BACKGROUND

Field of the invention

[0001] The present invention concerns a device for relieving back pain.

Prior and related art

[0002] Pain in the lower back may range from temporary sore and aching muscles due to strain from exercise or normal household and work activities to chronic intractable pain.

Whatever the cause, back pain is incapacitating, and there are several known treatments and associated devices.

[0003] Supporting the spine is known to relieve back pain and for aiding restitution. Corsets and support belts for this purpose are well known. Some of these devices are either hard to use or provide inferior support. For example, there are corsets that provide excellent support, but require that someone else than the user tightens various straps or belts. Other corsets are easy to put on, but provide inferior support. In addition, some of these support devices are bulky and indiscreet.

[0004] While the medical cause of intractable pain is unknown by definition, some treatments are known. Some of these treatments involve drugs or surgery. Since 1974, so-called transcutaneous electrical nerve stimulation, hereinafter abbreviated TENS, has been used to relieve intractable back pain. TENS generally involves applying electrical pulses at a sensory level, i.e. below the level required to trigger muscle activity, at a frequency above 50 Hz, and should not be confused with electro motoric stimulation. After some time, e.g. about an hour, TENS become ineffective for relieving pain, as the nerves stops responding to the stimulation.

[0005] Heat treatment is also much used for relieving back pain. The treatment may involve hot baths, various balms that stimulate blood circulation and gives a heating sensation etc. In general, heating the skin to a few degrees above normal body temperature, e.g. 41-44 °C, is considered ideal to relieve back pain effectively while avoiding any risk for skin burns that might occur at higher temperatures. Like TENS, heat tends to lose its relieving affect after some time, e.g. after around 20 minutes of treatment.

[0006] The objective of the present invention is to provide a device that solves or reduces at least one of the problems above, while retaining the benefits from prior art. More specifically, the invention should provide a device that provides better pain relief than the above devices, and that is safe, drug-free, easy to use, discreet and comfortable to wear. The device should be suitable for use at home, and the user should be able to use it without assistance. SUMMARY OF THE INVENTION

[0007] This is achieved by the invention according to claim 1. Further features and benefits appear in the dependent claims.

[0008] More particularly, the invention provides a device for relieving pain, the device comprising a support belt, an electrode area, a heating area and a rechargeable main unit configured to provide TENS through the electrode areas and heat through the heating area.

[0009] The device is particularly suited for back pain, but similar devices may be adjusted for other parts of the body. For clarity, an active area is divided into an area for TENS, e.g. in the form of two separate electrodes arranged to contact the skin of a user, and a separate heating area. Thus, the electrode and heating areas may overlap partially or fully, they may be interleaved, and the electrode area may have different sizes relative to the heating area in different embodiments. The active area typically comprise wires for Joule heating and electrodes for TENS.

[00010] The TENS and heat functions can be combined or alternate as controlled by the user, while the support belt provides continuous and relieving support.

[00011] The device preferably comprises a back plate configured to provide torsional rigidity to the support belt, and may optionally comprise the electrode and/or heat area. This also improves rigidity transverse to the support belt.

[00012] The back plate may comprise magnetic connectors for the main unit. Such connectors provides convenient attachment, and convenient release for recharging after use.

[00013] The magnetic connectors may provide electric contacts from the main unit to an electrode area and/or a heating area in the back plate.

[00014] An area of the back plate may be made of a material that is sufficiently conductive to provide TENS and provides sufficient resistance to produce heat. This can be achieved, for example, by providing small cross sections in parts of a metallic material to provide resistance, or by doping a semiconductor to provide the TENS electrodes.

Alternatively, the active areas may be divided into alternating fields providing TENS and heat, respectively. Numerous other configurations are conceivable.

[00015] The support belt preferably comprises an adjustable tensioning belt. Thereby, the support belt may comprise an inner belt that is conveniently connected and kept in place by Velcro-strips while the user connects, and possibly adjusts, the adjustable tensioning belt for proper support. The tensioning belt takes up the load along the belt. If the Velcro or similar means were omitted, the user would have to hold the belt while connecting straps to provide the support. In addition, several straps might be required to prevent the ends of the support belt from moving relative to each other in the direction lateral to the length of the belt.

