US 2230068 A
Description (OCR text may contain errors)
Jan. 28, F RQENSCH APPARATUS FOR TREATING VASCULAR DISEASES Filed July 14, 1938 W W a h mm 1501 2250/7 Patented Jan. 28, 1941 UNITED STATES PATENT QFFiCE APPARATUS FOR TREATING VASCULAR DISEASES 5 Claims.
This invention relates to the treatment of peripheral vascular diseases and refers particularly to instrumentalities for producing an intermittent venous hyperemia.
Without resorting to the sesquipedalian language of medical science and without attempting to state the scientific and somewhat theoretic-a1 explanation of how the production of intermittent venous hyperemia acts to produce beneficial results, it is desired to note that considerable research has been devoted to this therapeutic and that while various opinions have been expressed, it is generally accorded highly beneficial for the treatment of peripheral vascular diseases and especially obstructive vascular diseases. But the apparatuses heretofore available for effecting this treatment have been inadequate and objectionable.
In some of the devices heretofore in use for producing intermittent hyperemia, the limb to be treated was alternately subjected to a negative and a positive pressure through the application of suction on a boot encasing the limb.
Other methods employed an inflatable cuff secured about the limb to be treated and means to inflate it and thereby effect venous constriction. But in all past expedients, there has always existed the very serious possibility of applying either too high a suction or too great a pressure on the limb.
Usually, either suction or pressure pumps were used; and unless they were carefully controlled and regulated, the patient was in serious danger, to say nothing of the extreme pain to which he might be subjected.
This invention, therefore, has as one of its objects to provide instrumentalities for producing a desirable intermittent hyperemia by means of air pressure, but in such a manner that the extent of the pressure is positively limited and incapable of exceeding a predetermined maximum.
It is also an object of this invention to provide an apparatus of the character described which is absolutely safe in the hands of a novice and which does not entail the attendance of a skilled technician.
Another object of this invention is to provide an apparatus of the character described, which is entirely automatic in its operation and in which the frequency of the cycles and the duration of their individual steps is readily adjustable.
It is also an object of this invention to provide an instrumentality of the character described, which not only applies intermittent venous constriction upon the limb being treated, but also concurrently lifts and lowers the limb to afford mild exercise and permit the utilization of postural effects upon the blood flow.
With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described, and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.
The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:
Figure 1 is a side view of an apparatus constructed in accordance with this invention illustrating its manner of use and in which parts are broken away and in section; and
Figure 2 is a cross sectional view taken through Fi ure l on the plane of the line 2-2.
Referring now particularly to the accompanying drawing, in which like numerals indicate like parts, the numeral 5 designates a conventional inflatable and which is adapted to be strapped about the thigh of a patients leg, as illustrated.
As particularly shown in Figure 2, this cuff is in the form of a tube, preferably of rubber or other similar material, into which air is forced irough an inlet nipple 6. Air under pressure is supplied to the cuff through a tube or hose 1 attached to the nipple t and leading from the bottom of an upright cylinder 8.
The cylinder 8 is preferably mounted in a portable cabinet 9 which houses and supports the entire equipment, with the exception of the cuff 5, so that the apparatus may be readily moved about and located adjacent to the patients bed.
Reciprocable in the cylinder is a piston Ill. The piston iii of its own weight augmented by a stack of removable weights l I descends by gravity to compress the air in the cylinder and inflate the cuff 5 with a pressure determined solely by the total weight of the piston.
The fact that the pressure which it is able to exert upon the thigh through. the inflatable cuif is positively limited and predetermined by the weight of the piston is an important advantage of the present invention.
To enable the piston to be retracted after a complete descent or a partial descent depending upon the desired duration for the venous constriction, a check valve I2 is mounted in the hot- III tom thereof which opens upon an upstroke of the piston.
During the pressure cycle the Weighted piston of the pressure cylinder moves only far enough to compress the confined air in the cylinder, connecting tube and cuff to the desired degree which is determined by the total weight of the piston. When this point is reached, the descent of the piston is halted, unless a leak in the pressure system permits further descent. In this case, the piston continues its downward movement but without increasing the pressure in the cuff,
At the completion of the pressure cycle, the piston is caused to move upwardly in the cylinder. In consequence to the upward movement of the piston, the confined air expands to reduce the pressure in the cuff. Thus, the piston in its upward movement reduces the pressure in the system to slightly below atmospheric; and when such a condition is reached, the check valve I2 opens to allow air from the outside to enter the cylinder.
The retraction of the piston is eifected by an automatically operating mechanism which con sists preferably of a reversible electric motor I3 driving a drum M on which a tape or cable l5 connected to the piston is wound.
Where a reversible electric motor is used as described, its rotation in one direction winds up the tape Hi to retract the piston or lift it to the top of the cylinder and a reverse operation of the motor releases the piston for gravitational descent.
The operation of the motor I3 is controlled by suitable timing switches (not shown), mounted in a housing It. The specific manner in which these timing switches function to control the forward and reverse operation of the motor [3 and the time at which such operation takes place need not be described, for this mechanism is conventional and well known; suffice it to say that the mechanism is readily adjustable to enable the frequency of the cycles and their duration to be adjusted to suit any particular need.
