القلوب الصناعية

Before 1900, very few people died of heart disease. Since then, heart disease has become the number one killer in the United States. The age of technology has made life easier and made people more prone to heart disease. Before the Industrial Revolution, most people made their living through some sort of manual labor. Walking was the major means of transportation. Laundry was scrubbed and wrung by hand. Stairs were climbed, carpets were beat, and butter was churned.

As the length of the human life increases, there is an overwhelming need to prolong the inevitable. As technology advances, there are many ways to prevent or cure illnesses that may be fatal. The human body is essentially an advanced machine that is composed of many parts. Like any typical machine, the parts can become fatigued and fail, or quit functioning due to overuse or misuse. When the parts of the human body become dysfunctional, they need to either be repaired or replaced. The same is true with the human heart.

A Total Artificial Heart (TAH) is exactly what the name states, an artificial heart. It is placed in the body and imitates the functioning of a real human heart. It is designed to provide the same circulation, flow rates, and overall functions as the heart it replaces. Out of approximately 700,000 people who die each year from heart disease, only 2,000 receive heart transplants. A majority of the remaining individuals would greatly benefit from a replacement or transplant heart. The problem is that there are simply not enough transplants available to match the number required. Thus enters the area of research into total artificial hearts. These mechanical replacements can make up for the lack of available transplants. They would provide patients with a viable alternative to a diseased heart where no former option existed. The research into total artificial hearts has been progressing for a number of years and formally began in 1964 as a government funded program. Much progress has been made since the early days of TAH research, but much research must still be done before an acceptable and desirable solution is ready.


The Customer Needs:

The initial design of the total artificial heart focused on mimicking the natural heart. More recently, the total artificial heart (TAH) has been used for temporary support until a natural heart can be transplanted. One limitation of the total artificial heart is that the native heart must be removed. This shortcoming prompted the development of the ventricular assist devices.

In many cases, heart disease may be so advanced that there is no chance for a patient to survive the wait for a donor heart. Medical scientists have developed the artificial heart models that can keep patients alive until a suitable donor heart can be found.

Heart disease causes more than 700,000 deaths each year in the United States. Ongoing research has led to drugs, medical devices, and procedures that have provided effective treatment for many types of heart disease. There are still many individuals who suffer from end-stage heart disease who have few treatment options. Current breakthroughs in valve replacement and mechanical assist devices are buying patients additional time. Long-term total artificial hearts are now under development and scheduled for trials early in the next century.

The design of the artificial organ poses many problems. For example, the device must be compatible in size to that of a natural organ. The size becomes a constraint because the device must be able to perform very advanced functions when typically an advanced machine is large due to the many parts required to perform the function desired. For a successful product, the design must be a complex but compact one in order to be able to achieve the desired output in the limited space available.

The purpose of the artificial heart is to advance the art and science of mechanical circulation in patients with end-stage heart failure, with the ultimate goal being to identify appropriate indications for use of left and right ventricular assist devices and the total artificial heart in patient populations most likely to benefit from them.

"No matter how you look at it, it's a multibillion dollar opportunity"
"We're finally seeing his (Robert K. Jarvik) many, many years of efforts beginning to bear fruits"

Philips Nalbone, health care analyst in San Francisco.