[00016] The main unit is preferably operated by a remote unit. This allows the user to control the TENS and heat functions manually, i.e. activate and deactivate the functions independent of a pre-programmed sequence. Moreover, it has been found that the ability to control the treatment has an effect on the pain relief.

[00017] The electrode areas may be provided with removable gel pads. Such pads could increase the comfort when wearing the device.

[00018] The gel pad may comprise e.g. a soft rubber or a gel filled bag. Preferably, the gel pad has a sticky side for attachment to the electrode area and a protective cover to cover the sticky surface when the gel pad is not in use. Such gel pads may be used for a limited number of times, e.g. around 20 times. Several such gel pads are preferably provided with the device, and additional gel pads may be purchased separately.

[00019] In some embodiments, the main unit comprises storage configured to store a sequence of TENS and/or heat functions provided by the user. The storage could, for example, be configured as a circular buffer. This would enable the user to identify a sequence that turned out to provide superior relief for a particular condition, and download the sequence for later use.

[00020] In some embodiments, the remote unit comprises a processor for executing a sequence of TENS and/or heat functions. In these embodiments, the remote unit could conveniently be a smart phone, a tablet, a PC or some other common device already comprising a processor, and suitable controls for the device could be provided as a software application in a manner known per se. The sequence may be pre-programmed or downloaded from a device with storage as described above. Either way, the sequence may include adjusting the intensity of the TENS within predefined limits, and enables the user to repeat a particularly effective sequence for a given condition in a convenient manner.

[00021] In addition or alternative to a processor in the remote unit, the main unit may comprise an embedded processor for executing such a sequence of TENS and heat functions.

BRIEF DESCRIPTION OF THE DRAWINGS

[00022] The invention will be explained in the following detailed description with reference to exemplary embodiments and the accompanying drawings, in which:

Fig. 1 illustrates the device according to the invention. Fig. 2 shows a remote unit for controlling the device,

Fig. 3 is a detailed view of a main unit,

Fig. 4 shows a USB cable for charging and communication and a preferred charger,

Fig. 5 shows an optional gel pad,

Fig. 6 illustrates connecting the USB-cable to the main unit, and

Fig. 7 illustrates steps required to assemble and put on the device.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[00023] The drawings are schematic and not necessarily to scale. For ease of understanding, numerous details known to the skilled person are omitted from the drawings and following description.

[00024] Fig. 1 shows a device 100 according to the invention. The device 100 comprises a support belt 101-104 and a chargeable main unit 300 for providing TENS and heat.

[00025] More particularly, the support belt has an inner belt 101a, b with a back plate 102 for support along the spine of a user. Preferably, the inner belt 101a, b is provided with Velcro for initial fastening, e.g. a Velcro strip on an inside of a right part 101a and a corresponding strip on an outside of a left part 101b, such that the user can fasten the inner belt comfortably around his or her waist by applying the right hand part 101b of the inner belt over the left hand part 101a.

[00026] Preferably, a tensioning belt 104, also comprising left and right parts, is attached to the outside of the inner belt 101a, b. The tensioning belt is provided with a lock designed to withstand forces along the belt. Thus, the tensioning belt may be tightened to provide a solid and comfortable support without any risk for inadvertent opening of the Velcro-latch provided in the inner belt.

[00027] A main unit 300 is attached to the back plate 102 by means of magnetic connectors 103. Electronic circuits in the main unit 300 and/or back plate 102 are configured to provide TENS, e.g. single channel asymmetric biphasic square pulses with amplitude 0-160 mA and 0 - 80 V (adjustable at 500 Ω load). The pulse frequency is preferably above 50 Hz, e.g. 59 Hz, and the pulse width might be about 200 μ8. We note that this intensity is below the level required for electric muscle stimulation, and is found beneficial for relieving back pain. The TENS pulses are applied to the skin of the user through electrodes 301. [00028] In a particularly preferred embodiment, the TENS circuit is provided with a timer that limits the treatment to 60 minutes. A pause of 30 minutes is recommended before a new TENS treatment is started.

