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Improved Oxygen Bath To Heal Wounds, Lessen Number Of Amputations

June 19, 1998
Sandia National Laboratories
Sandia researchers are developing inexpensive sensors and lightweight pumps to simplify operation of a unique oxygen-bath system for healing wounds, pressure sores, and pressure ulcers--quickly and with reduced scarring.

ALBUQUERQUE, N.M.--In the presence of wheelchair-bound Bill "Willie" Shoemaker--America's winningest jockey until he suffered a severe spinal injury in anauto accident in 1991--representatives of the Department of Energy's SandiaNational Laboratories signed a $5.76 million cooperative research anddevelopment agreement (CRADA) with Northridge, California-based Numotech, Inc.,a company that conducts research about wounds and then designs new treatments.

The CRADA, signed in mid-June, engages Sandia researchers to develop inexpensivesensors and lightweight pumps to simplify operation of Numotech's uniqueoxygen-bath system for healing wounds, pressure sores, and pressure ulcers--quickly and with reduced scarring.

The product--helpful to the elderly, paraplegics, diabetics, and victims ofburns and severe abrasions--should be available for home use in approximatelythree years. The treatment, called Topical Hyperbaric Oxygen Treatment (THOT),involves surrounding the injured part with a plastic bag filled with a slightlyhigher percentage of oxygen than the atmosphere provides, and at a slightlyhigher pressure. Towards this end,Numotech is contributing $1.51 million in cashto Sandia and $3.9 million in in-kind contributions. The remaining money isoverhead and depreciation waived by DOE.

Among those attending the CRADA signing, in addition to Shoemaker, were Sandiaexecutive vice-president John Crawford; Numotech president Dr. Robert Felton;technique discoverer and developer Dr. Madelene Heng, a professor at the UCLASchool of Medicine and Chief of Dermatology at the Veterans AdministrationCenter in Sepulveda, Calif.; and Michael Kleinman, board member of thenon-profit Los Angeles-based Paralysis Project of America, which advances spinalresearch.

Pressure Ulcers May Cause Amputation And Death

According to Shoemaker, "People with spinal cord injuries are very susceptibleto skin breakdown and hence, development of pressure ulcers. Statistics indicatethat the incidence of pressure ulcers is about 50 percent amongst those withspinal cord injuries. The statistics get more ominous, though. Of those withpressure ulcers, an impressive number will be hospitalized as a direct result ofthat ulcer. Of those so hospitalized, an appalling number will die as a directresult of the ulcer."

Shoemaker became interested in Numotech's oxygen-bath technique when, aftersurgery on a bone infection that followed upon a pressure sore, he took a weekof the Numotech oxygen-bath treatments and was sufficiently healed to return tothe track immediately. "My doctors tell me that it would have normally takenfour to five weeks to heal that sore," he said.

Pressure ulcers, which are usually slow in healing and can be lethal, plagueparaplegics, diabetics, and victims of burns and severe abrasions, all of whomsuffer from loss of sensation in their bodies.

Pressure unfelt and therefore unrelieved can prevent blood from flowing in skincapillaries, says John Bode, a Sandia researcher who helped arrange the CRADA.Under such conditions, the skin breaks down in minutes and necrosis--thelocalized death of living tissue--can occur. Affected areas can go fromnecrotic to gangrenous, extend from skin to bone, and require amputation of theaffected part. Such situations are avoided in normal bodies by the tendency towiggle, which allows blood to flow through capillaries.

Reduce The Number Of Amputations

"If our system were widely deployed, it would reduce the number of amputationscaused by many medical conditions in this country by half," said Felton, a 1977University of New Mexico graduate who went on to achieve a doctorate inneurophysiology from UCLA. "One out of every three elderly people suffer fromthese problems. New Mexico will benefit immediately from being a pilot site withimmediate access to the technology."

The system, developed over 20 years by Heng, uses hyperbaric oxygen in a plasticbag around the affected part. In this technique, the oxygen is at only slightlyhigher pressures than ordinarily experienced.

The technique is different from oxygen-based healing sometimes attempted withinmetal chambers pressurized to two to three atmospheres and in which high oxygenconcentrations are breathed by the patient. Pressurized chambers are expensive,and require extensive technical monitoring, upkeep, and cleaning. Overly lengthytreatments can be dangerous. Excessive oxygen delivered to a clotted wound,rather than stimulating healing, may feed microorganisms or create freeradicals, harming the patient whose clotted blood is unable to produce theanti-free-radical components normally found in flowing blood, says Heng.

