US 2223669 A
Description (OCR text may contain errors)
Dec. 3,`194o. 2,223,669y l J ."K. FORSHEE ErAL THERAPEUTIC METHOD AND APPARATUS Filed Aug. 6, 1936 4 Sheets-Sheetl 3' De@ 3. 1940 J. K. FoRsHEE E'rAL 'l 2,223,669
THERAPEUTIC METHOD AND APPARATUS Filed Aug. 6,- 1936 4 Sheets-Sheet 2 Dec. 3, 1940. J, K. FORSHEE ErAL 22231669 THERAPEUTIC METHOD AND APPARATUS Filed Aug. 6,l 1936 4SheetsSheet 4 IIN.
2f) IN' l Il. I r I l J2.. 7s un Patented Dec. .3, 1940 PATENT ortica A THERAPEUTIC BIETHOD ANDPPARATUS James K. Forsliee, Edwin S. Humphreys, and Earl J. Hasney, Aurora, Ill.,
Bentson, Aurora, Ill.
assignors to Henry G.
Application August 6, i936, Serial No. 94,642 11 Claims. (Cl. 12B- 373) The invention relates to improved therapeutic apparatus and methods of utilizing the samein administering treatments and more particularly to methods and apparatus for fever therapy.
5 Numerous diseases have been found to respond favorably Ato treatment by artificially induced fever which, in some cases, exerts a direct iniluence through its bactericidal effect and, in other cases, acts indirectly by stimulating certain W body functions, and by increasing metabolism.
Various devices have been proposed for producing the fever condition including diathermic devices for transmitting a current of electricity n through the body of the patient, and radiothermy i devices in which the patient is placed in an electrical field produced by an alternating current of extremely high frequency. Apparatus has also been proposed for producing fever condition by the external application of heat, and it is with the latter type of apparatus that the invention is particularly concerned.
The field of artificial fever treatment has been somewhat limited by reason of the inherent disadvantages in the apparatus heretofore available. With the electrical apparatus, for example, there is considerable danger of inflicting serious burns on the patient. The apparatus for the direct application of heat has been characterized' by the extreme discomfort to which it subjects the 3 patient, largely by reason of the high external temperatures necessary to produce suilicient body temperature to obtain beneficial effects. More-4 over, while many of these devices have been more or less effective in producing fever conditions they f provide no means for positively controlling body temperatures. As a result, it is frequently found that there is an upward coasting of the patlents body temperature afterthe application of fever producing energy has been discontinued, with 4U occasional serious and even fatal results to the patient.' v
With the 'foregoing in view, it is the general object of' the present invention to provide improved methods and apparatus by which the disadvantages above set forth are effectually avoided, and by which the fever treatment may be administered with a minimum of discomfort and in a manner entirely safe to the patient.
and exact control of the patients body temperature, and to effectually prevent upward coasting of the same after the desired temperature is reached.
A further object is to provide an improved fever therapy cabinet having in combination with controllable means for supplying heat and moisture, 5 a cooling unit operative to reduce positively the relative humidity of the air in the cabinet.
Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings illustrating a preferred embodiment of the improved treatment apparatus, in which:
Figure l is a longitudinal, sectional view of a heat treatment apparatus embodying the features of the invention. l5
Fig. 2 is a transverse sectional view taken the line 2--2 of Fig. l.
Fig. 3 is a fragmentary plan view of certain of the control instrumentalities shown in Fig. 2.
Fig. 4 is a sectional view taken along the line 20 t-t of Fig. 1, showing the air conditioning equipment comprising a part of the improved treating apparatus.
Fig. 5 is a schematic representation of the electrical operating and control circuits of the appaf3 ratus.
Fig. 6 shows a modified form of the air conditioning unit and associated actuating and control mechanism.
Generally stated, the improved therapeutic ap- 3i' paratus comprises an elongated cabinet adapted to form a substantially air tight treatment chamber enclosing a portion of the patients body.
Preferably, the cabinet is of suiiicient length to accommodate a patient in a recumbent position, 3f the patient being supported bya suitable cot or stretcher4 preferably arranged to be moved into4 and out of the cabinet to facilitate handling of the patient before and after treatment. One of the end members of the cabinet may conven- 4l iently comprise a part of the cot assembly whereby the` cabinet is closed when the cot is moved into the'same and opened when the cot is Withdrawn. This end member is provided with a suitable opening through which the patients head 45 along Amay project during treatment.
Disposed within the cabinet is an air conditioning unit of novel and advantageous construction, automatic control devices for the unit, and means for circulating the conditioned air 50 through the chamber in a manner designed to -produce the most favorable reactions in the patient. The air conditioning unit includes a source of heat for heating the cabinet and a source of cold -for cooling the same. The latter is a par- 55 ticularly valuable feature, as it permits the temperature of the chamber to be quickly lowered at will, and thus provides a means for accurately controlling the patients body temperature. Suitable means is included in the air conditioning unit for varying the relative humidity of the air in the cabinet under accurate control. Manually adjustable automatic control mechanism associated with the unit coordinates theoperations of the various elements of the unit so that any 'reasonable desired temperature and humidity conditions may be established and maintained in the chamber. The term "air as used in the. speciication and claims is intended to embrace any suitable gas which may be used in the treatment chamber.
