10 Feb 2010
Interviews - 22.08.2006
Sydney-based engineer, John Woodward, has developed a revolutionary new implantable heart pump that gives a bad heart the chance to rest and recover.
The VentrAssist is an implantable pump designed as a permanent alternative to heart transplantation for people suffering congestive heart failure. The pump's only moving part is a rotating impeller, which ‘floats’ in the blood, reducing wear and potential for blood clots. The VentrAssist helps the heart to pump blood and does not require removal of the heart, providing the possibility for it to rest and recover. The pump is connected to an external controller and power source through a lead in the abdomen. VentrAssist technology is unique and the device is smaller, lighter and simpler than other artificial heart devices.
Designed and developed in Australia, the VentrAssist was first patented in 2001. By 2006 the product had been implanted in 50 people throughout Australia, USA, UK, Norway and New Zealand. Clinical trials were underway in the USA and completed in Europe, with an application underway for approval for sale of the device in Europe. The VentrAssist also received an Australian Design Award in 2006.
In 2004 the co-inventor of the VentrAssist, Dr John Woodard, spoke to the Powerhouse Museum about the features and operation of the VentrAssist, and his enthusiasm about being part of this project.
My name is John Woodard, I have a PhD in engineering from the University of New South Wales, and I am the inventor of the Ventracor artificial heart along with two other people from Sydney. I started this project back in 1998 and raised the initial money so I guess you could say I am the founder of the company.
The reason we decided to work on this device is that heart failure, which is a condition in which the heart can’t pump enough blood, is an increasing disease. Every year about ten percent more people suffer from heart failure and the only real cure is a heart transplant. Unfortunately the ratio of heart transplants that can be done to the number of people that need a heart transplant is about twenty to one. So in the United States, for example, about fifty thousand people need a heart transplant and yet about only two thousand are done. The other forty or fifty odd thousand people actually end up dying. So the reason we developed an artificial heart was to address that group of people that need a heart but will never get one.
It is a mechanical alternative to heart transplant. And so what we’re effectively doing is just replacing some part of the heart function that currently doesn’t work well in these patients. When we take a patient who needs a heart transplant they are usually very ill. And you put a device into someone who is bedridden, they are so weak in fact that they call it a chair to bed existence – the most effort that they can make is to get out of bed, walk a couple of paces to a chair and sit down. They’re so weak they can only do that. They actually get exhausted brushing their teeth – that’s how weak they are. You a put a device like ours in and in a month they are like you or I, walking around the street, normal. They can go back to playing sport, they can go back to doing whatever they were doing before. So it’s a very radical transformation. It is really a worthwhile thing to do if you can save those people from that very debilitating, unpleasant way to die and perhaps give them another ten to twenty years of normal life.
One of the interesting things about our device is the heart isn’t actually removed. The heart still stays in place and is assisted. In a number of Asian countries there is great resistance to heart transplantation – the heart is considered to be the site of the soul. So the mechanical device actually avoids that.
The major problems with current artificial heart devices are two-fold. Firstly, they are very large and they don’t fit most patients, and secondly they don’t last very long and they damage the blood. So there’s an engineering issue in terms of making them smaller, and also an engineering issue in terms of making them more reliable and more biocompatible.
There are basically two ways of pumping blood, you can either imitate the heart – and the heart really is just a bag which contracts and squeezes the blood out – and that’s the way most original artificial hearts were developed. They were just flexible bags that were somehow compressed and ejected blood through a valve. And that method requires the device to be fairly large because it has to eject blood at the same rate as the heart does so that the physical device has to be about the same size as the heart. The second way of pumping blood is to pump it like you would any other fluid – just like the water pump in your car – you have a rotating component called an impeller and that pushes the blood out at higher pressure. And that’s the method we chose to use. That means that the pump can be small and also can be highly efficient.
The pump we currently have is quite different to any other pump in the market. It has a suspended rotor which means the part that pumps the blood doesn’t touch anything, and that is pretty unique – there’s very few other devices that have that suspended rotor. And it looks completely different to anybody elses pump too it is quite unconventional.
