Patent Grant
6921373
The present invention relates primarily to a peripheral enhancing circulation system, and more particularly to a method and apparatus for improving and enhancing the circulation of fresh oxygenated blood to a patient's extremity.
Circulation enhancement boots have been known in the art for some period of time. One such boot is known as a “Circulator Boot,” has been available for several years. This boot is used to compress an extremity between 1–3 milliseconds after the QRS segment of the heart beat. By doing so, the superficial fluid in the leg is pumped back into the circulatory path. The pressure from the heart is at its lowest point when compression occurs. Therefore, by squeezing fluids back to the heart it not only aids in increasing heart flow and profusion to the heart; but also, by emptying the superficial veins and fluid in the leg, the pressure from the heart helps to push fresh blood into the extremity.
The following prior art discloses the various aspects in the design and use of the peripheral circulation enhancement system.
U.S. Pat. No. 5,458,562, granted Oct. 17, 1995, to G. F. Cooper, discloses an apparatus where blood circulation in an injured human foot is involuntarily promoted in a vacuum over-pressure cycle and in synchronism with the heart's systolic and diastolic pressure pulsations. In a preferred embodiment the circulation apparatus comprises an air tight boot contoured to the injured foot, a pulsed synchronized tourniquet for inhibiting blood flow to the injured foot during an over-pressure cycle and a control circuit which monitors the heart's systolic and diastolic pressure pulsations and provides electrical control signals to the pressure modulator to assure that the over-pressure and vacuum pulses are cyclic and in synchronism with the heart's systolic and diastolic pressure pulsations.
U.S. Pat. No. 5,514,079, granted May 7, 1996, to R. S. Dillon, teaches of a method and apparatus for improving the circulation of blood through a patient's heart and extremity. The method comprises applying external positive regional pressure on an extremity synchronously with the patient's heartbeat. An adjustable timing cycle is initiated at the QRS complex of the arterial pulse cycle. The timing cycle is based on an average time period between QRS complexes, which is calculated from a measurement of several successive QRS complexes in the patient's heart rate. Pressure pulses are applied in the end-diastolic portion of the arterial pulse cycle to reinforce the pulse that forces blood into the extremity. The pressure is then relieved prior to the next projected QRS complex to enable the next pulse to enter the extremity without undue obstruction, thereby promoting circulation of blood through the extremity. To promote circulation of blood through the heart, compression of the extremity is released shortly before the next projected QRS complex.
U.S. Pat. No. 5,674,262, granted Oct. 7, 1997, to D. M. Tumey, discloses a device and method for stimulating blood flow velocity in a leg of the body for the prevention of Deep Vein Thrombosis in an effective and relatively painless manner which, in one case, includes an apparatus for compressing a foot in a manner to drive a substantial amount of blood from veins of the foot therein into blood vessels of the leg and an apparatus operably associated with the compressing apparatus for electrically stimulating leg muscles as the driven blood from the foot passes through, such that the muscles drivingly enhance blood flow velocity.
With reference to Dillon, the heart monitor for Circulator Boot (CB) functions by utilizing the QRS segment of the heart beat which is ventricular contraction. It functions by triggering the compression at about 1–3 milliseconds after diastole. The CB uses a hard fiberglass shell with a specialized plastic air bag inside the shell. There is a Velcro sleeve around the extremity to control the outward expansion of the plastic air bag. This forces the plastic airbag to force its pressure inward. Also, the CB controller is mounted on top of the fiberglass housing. An “O” ring hooks to the underside of the valve directly. When the heart monitor opens the valve, a quick surge of air is forced into the plastic bag, and the valve releases to vent the entrapped air. Thus, the cycle is very rapid and in about one second the air compresses the extremity.
What is needed is circulation enhancement system that initiates the compression cycle by sensing when the heart reaches the “P” segment, and then slowly increases the applied pressure, compressing the extremity, until the back pressure from the heart is near the lowest point, thereby relieving the pressure while anticipating the next cycle. In this regard, the present invention fulfils this need.
