Some people can only rarely leave their homes or apartments because even mild exertion is enough to leave them short of breath. It would be better to say that their respiratory systems are incapable of absorbing enough oxygen from the ambient air during activity. These people suffer from a lung condition called COPD, chronic obstructive pulmonary disease. An overexpansion of the lungs, called emphysema, often results. 

The consequences for those affected are dramatic: The respiratory passages produce excess mucus, which is hard to eliminate by coughing. Patients get out of breath after the mildest exertion because their blood is not adequately enriched with oxygen. In severe cases, damage to the heart can result. 

Unlike acute bronchitis, COPD cannot be cured. The World Health Organization (WHO) estimates that 600 million people worldwide are afflicted with chronic obstructive diseases of the respiratory tract, that is, COPD and emphysema.

In Germany these conditions are the leading cause of disability and early retirement. They rank fourth in the U.S.A. and third in Europe as causes of death. By the year 2020, COPD will advance to third place among the leading causes of death worldwide.

“We think that about five to ten percent of the population suffer from chronic respiratory diseases, including not only COPD and emphysema but also asthma,” says Professor Thomas O. F.Wagner, head of the Department of Pneumology and Allergology at the Johann Wolfgang Goethe University, Frankfurt am Main.

“And the U.S. has around a million oxygen patients. This is just the tip of the iceberg, the most severely ill.” Besides medication, these people get the best respiratory relief from the direct administration of oxygen. Possible signs of COPD include wheezing and a feeling of constriction in the chest during exertion such as climbing stairs. 

“Most cases are directly associated with inhalative cigarette smoking,” says Wagner. Ninety percent of all COPD and emphysema patients are present or former smokers. 

In population centers, however, workplace stress due to pollutants or smog also irritates the breathing passages and leads to shortness of breath.

Patients get 99.78 percent pure oxygen
Karl-Heinz Hecker is out to help these people, for shortness of breath and a sense of suffocation are among the worst things a person can suffer. 

In the clear air of the Bavarian foothills of the Alps, in the town of Aschau im Chiemgau, Hecker – together with Professor Hans Kistenmacher of Linde Gas and Engineering Innovation Management – runs Linde Medical Devices GmbH.

The company, founded only in autumn 2005, is specialized in medical technology. 

“I’ve seen many hospitals from the inside, and I’ve spoken with doctors and scientists, and with patients – including children – who were coughing out their souls,” says Hecker, himself a father of three. 

The patient’s needs are his top priority: “We ask ourselves what the disease sufferer really needs.” 

Hecker has always wanted to “make devices for patients.”

His team’s latest development is the Oxy-Gen lite® oxygen generator, which uses electrolysis and fuel-cell technology to produce high-purity oxygen for medicinal use. 

“It’s 99.78 pure O2,” says Hecker, not without pride. This is what sets the new
generator, which is about the size of a boombox, clearly apart from conventional oxygen supply devices. 

“In contrast to oxygen concentrators, which merely compress the vital gas from the air and concentrate it to 92 to 93 percent, we are generating it.

We break down water, which of course is made up of an oxygen atom and two hydrogens, and use the resulting pure oxygen,” Hecker explains. And the COPD patient needs the oxygen. 

To build the device, Linde engineers combined electrolysis, the splitting of water into its atomic constituents by the use of electricity, with a proton-exchange-membrane (PEM) fuel-cell.

But the Oxy-Gen lite® does not just use electric current to break water down into oxygen and hydrogen; the fuel-cell puts the hydrogen atoms to work in their turn, making current. 

It furnishes roughly one-third of the power needed for the electrolysis process. The remainder comes through the power cable.

“We naturally have losses in the process. Otherwise, we’d have created a perpetual-motion machine,” Hecker points out with a laugh.

Part of the water humidifies the oxygen, which is delivered to the patient through a narrow tube and nasal prongs. Apart from electricity, all the device consumes is distilled water, about two to three liters a week. “And you can get that in any supermarket,” adds Hecker. 

An extra advantage of the Linde technology for the patient is natural humidification. 

