Thermal pattern generator

Abstract: A sequence of temperature variations are produced on a surface by a plurality of spatially separated thermoelectric means controlled by an electronic controller. Time control means produces a delay of at least sixty seconds between reversals of temperature gradient between two of the thermoelectric means. The invention has useful application in the relief of pain in the skin. A microprocessor can be arranged to pre-program thermal patterns to be selected and the hot intensity, cold intensity and time delay between sequences can also be selected. Patterns of temperature variation include checkerboard patterns, hot and cold waves, alternating left and right and side temperature changes, etc.

Description: The present invention relates to a method and apparatus for producing a repeatable series of temperature patterns on a surface, for example by selectively and independently controlling the heating and cooling of Peltier-effect thermoelectric devices in an array with a programmable microcomputer. The ability to decrease pain through the use of heat and cold is generally known. The patent literature includes several disclosures of devices which apply either heat and/or cold to control pain, see for example, U.S. Patents No. 3,168,895 and 4,294,254. The following reference articles also describe useful background information: ICE MASSAGE AND TRANSCUTANEOUS ELECTRICAL STIMULATION; COMPARISON OF TREATMENT FOR LOW BACK PAIN R. Melzack, M.E. Jeans, J.G. Stratford and R.C. Monks, Pain, 9:209-217, 1980, Elsevier/North-Holland Biomedical Press EFFECTS OF LOCAL HYPOTHERMIA ON REFLEX AND VOLUNTARY ACTIVITY Sara A. Mecomber, B.S. and Richard M. Herman, M.D., Physical Therapy 51(3) : 271-281, March 1971 ICE THERAPY IN SPASTICITY Karl Hartirksen, Acta Neurol Scandinav, 38(3):79-84, 1982 ACTION OF COLD ON SPASTICITY Osvaldo Miglietta, M.D., F.A.C.P. American Journal of Physical Medicine 52(4) 98-205, August, 1973 THE THERAPEUTIC USE OF COLD John M. Mennell, M.D. Journal of the American Osteopathic Association 74 (12): 1146-1158, August 1975 A REVIEW OF CRYOTHERAPY Jane E Olson, M.A. Physical Therapy, 52(8): 840-953, August 1972 THERAPEUTIC HEAT AND COLD Justis F. Lehman, M.D., C. Gerald Warren, and Stewart M. Sham, M.D. Clinical Orthopedics and Related Research 99(3-4): 207-245, 1974 GENERAL PRINCIPLES OF THERMOTHERAPY G. Keith Stillwell in Therapeutic Heat and Cold, D. Sidney Herman Licht and Herman L. Kornentez, Chapter 7, pp. 232-239, Pubs. E. Licht, New Haven, 1965 PHYSIOLOGICAL RESPONSES TO HEAT AND COLD Sydney Fischer and Sidney Solomon, Chapter 4, pp. 126-159, Pubs. E. Licht, New Haven, 1965, Second Edition. Several prior art devices employ Peltier-effect devices for producing hot and cold temperature changes on or in the human body. In particular, note U.S. Patents 2,938,356; 3,207,159; 3,295,522; 3,618,590; 4,585,002; Reissue 26,276 and French Patent No. 2,579,888. In general the foregoing Peltier-effect devices employ one or more tiles acting in unison, and typically at relatively high repetition rates, to apply heat and cold to a part of the body. U.S. Patent No. 4,585,002 entitled METHOD AND APPARATUS FOR TREATMENT OF PAIN BY FREQUENTLY ALTERNATING TEMPERATURE STIMULATION, is typical in that it discloses a pain treatment device in which the Peltier thermoelectric units are turned on and off as a group with a frequency in the range of 5 to 30 seconds, and preferably with a period shorter than one minute. The invention set forth in this disclosure is different from the devices such as described in U.S. Patent No. 4,585,002 in that the period of the reversals of temperature grade in one sense between two thermoelectric means is greater than one minute and also in that a variety of different temperature patterns are applied to the affected area the thermoelectric means which create the temperature patterns being independently controlled. The variety of patterns is believed preferable to the predictable and monotonous application of heat and cold in that adaptation is not likely. Insofar as understood, none of the prior art inventions teach or suggest the present invention. SUMMARY OF THE INVENTION Briefly described the invention comprises a device and a method for producing a repeatable series of temperature change patterns as set out in Claim 1 and in claim 10 respectively. In one example, a microcomputer is attached to an array of Peltier-effect tiles arranged in an organized manner - for example, two rows of four tiles each. The array of Peltier tiles can be placed against the lower back in order to reduce lower back pain or on the forehead in the case of headaches or the like. A program selector includes between one and m toggle switches in a bank that