It is therefore an object of the present invention to provide a peripheral circulation enhancement system that utilizes a heart monitor to observe a patient's heartbeat.
It is another object of the present invention to provide a peripheral circulation enhancement system that utilizes a heart monitor to observe a patient's heartbeat to sense the “P” segment of the heart wave.
It is still another object of the present invention to provide a peripheral circulation enhancement system that utilizes a heart monitor to observe a patient's heartbeat to sense the “P” segment of the heart wave and to count every beat, every second beat or every third beat.
It is still yet another object of the present invention to provide a peripheral circulation enhancement system that utilizes a heart monitor to observe a patient's heartbeat to sense the “P” segment of the heart wave and when the selected number of beats is attained, initiate the compression cycle.
Another object of the present invention is to provide a peripheral circulation enhancement system that utilizes a heart monitor to observe a patient's heartbeat to sense the “P” segment of the heart wave and when diastole is reached, being the lowest pressure from the heart, the internal pressure within the boot is slowly decreased by allowing the entrapped air to be released to the ambient.
Still another object of the present invention is to provide a peripheral circulation enhancement system that utilizes a double wall formed boot, having an expandable spandex-like material inside and an outer membrane of a formed soft flexible plastic.
A final object of the present invention is to provide a peripheral circulation enhancement system that utilizes a controller having two flow regulators, one to control the slowly increasing volume of air entering the compression boot, and one to control the slow release of the air entrapped within the compression boot.
The present invention relates to a medical device designed to enhance circulation to the extremities of the human body. It consists of a compression boot, which is made of a two-sided poly-plastic material. The outer casing is more rigid than the inner casing. When air is pumped into the boot, the outer casing expansion is restricted, while the inner air bladder, made of a plastic-spandex like material, is allowed to expand. Therefore, the inner air bladder expands inwardly thus creating compression to the extremity.
The control box is comprised of a solenoid valve, which will open and close at a specific timing. Compressed air of about 90 psi is applied to the control box, where the solenoid valve controls its cycling between being open or closed. An adjustable pressure control valve permits the air pressure to the boot to be adjustable between 25–35 psi to maintain a constant pressure. Thus, the flow of air out of the controller to the compression boot will be less than the pressure source.
A heart monitor records the beating of the heart. Just as the heart reaches about one millisecond after the systolic pressure (P-wave), it sends a signal to the controller to energize the solenoid valve in the controller to open and allow air to enter into the compression boot. By the time the air builds up in the compression boot, the heart should be just before or nearing diastole. Therefore, the pressure against the extremity will not meet with a blood pressure resistance due to blood pressure at or near the highest or peak value. Instead the blood pressure of the body will be nearing the lowest value but not quite at the lowest value.
The present invention allows the compression of superficial fluids and compression of superficial veins to be met with less resistance from the systolic blood pressure; therefore, the fluid will be forced out of the area. It is at this point that the solenoid valve closes, allowing the compression boot to relax. At this point the heart is starting to increase pressure to reach the systolic pressure. As this occurs, the blood will be easily rammed to the extremity because the prior emptying of fluid has decreased the pressure in the extremity. Thus, the circulation of fresh oxygenated blood is enhanced to the extremity.
A complete understanding of the invention may be obtained by reference to the accompanying drawings when taken in conjunction with the detailed description thereof and in which;
A better understanding and appreciation of these and other objects and advantages of the present invention will be obtained upon reading the following detailed description of the preferred embodiment when taken in conjunction with the accompanying drawings.
Referring now to the drawings and to
In the preferred embodiment, an oil-less and waterless air compressor 20 is used to create the air pressure necessary to operate and inflate the enhancement boot of the present invention, although other sources of pressurized air, up to 90 psi, may be used. In most cases a simple air compressor that will provide 20 to 30 psi will suffice.
The controller box 25 is connected via an inflow hookup to bring the air in from the air compressor 20. A manually operated, adjustable pneumatic pressure control valve 35, having a calibrated dial, is used to control the air pressure that is applied to the compression boot.
