US 2113253 A
Description (OCR text may contain errors)
April 5, 1938. A. N. GRAY THERAPEUTIC APPARATUS Filed Dec. 24, 1935 INVENTOR 4 N. an 5.3 mew- M ATTORNEY Patented Apr. 5, 1938 UNITED STATES PATENT OFFICE THERAPEUTIC APPARATUS Application December 24, 1935, Serial No. 56,039
This invention relates to a therapeutic apparatus and more particularly to an apparatus for passive vascular exercise.
In the medical treatment of certain affections of the blood vessels, especially of the limbs, it is found that treatment by subjecting the part ail'ected to superficial pressure alternating between more than atmospheric and less than atmospheric may be beneficial.
An object of the present invention is to provide an improved apparatus for subjecting a part of the human body to pressure above and below atmospheric alternately.
One embodiment of the invention comprises a rigid walled chamberhaving an opening through which a part of a body may extend into the chamber, means to seal the entrance around the part independently against loss of air from or intrusion of air into the chamber, and means to produce air pressures within the chamber alternately above and below the external pressure.
Other objects and characteristic features of the invention will appear from the following detailed description of one embodiment thereof taken in connection with the accompanying drawing in which the single figure is a diagrammatic representation of an apparatus constructed in accordance with the invention.
The embodiment of the invention herein disclosed comprises an open ended chamber l having rigid side walls I! and a rigid end wall l2 all preferably of transparent material such as glass, celluloid, or other suitable material for the reception therein of a part of the body to be subjected to treatment, here shown as a human leg.
The chamber is provided with a pressure gauge l3 of any appropriate and known construction to indicate the pressure within the chamber and an adjustable constant pressure vacuum relief valve l4 also of any suitable and known construction which may be adjusted to admit atmospheric air to the chamber whenever the pressure within is less than that without by a desired predetermined amount. At l5 one end of an inlet tube or pipe I6 is connected to the interior of the chamber to supply fluid under pressure thereto or to draw fluid therefrom, An adjustable constant pressure relief valve I1 is connected in the fiuid supply line or pipe Hi. This valve I! may also be of any suitable known construction, adjustable to allow fluid to escape from the pipe l6 into the atmosphere whenever the fluid pressure in the pipe I6 and chamber I 0 exceeds the external pressure by any desired predetermined amount. Thus the valves II and I! may be set to confine the fluid pressure in the chamber between any two respective predetermined maximum and minimum values within the total range open to the apparatus.
The other end of the fluid line It is connected 5 to a control valve generally indicated at I8, and here shown as a conventional slide valve having a housing IS, a slide 20, a chamber 2|, a delivery port 22, an inlet port 23, and an exhaust port 24. The inlet port 23 is connected by a pipe or line 25 to the pressure output member 21 01? a fluid pump, fan or blower 29 of any suitable construction, and the exhaust port 24 is connected by a pipe or line 26 to the suction or exhaust inlet member 28 of the device 29.
The apparatus as here shown and-described is adapted to use atmospheric air as the pressure transmitting fluid, although theinvention is not limited to suchuse and may easily be modified in self-evident ways to create plus or minus pressures of other fluids, eithergas or liquid, within the chamber ID.
If, in the present embodiment, the device 29 be a centrifugal blower or the like as shown, the pressures in the chamber Ill and the larger variations thereof will be even and smooth.
.However, if a reciprocating pump or the like he used asthe element 29, the chamber pressures whether grossly constant or varying will be sec- 30 ondarily vibrant due to the pulsations produced by the rapidly recurring strokes of the pump.
The pump, fan or blower 29 is driven, as by a belt 30, from a motor 3|, here indicated as an electric motor of any suitable construction supplied with current by means not shown from a source not shown. However, if the device is to be used in a location where electric power is not available, any other suitable device may be used in place of an electric motor as the element'3l. A reduction gearing 32 and an adjustable speed changing device generally indicated at 33 are connected to the motor 3| to drive an adjustable cam device generally indicated at 34. The cam device in turn is abutted by a cam roller 35 mounted in one end of the slide 20 of the valve I8. Devices 32, 33 and 34 may be of any suitable and known constructions appropriate to their respective functions.
The open end of the chamber I0 is provided with a removable and interchangeable sealing device. Thls sealing device comprises a pair of generally conical, flexible, and preferably elastic members 40 and ll of some suitable, fluid impervious materialsuch as rubber, rubber coated able impregnatingor coating material. The inner peripheries oi the larger-ends oi the members are proportioned to fit snugly over the outer periphery of the open end of the chamber as shown, to make a fluid tight joint therewith, while the respective inner ends of the members 40 and ll are proportioned to fit snugly but without excessive pressure around the human leg or other part to be treated. If desired or necessary, a sealing band 42 or the like may be used to hermetically seal the joint between the chamber wall and the members 40 and 4! as shown. The members 40 and M may be separate cuffs or sleeves as shown or may be integrally united in a fold under the band 42. i
In operation of the device as shown, a human limb to be treated is placed in the chamber as indicated in dotted lines with the sealing members applied to the limb substantially as shown in the drawing, to be effectively snug but preferably not tight enough to interfere with the blood circulation therein. The valves H and I4 are then adjusted to prevent any pressure variation above or below the desired maximum and minimum values. The speed change device 33 is adjusted to drive the cam device 34 at the speed necessary to produce the desired frequency oi cyclic operation oi the slide 20. The cam device 34 is adjusted to produce the desired form or nature of motion of the slide within each cycle, and the motor device 29 is started.
