An ice bath

Abstract

An immersion ice bath for a human or animal, wherein the ice bath 10 comprises a receptacle section 12 for holding water 14 and a refrigeration system 16 for cooling the water 14. The receptacle secti

Description

Field of the Invention This invention relates to an immersion ice bath, particularly for a human or animal, and a method of operating the same. Background to the Invention Cold water immersion, in which a person is immersed in cold water, is becoming increasingly popular, particularly with people that have undertaken sporting activity. Some studies have suggested that cold water immersion and the use of ice baths improves health and sporting performance. Ice baths, which are used in cold water immersion, exist in various forms, including bins or plastics material containers filled with ice and water; however, there is a growing need for purpose-built ice baths, which are baths or tubs that are specifically designed for cold water immersion. Such ice baths normally comprise a larger receptacle region that is filled with water and ice. In recent times, such devices have been designed to incorporate a refrigeration unit to cool the water held therein and there are some devices in which the water receptacle of the ice bath is chilled to a temperature where ice forms on the inside of the receptacle. In ice baths with refrigeration units therein, oftentimes, prior to using the ice bath, the user must turn off the refrigeration system in good time before they wish to enter the ice bath. This allows any ice that has formed inside the receptacle section to defrost and detach from the internal surface of the receptacle. If the user does not turn off the unit in good time, there are safety concerns in respect of the user sitting on a layer of ice. When the ice has detached and floats to the surface of the water, it often needs to be broken up, which is undertaken by hitting the ice with a tool. This manual process can be dangerous, particularly in respect of ice chips coming off the block of ice when struck with a sharp implement. Additionally, striking the ice increases the risk of damage to the ice bath itself. GB2602584 discloses an ice bath in which ice is formed within the receptacle of the ice bath. After a pre-determined time, a defrost mode is activated and the ice is released from the receptacle. Additionally, due to the shape of the ice formed therein, the ice naturally breaks up. Where a refrigeration unit is employed in an ice bath, rather than simply pouring ice into a receptacle, ice formation within the ice bath is dependent upon a number of factors, including the ambient temperature, the insulation of the receptacle and the ambient humidity. Additionally, the water quality may need to be taken into account, particularly in respect of any impurities that might be present that could affect the temperature at which the water freezes, for example, if salts and other contaminants are present in the ice bath, for example from users entering the water when sweaty or dirty. Summary of the Invention Accordingly, the present invention is directed to an immersion ice bath for a human or animal, the ice bath comprising a receptacle section for holding water and a refrigeration system for cooling the water, wherein the receptacle section can be chilled by the refrigeration system to create ice therein, and wherein the ice bath is provided with an ice detection system to detect ice formation within the ice bath. Thus, the present invention is in the form of an ice bath, into which is incorporated an ice detection system that can determine whether ice has formed within the receptacle of the ice bath. It is preferable that an internal surface of the receptacle is cooled so that a layer of ice forms on the internal surface of the ice bath receptacle. In a preferred arrangement, the ice bath is provided with a refrigeration section that cools the receptacle section of the ice bath to a low temperature so that ice can form on the internal surface of the receptacle section, for example, minus 10 degrees, although between minus 4 degrees and zero degrees may be sufficient. The internal surface that is cooled may be the side and / or the base of the receptacle, or another internal section. The ice should be formed within water, or other liquid, that is held in the receptacle. Thus, ice can be formed on any internal surface of the ice bath. Preferably, the ice detection system comprises a sensor and a central processing unit, and wherein the signal from the sensor is provided to the central processing unit. The central processing unit can monitor the signal from the sensor to determine whether ice has formed. Additionally, the thickness of any ice layer may be calculated from the signal received from the sensor. It is advantageous that when the signal received from the sensor of the ice detection system reaches a predetermined threshold, the central processing unit stops the refrigeration system, and it is particularly advantageous that the ice bath further comprises an ice release system. This means that when the refrigeration system is stopped, the ice release system can be started. Sthe