Special Report: Technology Breakthroughs
December 1, 2001
Special Report: Technology Breakthroughs
Rehab researchers explore technology on the not-so-distant horizon
VA engineers develop pulmonary improvement devices
(Editor’s note: For the next two months, Rehab Continuum Report will feature special reports about new technology that may one day help rehab therapists in treating pulmonary, spinal cord injury, and other rehab patients. This month’s report brings you news of a robotic wheelchair, a machine that measures breathing flow during exercise, and a device that measures energy expenditures during activities of daily living. Look in next month’s issue for a story about computerized wheelchair ramps that produce stationary exercise opportunities for paraplegics.)
New rehab technology in the digital era continues to offer rehab patients hope for improving their physical stamina and health. While it took thousands of years for humanity to move from hand crutches to electric wheelchairs, the 21st century may soon deliver a robotic, voice-activated wheelchair system.
A wheelchair system under development would navigate an apartment or house for wheelchair-bound patients who have neurological and sensory deficits that prevent them from safely operating a power wheelchair. (See "Robotic wheelchair would give more mobility," in this issue.)
Likewise, therapists working with patients who have chronic obstructive pulmonary disease (COPD) traditionally have had to rely on breathing exercises, repeat instruction, and stationary exercise equipment to teach patients how to inhale and exhale properly. Now technology exists that will use a computerized screen to teach patients how to breathe correctly.
"We’re in the middle of eight different research projects now, and they’re all in different stages of completion," says Edwin Langbein, PhD, research health scientist at Edward Hines Jr. Veterans Affairs (VA) Hospital in Hines, IL.
Here is a look at several of the research projects VA investigators have been developing and hope to bring to market soon:
• Devices created to assist rehab patients with breathing and exercise: Spinal cord injury (SCI) patients often have a sedentary lifestyle that makes them susceptible to obesity, heart disease, and other chronic illnesses. VA researchers have been working on developing a device that would determine how much energy SCI patients expend doing activities of daily living (ADL), Langbein says.
The next phase of the project is to recruit participants to field-test the device and keep a seven-day activity recall form so their caloric expenditure can be compared with their level of activity, Langbein says.
Electrical stimulation assists in coughing
Another research project involves helping SCI patients develop optimal parameters using electrical stimulation of abdominal muscles to assist in coughing, Langbein says.
These patients have tetraplegia and pulmonary complications that can be a major source of morbidity and mortality, and coughing helps them, Langbein explains.
Patients involved in the study of the program are using stimulators six days a week in 20-minute sessions that use a protocol of tension-relaxation-tension-relaxation. Four to eight electrodes are attached to the abdomen.
"So the objective here is to create a type of procedure where individuals could place these electrodes on the abdomen," he says. "And on a daily routine, similar to sit-ups, the procedure would use electrical stimulation to contract and intensify these muscles."
Because the muscles would be stronger when stimulated during a cough, they would be more effective in helping the patient expire air and in moving materials out of the airway, Langbein adds.
"If you can imagine somebody placing their hands on your abdomen and giving it a good push, the same effect is accomplished using stimulating electrodes," Langbein says.
Because this particular project uses existing technology in a new way, it may not be long before it’s available for home and rehab use, Langbein says. "We have been working on it for about four years, and we’re ready to move from laboratory to home."
System reduces hyperinflation
• Ventilation feedback training system: VA researchers have spent years working on developing a rehab program that integrates feedback on breathing for use with COPD patients.
"It provides patients with feedback with regard to inhalation and exhalation, and our objective is to reduce problems with hyperinflation due to exertion," Langbein says. "With COPD patients, this is a condition created when the patient doesn’t fully empty the lungs on each breath." When this happens, the patient’s lungs accumulate air and the turnover of new air isn’t optimal, causing the patient to become breathless.
"We have found in our pilot data with our ventilator feedback system that we’re able to control the rate at which the hyperinflation becomes a problem for these patients," Langbein says.
"People have tried this technology before, but it’s usually in an individual at rest," he adds.
Study results of the device will soon be published, but anecdotal evidence has been gratifying, Langbein says.
"We had individuals who were on oxygen therapy and their goal was to walk their daughters down the aisle at a wedding without having to drag their oxygen tanks around," he recalls. "They did succeed, and this can make a big difference in quality of life."
The VA lab has been training COPD patients in three groups: those who only receive ventilation feedback training, those who only receive pulmonary rehab exercise, and those who receive both ventilation feedback training and exercise.
The program combining ventilation feedback training with exercise lasts 18 weeks. Patients begin by learning to use the ventilation feedback technique while sitting still for six weeks, followed by six weeks of training while exercising on a stationary bike, and concluding with six weeks of walking while training three times a week.
The feedback training device looks like a donut-shaped disk with a short tube that the subject puts in the mouth. When seated on a bicycle seat or while standing on a treadmill, the subject can see the computer screen while breathing through the pneumotachometer, which is interfaced with the computer, says Linda Fehr, MS, electrical engineer with Edward Hines Jr. VA Hospital.
Hitting the target with exhalation
Meanwhile, the computer screen displays a horizontal white bar that crosses the screen and is controlled by the person’s breathing. The screen is cut in half, with the left side relating to the person’s inhalation and the right side relating to exhalation, Fehr says.
"The thick white horizontal bar extends to the left as someone breathes in, and as the person exhales it moves to the right, but it keeps moving as they breathe," Fehr explains.
There also are target circles, and as the person pushes the air out, it hits a green target, scoring up points for hitting and missing like a video game, Fehr adds.
Providing a point-system incentive, the goal of using the device is to convince patients to change breathing behavior.
"It becomes a very competitive thing," Fehr says, adding that she has seen patients try harder when they have missed the target.
If the device were available in a therapy setting, therapists could set expiration and inspiration ratios and respiratory flow rates, Langbein explains. "So instead of having a ratio of one second to one second, we could have a ratio of one second to 2.5 seconds of expiratory time, for example."
While testing the device, investigators found that patients quickly learned to cheat on their scores by taking shorter inhalations so that the machine would give them a point after shorter exhalations. However, once that problem was discovered, investigators adjusted the software to control the inhalation time, so that if someone didn’t breathe in for a set duration of time, the target wouldn’t light up, Fehr says.
If the device proves successful in clinical trials, then the next phase will be a multicenter trial used in pulmonary education programs. After that, the device could be available for home use if it is approved by all regulatory and patent agencies.
Patients can apply learning in real life
Although VA investigators have worked on the device for years, they have recently discovered that a similar machine was recently put on the market by a Virginia-based company called Sierra Biotechnology Co. The company’s web site (www.sierrabiotech.com), which does not list a physical address or phone number, provides information about a Biofeedback Incentive System that uses a visual analog display on a computer screen to show the inspiration and expiration breathing pattern.
"Our program has a graphic display of a bar shooting a target, and their program looks like a wave forming with rising and falling when you breathe," Fehr says, noting the differences between how the two machines record feedback.
When the VA’s device is available, it will be possible for patients to use it in a rehab therapy setting to learn breathing skills that they can practice on their own at home, Langbein says.
"When COPD patients are confronted with a flight of stairs, they can start utilizing this form of breathing so that they won’t get breathless when climbing the stairs," Langbein says. "We’re helping them make the transition with training from the lab for use in their daily lives."
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