The circulating means provided in` the present instance is especially arranged to produce zones of different temperatures within the chamber. To this end it includes an air distributingvtunnel so arranged that the air is circulated at a comparativelyvslow rate at the rear end of the chamber,ywhereby the temperature at that end is maintained substantially above the temperature in the forward end of the chamber. Thus, a greater degree of heat may be applied to the extremities 'of the patient with highly beneficial results and with a minimum of discomfort to the patient.
Means is also provided for varying the air pressure in the cabinet either above or below atmospheric pressure. In its preferred form, this means includes a motor driven pump, together with suitable valve mechanism for connecting either the intake or discharge ports of the pump with the cabinet. Adjustable automatic control means is provided in the cabinet for controlling the operation of the pump to avoid undesirable extremes of pressure.
The therapeutic apparatus above generally Adescribed may be utilized to administer heat treatment according to any of the established methods heretofore employed. In addition, the apparatus lends itselfreadily to an improved method of treatment which is materially safer for the patient and which subjects the patient to a minimum of discomfort while obtaining the full benefits o f high body temperatures.
In carrying out the improved method of treatment, the patient is placed in the cabinet which may be substantially at room temperature. The
patient is then given a preliminary humidity treatment, without any substantial increase in the temperature of the chamber. In this preliminary treatment, the relative humidity of the air in the chamber is built up quickly to between and 90% by means of apparatus provided for this purpose in the air conditioning unit. 'I'he preliminary treatment stage may be maintained for a period of fifteen minutes or more, as determined by the condition and reactions of the patient. The relative humidity is then quickly reduced to the comfort zone which is i'n the neighborhood of 50% to 55%. At the same time, the heater of the air conditioning unit is started in the operation to raise the cabinet temperature to the desired point, the remainder of the treatment following along the lines of the methods heretofore employed orthe improved method to be described hereinafter.
The improved method of treatment above described is particularly advantageous in that it produces reactions in the body which tendto prevent excessive perspiration when heat is applied thereto for inducing a teven condition.
Thus, loss ofwater and chlorides is materially reduced, and the side reactions to fever such as nausea, tetany, heat prostration, etc., are substantially lessened or prevented.
The improved therapeutic .apparatus is particularly advantageous in carrying out an imthe cabinetis `then raised slightly above body temperature, and is maintained at this point until the patient exhibits a slight fever, as, for example, an increase of approximately one degree above normal body temperature. The cabinet temperature is then lowered rapidly to a point substantially below body temperature and is maintained'there until the patients temperature recedes, preferably an amount somewhat less than the rise obtained by the application of the heat; Application of heat is then resumed, the cabinet temperature being raised'slightly above the maximum temperature reached in the. previous heating stage and continued until the patient. exhibits the desired rise in body temperature, which may be slightly higher than that previously reached. The heat application is followed by another cooling period to reduce the patients temperature, preferably .by an amount somewhat less than the rise obtained in the preceding heating period. 'I'his cycle of alternate heating andcooling with corresponding increases and decreases in body temperature isv repeated until the desired maximum fever temperature isl reached, `whereupon the contrast treatmentv may be, discontinued and a steady cabinet temperature maintained, or ,the contrast treatment may be continued further with the patients temperature being varied between the maximum desired point and la. predetermined desired lower point. v
-It has been found that the alternate increase and decrease in body temperature contemplated by the improved method above described is considerably more effective in increasing metabolism than a straight increase in body temperature such as has heretofore been the practice. The results obtained in experimental uses indicate that the metabolic rate increases substantially as rapidly -during the recession of the fever a's it does during the increase thereof. Thus, when the primary consideration is simplyto increase the metabolic rate, the desired increase may be obtained at a-substantially lower body temperature than has heretofore been practical, which -is greatly to the 'advantage of the patient for reasons that will be readily aparent.
Under certain conditions, however, relatively high body temperatures are required to obtain the desired results, as for example the bactericidal eect of a fever condition. It has also been found that, with the contrast method of treatment, body temperatures as high as 106 degrees F., can be obtained in a relatively short time with cabinet temperatures not exceeding de-` grees F.,'whereas with prior treatment methods and apparatus, cabinet temperatures as high as v degrees F., have been the usual thing. The lower cabinet temperatures are much easier on the patient, both from the\standpoint of comfort and safety, and for this reason are to be 'las preferred over the higher temperatures heretofore employed.