A main switch I? is preferably mounted on the outside of the portable cabinet to control the con nection of the electric control and driving instrumentalities with a source of current which may be conducted thereto by a flexible cord 18.
As illustrated, the nipple 6 has a branch leading therefrom for the attachment of another hose or tube l9 which leads to a pressure gauge 20 preferably mounted on the cabinet in a position to be readily visible. The gauge illustrated is of the mercury type and accurately registers the pressure applied on the limb.
While this pressure may be any amount within a wide range as determined by the weight of the piston, it being appreciated that the number of individual weights ll may be increased or decreased so that the pressure may be set to suit any requirement, in ordinary instances a pressure of 80 mm. of mercury is employed. For adding or removing weights 5 i, the cabinet has a door 2| affording access to the piston.
It is also desired to point out that the duration of the pressure applied may range from a matter of seconds to minutes and that, likewise, the frequency of the cycles is variable within wide limits ranging from seconds to minutes. r
In addition to periodically producing hyperemia in the limb being treated, it is desirable to concurrently lift the limb and lower it so that the benefits of postural effect upon the blood flow can be utilized. When the limb is elevated, the
arterial pressure falls and the venocapillary bed empties and makes room for fresh blood.
This elevation and lowering of the limb is done concurrently with the application of the venous constriction and is conveniently effected by means of a cradle 22 hung from a davit-like support 23 carried by the cabinet and raised and lowered by means of a cable or tension member 24 upon which a pull is periodically exerted by automatically controlled mechanism contained Within the cabinet.
Preferably a reversible electric motor 25 actuates a drum 26 to wind up a tape 2'! attached to the cable for elevating the limb, and actuates the drum in the opposite direction to lower the same. The operation of the motor 25 is controlled from switches contained within the housing IS in the manner well known; and to insure the motor stopping at the proper positions, an electromagnetic brake 28 of conventional design is operable upon the motor shaft.
The cradle 22 preferably also incorporates a housing 29 into which the patients leg projects, as illustrated, and which is heated in any suitable manner to a desired temperature so that the benefit of local heat application is also made available.
While, as stated, it is desirable to have the lifting and lowering of the limb concurrent with the venous constriction, it will be readily apparent that the automatic mechanism for lifting and lowering the limb may be utilized as an exerciser independent of venous constriction.
From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art that this invention. provides an entirely safe manner of effecting venous constriction of a patients limb with readily variable pressures and at controllable time intervals particularly adapted to the pati nts individual needs; and that the apparatus is extremely simple in construction and operation and does not require the presence of skilled technicians so that the device lends itself well to home treatment.
What I claim as my invention is:
1. In an instrumentality for treating peripheral vascular diseases by intermittent venous hyperemia: an inflatable cuff adapted to be applied about a limb to be treated and operable upon inflation to apply a venous compression on the limb; a pressure cylinder; means connecting the lower portion of the pressure cylinder with the cuff so that air expelled from the cylinder through said means inflates the cuff; a weighted piston reciprocable in the cylinder and operable to expel the air therefrom to inflate the cuff to a predetermined pressure positively limited by the weight of the piston; and automatic means for periodically elevating the piston and releasing it for gravitational descent.
2. In an instrumentality for treating peripheral vascular diseases by intermittent venous hyp-eremia: an inflatable cuff adapted to be applied about a limb to be treated and operable upon inflation to apply a venous compression on the limb; a pressure cylinder; means connecting the lower portion of the pressure cylinder with the cuff so that air expelled from the cylinder through said means inflates the cuff; a weighted piston reciprocabie in the cylinder and operable to expel the air therefrom to inflate the cuff to a predetermined pressure positively limited by the Weight of the piston; electrically driven means for periodically elevating the piston and releasing the same for gravitational descent; and a timed control for said electrical means adjustable to enable variation of the duration of the pressure period and the frequency of the cycles.
3. In an instrumentality for treating peripheral vascular diseases: means for periodically producing a positively limited pressure comprising, a cylinder, a piston reciprocable therein and movable by gravity in its compression stroke; electric motor driven means for periodically retracting the piston and releasing it for gravitational descent; and an adjustable time switch for regulating the operation of the motor so that the frequency of the periodic pressure pulsations and their duration is adjustable.
l. An instrumentality for treating peripheral vascular diseases and the like comprising: a portable supporting structure and a pressure cylinder carried thereby; a weighted piston reciprocable therein and movable in its compression stroke by gravity; electric motor driven means for periodically retracting the piston and releasing it for gravitational descent carried by said portable supporting structure; and means also carried by the portable supporting structure for intermittently elevating a limb to be treated in predetermined relation to the pressure strokes of the piston.
5. An instrumentality of the character described comprising: a portable cabinet; an upright air cylinder therein; a duct leading from the lower portion of the cylinder to the exterior of the cabinet; a weighted piston slidable in the cylinder and movable by gravity in its compression stroke; electric motor driven means within the cabinet for periodically retracting the piston and releasing it for gravitational descent; an overhanging elevated support carried by the cabinet; means including a flexible tension member supported from said overhanging support for elevating a patients limb; electric motor driven means inside the cabinet for periodically applying a pull on said tension element; and adjustable time switchesfor automatically controlling the operation of said two electric motor driven means.
FERDINAND J. ROENSCH.