The principle of a pump is pretty simple, it takes fluid at one pressure and delivers it at a higher pressure, and that’s exactly what our pump does. It has a spinning impeller that sucks the blood into the top of the pump and pushes it out at higher pressure through the bottom of the pump. So it’s just a spinning, rotating element inside. The unique part of our device is that the impeller is suspended in the blood, so it doesn’t touch the sides, doesn’t wear out and doesn’t grind the blood cells up.
To implant this device the surgeon opens the chest through the sternum, which is the breast bone at the front of the chest, pulls the ribs apart, dissects down to find the heart, and then basically punches a great big hole in the end of the left ventricle - about the size of a garden hose I guess you could say - and connects our pump up to that. [The surgeon] then plumbs the other end of our pump, the delivery end, around to the aorta, which is the big artery leaving the heart that’s about the diameter of a thumb. Our pump basically sucks blood out of the heart and pumps it up to the aorta where the heart would ordinarily deliver it.
At the end, the ribs are pulled back together and wired with stainless steel wire, which is standard surgical practice. Because it is through the breast bone, the pain is surprisingly minimal, people are up and about within a little while. It’s not such a bad thing, there are not too many muscles cut and people are often walking a week later; a month later they’re home.
People have been trying to develop artificial hearts since 1964, and nobody’s really got it right. So here’s a chance to do something really quite unique, to help save people’s lives, to play with the best engineering toys, I mean we do diamond coating and laser welding and we have all the best engineering toys. So the motivation is that we’re all having tremendous fun. And I think that’s characteristic of most biomedical engineering projects – people love what they do. It’s very hard work I might add – most people get in early and leave late, we have to do a lot of travel because our market is in the United States and Europe. So a lot of us travel, sometimes monthly, it takes over your life. But most people say they wouldn’t want to do anything else.
There are also huge risks in this business. We haven’t had a device run for more than a year, for example – but we’re reasonably assured that it will because we have had devices on test on the bench for more than that time. We don’t know how it will go in some patients with particular conditions because we have never tried it – there are technical risks. There are market risks that some other big company might come along and swamp us tomorrow. You’ve just got to live with it I think. Most of us are risk takers. We’re all pretty much on edge and 'type A' people, but we wouldn’t have it any other way.
Interview recorded June 2004.
Ventracor Ltd
Australian Design Awards entry
Australian Design Awards exhibition
TAGS
+ VentrAssist
+ Ventracor articficial heart
Designed and developed in Australia, the VentrAssist was first patented in 2001. By 2006 the product had been implanted in 50 people throughout Australia, USA, UK, Norway and New Zealand. Clinical trials were underway in the USA and completed in Europe, with an application underway for approval for sale of the device in Europe. The VentrAssist also received an Australian Design Award in 2006.
In 2004 the co-inventor of the VentrAssist, Dr John Woodard, spoke to the Powerhouse Museum about the features and operation of the VentrAssist, and his enthusiasm about being part of this project.
My name is John Woodard, I have a PhD in engineering from the University of New South Wales, and I am the inventor of the Ventracor artificial heart along with two other people from Sydney. I started this project back in 1998 and raised the initial money so I guess you could say I am the founder of the company.
The reason we decided to work on this device is that heart failure, which is a condition in which the heart can’t pump enough blood, is an increasing disease. Every year about ten percent more people suffer from heart failure and the only real cure is a heart transplant. Unfortunately the ratio of heart transplants that can be done to the number of people that need a heart transplant is about twenty to one. So in the United States, for example, about fifty thousand people need a heart transplant and yet about only two thousand are done. The other forty or fifty odd thousand people actually end up dying. So the reason we developed an artificial heart was to address that group of people that need a heart but will never get one.
It is a mechanical alternative to heart transplant. And so what we’re effectively doing is just replacing some part of the heart function that currently doesn’t work well in these patients. When we take a patient who needs a heart transplant they are usually very ill. And you put a device into someone who is bedridden, they are so weak in fact that they call it a chair to bed existence – the most effort that they can make is to get out of bed, walk a couple of paces to a chair and sit down. They’re so weak they can only do that. They actually get exhausted brushing their teeth – that’s how weak they are. You a put a device like ours in and in a month they are like you or I, walking around the street, normal. They can go back to playing sport, they can go back to doing whatever they were doing before. So it’s a very radical transformation. It is really a worthwhile thing to do if you can save those people from that very debilitating, unpleasant way to die and perhaps give them another ten to twenty years of normal life.
