Medical technology: A new, low-cost design for an artificial heart takes its inspiration from an unusual source—the cockroach

EVOLUTION has favoured cockroaches above human beings, at least when it comes to the functioning of the heart. A cockroach’s heart will continue to beat even when one of its chambers has failed; in similar circumstances, a man will die. Now a team led by Sujoy Guha of the Indian Institute of Technology, Kharagpur, has created an artificial human heart based on a cockroach’s, which they believe will be unusually robust and affordable.

A cockroach’s heart is a tube that runs the length of its body. It has 13 chambers, linked like a string of sausages. As each chamber contracts, the blood within is pumped to a higher pressure. Each successive chamber increases the pressure. A human

or feline or canine

heart, by contrast, has four chambers. Two of these pump blood to the lungs, where it picks up oxygen, then the other two pump this oxygenated blood throughout the body. One of these four chambers—the left ventricle—contracts most strongly to pressurise the blood.

The artificial hearts developed so far have mostly mimicked human ones. The first devices, developed in the 1950s and 1960s, were large machines placed on trolleys next to the patient and attached by tubes. Modern artificial hearts are less cumbersome, but they are still rather unwieldy because they use compressed air to pump the blood and are powered by heavy batteries. They are used temporarily, usually for a few days or weeks, until a real heart is available for transplant.

Instead of trying to mimic the action of the left ventricle, Dr Guha’s design uses a multi-step approach borrowed from the cockroach. His device, made from plastic and titanium, is the same size as a human heart but with five chambers arranged like the layers of an onion. Each chamber acts in succession to increase the pressure of the blood. The contraction of each chamber is controlled by a motor driven by bulky batteries. The artificial heart is being tested on goats, with human trials scheduled for next year. If these are successful, the device could be on the market in three to five years.

The multi-step approach makes this artificial heart much cheaper to build than those that use compressed air to pump the blood. Dr Guha says it would cost $2,000-2,500.

Add in the costs of protection from liability lawsuits, and I’ll bet the new artificial heart will come in for $50,000 or so.

This article nearly inspired me to make another 30 year prediction for the record: that artificial hearts will be available for cats and dogs by 2039. But, although I am excited by advances in artificial heart technology, I am not going to make that prediction.

Instead, I predict that within 30 years stem cell technology will allow veterinarians to grow new hearts for cats and dogs from their own tissues.

Sandra
Philadelphia, PA

Don’t do it.

A Cane Corso is a Cane Corso regardless of whether her ears are cropped and her tail is docked. A Cane Corso is a Cane Corso whether she has four legs or three and two eyes or one. A Cane Corso is a Cane Corso whether she is black, fawn, or brindled.

The breed standards for many breeds call for tail docking and ear cropping. The breed standards are on the wrong side of history.

Here is another 30 year prediction, to go on the record with my 30 year prediction yesterday regarding antibiotic feed additives. In 30 years, almost nobody will own dogs with cropped ears or docked tails.

There are two reasons why I am confident of this. First, public opinion is rapidly turning against the practices of ear cropping and tail docking.

You alluded to the second reason why the practices will die out in your question. Fewer and fewer vets are willing to perform the procedures. I do not perform them. Nor do most of the vets I know.

The vast majority of vets who dock tails and crop ears are older. In 30 years they won’t be practicing. You won’t be able to get your dog’s ears cropped even if the breed standards haven’t changed.

But they will change. The inevitable cannot be delayed forever.

Photo: Look at those beautiful ears! By Claudio Domiziani. License: CC.

Consider the case of California’s Humane Farming Initiative, a ballot measure that passed by a landslide last November. The law states that by 2015 farm animals must be allowed enough space to stand up, turn around, and stretch their limbs. Pigs, egg-laying hens, and veal calves will benefit most from the new law.

When the initiative passed, some farmers and food animal veterinarians squealed louder than the pigs the law was designed to help. A few of them protested that the law will end agriculture in California.

I beg to differ.

I believe that California’s farmers will adapt to the new regulations. When the rest of the world implements similar measures (and it will), California’s farmers will be ahead of the game. The law will help California remain a dominant agricultural powerhouse.

A sea change has occurred in the public’s beliefs about animal welfare. Opponents of the Humane Farming Initiative couldn’t sense that change, but I believe that California’s farmers and food animal vets will benefit from it.

Many food animal veterinarians and two major veterinary organizations now have failed to notice a different sea change. They have taken postions on an issue that places them squarely on the wrong side of history. The organizations are the American Veterinary Medical Association (AVMA) and the California Veterinary Medical Association (CVMA). I am a member of both organizations.

At issue is the routine use of antibiotics in livestock.

When I was in veterinary school, I was surprised to learn that antibiotics are added to animal feeds for reasons other than disease control or prevention. Feed manufacturers may add antibiotics (such as tylosin) simply because they can cause animals to grow slightly more efficiently. This reduces the total amount of feed needed for each animal. It reduces the time to slaughter. It increases profit margins, in theory. In practice, since so many farm animals receive antibiotics I suspect that the competitive advantage farmers gain from the medicines is wiped out.

I doubted in veterinary school, and I still doubt, that adding antibiotics to animal feeds simply to increase efficiency by a few fractions of a percent is worth the risks.

What are the risks? Excessive use of antibiotics is linked to antibiotic-resistant bacteria that may pose health risks to animals and people. And if antibiotics aren’t withdrawn from feed for an adequate length of time before slaughter, residues of the drug can end up in meat (controls are in place to prevent this, but it has been known to happen nonetheless).

Let’s face it: using antibiotics simply to make animals grow more rapidly does not pass the smell test. That’s how I see it, and that’s how I’m betting more and more people are going to see it. (Consider the backlash against rBST in dairy cows. In my opinion, rBST is safer than antibiotics.)

Here is my prediction for the record. In 30 years, antibiotics no longer will be used to promote efficient growth in food animals. Nobody wants tylosin in his turkey sandwich.

Yet the CVMA and the AVMA, pandering to food animal vets who have failed to sense the sea change, are proudly and actively on record in favor of using antibiotics to promote animal growth.

The CVMA recently published a newsletter in which it bragged about its role in defeating a bill in that would have required school districts to purchase meat from animals that were not fed antibiotics.

At around the same time, the AVMA sent me a link to a legislative action alert. The AVMA appears to be working to generate opposition to a bill in the US senate that would restrict antibiotic use to disease treatment and prevention.

It’s too bad. In my opinion, the elimination of antibiotics from animal feeds is inevitable. The CVMA and AVMA should be leading the way on this issue. Instead, they are standing myopically in the way of a change that I believe could benefit farmers and food animal vets in the long run.

And speaking of myopically attempting to prevent the inevitable, tomorrow we’ll talk about people who support breed standards that call for ear cropping and tail docking.