Lower Oressures, Lightweight Equipment

Researchers of the Sandia-Numotech venture make use of much lower pressures,intend to develop accurate, simple, lightweight, inexpensive sensors and pumps,and hope to make the benefits of only mildly oxygen-rich care available to thepublic at far lower costs.

Sensors will permit automated or semiautomated monitoring for hospital nursesnot specifically trained for the task and, in a later stage of development,enough simplicity of operation for patients to use the equipment at home. Safetyfeatures will include automatic shutdown if pressure levels are too high or ifthe predetermined treatment time is exceeded. For home use, a highly portable,user-friendly, inexpensive oxygen delivery system will be developed by Sandia.

Said Shoemaker in a prepared statement: "... The process developed by Dr. Hengis now being perfected through a research effort supported by Sandia NationalLaboratories and Numotech, Inc. This joint effort envisions a process of healthcare where topically applied hyperbaric oxygen can be taken into the home, thusobviating the need for expensive equipment or hospitalization in many cases. Ialso learned that this process can be used for the treatment of burns, diabetic,venous, and arterial ulcers and as a post-surgical treatment to acceleratehealing."

"We'll be trying to find out the optimum amount of oxygen to use for thetreatment to be maximally successful," says Bode. "Some chemical reactions workagainst each other, in control molecules that cause a reaction to go one way oranother, and it's not understood how to make it most effective in an engineeringsense. We know the technique works, but we want to understand its boundaries."

A Simple, Internal Pressure Sensor

The technique is, amazingly, currently operated by feel by Heng, said Sandiaresearcher Mark Vaughn. "She has to go around in her hospital and push with herfingers on the oxygen bag to estimate the pressure. And, she has to train everyperson who uses the technique to feel how much pressure is enough."

Mark and project manger Keith Miller for starters have applied for a patent(through Sandia) on a spring-loaded internal pressure sensor, made of plastic"cheap enough to be thrown away." The sensor is nonelectrical and can be readby a nurse who may be monitoring the health of a number of patients from 10 feetaway.

"Heng's is really an astonishing technique," says Vaughn. "Even at themicroscopic level, wounds seem to heal without scar tissue."

In addition to its humanitarian and economic benefits, the project is ofinterest to Sandia because sensors developed to detect minute amounts ofeffluents expelled by healing wounds during the Topical Hyperbaric OxygenTreatment are similar to ones used to detect minute amounts of trace elementsfrom aging nuclear weapons to indicate their state of reliability.

Though other oxygen treatments are available, Numotech's patent-pending chamberis shape-adaptable, portable and disposable; its pressures and oxygen percentagefigures have been developed by one of the leading researchers in the field, andresearch is ongoing into systems which will improve the delivery and monitoringof THOT.

Sandia is a multiprogram DOE laboratory, operated by a subsidiary of LockheedMartin Corp. With main facilities in Albuquerque, N.M., and Livermore, Calif.,Sandia has major research and development responsibilities in national security,energy, and environmental technologies.

Sidebar: A Battery-Power Pneumatic Seat Cushion For Wheelchair-Bound

Sandia previously worked with Numotech to develop a battery-powered pneumaticseat cushion designed to prevent pressure ulcers from occurring in personsconfined to wheelchairs.

The collaboration began in 1994 under the New Mexico Technology DeploymentProgram (NMTDP) and involves scientists from the University of New Mexico whospecialize in training and equipping persons with disabilities with assistiveequipment.

It has helped improve a seat consisting, in part, of four pairs of air bladders,cyclically inflated and deflated by battery-powered pistons--a motion thatcreates the same wiggling effect that the body's muscles do when operatingnormally, preventing sustained pressure on the buttocks, lower back or thighs.Such pressure can retard blood flow and oxygen exchange and cause tissue toweaken. In the right environment of moisture and temperature, bacteria canattack vulnerable tissues and cause pressure ulcers.

The device is currently at New Mexico State University's Advanced ManufacturingCenter for production studies. Funding for production of the device, as well asfor the hyperbaric oxygen treatment, is being sought by Technology VenturesCorporation, a subsidiary of Lockheed Martin. The NMTDP was sponsored by theDefense Advanced Research Projects Agency (DARPA), the Department of Energy, andthe State of New Mexico.

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Sandia National Laboratories. "Improved Oxygen Bath To Heal Wounds, Lessen Number Of Amputations." ScienceDaily. ScienceDaily, 19 June 1998. <>.
Sandia National Laboratories. (1998, June 19). Improved Oxygen Bath To Heal Wounds, Lessen Number Of Amputations. ScienceDaily. Retrieved April 30, 2017 from
Sandia National Laboratories. "Improved Oxygen Bath To Heal Wounds, Lessen Number Of Amputations." ScienceDaily. (accessed April 30, 2017).