MEDICAL DEVICEThe invention relates to a medical device for relief of back pain and more particularly to a pneumatically operated device which is cyclical in its phases of inflation and deflation, and which has provision for adjustments to assure most tolerable comfort in the course of a given treatment.
Many people suffer backache if they are obliged to lie on the back, and back pain is a major problem after surgical operations such as a hip replacement, in which case it is obligatory that the patient lie on his back.
To counter this problem, I have devised what I term a "BackPump." The cause of the back pain is immobility; in each position of the spine, be there flexion, extension or rotation, specific ligaments and joints are stressed and, after a short time, become painful, probably because their blood supply is or has become compromised. During natural sleep, this problem is overcome by frequent movements.
Briefly, the device of the invention is an inflatable pillow, shaped to fit in the concavity of the lumbar spine -the "hollows of the back. The pillow is inflated slowly over a period of one or two minutes and is then deflated, perhaps more rapidly.
The invention will be described in greater detail in conjunction with the accompanying drawings, in which:Fig. 1 is a simplified view in perspective of a bed or mattress, to which an inflatable device of the invention has been strapped so that a patient who must lie on his back, as after a hip-replacement operation, will be positioned for therapy through use of the invention the patient being shown only by phantom outline; Fig. 2 is an enlarged sectional view, of the inflatable device of Fig. 1, taken at 2-2 in Fig. 1, and shown inflated but without the patient;Fig. 3 is a view similar to Fig. 2, with a schematic indication of the patient's body section, at the lumbar region and gravitationally loading the inflatable device;Fig. 4 is an illustrative graph of inflation pressure verses time in one selected use of the invention;;Fig. 5 is a view in perspective of another inflatable device of the invention;Fig. 6 is a view similar to Fig. 2, for the inflatable device of Fig. 5;Fig. 7 is a schematic diagram of an automatically controlled pneumatic supply system for either of the inflatable devices of Figs. 1 and 5;Fig. 8 is a schematic diagram of another pneumatic supply system for either of the inflatable devices of Figs. 1 and 5; andFig. 9 is simplified diagram to illustrate two correlated functions in the system of Fig. 7, both functions being to the same time scale.
In Fig. 1, an inflatable device 10 in the nature of a pillow is of generally rectangular planiform and is to be understood as firmly referenced to a cot or bed mattress 11, via a strap 12 which may wrap the mattress, with ends removably recurred to each other or to the underside of device 10. The device 10 may comprise like upper and lower rectangular panels 13, 14 sealed to each other continuously around their periphery 15. Transverse tie elements 16 sealed to the respective panels establish local limits of inflated spacing between panels 13, 14, creating a tufted appearance. Preferably, the tie elements 16 are along two spaced parallel alignments, here shown as three spaced tie elements on a left-side alignment which is at short lateral offset inward of the left edge of the pillow 10 in Fig.
1, and as three further spaced tie elements on a right-side alignment which is at similar offset inward of the right edge of the pillow.
In use, a patient is so positioned on the bed that the small of his back, i.e., his lumbar spine region, is lapped by the device 10, presenting the sectional appearance of Fig. 3, wherein the patient's body section 17 is symbolized at the lumbar region. An electrically operated inflation pump 18 alongside the bed is connected by flexible hosing 19 to the inlet fitting 20 of device 10. For demonstration purposes, a commercial source of inflation/deflation control will suffice at 18, one of the Flowtron machines of the Huntley company being suitable, for example.
As suggested by the graph of Fig. 4, an inflation/deflation cycle for use of the invention may follow a pattern of relatively slow use in the course of one minute from a minimum, say, of about 10-mm Hg, to a maximum of about 50-mm Hg, with prompt release of inflation air, to produce a deflation rate which may be faster than the rate of inflation. Repetition of the cycle may commence roughly four minutes after commencement of the previous inflation. Also, a heavy dot-dash line in Fig.
4 suggests an optional retention of inflation pressure at the peak, thus delaying the deflation by what is shown as approximately one minute.
In the modification of Fig. 5, an inflatable pillow-like device 25 is again of rectangular planiform, to overall dimensions X1 by Y, wherein sealed edge seams are peripherally continuous and further wherein, in place of the tufted alignments described for Figs. 1 to 3, the upper and lower panels are further sealed to each other on spaced parallel left and right alignments 26, 27. This relationship sets the stage for three independent inflatable volumes 28, 29 and 30, which preferably have internal short tubular interconnection, suggested in Fig. 5 at 31 between the large central inflatable region 30 of dimensions X2 by Y and the left-side inflatable region 28', and at 32 between the central inflatable region 30' and the right-side inflatable region 28'. A single supply tube connection 33 suffices, at a corner of the central inflatable region 30'.It is preferred that check-valve structure be associated with each of the interconnections 31, 32, such that volumes 28, 29 will remain inflated while the central volume 30 is subject to the inflation/deflation cycle of choice. The check valves of internal connections 31, 32 are not shown inFig. 6, but they are schematically indicated at 31', 32' in Fig.
7.
In Fig. 3, as applied for the modification of Figs. 5, 6 and 7, the central area 22 of device 10, i.e., the inflatable region between the respective rows of tie elements, bears the brunt of body weight, leaving the left (23) and right (24) regions at such relatively great inflation as to develop a measure of lateral stability for the patient's body. He is in effect cradled by and between the more greatly inflated leftside and right-side regions 23, 24, thus gently restraining him from twisting or turning his body as his physician's order remains for him to stay on his back.
