An artificial lung developed by researchers at Case Western Reserve University has reached efficiencies akin to the genuine organ using air—not pure oxygen as current man-made lungs require. While use of the device in humans is still years away, the device is a step forward in creating an easily portable and implantable artificial lung, according to the development team.
A paper describing the device and the research appears in the journal Lab on a Chip.
The prototype device was built by following the natural lung’s design and dimensions. The researchers first built a mould with miniature features and then layered on a liquid silicone rubber that solidified into artificial capillaries and alveoli, and separated the air and blood channels with a gas diffusion membrane.
By making the parts on the same scale as the natural lung, the developers were able to create a very large surface-area-to-volume ratio and shrink the distances for gas diffusion compared to the current state-of-the-art devices. Tests using pig blood show oxygen exchange efficiency is three to five times better, which enables the use of air instead of pure oxygen as the ventilating gas.
The developers of the device estimate that a unit measuring 6-inches by 6-inchees by 4-inches tall—or about the volume of the human lung—could be used in humans. In addition, the device could be driven by the heart rather than requiring a mechanical pump.
Current artificial lung systems require heavy tanks of oxygen, limiting their portability. Due to their inefficient oxygen exchange, they can only be used on patients at rest and not while active. In addition, the lifetime of the system is measured in days.
The development team is now working to develop a coating to prevent clogging in the narrow artificial capillaries and on construction techniques needed to build a durable artificial lung large enough to test in rodent models of lung disease. Within a decade, the group expects to have human-scale artificial lungs in use in clinical trials.
The group envisions that patients would tap into the devices while allowing their own diseased lungs to heal, or use an implant as a bridge while awaiting a lung transplant.
Source: Case Western Reserve University