permits the user to select a series of temperature change patterns or sequences. The program selector is connected to the microcomputer which scans the setting of the toggle switches and controls the array of Peltier-effect tiles to produce selected output patterns in series. It has been found that pattern changes with a period greater than one minute in this context appear to be quite effective. The program selector switches might be set, for example, to choose a wave pattern, then a checkboard pattern, then an alternating right and left side pattern, etc. Once the series has been run, it is repeated indefinitely until the unit is either turned off or the program selector switches are modified to produce a different series of patterns. The temperature extreme of the heating and cooling of the Peltier-effect tiles is controlled by a heat intensity control and a cold intensity control connected to the microcomputer respectively. The delay between sequences is controllable by a delay control unit. These and other features of the present invention will be more fully understood by reference to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block schematic diagram of the preferred embodiment of the invention. Figure 2 illustrates the setting of the toggle switches on the program sequence selector with Program Nos. 3, 5 and 8 shown selected. Figure 3 illustrates a typical series of temperature change patterns or sequences produced by the toggle switch settings on the program selector of Figure 2. Figure 4A is a perspective view of an array of Peltier-effect tiles attached to a corset for application to the lower back of a patient. Figure 4B is a cross-sectional, sagittal plane view of the Peltier-effect tiles applied to the lower back of the patient shown in Figure 4A. Figure 4C illustrates the microcomputer control console electrically attached to the corset applied to the lower back of a patient. Figures 5A - 5C comprise a detailed schematic view showing the specific elements which comprise the invention more generally illustrated in Figure 1. Figure 6A illustrates sequence No. 1 which comprises opposing waves starting with the tiles in the lower left hand corner and upper right hand corner hot. Figure 6B illustrates sequence No. 2 which comprises a wave starting with the tile in the lower left hand corner and the tile in the upper right hand corner cold. Figure 6C illustrates sequence No. 3 in which a pair of adjacent tiles are hot while the rest of the tiles are off and wherein the hot pair moves up the array like a wave, followed by a delay during which times all tiles are off. Figure 6D illustrates sequence No. 4 which is similar to sequence No. 3 in Figure 6C wherein a pair of tiles are cold while the other tiles are off and in which the cold pair travels up the array like a wave, followed by a delay. Figure 6E illustrates sequence No. 5 in which all of the tiles on the left are hot, and all of the tiles on the right are cold, followed by a delay, followed by a reversal of the pattern, followed by a subsequent delay. Figure 6F illustrates sequence No. 6 in which one tile on the left is cold, and one tile on the right is hot, which advances as a wave, followed by a delay, followed by a reversal of the pattern, followed by a subsequent delay. Figure 6H illustrates sequence No. 8 which comprises a checkerboard/wave combination, followed by a delay, followed by a reversal of the pattern, followed by a subsequent delay. Figure 6I illustrates sequence No. 9 which comprises a random pattern, but wherein the pattern of hot and cold does not change direction more often than once every 60 seconds, followed by a delay. Figure 6J illustrates sequence No. 10 in which alternate pairs of tiles are hot and cold, followed by a delay, followed by a reversal of the pattern, followed by a subsequent delay. Figure 6K illustrates sequence No. 11 in which alternate pairs of tiles become hot and then cold, advancing as a wave, followed by a delay, followed by a reversal of the pattern, followed by a subsequent delay. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT During the course of this description like numbers will be used to identify like elements according to the different views which illustrate the invention. The preferred embodiment of the invention 10 is illustrated in the block diagram of Figure 1. A portable, battery operated, microcomputer 12 is connected to and controlled by a program selector 14, a hot intensity control 16, cold intensity control 18 and delay time control 20. Microcomputer 12 is also connected to 8 control circuits containing digital logic and push-pull power amplifiers 24A-24H which in turn are respectively connected to 8 Peltier-effect tiles 22A - 22H. The Peltier tiles 22A - 22H are connected in an array 22 similar to that shown, for example, in Figures 4A and 4B. According to the preferred embodiment of the invention the microcomputer 12 comprises a R6500/1EAB3 microcomputer manufactured and sold by Rockwell International. The program selector 14 is shown in detail in Figure 2. Each of the 8 toggle switches 26A - 26H in the bank 14 is employed to select one of a group of different temperature sequences which may be generated on the tiles 22A - 22H. As used in this disclosure the term "pattern" is used to describe a fixed thermal pattern at a specific point in time (e.g. at the 16th second from the beginning of operation, i.e. second zero) and "sequence" means the thermal pattern over time which may or may not change as shown in Figures 6A - 6M. The term "series" is used to define a string of one or more connective sequences (e.g. sequences 3, 5 and 8 as shown in Figures 2, 3 and 4C) which preferably repeats after it gets to the last sequence in a string. A typical repeating series 28 of different temperature patterns or sequences is illustrated in Figure 3. Temperature series 28 is applied to the skin of a user through tile 22A-22H as shown in Figures 4A and 4B. A corset 34 holds the tiles 22A - 22H against the skin 32 adjacent the lower back 30 of the pain sufferer 36 as shown in Figure 4C. Corset 34 comprises an interior plastic foam layer 42 which supports thermoelectric tiles 22a-22h and is covered by an exterior elastic band 44. A hook and loop fastener material 40 such as Velcro® is employed to attach the two ends of the corset 34 together. The selectivity of the attachment material 40 and the elasticity of the outer layer 44 make it possible for the corset 34 to accommodate patients 36 having different sized waist measurements. Initially the patient 36 gets into the corset 34 which contains a plurality of thermoelectric tiles 22A - 22H arranged in a regular 2 x 4 array. The thermoelectric tiles 22A - 22H are positioned so as to be in direct contact with the skin 32 adjacent to the pain area. The invention 10 can also be employed to relieve pain in other areas such as the head in the case of headaches, neck pain, joint pain and the like. Patient 36 initially selects between 1 and m preprogrammed thermal sequences by the appropriate setting of the toggle switches 26A - 26H of program selector 14 as illustrated in Figures 2 and 4C. Patient 36 also selects the high and low temperature limits as set by the hot intensity control 16 and the cold intensity control 18 respectively as well as a delay time on delay time control 20. Delay time control 20 controls the time during which all of the tiles 22A - 22H are turned off. Hot intensity control 16, cold intensity control 18 and delay time control 20 may comprise three K-elements toggle switch banks or three 2 k -position rotary switches. In the embodiment shown in Figures 5A-5C K=2 and the control comprises three, two-switch toggle pairs. When powered the internal program of microcomputer 12 reads the hot intensity control 16, the cold intensity control 18 and the delay control 20 and sets internal parameters according to appropriate look-up tables. The microcomputer then proceeds in sequence to interrogate the state of each of the m (in this case 8) switches 26A - 26H in the program selector 14 as illustrated in Figures 1 and 2. If a switch 26A - 26H is on, then one cycle of the corresponding thermal sequence or pattern will be applied to the tiles 22A - 22H. If a switch 26A - 26H is off, the next switch will be interrogated immediately. For example, if switch 26D is off, then switch 26E will be interrogated next. After all of the switches 26A - 26H have been interrogated, the time series is repeated indefinitely. The following is a specific example of the sequence selection process. As shown in Figure 2, switches No. 3, 5, and 8 (26C, 26E and 26H) of an 8-switch program selector 14 are turned on. The microcomputer 12 first interrogates switch No. 1 (26A) Since switch No. 1 (26A) is off, the microcomputer 12 immediately proceeds to switch 2 (26B) Switch 2 (26B) is also off so the microcomputer 12 next tests switch 3 (26C) Switch 3 (26C) is on so the program jumps to the sequence subroutine represented by switch 3 which applies a pre-programmed thermal temporal-spacial pattern to the array of tiles 22A - 22H. In this case, for example, sequence No. 3 as shown in Figure 3 and 6C, might be a heat wave followed by a delay. When a given thermal sequence is completed control is passed back to the microcomputer 12 which resumes by testing the state of switch No. 4 (26D) and so forth. The series of patterns or sequences 28 produced by the setting of the switches in Figure 2 is illustrated in