One big problem in long-term oxygen therapy is that oxygen, containing no humidity as it comes from the appliance, dries out the mucous membranes and the eyes. For this reason, all conventional devices up to now have over-humidified the oxygen, consuming a relatively large amount of water. 

Christian Gunkel, a research and development engineer of Linde Medical Devices, explains: “By virtue of our special generating process, the gas already has a relative humidity of 80 percent, so the patient is protected against drying in the nose and throat.”

The patient controls the machine
The high-tech device offers another advantage to the patient, though: Oxy-Gen lite® provides the patient with oxygen on demand only, using a special microchip controller and precision sensors. “The patient controls the machine, not the other way around,” says Gunkel.

“Our generator delivers oxygen at just the right moment, taking its cue from the patient’s own breathing and requiring no conscious action.” In human respiration, the air taken in during the first fractions of a second is what actually reaches the lungs. The rest of what is breathed in serves as a sort of packing, not getting into the lungs but being breathed right back out again. 

“So it is important to meter the oxygen in through the nasal prongs at the optimal time so that it joins the inhaled stream, passes into the lungs and gets transferred to the blood,” Hecker explains. 

Special sensors monitor the patient’s requirement, involuntarily signaled through the breathing pulse, and issue a command to supply oxygen. 

The process is controlled by software also developed by Hecker and his team. Gunkel
describes the advantages of the “smooth ramp” function: “This way, we get a smooth rise in pressure without extra irritation to the mucous membranes.”

About 80 percent of people for whom long-term oxygen therapy is prescribed need at most two liters of oxygen per minute. “A patient requires up to 16 hours of oxygen in the day, depending on the severity of illness,” Wagner says, “but some need it around the clock.” 

Linde’s medical technology experts accordingly laid special stress on the product’s noise output. “Patients have again and again complained that the sound of conventional concentrators keeps them from sleeping,” says Hecker, who has worked in medical technology for some 30 years. 

He and his 17-member manufacturing and development team therefore worked to reduce the noise level. When the Oxy-Gen lite® is “making oxygen” it emits about 35 dB(A), the same as a very quiet room fan at a low setting. Oxygen concentrators typically generate 40 to 50 dB(A) and are thus more than twice as loud – about on a par with a refrigerator. The extra noise, according to experts, can lead to attention disorders.

But Hecker did not simply want to build a quiet machine. Mobility is also important to him: “Most lung patients have very restricted mobility. Conventional concentrators are bulky and heavy, weighing up to 30 kilograms,” he says. “A patient who lives in a large apartment or house must either lay long hoses or install connectors everywhere.” 

The new Linde product is helpful in this area too. The device weighs just ten kilograms or so and is easy to transport. “We have already installed a unit in the car
of a commercial representative who is in the field some twelve hours a day and can’t do without his oxygen,” says Hecker, who is now working to miniaturize the device further.

Boom in the oxygen business
The top priority for now is to increase production and further optimize costs. An application was filed in April to have Oxy-Gen lite® listed in the catalog of medications and appliances issued by the German association of health-care insurers. 

As of about May 2006, physicians will be able to prescribe the device, “but patients can also buy the Oxy-Gen lite® themselves,” Hecker adds.

At present the Linde plant at Aschau can produce about 2000 units per year and is seeking to boost its annual capacity to 3000 by early 2007. “At that point, though, we will have to outsource manufacturing,” says Hecker. Worldwide sales of oxygen delivery devices now stand at around 400,000, and the trend is upward because other fields have also been discovering uses for pure oxygen.

Hecker knows that oxygen can have an invigorating effect in cases of stress or exhaustion due to routine daily activity. He takes a regular daily dose of oxygen and has his own Oxy-Gen lite® humming away just behind his desk. He says a daily stroll in the clear mountain air is “the best thing I can do for my health,” but when he can’t take a walk, “the Oxy-Gen lite® helps me feel a lot better.”

Michael Kömpf, based in Munich, is a freelance journalist focusing on research and technology. He writes for (among others) the customer publications of major industrial firms and edits magazines in the corporate publishing field.