In the position of the parts shown, fluid under pressure will be driven through the line 25, port 23, port 2!, pipe l6, and valve il into the chamber until the desired maximum pressure therein is reached, when the valve i1 will operate to prevent any iurtherincrease of pressure. Meantime, air ior this purpose is supplied to the blower from the outside atmosphere through an intake port 36 in the slide valve, and the line 26. After a predetermined time dependent on the adjustment of both the devices 33 and 34, the cam device 34 actuates the slide 20 to close the ports 38 and 23, and to open the port 24 and also a port 31 in the slide valve, the latter port opening into the atmosphere. The device 29 now draws air from the chamber i0 via the line it, port 24 and line 26 and exhausts through the line 25 and the port 31, thus reducing the pressure in the chamber to the predetermined minimum at which the adjustable valve ll opens to admit air to the chamber. Again after an interval dependent upon the adjustment of the-devices 33 and 3|, the slide 20 is actuated to close the ports 31 and 24, and to open the ports 38 and 23, whereby the entire cycle begins again.
In practice the various cooperating parts may be so proportioned and connected that the time required for one complete cycle of operation may be varied from a minimum of the order of ten seconds and a maximum of the order of three minutes, while the maximum and minimum pressures in the chamberv l0 may in some cases be respectively of the order of ten to thirty millimeters of mercury above and sixty to one hundred millimeters of mercury below the prevailing pressure outside the chamber. The ratio of time of plus pressure to time oi minus pressure within a cycle oi operation may preferably be ad!- justable by means of the device 34 from substantially an entire cycle oi plus with substantially no minus to vice versa. Also, if desired, the slide and the ports oi the valve ll may be so proportioned and arranged in a self-evident way that there-wlll-be periods in each cycle oi normal pressure between periods of positive and negative pressm'e.
It is to be particularly noted that during periods oi minus pressure in the chamber it, while the member 40 may tend to be lifted irom the limb by greater pressure on its outer side than on its inner, the member I is applied more clomlyto the limb by the same condition; and when there is plus pressure in the chamber, the member 40 is held in sealing relation to the limb by greater pressure on its inner than on its outer side. Thus a close seal is maintained by the sealing device comprising the two members 40 and H without necessitating any such pressure thereof on the limb as would interiere with the natural circulation, normal or abnormal in itself, in the limb. If the member 4| alone were.
used, the elastic constriction of the member about the limb would have to be depended upon to seal against plus pressure; while if the member All alone were used, its elastic constriction would only resist breaking the seal by minus pressure.
It is also to be noted that by using the inwardly conical ring 42 to constrict the edges of the sleeves 40 and 4| against the outwardly conical wall of the chamber ll, means are provided to hermetically seal the joint between the wall and the member 40 and also the joint between the members 40 and 41 when the latter are not made in, one piece. In either event there is no perforation of the wall II or of the members 40 and H for the passage of bolts or other clamping means.
As the treatment is found to be effective among other things in certain affections oi the vascular system involving obstructions or hindrances to the normal flow of blood therein, it is important that the possibly abnormally difllcult flow be not additionally interfered with during treatment by unnecessarily or avoidably tight ligatures or constrictions of any kind.
The apparatus as herein disclosed is shown as adapted for and applied in use to a leg, but the invention is not limited to such use only but may he obviously modified by mere change in dimensions to be used on other or more extensive portions of a body.
The times and ratios relative to the cycle and frequency of operation above described are merely illustrative, and an apparatus embodying the invention may be constructed to have substantially any desired combination oi values and variabilities oi values in these respects. The embodiment of the invention herein described is illustrative only and may be widely modified and departed from without departing from the spirit and scope of the invention as pointed out in and limited solely by the appended claims.
What is claimed is:
1. In a therapeutic apparatus having a chamber adapted to receive a limb to be treated through an aperture in the wall thereof and having means to produce positive and negative fluid pressures within the chamber, a sealing device for sealing a limb extending through the aperture into the chamber to the chamber wall, said sealing device comprising a pair of sealing members each extending from the chamber wall to the limb, and means for hermetically sealing the joint between the sealing members and the chamber wall, one member being effective to prevent the passage of fluid between the member and the limb when the pressure within the chamber is positive and the other member being similarly eflective when the pressure is negative.
. 2. In a therapeutic apparatus having a chamber adapted to receive a limb to be treated through an aperture in the wall thereof and having means to produce positive and negative fluid pressures within the chamber, a sealing device for sealing a limb extending through the aperture into the chamber to the chamber wall. said 10 sealing device comprising a pair of flexible sealing sleeves each extending from the chamber wall to the limb, and a constricting ring for hermetically sealing the joint between the sealing sleeves and thechamber wall, one sleeve being effective to prevent the passage of fluid between the sleeve and the limb when the pressure within the chamber is positive and the other sleeve being similarly efl'ective when the pressure is negative.
ALVIN N. GRAY.