New Type Of Artificial Lung Created

cylonlover writes "Researchers have created an artificial lung that uses air as a ventilating gas instead of pure oxygen — as is the case with current man-made lungs, which require heavy tanks of oxygen that limit their portability. The prototype device was built following the natural lung's design and tiny dimensions and the researchers say it has reached efficiencies akin to the genuine organ. With a volume roughly the same as a human lung, the device could be implanted into a person and even be driven by the heart."

Comments

air exchange?

[rbrausse]

TFA/TFS says that the blood stream through the lung is driven by the normal blood circulation - so far so good.

but what about air exchange? the thing doesn't look flexible, so I think it is not possible to use the biological muscle-driven air stream. The information in the article are sparse, only "while air is fed into the gas inlet" mentions the topic of the air flow.

this is only a first step, mechanical ventilation is still needed (and with the need of external devices this implanted lung is imo not useful, not only maintenance is harder but the patient has additionaly the danger of complications without the result of an apparatus-free life)

Underwater breathing

[Dthief]

interesting post on the actual website that I thought I would re-post - can you create a similar technology that mimics a gill and would allow either underwater, or both under and above water breathing. though the air/liquid exchange is still an important issue for both. might require carrying a battery powered pump

Re:Underwater breathing

[demonlapin]

Your lungs are able to extract oxygen from air because there is more oxygen in the air than in the blood. Your blood carries this oxygen to the tissue, where the blood has more oxygen than the tissue - the oxygen then diffuses into the tissue.

In theory, you could do this with an adequate flow of surface seawater (which has a partial pressure of O2 very similar to that of air), but the fact that the oxygen content of seawater is minuscule compared to the oxygen content of air means that you're going to need an enormous water flow. You should be able to extract about a fourth of the oxygen in the seawater before the partial pressure will go low enough that no further net diffusion of oxygen will occur (human not under load typically extract about a fifth, but let's be conservative here). Given that the oxygen content of fresh water is about 0.0089 g/L H2O, that's about 12.5 mL O2 per liter of water. Humans need about 250 mL O2 per minute at rest, so you'll need to extract all the oxygen from 20 L/min of fresh water saturated with air in order to supply each person. However, they're going to need at least four times that flow due to the difficulty of extraction, so now we're up to 80 L/min of water flow at rest, even if you don't consider the efficiency of the exchange process.

The way around this is to do something that captures more of the oxygen content of the water - usually by binding it to some intermediate (as we, and fish, do - hemoglobin is one such). The problem is that the human heart can't handle that level of cardiac output for it to happen within an all-blood system, and that any molecule which can extract a large measure of the oxygen available in water isn't going to give it up easily - it will have an oxygen dissociation curve that lets go a significant amount of the oxygen only at very low tissue pO2. Unfortunately for us, "tissue" in this case is the breathing-air side of the artificial lung. So you can choose chemical sequestration, but that presents the same problem - unless you can figure out some way for humans to live with much lower tissue pO2, you're going to have to expend a lot of energy dissociating that oxygen from whatever carrier you use to get it up to a usable concentration for humans. Fish have much lower metabolic oxygen requirements and so can live with lower tissue pO2.

Re:So...

[Opportunist]

Ummmmmm... I've seen people die from heart attack and people die from lung cancer.

Bluntly? I'd take the heart attack. At least it's over quickly. You do NOT want to die from lung cancer. The execution equivalent would probably be crucifixion.