Having in mind the foregoing general 'description of the improved therapeutic method and apparatus, themechanical construction of the preferred form of apparatus illustrated in the drawings will now be described in detail. Referring to Figs. 1 and 2, the cabinet which `forms the treatment chamber comprises a cylindrical metal shell 6, supported in a substantially horizontal position by a metal frame structure or base 1, arranged to rest on the door A. The cabinet is provided with a metal lining, which, to facilitate assembly, is constructed with an upper section 8, extending around the upper portion and sides of the shell, and a lower portion 9 extending around the lower portion of the shellv and overlapping' the edges of the section 8 to completely line the shell. AThe lining is held in spaced relation to the shell 6 by spacing members` I disposed at opposite ends of the shell, and the intervening space may be filled with suitabley insulating material II to prevent heat loss.
As herein shown the shell 6 is provide'd with annular end members I2 and I3 which serve to strengthen the assembly and provide a support for cover plates I4 and I5 closing the front and rear ends of the cabinet, respectively. Each end member is formed with an annular channel I6 adapted to receive the end of the shell, and a packing ring I1 of rubber or other suitable material is wedged into the channel around the shell to provide a substantially air tight seal between the parts. Tie rods I8 extendingthrough the space between the shell 6 and the lining and suitably secured to the end members I2- and I3 hold the parts together to form a sturdy, rigid structure.
To facilitate opening and closing of the cabinet, the end member I2 carries a plurality of hook shaped latch members I8EL adapted to coact with quick acting clamping devices I9 on the cover plate I4, which is utilized to close the front end of the cabinet.4 A soft rubber gasket I 9a is interposed between the member I2 and the cov'er plate to provide an air tight seal when the plate is drawn into engagement therewith by action of the clamping devices in cooperation with the latch members. The cover plate I which closes the rear end of the cabinet may be bolted or otherwise secured to the end member I3. As herein shown, the plate, is also utilized as a support for an air conditioning unit and other apparatus to be described in detail hereinafter.
A suitable cot or stretcher, generally designat- `ed by the reference character 2 I, is provided for supporting the patient in the cabinet in a recumbent position. As shown in Figs. 1 and 2, the cot comprises a pair of elongated side bars 22 joined by cross members 23 and secured at one end to the inner side of the front cover plate I4. The cross members 23 are suitably formed to constitute stretcher supports and to this end are provided with side rails 2d of wood or other suitable material extending longitudinally of the cot. A fabric strip 25 suspended between the side rails provides a-comfortable 4and sanitary support for the patient. Toenable the tension of the fabric sheet to be adjusted to meet the requirements of different patients, one of the side rails 241s mounted on a bracket 2B pivotally supported on the cross member 23 for movement to- -ward or from the other side rail. The bracket a pawl 28' carried on the crs member 23 and normally urged into engagement therewith by a spring 23, thus locking the bracket in any desired set position.
To facilitate removal andvreplacement of the 5 25a, within which is disposed an elongated rod 30 of metal or other suitable material. When the fabric sheet is 4placed in position, `the folds 25a and their enclosed rods 3U are drawn under edges of the sheet are formed with a hem or fold'10 the-lower edges of the side rails 24 with the rods 15 disposed at the rear thereof. Cam members 3i pivoted on the cross member 23 and bracket 26, respectively, are'arranged to clamp the rods 30 against the side rails when in operated position, and thus serve to hold the fabric sheet securely in place. To release the sheet for removal from the cot, the cam members are rocked out of engagement with the rods, thereby releasing the same and permitting removal of the sheet.
The cot 2| is arrangedto be moved into and out of the cabinet to facilitate handling of the patient before and after treatment. For this purpose, it is supported at its inner end by rollers 32 journaled ,on the side bars 22 and arranged to operate on a track formed by rails 33 extending longitudinally of the cabinet. The other end of the cot is secured to the cover plate I4 which, as shown in Fig. 1, is provided with legs 34 equipped with castors 35 adapted to rest on the iioor A. Thus the entire cot assembly including the stretcher and the cover plate may be moved easily relative to the cabinet to withdraw the stretcher from the cabinet so that the patient to be placed thereon and to be moved into the cabinet with the patient in place.
Referring more particularly to Fig. l, it will be observed that the cover plate I4 is especially formed with a view of permitting the patients treatment. To this end, the plate is provided with a suitable aperture 36 in substantial alinement with the top of the cot 2I. The vcentral portion of the plate I4 in which the aperture 36 is located is formed to lie at an angle relative 50y vhead to project from the cabinet during the plate I4 and surrounding the aperture 36 isf/an 55 annular frame 31 having an inwardly opening channel adapted to provide a seat for an inflatable rubber collar 38 which may be placed around the patients neck and inflated Within the channel. The collar 38 provides a relatively tight 60 seal for the cabinet without subjecting the patient to excessive pressure. A
An adjustable head rest is carried on the outer side of the cover plate for supporting the patients head during treatment. As herein shown,
the head rest comprises a fabric strip 39 anchored at .one end to a rod 40, carried on the plate I4 and at the other end to a roller 4I jour- 'naled on a rod 42 also carried by the plate. A manually operable clamping' member. 43 operatively associated with the roller 4I is arranged *to clamp the roller to the rod to hold the strip 39 in adjusted position.
