The Biofeedback Incentive System tm is a unique analog display of the entire inspiration and expiration breathing pattern, which defines precisely the entire respiratory cycle. An infinite variety of breathing patterns may be created to satisfy individual patient needs, i.e. a "Breathing Prescription." The patient sees their breathing performance in real time, and attempts to match their signal with the programmed visual analog, i.e. this is a visual biofeedback training system.
The training method is particularly efficient in teaching new breathing patterns. This is thought to be due to the unique display method of autoscaling the breath volume and respiratory rate.
See US Patent No. 3,991,304 "Respiratory Biofeedback and Performance Evaluation System" for further details.
For a discussion of the Theory and System Methodology related to the BIStm training system you may go to Theory and Papers
As noted in the diagram, the Breath Volume (Tidal Volume) is plotted against Time. A very simple linear inspiration and expiration breathing pattern is shown.
The BIS Display © is unique, in that the Tidal Volume and Time parameters are internally calibrated to expand and fill the working area of the screen. This makes full use of the display area, but the benefits of this display are much more subtle.
Standard displays show small breaths with a small waveform and big breaths with a big waveform. A small and large breath display in the BIS system looks exactly the same because they have been autoscaled to a full screen display. Likewise a standard display shows a rapid breathing rate as a short, rapidly repeating waveform, and a slow breathing rate as a longer, slowly repeating waveform. In the BIS Display © the visual time display likewise appears exactly the same, with the visual image of a slow or rapid breath appearing to be identical, but with each respiratory cycle refreshing and starting over at the appropriate time rate.
Because the different breathing patterns look the same (or nearly the same, depending on other components of the waveforms), the patient is better focused on the feeling within themselves in achieving the particular respiratory performance. And if patients can feel these breathing sensations they can learn faster and are better able to reproduce the learned breathing pattern even when they do not have the visual display to prompt them. This is why the BIS Display © is such an effective teaching system.
The BIS Display © takes a little getting used to, but the effort is well worthwhile, because this unique display now permits primary breathing patterns to be standardized.
Whether a patient is large and breathing slowly, or small and breathing rapidly, their Primary Breathing Pattern is displayed in a standard manner for comparison and research purposes. This is a significant advantage if one is trying to imprint a new breathing pattern in a patient, by having them both seeing what they must do in a standard manner while feeling what is actually happening.
In practice, the patient's real time breathing performance is displayed, and the patient attempts to match their breathing with the programmed breathing pattern. The patient is precisely prompted to follow the programmed pattern by a flashing cursor (not shown) on the visual analog.
Given the fundamental equation Breath Volume = Flow X Time, if the patient breathes the correct volume of air in and out of their lungs in the correct time domain, the BIS device is essentially therefore a real time precision air flow control system.
Having established the Primary Breathing Pattern the operator is now ready to define the more subtle and interesting Secondary Breathing Patterns. This is done by simple menu selection of the following:
NOTE - All subsequent pictures are "screen dumps" of actual BIS images.
By menu selection the I:E Ratio may be manipulated as shown.
There is normally a slight pause at the end of inspiration, and a longer one at the end of expiration. This is defined as the "Hold Time." Inspiration Hold is set as a percentage of the time of inspiration, and Expiration Hold as a percentage of the time of expiration.
The first picture shows inspiration and expiration hold times of 10%. Note that because the expiration time is longer (the I:E Ratio being fixed at 1:1.5), the expiration hold time is also longer. The second picture shows inspiration and expiration holds of 15% and 20% respectively. The third picture shows respective inspiration and expiration holds of 35% and 50%. Note how changing these simple relative hold times is beginning to shape the waveforms.
These parameters may be combined in various ways to synthesize virtually any breathing pattern. Note the following examples:
Here the I:E Ratio is constant at 1:1.5, and the same curvilinear waveform is used throughout. Inspiration Hold is changed from 0% to 10% and 20%. Note how the curvilinear waveform changes.
The patient breathes through a differential pressure flow transducer, and in real time their Inspiratory and Expiratory breathing patterns are displayed in the BIS volume/time format. A cursor flashes along the programmed visual analogs in the correct time domain, to prompt the patient to breathe in and out.
A manual function key may be used to re-set the system to zero, to synchronize the patient to the BIS display, and may later be used as necessary to re-synchronizes if the patient is not coordinating with the BIS display.
