Implantable Platform Continuously Monitors Tissue Oxygen

A new system based on implanted biosensors allows the continuous and long-term monitoring of oxygen levels in subcutaneous tissues in the upper extremity, shoulder, or lower extremity.

The Lumee Oxygen Platform is an instrument adjunct to the treatment of peripheral artery disease (PAD), which is based on tiny, flexible biosensors 5 mm long and approximately 500 microns in diameter injected into subdermal tissue. Each biosensor is made of a bioengineered hydrogel fiber that forms a porous, tissue-integrating scaffold that induces capillary and cellular ingrowth from surrounding tissue. The smart gel is linked to a fluorescent molecule that signals the presence of oxygen.


The platform is comprised of the novel hydrogel biosensors, a specially designed biosensor injector, an optical reader, and a touch screen user interface. Either taped to the skin’s surface or held by hand, the optical reader transmits light through the skin to the embedded biosensor, which emits a corresponding fluorescence that is proportional to oxygen concentration. The data is relayed to the touch-screen tablet computer for an encrypted personal record and historical tracking.

The Lumee Oxygen Platform, a product of Profusa (San Francisco, CA, USA), has received the European Community CE mark of approval. According to the company, the smart hydrogel biosensors may have many other applications for consumer health and wellness, including management of other chronic diseases such as diabetes and chronic obstructive pulmonary disease (COPD), but should not be used as the sole basis for diagnosis or therapy.

“Acquiring the CE Mark is a major milestone our development team and regulatory partners have worked hard to achieve,” said Ben Hwang, PhD, chairman and CEO of Profusa. “Thanks to their dedication and commitment, vascular interventionalists in Europe can now have a revolutionary monitoring device that enables them to better treat their patients and improve their quality of life.”

“The muscles and other tissues of the arms and legs need oxygen and nutrients to function properly; in PAD the arteries that feed the extremity are blocked by plaque composed of cholesterol and other calcified substances,” said Miguel Montero, MD, associate professor of surgery at Baylor College of Medicine (Houston, TX, USA). “When low tissue oxygen is detected early, more treatment options can be considered and the need for catastrophic amputation can be avoided.”

Decreased tissue oxygen levels in the lower limbs of PAD patients can lead to disabled walking, or in more advanced cases, gangrene and subsequent amputation. By continuously measuring tissue oxygen levels in the ischemic limb before, during, and after treatment, appropriate therapy can be administered in a timely fashion before advanced symptoms appear.

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Baylor College of Medicine