In the particular construction illustrated in the drawings, the rails 33 constituting the cot supporting track are carried on brackets 44 extending transversely of the cabinet and disposed elements 46 at each end arranged to engage the lower edges of the lining 8 to hold the lining in its proper place.
In addition tosupporting the track rails 33, the brackets 44 are arranged to support an elongated, inverted, generally V-shaped trough '41 which denes an air distributing tunnel extending longitudinally through the cabinet below the cot 2I through which'conditioned air is supplied to the cabinet. As will be seen by reference to Fig. 1, the lateral edges of the trough d1 taper from front to rear so as to provide tapering, elongated openings 48 extending along each side of the cabinet. Preferably, the arrangement is such that the width of the opening increases gradually toward the front end of the cabinet Soth'at a greater volume of air is discharged into the front end of the cabinet than is discharged into the rear end thereof. By reason of this arrangement, the air is circulated at a substantially higher rate in the front end of the cabinet and the temperature at that point is materially lower than at therear end of the cabinet where air is circulated at a slower rate. Thus more heat is applied to the extremities of the patient vthan is applied to the upper part of the patients body, which is highly advantageous as heretofore ex- -plained sembled in a unitary structure and enclosed in a? housing providing a system of communicating compartments and passages arranged to direct the flow of air to the various elements in the proper sequence.
The heating element 50 may be of any suitable type suchas the electrically energized resistance heater illustrated. The cooling element 5I likewise may be of conventional construction, the element illustrated being a cooling unit such as is ordinarily used in domestic refrigerators and includes a cooling coil 53 with suitable radiating fins 54. Any suitable vmeans may be employed for supplying refrigerant to the coil 53.` In the preferred form of the apparatus, this means comprises a refrigerant compressor 54 arranged to be driven by an electric motor 55. Refrigerant is supplied by the compressor through a duct 56a to a receiver 58, thence by way of a duct 56 and an expansion valve 51 to the cooling coil 53, a -return duct 51 serving to return the refrigerant to .the low pressure side'of the compressor. In the present instance, the compressor and associated apparatus are mounted on a shelf 58 mounted on the frame 1 immediately below the cabinet 6.
The humidifying element 52 includes an'evaporating pan 6I) heated by an electrically energized resistance heater 6I of any suitable type. Water is delivered to the evaporating pan through a suitable tube 62 from -a storage tank 63. A needle valve 64 is provided to regulate the rate at which water is delivered to the pan and a solenoid operated valve 65 operated by a solenoid 66 is provided for controlling the now of water from the tank 63. As herein shown the tank is disposed within the cabinet and suitable connections generally indicated by reference character 81 are provided to permit lling from ,the out- 'side of the cabinet and for indicating the amount across the face of the cover plate. A pair of spaced flanges 15 extend inwardly from the flanges 1I and 13 respectively to denne the compgrtments 68 and 10 and the connecting passage 6 Immediately belowy the iiange 13 is a second chamber 16 formed by a generally arcuate flange 11 connecting at opposite ends to extensions of the flanges'12 and 14. The evaporating pan 6l) is mounted in this chamber below the compartment 68. Also mounted in the chamber is an electric fan 18""for discharging conditioned air into the air tunnel. As will be seen by reference to Fig. 1, thefan 18 is removably supported on l the cover plate I5 so that it may be readily removed for adjustment' or repair without disturbing the other elements of the air conditioning unit.
As herein shown, the compartments 6,8 and 18 and the chamber 16 are covered by a plate 41I! bolted or otherwise secured to the various flanges. An aperture in the plate 18 in alinement with the fan 18 provides an outlet through which the conditioned air may be discharged into the air tunnel. v'I'he plate 19 terminates at the flange 1I thus leaving the space above the compartments 68 and 10 open to the interior of the cabinet, thereby providing an outlet through which the air may be withdrawn from the cabinet for circulation through the air conditioning unit.
Preferably, two separate ports are provided in the ilange 1I for withdrawing the air from the cabinet. One port 80 communciates with the heating compartment 68 and the other port 8| communicatesnwith the cooling' compartment 1I). These ports are provided with hinged dampers 82 and 83 respectively, connected by an arm 84 pivoted intermediate its ends on a bracket mounted on the cover plate I 5. 'I'he arrangement is such that, when one damper is closed, the other is opened, and in the present instance the several parts are so balanced that the damper 83 will move into closed position and damper 82 will open under normal conditions. v
Suitable meansis provided for opening the -damper 83 and closing the damper 82 when reconnected by a rod 81 with an armature 88 of 'a 75 solenoid 89. When the solenoid is energized, the armature and connecting rod operate to move the damper 83 into open position and, Aat the same time, through the operation of the arm 84 the damper 82 is moved to closed position. Thus the air drawn from the cabinet may be directed selectively either through the heating compartment.68 alone or through the cooling compartment 10, passage 69 and heating compartment 68 in series.