This shows the BIS device in action. Note the programmed inspiration / expiration waveform, and now with a cursor prompting in the correct time domain. In the first picture the patient's real time inspiration pattern is below the programmed analog, therefore indicating inspiration has been too slow. The patient therefore has a visual prompt to breathe in faster, and therefore get back on the programmed waveform. In the second picture the patient's performance is above the programmed inspiration, indicating inspiration is too fast, and visually prompting the patient to slow down and return to the desired program.
In the first picture, inspiration performance is quite good, but on expiration the patient analog above the programmed analog indicates that expiration is too slow, and that further expiratory effort is needed to get back on track. In the second picture, inspiration performance is near perfect, but that expiration is too fast, as the patient performance display is below the programmed analog.
In practice, most patients, even though they may be elderly or have poor coordination, generally are following the BIS program within five to ten minutes of practice. Considering how difficult it usually is to teach breathing patterns in traditional ways, this rapid breathing training is remarkably efficient. Further details of breathing training (or Breathing Exercises) for Pulmonary Rehabilitation may be obtained by an e-mail request.
Quality control of patient performance is essential, and particularly so for research purposes. The BIS device does this by the so-called Phantom Line concept. Phantom Lines are optional plus and minus visual error limits placed above and below the desired programmed line. They are defined as a percentage of the Tidal Volume. For example, a 10% Phantom Line in a program with a 1,000 cc Tidal Volume, would give Phantom lines placed 100 cc's above and below the desired program analog. If the patient's performance hits a Phantom Line, this is indicated by an audio / visual signal.
The following pictures indicate Phantom Lines. The first picture is a simple linear program with a +/- 25% error limit. The second is a linear waveform with +/- 10% error limits.
The following pictures indicate Phantom Lines in a more typical curvilinear patient program. The first picture has a +/- 25% error limit, and the second a more stringent +/- 10% error limit. Note how easy it is to define very exacting patient performance.
The following indicates Phantom Lines in action. The first picture shows inspiration performance that is not perfect, but within the Phantom Lines and therefore acceptable. The second picture notes the patient performance outside the Phantom Lines, and therefore deficient performance, which triggers audio/visual alarms.
The next pictures indicate adequate inspiration performance, and with the first picture likewise indicating not perfect, but acceptable expiration performance within this defined error limit. The second picture indicates excessively slow expiration falling outside the Phantom Lines and therefore triggering alarms.
This patient example is that of a 77 year old lady with severe Emphysema.
The first picture is a record of spontaneous breathing, obtained with the patient's screen blanked and therefore without BIS prompting. For standardization purposes, and for follow-up comparison (and to compare with different patients), this first picture is always set at a Tidal Volume of 1,000 cc's, and with a Respiratory Rate of 10 breaths per minute. Note that she is breathing about 500 cc's Tidal Volume at a Rate of about 18 breaths per minute. The second picture is with her first attempt at BIStm training, and after only five minutes of practice.
The Breathing Prescription settings here are Tidal Volume 800 cc's, Rate 11 breaths per minute, I:E Ratio 1:2.4.
Note the immediate improvement in her increased Tidal Volume and decreased Respiratory Rate, as well as a prolongation of the Expiratory Time.
This is a typical Breathing Pattern to prevent and/or correct Air Trapping and Dynamic Hyperinflation.
A fundamental and controversial question is whether or not these learned breathing patterns are retained, and used without BIS prompting. The answer appears to be "yes" in the majority of patients.
The following pictures were obtained in this patient almost five months after starting BIStm Breathing Exercise training. Note in the first picture of spontaneous breathing performance she now has a larger Tidal Volume of about 650cc's, a slower respiratory Rate of about 13 breaths per minute, and a well prolonged Expiratory Time. She is now has a breathing pattern substantially closer to the Breathing Prescription. The second picture shows her high level of skill in following the BIS training breathing pattern.
These final records were obtained almost four years after starting BIStm training. Note in the first picture the Tidal Volume is about 650 cc's, the Rate about twelve breaths per minute, and the Expiration phase now longer and mimicking the training pattern.
Long term retention of learned breathing patterns is certainly possible in most patients.
Further details about the Biofeedback Incentive Systemtm device and it's use in Emphysema Pulmonary Rehabilitation and Asthma programs may be requested by e-mail.
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