Figure 3. Since the minimum delay is 60 seconds, all sequences last longer than one minute. It is also true generally that within a given sequence the temperature of any specific tile 22A - 22H is never reversed (that is hot-to-cold or cold-to-hot) so that thermal gradients are never reversed more often than once per minute. The preferred operating range of tiles 22A-22H is 19 degrees celsius to 44 degrees celsius with a preferred cold temperature of 19 degrees celsius and a preferred hot temperature of about 41 degrees celsius. From the foregoing example it should be clear that the patient 36 has the unique ability to select different patterns or sequences of hot or cold cutaneous thermal stimulation simply by changing the switch settings of the program selector 14. This feature is deemed essential to avoid adaptation to thermal stimulus. According to the preferred embodiment 10 the entire device is powered by rechargeable batteries so that it is portable. Other examples of program sequences 28 are best demonstrated in a low-back model unit 34 which involves 8 tiles 22A - 22H arranged in a 2 x 4 rectangle lining the paraspinal muscles of the lower back 30 as shown in Figures 4A and 4B. Some possible sequences might be the following: Sequence No. 1 (Figure 6A) A pair of heat waves starting at opposing ends and on opposing sides of said array followed by a 60 second delay. Sequence No. 2 (Figure 6B) A cold wave, similar to sequence No. 1 above, in which a pair of cold waves starts from opposing ends and opposing sides of said array, followed by a 60 second delay. Sequence No. 3 . (Figure 6C) The lower two tiles 22D and 22H hot for 10 seconds, then the next pair of tiles 22C and 22G hot (with the lower ones 22D and 22H turned off) for 10 seconds, then the next pair 22B and 22F on (i.e. hot) for 10 seconds (with all others off) and finally the top pair 22A and 22E hot for 10 seconds, followed by delay time of more than 30 seconds. This sequence is referred to as a heat wave. Sequence No. 4 . (Figure 6D) A cold wave generated in a manner similar to the heat wave described in sequence 3 above. Sequence No. 5 . (Figure 6E) All tiles on the left 22A - 22D are hot while the tiles on the right 22E - 22H are cold for 10 seconds, then a delay of 60 seconds, then reversal of above pattern, i.e. tiles on left cold, right hot, then a subsequent delay. Sequence No. 6 . (Figure 6F) A sequence similar to No. 5 but as a wave, then a delay of 60 seconds, then reversal of the pattern, then a subsequent delay. Sequence No. 7 . (Figure 6G) A checkboard pattern of hot and cold tiles alternatively (e.g. 22A, 22C, 22F and 22H on hot with 22B, 22D, 22E and 22G on cold) for 10 seconds and then a delay of 60 seconds, then a reversal, then another delay. Sequence No. 8 . (Figure 6H) A checkboard pattern similar to No. 7 above except in the form of a wave, then delay, then reversal, then another delay. Sequence No. 9 . (Figure 6I) A random pattern in which the hot and cold tiles are turned on intermittently and do not change thermal direction more frequently then once per 60 seconds. Sequence No. 10 . (Figure 6J) Alternate pairs of tiles are hot and cold, followed by a 60 second delay, followed by a reversal of the pattern, then a subsequent delay. Sequence No. 11 . (Figure 6K) An alternating hot/cold pair wave, followed by a 60 second delay, followed by a reversal, then another delay. Figures 5A - 5C comprise a detailed electronic schematic of the elements which comprise the preferred embodiment of the present invention 10. The major elements which comprise the invention are identified in the table below. Element Description J2 Connector, 6 pin J1 Connector, 16 pin right angle Q5 NPN Transistor, (To-220); Model No. MJE3055T Q3 PNP Transistor, (To-220); Model No. MJE2955T Q2 NPN Transistor, (To-92); Model No. 2N3904 Q1, 4 PNP Transistor, (To-92); Model No. 2N3906 C8 Capacitor, 0.33 microfad C5 Capacitor, 10 microfad C1,2,3,4,9 Capacitor, 0.1 microfad R10 Resistor, 560 K ohm, 1/4 w R4, 7 Resistor, 50 ohm, 1/4 w R2 Resistor, 10 K ohm, 1/4 w R1,3,5,6 Resistor 1 K ohm, 1/4 w Y1 Crystal, 14 PIN DIP, 2MHZ SW1,2 Dipswitch, 16 PIN RP1,2 Resistor Pack 2K, 10 PIN SIP U6,7,8,9 I.C., 14 PIN DIP, Quad 2 Input Hand buffer, Model No. 138 U3,4,5 I.C., 14 PIN DIP, Hex Inverter, Model No. 104 U2 I.C., 40 PIN DIP, Microprocessor, Rockwell, Model No. 6500/1EB1 U1 I.C., 8 PIN DIP Timer, Model No. LM555 Microcomputer ports A and B control polarity and duration of power applied to the thermoelectric tiles, 22a-22b. The polarity of the power determines whether a given surface of a tile gets hot or cold. Each port contains eight bits and each bit is assigned for the control of a single tile, 22A-22b respectively. Port A controls whether