As will be seen by reference to Fig. 4, the passage 69 opens into the lower end of the cooling compartment and into the upper end of the heating compartment. The cold air drawn fromthe cooling compartment is thus circulated over the heating element 50 and discharged through an outlet port 90 into the chamber 16 from which the air is delivered to the air tunnel. A hinged damper 9| at thedischarge end of the passage is arranged to prevent the iiow of air from the heating compartment to the cooling compartment without interfering, however, with air flow in the reverse direction. In the preferred construction, the evaporating pan 60 is located immediately below the outlet port 90 so that the water vapor produced thereby will be ithoroughly mixed with the air before being returned to' the cabinet.
It will be apparent that the above construction provides an air conditioning unit capable of delivering air at any reasonable desired temperavture and humidity. By opening the damper l82 the air may be circulated over the heating coil alone when desired. If a higher degree of humidity is required, water may be supplied 'to the evaporating pan 60 so that the heated air will receive ladditional water vapor. On the other hand, if it is desired to reduce the humidity while increasing the temperature of the chamber,
damper 83 may be opened so that the air drawn in from the cabinet is first passed over the cooling coil which, in this case, serves to remove excess moisture therefrom. The moisture thus collecting on the coils of the cooling element may be drained oi through'a suitable drip pan 92 and drain pipe 93 located below the cooling element.
After being dehumidied, the air is passed over the heating element 50 and discharged into the air tunnel .in the usual way. In this case, of course, operation of the humidifying apparatus is discontinued by interrupting the supply of -water to the evaporating pan.
When it is desired to quickly reduce the temperature of the cabinet, energization of the heating element 50 may be discontinued and the damper 83 opened so that the air is drawn over the cooling unit 5| and discharged without heating through the'outlet. port 90. If desired, of course, the coolV air may be given an additional moisture content by operating the humidifying apparatus in the usual way.
In the preferred form of the apparatus, autoi matic control devices are provided for controlling the operation of the various elements of the air conditioning unit so that desired temperature and humidity conditions may be established and maintainedwithin very close linits. These are arranged for accurate manual adjustment to provide a wide range of cabinet temperature and the .control mechating mechanism arranged to shift a movablev switch member 98 (Fig. 6) into operative engage- The thermostatic device 'may be of any.-
ment with either of two stationary contact members 99 and |00. A manually operable adjusting knob |0| is provided for adjusting the relative positions of the switch arm and contact members so that the device may be set to effect switch closure at any selected temperature. For convenience in effecting this adjustment, a graduated dial |02'is associated with the manual operating member. y
'I'he humidostat 9.5.may vbe of any suitable type, and in the present instance is mounted bodily within the cabinet. This device includesa movable switch arm |03 engageable with one or the other of two stationary contacts |04 and |05 to complete circuits to be described hereinafter. Manually operable adjusting means is provided for adjusting the device to eiect contact closure under the desired predetermined humidity conditions. In the present instance this manually operable means includes a knob |06 carried by a rod |01 having a bevel gear connection |08 (Fig.
2) with the operating element of the humidostat.
y switching mechanism for controlling an air pump motor to beV described hereinafter. A manually operable knob l2 equipped with a graduated dial H3 is provided for adjusting the pressure device.
As herein shown, the various control instrumentalities and their adjusting mechanisms mounted in a, housing ||4 secured to the outer shell 6 of the cabinet at a point where the various manual adjusting members may be conveniently reached by the operator of the apparatus. The housing is closed by a cover plate ||5 to protect the apparatus, the plate having a, suitable window ||6 through which the graduated dials |02, |09 and ||0 may be viewed.
Referring now to Fig. 5, the operation of the automatic control mechanism will be described briefly. 1n the embodiment illustrated, power for operating the apparatus is takenv from a line I|`| through a suitable switch I I8, operablemanually to open and close the line. The heating element 50 is bridged across the conductors of the line in series with the stationary contacts 99 and the switch arm 98 of the thermostatic device, so that when the temperature of the cabinet reaches a predetermined minimum point, the heating element will be energized. When the temperature of the cabinet rises above the predetermined minimum point, the movement of the switch arm 98 from engagement with the contact 99 serves to deenergize the heater. The contacts 99 and |00 are so positioned that, upon a further slight rise in cabinet temperature to a maximum`point of, for example, two degrees above the desired temperature, the switch arm engages the stationary contact |00 to complete a circuit for the damper operating solenoid 89. The solenoid opens the damper 83 and closes the damper 82, as previously explained, so that the air drawn from the cabinet is circulated over the cooling' element and, since the heating element is deenergized, cold air is delivered to the cabinet.
