may damage other organs within the body.

A solution may be using new materials which are more lightweight and still are robust

What are some upcoming technologies regarding artificial hearts?

Some upcoming technology is TET which can allow wireless charging.

What is heart failure

a condition where the heart cannot pump enough blood to meet the bodys needs

In which heart failure stage are VADs typically considered

Stage/Class D, when symptoms are refractory and special intervention is needed

What trend is shown in later LVAD survival data

survival improved over time, especially with continuous flow LVADs

What lifestyle factors contribute to the problem source?

Poor diet, obesity, lack of exercise

What major diseases are listed as sources of the problem?

Coronary artery disease and ventricular disease

What are the main engineering challenges in producing artificial hearts?

Size, weight, material, power, price, shear stress causing hemolysis, thrombosis risk, and investment

What does hemolysis mean in artificial heart devices?

Damage or rupture of red blood cells due to high shear stress.

Why is thrombosis a concern in artificial hearts?

Blood contacting artificial surfaces or poor flow paths can promote clot formation

What solutions are listed for mechanical heart support?

VAD, RVAD, BiVAD, and TAH

What pump types can be used in LVADs and RVADs?

Axial flow pumps, centrifugal pumps, and pusher plate pumps

What future improvements are suggested for artificial hearts?

Smaller, lighter, lower power use, greater efficiency, less blood damage, and transcutaneous energy transfer

What is a key advantage of rotary blood pumps?

Small size and low mass, Low blood damage, low cost, low-noise operation, and shorter ICU stay

What are the potential disadvantages of rotary blood pumps?

Monitoring and control problems, risk if pump fails because there are no valves, and limited long-term experience with non-pulsatile flow

What is the flow rate, rpm, power requirement, bearings, seals, control modes of the Jarvik 2000

5–6 L/min, 8,000–12,000 RPM, 7–10 W, Ceramic bearings, No seals, Heart-rate responsive or fixed mode

What is the flow rate, power requirement, sensors of the NASA-Micromed-DeBakey

5–10 L/min, 6 W, Flowmeter

What is the max flow rate, rpm, weight, control modes of the HeartMate II

Up to 10 L/min, 8,000–15,000 RPM, 370 g, Pump speed modulation

What is the size, weight, power requirement, coatings, bearings of the INCOR Axial Flow Pump

82 mL volume, 30 mm diameter, 12.2 cm length, 200 g, 3.5 W for the motor and 0.8 W for the bearings, Heparin coating, Magnetically levitated bearings

What is the flow rate, rpm, weight, sensor, seals, placements, flow range of the Impella

About 4.5 L/min, 30,000 RPM, 5g, Pressure sensor, Purge flow seal, direct placement and femoral placement, 4.5 to 5 L/min

What does the battery backup of the console need to provide

about 60 minutes

What safety feature does the mobile console include for flow?

Individual flow-limit setting with alarm

What are the technical objectives for future rotary blood pumps?

Small size, low weight, long-term durability, pulsatility option, low shear stress, efficient washout, low power consumption, adaptive control, transcutaneous energy transfer, magnetic bearings, and low noise

What are the general objectives for future rotary blood pumps?

Compact design, minimal invasiveness, full implantability, long-term use, easy handling, exchangeability, safety, reliability, mobility, home support, no hemolysis, non-thrombogenicity, and low cost

Why is low shear stress an important future objective?

To reduce hemolysis and blood damage

Why are magnetic bearings useful in future pumps?

They can reduce wear, contact, and potentially thrombosis and blood damage

Why is transcutaneous energy transfer desirable?

It could reduce the need for percutaneous wires and lower infection risk