When man is serene, the pulse of the heart flows and connects, just as pearls are joined together or like a string of red jade, then one can talk about a healthy heart.”
- The Yellow Emperor’s Canon of Internal Medicine, 2500 B.C.
• Heart disease is the single leading cause of death in the developed world today.
• Nearly 1 in every 3 people die of heart disease.
• WHO estimates that 60% of the world’s cardiac patients will be indian by 2010.
These statistics are certainly alarming and cardio-vascular medicine as we know it today requires a major innovation if these statistics are to change in the near future. Most cardio-vascular diseases involve heart failure, cardiac arrest or a heart attack leading to a heart failure which leave no other option than to replace the heart. Now, here are the truly frightening statistics. Donor hearts are sufficient for only about 30% of the patients. 10 – 20% of heart patients die annually on the waiting list. In the light of the bleak picture these stats paint, it is heartening to know that IIT Kharagpur is at the forefront of the solution to this problem. Prof. S.K. Guha of the School of Medical Sciences and Technology along with his team working on the Artificial Heart Development Program have developed an indigenous alternative to a biological heart. What really makes this project stand out is the economic viability of the product, which will be available for a fraction of the cost of the imported alternatives.
What exactly is an Artificial Heart?
As the name clearly suggests, it is a scientific device aimed at emulating the essential functions of the heart. But to what extent? Well, that depends on the exigency and the structural make of the product. There are many variations available in the market. While a pacemaker just regulates the beating of the heart by synchronizing the electrical signals to it, a ventricular assist device(VAD) such as a seminal Jarvik 7 aids the weakened ventricles with the pumping of blood to all parts of the body. So in which category does this product fall? It’s called the TAH (Total Artificial Heart) and it probably comes closest to the working of an actual biological heart. It seeks to replace the ventricular functions of the heart completely and up till now has been used only in extreme medical complications.
The product developed at IIT Kharagpur makes use of two identical ventricular pumps each consisting of a miniaturized, staged, multi-actuated pump system with a series of interconnected chambers under a single housing. Its unique design is based on the 13 chambered heart of a cockroach. This ensures survival even in case of failure of one of its chambers, a significant improvement over the limitations of the human heart. The TAH combines the peristaltic aortic pump with heart pumping and its multi staged actuated pump guarantees step wise supply of blood. The multi-staged nature also guarantees that the build-up of pressure is alleviated hence reducing the power required. Much like walking up a set of stairs takes much less effort than jumping the same height. The valves between the chambers are magnetically controlled and the diaphragm membranes utilize a motor having a variable electromagnetic arm for compression. This innovation solves a significant problem with previous versions of the TAH, namely, that of thrombosis due to fatigue of blood cells experienced during the opening of the heart valves.
How big an innovation is this?
Artificial heart transplant dates back to as early as 1969.Dr. Denton A. Cooley and Dr. Domingo Liotta of Houston had performed a remarkable surgery and had managed to keep alive a patient for nearly a week. Recent products in this field include the CardioWest temporary Total Artificial Heart which got FDA approval only after 10 years of rigorous clinical study and trials. The AbioCor Replacement Heart is also available. However it has not yet achieved its purpose of simulating the human heart in totality. The latest parallel in this segment is being developed by EADS (makers of the AIR BUS) in collaboration with Dr. Alain Carpentier and they are attempting to develop a physiological feedback capacity which would increase viability of the product manifold. The product developed by Prof S.K Guha and his team is the first of its kind in India and has considerably pushed the bounds of longevity, affordability and efficiency..
Why the hype?
The TAH being developed at IIT Kharagpur has certainly got some commendable features.
1. The Cost – Our indigenous TAH is being developed with the target price of Rs. 1 Lac which is peanuts compared to the going rate of about Rs. 30 lac. In a country like India, this key factor widens its scope exponentially. A major cost saving factor is the fact that it is indigenous it-self as a large portion of the exorbitant price tag on the foreign TAHs is due to import duties.
2. The Design – The concept is based on the heart of cockroach which has 13 chambers and it is supposed to increase its efficiency considerably.
3. The Durability – Its distinctive placement of series of diaphragms divides the load of the pump uniformly which in turn increases its longevity substantially.
4. Successful Animal Trials – The trials on small animals have yielded encouraging results. The team has recently secured permission from Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) for doing experiments on larger animals like goats taking the artificial heart a step forward.
The Bare Reality
Although most of the artificial heart projects have been developed to completely replace the defective biological heart, till now it is mainly being used as a bridge to the transplantation of the heart from some donor. What does this mean? Due to acute shortage of human donors, it is not always possible to procure the donor heart at the right place at the right time. The artificial heart then comes into play and temporarily executes the functions of the heart. In addition to this the CardioWest TAH took 10 years to be approved and all current projects are required to meet stringent norms for human trials which are quite a long and cumbersome process. So its commercial reality seems a distinct possibility as of now.
The recent successful animal trials and the great economic affordability are reasons to cheer about. We wish them all the best.
For a more comprehensive coverage read our April 23, 2009 issue.