The humidostat 95 is arranged to control the damper solenoid 89 independently of the thermostat 96 to provide for passing the air over the cooling unit to dehumidify it with the heater either operating or inactive. T o this end the switch arm |03 is arranged to engage the sta-I tionary contact |04 when the relative humidity reaches a predetermined maximum point. The
humidostat also is arranged to control the valve operating solenoid 66 to control the supply of water to the evaporating pan 60. This control is eiected by engagement of the switch arm |03 with the stationary contact |05 upon the relative humidity reaching a predetermined 'minimum point.
In the illustrative embodiment, the heating coil 6| for the evaporating' pan is connected directly across the power line so that the c oil is energized at all times during the operation of the apparatus. To prevent over-heating of the pan, a thermostatic switch I9 is provided. 'I'his switch may be of any suitable type and is preferably connected in series with the heating unit 8 i.
The refrigerant compressor motor 55 is connected directly across the power line so that the cooling unit is available for use at -all times when the switch ||8 is closed. In order to maintain the temperature of the cooling element 5| at a uniform low'temperature, a thermostatic switch |20 of conventional type is connectedl in series with the compressor motor. l As shown in Fig. 4, this switch may be attached directly to the cooling coil of the element 5| in accordance with the usual practice in commercial refrigeration.
'I'he electric fan I8 is also connected directly across the power line so that the fan operates at all times when the main switch ||8 is closed. Thus, the air is circulated through the air -conditioning unit and cabinet at all times when the apparatus is in use.
In the preferred form of the apparatus, the air pumpmotor is connected to the power line through suitable switching mechanism controlled bythe pressure responsive device 0 and a manually operable switch |2|. The latter switch provides for disconnecting the pump motor Without interfering with the operation of the air conditioning unit when treatments are given at normal atmospheric pressure. 'I'he switch mechanism is arranged te stop the motor when a predetermined cabinet pressure either above or below atmospheric pressure is attained and thus guards against excessively high or low pressure in the cabinet.
As herein shown, the motor is arranged to drive a sui-table air pump |22 having an intake or suction line |23 and a discharge or pressure line |24. These two lines are connected to opposite ports of a four-way valve |25 which, in the present inventiongfis arranged for manual operation. One of the intermediate ports of the valve |25 is openv to-,the atmosphere and the other is connected by a tube |26 with the interior of the' cabinet. Thus, by operating i the valve, either thesuctionline y|23 or the pressure line |24 may be selectively-connected' with the cabinet so that the pump |22 will be 'eiective to raise'forrlower the cabinet pressure as' determined byfxthe settingv of the pressure vresponsive device'||0.-'-r:f-. l l
Asfshown'in l'Fign1 of.' the drawingsrthe tube,
V|26 fentersuthe cabinet through Ian aperture |21' formed in the lining 9 and shell 6. A tubular member |28 `secured to the shell 6 below the aperture and enclosing the end of the tube provides an air tight seal for the same and forms a well for receiving any water that may collect in the cabinet due to condensation or the like. A drain pipe |29 equipped with a valve |30 provides a convenient means of draining the co1- lected Water from the well.
lHaving in mind the construction and arrangement of the various elements of the preferred form of treatment apparatus above described, the
A operation of the apparatus and particularly of the vair conditioning unit and automatic control devices will now be discussed briefly. By way of example, it will be assumed that a patient has been placed in the cabinet and that the front cover plate I has been clamped in place. The cabinet may be at ordinary room temperature, as for example, 75 degrees F.
In the event that the patient is to be given the preliminary humidity treatment, the thermostat 94 will be set for the room temperature while the humidostat is set for a relative humidity of say 85%. When the main switch H8 is closed, the fan 'I8 and refrigerating motor are started and the heater 6| of the evaporating pan is energized. By reason of the adjustment, switch arm |03 of the humidostat engages contact |05 to close a circuit for the valve solenoid 68. The solenoid opens the valve 65 permitting water to vflow -from the tank 83 to the evaporating pan S0,
the rate of ilow and thus the time required to attain the desired degree of humidity depending upon the setting of the needle valve |54.v `The water vaporthus produced is mixed with the air and circulated through the cabinet by the fan 18. When the proper degree of humidityis reached, the switch arml |03 moves out of engagement with contact |05 thereby interrupting the circuit of the valve solenoid and permitting the valve to close and shut oit the flow of water to the evaporating pan.