One of the interesting things about our device is the heart isn’t actually removed. The heart still stays in place and is assisted. In a number of Asian countries there is great resistance to heart transplantation – the heart is considered to be the site of the soul. So the mechanical device actually avoids that.
The major problems with current artificial heart devices are two-fold. Firstly, they are very large and they don’t fit most patients, and secondly they don’t last very long and they damage the blood. So there’s an engineering issue in terms of making them smaller, and also an engineering issue in terms of making them more reliable and more biocompatible.
There are basically two ways of pumping blood, you can either imitate the heart – and the heart really is just a bag which contracts and squeezes the blood out – and that’s the way most original artificial hearts were developed. They were just flexible bags that were somehow compressed and ejected blood through a valve. And that method requires the device to be fairly large because it has to eject blood at the same rate as the heart does so that the physical device has to be about the same size as the heart. The second way of pumping blood is to pump it like you would any other fluid – just like the water pump in your car – you have a rotating component called an impeller and that pushes the blood out at higher pressure. And that’s the method we chose to use. That means that the pump can be small and also can be highly efficient.
The pump we currently have is quite different to any other pump in the market. It has a suspended rotor which means the part that pumps the blood doesn’t touch anything, and that is pretty unique – there’s very few other devices that have that suspended rotor. And it looks completely different to anybody elses pump too it is quite unconventional.
The principle of a pump is pretty simple, it takes fluid at one pressure and delivers it at a higher pressure, and that’s exactly what our pump does. It has a spinning impeller that sucks the blood into the top of the pump and pushes it out at higher pressure through the bottom of the pump. So it’s just a spinning, rotating element inside. The unique part of our device is that the impeller is suspended in the blood, so it doesn’t touch the sides, doesn’t wear out and doesn’t grind the blood cells up.
To implant this device the surgeon opens the chest through the sternum, which is the breast bone at the front of the chest, pulls the ribs apart, dissects down to find the heart, and then basically punches a great big hole in the end of the left ventricle - about the size of a garden hose I guess you could say - and connects our pump up to that. [The surgeon] then plumbs the other end of our pump, the delivery end, around to the aorta, which is the big artery leaving the heart that’s about the diameter of a thumb. Our pump basically sucks blood out of the heart and pumps it up to the aorta where the heart would ordinarily deliver it.
At the end, the ribs are pulled back together and wired with stainless steel wire, which is standard surgical practice. Because it is through the breast bone, the pain is surprisingly minimal, people are up and about within a little while. It’s not such a bad thing, there are not too many muscles cut and people are often walking a week later; a month later they’re home.
People have been trying to develop artificial hearts since 1964, and nobody’s really got it right. So here’s a chance to do something really quite unique, to help save people’s lives, to play with the best engineering toys, I mean we do diamond coating and laser welding and we have all the best engineering toys. So the motivation is that we’re all having tremendous fun. And I think that’s characteristic of most biomedical engineering projects – people love what they do. It’s very hard work I might add – most people get in early and leave late, we have to do a lot of travel because our market is in the United States and Europe. So a lot of us travel, sometimes monthly, it takes over your life. But most people say they wouldn’t want to do anything else.
There are also huge risks in this business. We haven’t had a device run for more than a year, for example – but we’re reasonably assured that it will because we have had devices on test on the bench for more than that time. We don’t know how it will go in some patients with particular conditions because we have never tried it – there are technical risks. There are market risks that some other big company might come along and swamp us tomorrow. You’ve just got to live with it I think. Most of us are risk takers. We’re all pretty much on edge and 'type A' people, but we wouldn’t have it any other way.
Interview recorded June 2004.
Ventracor LtdAustralian Design Awards entryAustralian Design Awards exhibitionTAGS
+ VentrAssist
+ Ventracor articficial heart