In the system of Fig. 7, the inflatable device 24 has already been identified and described, but the inflatable device 10 of Figs. 1 to 3 may be equally well served by the same system. The system shown operates from a household or other electric-mains connection 35 to relay means 36 which is shown to include manual means for selectively starting and stopping operations. Relay means 36 provides electric power to the motor M of an air pump P having a check value 37 in its output-line flexible connection 38 to the inflatable device 25. A solenoid valve 39 in an exhaust line 40 will relieve inflation pressure in device 25 (or 10) when solenoid valve 39 is in open condition, such relief being subject to a rate determined by the setting of a throttle valve 41 in line 40.A pressure-sensitive switch 42 having a sensing connection to line 40 will be understood to have first normally open contacts which close to supply excitation voltage to solenoid value 39 when an upper limit of pressure is achieved in lines 38, 40; this circumstance can open line 40 for relief of inflation pressure in the inflatable volume 30, but volumes 28, 29 will remain inflated due to check-valve action at 31, 32'. The level at which discharge of inflation air thus commences can be selected by manual adjustment at 43, as to an upper level of 50 mm Hg. A branch connection 44 from the same outlet of switch 42 is shown to relay means 36, for shutting off motor M.
The pressure-sensitive switch means 42 will be understood to have second normally open contacts which close to determine cut off of solenoid-excitation voltage upon sensed determination that a predetermined low pressure exists in lines 38, 40; at closure of these contacts, a further line connection 45 to relay means 36 will serve to reinitiate the described cycle or to provide a selectively delayed re-initiation thereof, by either directly, or after a predetermined delay, reconnecting electrical supply to motor M. Again, a low pressure limit for switch means 42 may be adjustably selected at 46.
In the inflation/deflation system of Fig. 8, a control means 50, with separate manually adjustable devices, as at 51, will provide the essential functions described in connection with Fig. 7, but operating entirely from a source of compressed air, as is so commonly available in a hospital, or as may be supplied from a suitably charged pressurized container, commonly available in rescue vehicles. Such a supply is schematically indicated at 52, in conjunction with a pressure-reducing regulator valve 53 in a line 54 to the control means 50.
Inflation via means 50 is direct to the device 25 via line 55, and deflation may be internally addressed within means 50, with discharge of inflation air at 56.
The coordination of solenoid operation and motor (M) excitation is demonstrated by the upper and lower graphs of Fig.
9, wherein solenoid valve 39 is seen to be closed with pump motor M running for the inflation part of the cycle to the point of motor disconnection and commencement of deflation, at the same time (e.g. at the 2-minutes time shown in Fig. 9). On the other hand, once switch 42 determines that the low pressure limit has been reached (e.g. at the 4 minutes time shown in Fig.
9), the solenoid valve 39 is closed, but the next inflation pumping may have to await lapse of a preselected delay in restarting the motor. In Fig. 9, such delay is shown to be one half of a minute, namely at time T = 4.5 minutes.
Clinical experience to date is encouraging. A patient who has had painful, fitful, sleepless nights, feels prompt soothing relief. Using the Flowtron device mentioned above wherein inflation pressure is adjustable from 30 to 90-mm Hg, a cycle of gradual inflation during 1 to 2 minutes, followed by a hold of about a minute (as suggested by the horizontal portion of the phantom line in Fig. 4), and rapid deflation over about 5 seconds can produce an immediately recognizable reduction in back pain, within two or three cycles of use. But it is also recognized that a cycle program that is best for one patient may not be best for another.My present thinking is that overall cycle time should be adjustable in the range of 15 seconds to five minutes, and preferably about 1.5 to 2.5 minutes, that gradual inflation should be selectable in the range of 10 seconds to about five minutes, and that deflation should be so adjustable (e.g. at 41) as to be in the range of 2 seconds to five minutes. Thus far, I have been unable to establish critical limits of these variables, for general use, with any greater certainty than expressed above for indicated ranges.
The construction of the devices 10 and 25 is not particularly critical. The rectangular planiforms shown are known to be useful but perhaps not optimal. The material of the pillow may be a woven fabric such as a light weight canvas with suitable elastomer sealing as by impregnation or lamination.
The dimensions given in Fig. 5 and currently preferred areX1 = about 18 inches (45 cm), Y = about 8 inches (20 cm), and X2 = 10 to 12 inches (25 cm to 30 cm).
The invention is not limited to the in-bed, lying-on-the back situation described above. What is believed to be important is that means be provided for intermittent gently urged local movement of the lumbar spine, at a rate which is relatively slow to build, and more rapid to restore in response to weight of the body. In the case of a 77 year old patient who has been ordered to lie on his back, use of the described treatment has been accompanied by disappearance of pain as his back has been forced to move; and if he has had no pain until he gets into his bed to lie on his back, the recurrence of pain can be prevented.
In other applications, the described inflatable pillow may be incorporated in the back of an automobile seat, with use of the cigarette lighter outlet in the vehicle to run the necessary pump and control functions. Also, the described inflatable pillow may be incorporated into a garment such that when the user is seated, as at his desk and with the pump and control functions detachably connected to the mains and to the pillow there can be a relief of his back pain; the pillow may be detachably retained to the garment, as by zipper closure of a suitable pocket forming part of the garment.