tiles are powered or not, while port B determines whether tile surfaces that are in contact with skin get hot or cold when powered. Bit No. 0 of ports A and B (PAO, PBO in Figure 5B) controls tile 22a; bit No. 1 controls tile 22a; and so forth. The logic gates U6-U9 (2 input NANDs with open collector outputs) are arranged so that either both power transistors Q3-0 through Q3-7 and Q5-0 through Q5-7 in Figures 5B and 5C which are connected together in push-pull are turned 0FF in which case the respective tile is not active, or one or the other of the transistors (i.e. Q3-0 through Q3-7 or Q5-0 through Q5-7) is turned ON in which case the respective tile heats up or cools down. Under no conditions are both transistors turned ON as this would short out the power supplies. It is believed that the programming of the microprocessor 12 is within the skill of one ordinarily skilled in the art given this disclosure. Although the embodiment has been described in connection with apparatus for treating pain by creating a series of temperature patterns in a sequence on the skin adjacent the pain, it could be applied to any apparatus for creating a series of temperature patterns in a sequence on a surface and the method aspect of the invention could be used for any such application.

Claims: Apparatus for creating a series of temperature patterns in a sequence on a surface, said apparatus comprising : a plurality of spatially separated, thermoelectric means for producing a temperature change in said surface in response to an electrical input; electronic controller means connected to said plurality of thermoelectric means for independently controlling each of said thermoelectric means so that said plurality of thermoelectric means creates a sequence of temperature variation on said surface; and time control means for producing a delay of more than sixty seconds between reversals of temperature gradient in one sense between two thermoelectric means. The apparatus of claim 1 further comprising : program selector means connected to said electronic controller means for selecting at least one pattern from a plurality of possible patterns for reproduction by said plurality of thermoelectric means. The apparatus of claim 2 wherein said thermoelectric means comprises a means that can become hot and cold from an intermediate baseline temperature. The apparatus of claim 3 wherein said thermoelectric means comprises Peltier-effect means. The apparatus of claim 4 further comprising: hot intensity control means connected to said electronic controller means for controlling the hot intensity of said thermoelectric means; and, cold intensity control means connected to said electronic controller means for controlling the cold intensity of said thermoelectric means. The apparatus of claim 5 wherein at least one of said plurality of thermoelectric means is OFF during any given pattern sequence so as to produce the effect of a moving pattern of temperature change. The apparatus of claim 6 wherein said electronic controller means comprises a programmable microcomputer which continuously scans the setting of said program selector means thereby causing said thermal patterns to change in a repeatable series. The apparatus of claim 7 wherein at least one Peltier-effect means alternates between an on and off condition while at least one other Peltier-effect means alternates in an opposite direction between an OFF and ON position respectively. Apparatus as claimed in any one of the preceding claims wherein said thermoelectric means are arranged in a rectangular pattern and said controller means is arranged to produce a pattern selected from a wave pattern, a pattern in which the temperatures two diagonally opposite corners of the rectangular pattern vary in opposite phase with the other two diagonally opposite corners, a random pattern, and a two-wave pattern. A method of creating a series of temperature patterns in a sequence on a surface, said method comprising the steps of: (a) placing a plurality of temperature changeable, spatially separated, thermoelectric means on said surface; (b) independently varying the temperature of each thermoelectric means to produce changeable temperature patterns in a sequence on said surface; (c) introducing a delay of more than sixty seconds between temperature patterns in a given sequence before a reversal of temperature gradient in one sense for any given thermoelectric means with respect to another thermoelectric means of the plurality; and (d) repeating steps (b) and (c) above.

Inventors: CHIURCO ANTHONY A, LITTMAN MICHAEL G, CHIURCO, ANTHONY A., LITTMAN, MICHAEL G.
Applicants: THERMAPEUTICS INC, THERMAPEUTICS, INC.
Application year: 1989
Main classification: A61F7
IPC codes: A61F7