At the end of the preliminary treatment period, the humidostat is manually set back to a lower point, as for example 50% relative humidity. Since the relative humidity of the air in-the cabinet is above this point, switch arm |03 will engage the stationary contact |04v thereby completing the circuit for the damper noperating solenoid 89. The solenoid opens the damper 83 and closes damper 82 so that the air drawn from the cabinet is circulated over the cooling element' 5| which is maintained at a' low temperature by the operation of the compressor 54 under control of the thermostat |20. Contact with the cooling element cools the air below the dew point, the moisture condensing on the coils of the element and the dehumidiiied air passing on through the unit and back to the cabinet. When the proper degree of humidity is attained. switch arm |03 moves away .from the contact |04 to' deenergize the damper solenoid and permit the dampers to return to their normal positions with damper 82 open and damper 83 closed.
At the same time the humidostat is set back, the thermostat 94 may be adjusted to call for an increase in cabinet temperature tov degrees F'. for example.Y As a resulto! this adjustment, -switcharm 98 engages contact 99 toenergize the` heating element 50 whereby'th'e dehumidied air "discharged from 'the cooling Ycompartment is kheated and the cabinet is raised to the desired temperature.' When the cabinet; temperature reaches 10U-degrees F., vthefswitch arm moves away from thecntact to deenergize the heater.
Cabinet temperature is maintained at the desired point with slight variations under control of the thermostat 94. When the temperature falls below this point, the heater is energized by the engagementJ of the switch arm 98 and contact 99. In case the temperature rises to a predetermined maximum point which may be a degree or lso above the desired temperature, the damper solenoid will be energized to introduce cold air into the'cabinet due to switch arm 98 -engaging contact |00. When the temperature falls -to the desired point, the damper solenoid is deenergized to .discontinue the supply of cold air to the cabinet.
When it is desired to lower the cabinet temperature, the thermostat 94 is set accordingly and operates to deenergizethe heating element 5l) and energize the damper solenoid 89. During these temperature changes, the humidostat 95 operates to automatically maintain the proper degree of humiditymin the cabinet. A
The above described operations may be carried -on at 'normal atmospheric pressure or at 25 pressures either above or below. such normal pressure by placing the air pump |22 in operation. In this case, the pressure responsive device will be manually set to maintain the desired pressure in the cabinet.
'I'he modified form of the air conditioning unit shown in Fig. 6 is designed to provide means whereby extremely rapid cooling of the treatment chamberV may be effected with a refrigerating milt of yrelatively small capacity. To this end, the 35 refrigerant' compressor 54 is arranged to supply refrigerant Ito a cooling coil |3| disposed in a storage tank |32 containing a suitable fluid such the like having a low freezing point.
asroil or A pump' |33 driven by. an electric motor |34 is arranged -to circulate the cooledr fluid from the storage tank'through the cooling element 5|.
With this'arrangement, the uid in the storage tank may be cooled to a very low temperature during the idle periods of the treatment apparatus. Thus, a large volume of pre-cooled fluid is 4 available for immediate use when required, permitting the cooling element 5| to be operated at a substantially lower temperature than is practicable with the compressor directly connected thereto and thereby providing a convenient' "o means for very quicklycooling the treatment chamber. 3
The storage tank |32 may be of metal or of other suitable material and is preferably covered by a thick layer of insulating material |35 to pre- "5? vent thermal losses. The insulating cover may be vcovered by a suitable casing |36. With this arrangement; the thermostaty for controlling the operation of the refrigerant compressor motor 55 is mounted in the storage tank.
As will be seen by reference to Fig. 6, the housing for the air conditioning unit 20 is simplified in the modified form ofthe apparatus by omission of the inlet port 89 of the heating compart- 65 ment 68 and utilizing the inlet port 8| exclusively for withdrawing air from the treating-chamber. Likewise the dampers A82 and 83 and the associated damper operating mechanisms are dispensed with.
7o In the present instance.' the cooling element 5|.
is rendered effective only when it is required to cool the treating chamber or to reduce the humidity thereof.- To this end, a solenoid 89* connected in the control circuit in the same manner 75 as the 'solenoid B9 is arranged to control Athe operation of the pump d is energized under control of the thermostat 94 when the thermostat calls for less heat in the treating chamber and also under control of the humidostat 95 when the latter calls for a lower humidity. A switch |35 is closed by the solenoid when energized to complete the circuit for the motor |34. The other elements of the control system operate in the same manner as'in the preferred embodiment hereinbefore described.
It will be apparent from the foregoing that the invention provides new and useful methods and apparatus for fever therapy. By utilizing the improved methods,vthe full benefits of the fever treatment may be obtained with a minimum of discomfort and in a manner entirely' safe to patient. The loss of water and chlorides is materially reduced and the side reactions to fever 'are lsubstantially lessened or prevented. Moreover, metabolism may be increased and other body functions stimulated at external and body temperatures substantially lower than heretofore required for equivalent results. l
The apparatus provided for carrying out the improved and other therapeutic methods is efficient and reliable in operationand is subject to extremely accurate control. It includes novel y and useful structural features which greatly facilitate the handling of patients. It also includes air conditioning apparatus of improved construction, together with manually adjustable automatic control mechanism providing greatflexii bility of adjustment with extremely accurate control. The temperature to which the patient is subjected may be quickly raised or lowered at will. Humidity conditions may also be varied as desired to produce the most beneficial results.