[00029] The main unit 300 comprises a chargeable battery for storing the energy for TENS and also for providing heat through the back plate 102 and/or electrodes 301. In a particularly preferred embodiment, the heat is supplied at a temperature of 42 °C and a timer is provided to turn off the heat after 20 minutes.

[00030] Fig. 2 shows a remote control 200 for controlling the main unit 300. By using the remote control 200, the user does not need to remove the support belt in order to access buttons on the main unit 300, and there is no need to provide control buttons on the belt, e.g. outside the part 101a of the inner belt. The remote unit 200 as shown comprises the following controls: Remote unit On/Off 9, TENS On/"+" button 10, TENS Off/"-" button 11, HEAT On/Off button 12, TENS signal light 13 and HEAT signal light 14. These controls allow the user to wear the support belt, e.g. at home, all day if desired, and to control the device in a convenient and safe manner.

[00031] Fig. 3 shows the main unit 300 in greater detail. In this embodiment, the main unit comprises the electrode areas 301 described above, and a housing 302 for electronics and a chargeable battery, e.g. a Li ⁺ -battery. A Main unit On/Off switch 7 and a Main unit Indicator light 8 are provided on the main unit 300, as they need not be accessed by the user while he or she wears the belt and as this location simplifies the design of the remote unit 200 and main unit 300. In particular, there is no need for a standby mode in which the main unit saves power and merely waits for an On-signal from the remote unit.

[00032] The Main unit Indicator light 8 preferably comprises an LED that indicates active, inactive and charging states, for example Off: no light, Charging: blinking light and On: steady light.

[00033] Fig. 4 shows a USB cable 401 and a charger 402 with contact pins for a domestic mains outlet and a port for the USB cable 401. The main unit 300 is charged though the USB cable 401, either from the charger 402 or from another USB -port, e.g. on a PC.

[00034] The USB cable may also be connected to a computer or similar device for other purposes, e.g. uploading firmware, software or a sequence of TENS and heat functions from a PC to the main unit 300 or download logs, i.e. usage data, from the main unit 300 to a PC or similar device. This is further described below.

[00035] Fig. 5 shows an optional gel pad 500 comprising a bag 501 with a protective cover 502. The bag 501 has a sticky surface for temporary attachment to the electrode area 301. The protective cover 502 is provided to protect the sticky surface when the gel pad is not in use. Each gel pad 500 may be used a limited number of times, e.g. around 20 and is intended for use by one user. Preferably, several gel pads 500 are provided with the device 100, and additional gel pads 500 may be purchased at a later time.

[00036] Fig. 6 is a perspective view of the main unit 300, and illustrates how the USB-cable 401 can be plugged into and withdrawn from the main unit 300.

[00037] Fig. 7 illustrate the steps required to use the device according to the invention. In step 1, the support belt is oriented with the magnetic connectors 103 at the bottom. In step 2, the tensioning belt 104 is adjusted. In step 3, the main unit is attached to the back plate 102 by means of the magnetic connectors 103. In step 4, the device is placed on the lower back of a user such that the two electrode areas 301 are placed beside the spine, one electrode area on each side of the spine. In step 5, the inner belt is fastened temporarily by applying the right hand part 101a of the inner belt over the left hand part 101b. This brings the Velcro-strips described previously in contact with other. Finally, left and right parts of the tensioning belt 104 are connected by an associated lock. The tensioning belt and associated lock take up loads along the belt, and provides a better and more reliable support than the support that can be provided by Velcro-strips on the inner belt.

[00038] We note that the remote unit 200 with controls can be implemented as a software application, for example on a smart phone, a tablet or other device comprising a processor and a suitable communication link, in practice an RF-based link. A generic processor and suitable storage in such a remote unit 200 and/or in the main unit 300 enables the user to identify sequences of TENS and heat functions that proved to be particularly effective for a given condition, and to repeat that sequence at a later time. The sequence may be pre-programmed or downloaded from a storage, e.g. flash memory, in the main unit. The actual distribution of memory and processing power between the remote unit 200 and main unit 300 is a design issue left to the skilled person.

[00039] While the invention has been described by means of examples, the scope of the invention is defined by the following claims.