By observing the pressure indicator 40, the adjustable pneumatic pressure control valve 35 is set to provide preferably twenty-five psi from the control box 25 to the peripheral enhancing boot 30, although the applied pressure can typically range between twenty to thirty pounds per square inch from the control box, dependant upon the application.
Also inside the control unit 25 is preferably, a solenoid 46 operated, pneumatic 3-port air valve or valve actuator 45, which will ope waveform pulse. When the valve opens, a volume of air will be allowed to flow into the boot 30, thus filling the boot creating the compression. Upon detection of the diastolic U segment, the valve 45 closes, shutting off the supply of air to the boot, while simultaneously exhausting the entrapped air in the boot to the atmosphere, via exhaust port 47.
The novel heart monitor 15 of the present invention conditions the signal derived from the EKG waveform to actuate the pneumatic valve 45.
Turning now to
There is shown in
Other than the wire leads from the heart monitor to the solenoid valve inside the controller box, simple plastic tubing 125 is used to carry air from the controller to the enhancement boot itself. The enhancement boot expands just so much and when the air valve is closed, the boot starts to lose the pressure thus shrinking in size. Thus, it is getting ready for the next heart beat when blood is forced into the extremity while there is no compression.
This same cycle can be repeated at every heartbeat, every other heartbeat, or the relaxation period can be extended to a plurality of heartbeats. Therefore, on one beat, fluid is pushed out of the extremity and on the next beat fluid (blood) is pushed, by the heart, back into the extremity.
Shown in
With reference now to there is shown Wigger's diagrams that are good for showing that the electrical activity (depolarization) recorded on an EKG actually occurs well before the actual mechanical contraction of the atria and ventricles.
The EKG shown at the bottom of the Wigger's diagram illustrates normal sinus rhythm. Atrial and ventricular contraction are shown as pressure changes in the atria, ventricles and aorta. The dotted lines have been included to correlate the time of occurring mechanical activity relative to the EKG activity.
Hence, the present invention utilizes the P segment (Auricular contraction) to start the flow of air into the boot. Therefore the boot will not reach full internal pressure or full compression until near or at diastole, which is the most desired.
Typical Operation
The heart monitor, when attached to the patient, will sense when the heart reaches the “P” segment of the beat (Auricular contraction). It then sends a signal to the control box to energize the solenoid of the pneumatic valve inside the controller. The valve opens, releasing up to 90 psi of compressed air to flow into the adjustable pneumatic pressure valve, where it reduced preferably to 30 pound per square inch into the peripheral boot wrapped around the leg. This boot has a firmer membrane on the outside that does not expand. The inner portion of the boot has a softer cloth membrane which when the air enters the inner chamber will cause the inner membrane to expand slowly and compress the extremity. By the time the inner membrane expands, the heart should have just passed ventricular contraction; therefore, the backpressure from the heart should be near the lowest point. Thus, it will be easy to empty the leg of excess fluids and the superficial veins.
Now the valve will close. At this point air will slowly start to leak out of the boot, which is what we want it to do, thereby reducing the pressure on the extremity. On the next beating of the heart, blood forced by the heart will flow into the extremity. Since the boot is no longer full, there will be no backpressure in the leg so it will make it easier for the heart to push blood into the extremity. On the next beating of the heart, the same cycle will be repeated.
As is shown in
Summarizing, the heart monitor has the capability of beating at every heartbeat, at after the second, or third or fourth heartbeat. By allowing for a variably selected period of pneumatic relaxation, the circulation enhancement system will assist in bringing fresh oxygenated blood to the extremity, which is necessary for healing of various types of leg and foot ulcers.
An alternative embodiment is shown in
It should be understood that although the present invention is described in detail for its particular embodiments, there may be other variations and modifications that will become apparent to those who are skilled in the art upon reading this specification, and that these modifications or variations that can be made should not detract from the true spirit of this invention.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4077402 | Benjamin et al. | Mar 1978 | A |
| 4343302 | Dillon | Aug 1982 | A |
| 5458562 | Cooper | Oct 1995 | A |
| 5514079 | Dillon | May 1996 | A |
| 5674262 | Tumey | Oct 1997 | A |