' We claim as our invention: i
1. A therapeutic fever apparatus comprising, in combination, a cabinet having a chamber confining a body of air and adapted to receive the body of a patient to be treated, means for producing a motor |34. The solenoid v forced circulation of the body of air in the chamber, controllable means for supplying heat to the circulating body of air, controllable moisture supply means for increasing the moisture content of the air, and means comprising a cooling unit interposed in the path of the circulating air and operative when the heat and moisture supply means are cut off to effect a rapid and substantial reduction in the 'temperature and relative humidity of the air in the cabinet.
2.*A therapeutic fever apparatus comprising, i
in combination, a cabinet having a chamber coniining a body of air and adapted to receive the body of apatient to be' treated, means for producing a forced circulation of the body of air in the chamber, controllable means for supplying heat to the circulating body of air, controllable moisture supply means for increasing the moisture content of the air, and means including a cooling unit operative when the heat and moisture supply means are cut oil to effect a reduction in the temperature and a rapid and substantial reduction in the relative humidity of the whole body of air in the cabinet.
3. The method of artiflciallyinducing and controlling fever in the human bodywhich comprises subjecting the body of a patient under treatment to a conilned circulating body of air, supplying heat and moisture to the air, toinduce a desired degree of fever, and when the fever induced exceeds the desired degree-rapidlyand substandaily cooling the confmeibody of air m the i course' of its circulation to reducesits temperature 75 p and to sharply reduce its relative humidity and then recirculating it over the patient.
4. The method of inducing and controllingA fever in the human body which comprises subjecting the body of the patient to be treated to a circulating current of moist air heated to a temperature suflicient to induce fever in the body, and eiecting a sudden and substantial drop in y the relative humidity of the air circulated over the body to prevent an undesired increase in the internal temperature or pulse rate of the patient.
5. The method of artificially inducing and controlling fever in the human body which comprises subjecting the body oi"v a patient under treatment tient under treatment, initially maintaining the air circulating over the patients body at a temperature substantially above normal body temperature and maintaining such air at a high relative humidity of the order of 80 per cent, and
after such initial -period continuing the temperature of. the air owing over the patients body at a point substantially above normal body temperature but with the humidity of the air decreased to an intermediate value of the order of magnitude of 50 per cent relative humidity.
'7. A method of fever therapy for human beings in which at least a portion oi the patients body is heated to a temperature above normal body temperature in a closed chamber, which includes the step of checking sudden and inadvertent rises in the patients body temperature andvpulse rate above predetermined levels during the course of the treatment by artificially chilling a body of air to a temperature substantially below ordinary room air temperature of the order of 75 F. to dehumidify the same to value of relative humidity sharply below that previously prevailing inthe air about the patient and circulating the dehumidied air over the patient until the patients pulse and body temperature are reduced to a desired point.
8. The method cf fever therapy for human beings in which the major portion ofthe patients body including the torso andlimbs is disposed in a closed chamber, which comprises circulating heated air of high relative humidity 'over' the body of the patient until an articial fever of desired degree is attained, then passing the circulating body of air in said chamber over acooling unit having a temperature substantially below the freezing point of Water so as to reduce the' temperature of the airV passing over the patients ,body and at the same time extract moisture from the air to reduce sharply the humidity thereof, and continuing the circulation of said body of air over the cooling unit and the body of the patient successively until the patients pulse rate and body temperature are reduced to a desired point.
9. A method of fever therapyfor human beings in which at least a portion of the patients body is heated to a temperature above normal body temperature by circulating about it a conned body of heatedair, which includes the step of cooling and reducing the relative humidity of the conned body of air before recirculating it over the patient by passing it through a refrigerating unit in order to accurately and precisely control the temperature and relative humidity to which the patient is subjected within any desired limits irrespective of prevailing outside temperature and humidity conditions.
10. In a therapeutic apparatus the combination with a closed chamber dimensioned to receive the body of a patient, and means for heating the air conned within the chamber and circulating it over the patients body to induce a fevertherein, of means for artificially cooling and reducing the relative humidity'of the air trapped in the closed chamber and recirculating it over the patient.
11. In a therapeutic apparatus the combination with a closed chamber dimensioned to receive the body of a patient, and means for heating the air within the chamber and circulating it over the patients body to induce a fever therein, of a storage reservoir adapted to contain a body of low .freezing point liquid, refrigerating means for cooling the liquid in the reservoir to impart to it a large heat absorbing capactiy, and means for y circulating air from the chamber in heat exchange relation with the chilled liquid to sharply dehumidify the air and for then recirculating it into the chamber.
EDWIN. S. HUMPHREYS. JAMES K. FORSHEE. EARL J. HASNEY.-