ice release system can release any ice that forms on the internal surface of the ice bath. In one arrangement, this may be a heating arrangement that warms the receptacle to detach the ice. Where the receptacle is metal, the cooling and heating system(s) can be placed on the external side of the receptacle section and the cold / heat conducted through to the internal surface. The present invention can be incorporated into an ice bath having a receptacle section and a temperature control element adjacent thereto and arranged to adjust the temperature of the receptable section, wherein, the temperature control element is connected to: a refrigeration module that reduces the temperature of the receptacle; and a heating module that increases the temperature of the receptacle. The refrigeration module, or unit, is arranged to cool the receptacle and to create ice on an internal surface of the receptacle. Once a layer of ice has been created on the internal surface of the receptacle, the heating module can be employed to raise the temperature of the same surface of the receptacle to a degree at which the ice detaches from the internal surface. As a result, the ice will float to the surface of the ice bath. The use of the defrost module, or heating module, allows for the ice to be released at a particular thickness, which can be determined from the signal from the sensor. Ideally, the heating module will quickly release the ice from the internal surface of the receptacle, without significantly increasing the temperature of the water. Thus, the heat from the heating module can be relatively high to allow for quick release of the ice, after which the heating module can be turned off again to avoid heating the water in the ice bath. The sensor can be used to determine when the ice layer has been detached from the internal surface of the receptacle, thereby signalling when to shut off the heating module. In one arrangement, the sensor is an optical sensor that receives a light from a light source, such as a beam of light, and wherein the light received by the optical sensor is attenuated upon the formation of ice. The sensor may receive light directly from the source or it may receive a reflected signal. It will be appreciated that the received signal will change, and may be reduced, as ice forms in the route between the light source and the optical sensor. The ice layer may disrupt the reflection of light so that less light is reflected to the optical sensor. Where an optical sensor is employed, the optical sensor can be positioned in the base of the receptacle and the light source is supplied by a laser positioned thereabove. As set out before, the light may be reflected onto the sensor, so the optical sensor may be positioned in a different location, such as adjacent the light source. The light source may be a laser, a light emitting diode arrangement or another source. Additionally, the light may be in the visible spectrum, or it may be outside the human visible range, for example, ultraviolet light. It is preferable that the light source, is a laser that is contained within a protective case adjacent an edge of the receptacle. By having the light source contained within a protective case, the light source is less likely to become damaged. Additionally, the path between the light source and the optical sensor may be protected, for example by a cage, to prevent contaminants entering the optical path, which could cause a false positive reading. When using an optical sensor and a light source, the refraction between water and ice at the boundary where the state change occurs. The system can be calibrated when the water is at a known temperature where no ice will be present, for example, five degrees. In an alternative arrangement, the sensor may be a capacitive sensor that measures the capacitance of the water within the receptacle, wherein and ice formation changes the capacitance sensed. The single capacitive sensor can be placed onto the internal surface of the receptacle of the ice bath to monitor the state of the water in contact with the internal surface. As the water changes state, the capacitance changes accordingly. It will be appreciated that a plurality of capacitive sensors can be placed within the receptacle. In another arrangement, an acoustic system can be used to identify ice formation. Preferably, the acoustic detection is employed through use of ultrasound, which is considered to have a frequency above 20 kHz, although other frequencies may be possible. Thus, an acoustic emitter is directed at the receptacle and a transducer monitors the returned signal. The acoustic emitter may be continuous, or it may pulse. Where a pulsed signal is emitted, the timing of the pulse can be set according to the anticipated speed of freezing the liquid in the immersion ice bath. An advantage of an acoustic system is that the acoustic emitter can be located externally of the receptacle, which is to say that water is contained within the receptacle and the source of sound can located on the opposite, external side of the receptacle, thereby keeping it dry. The signal is emitted towards the ice bath receptacle and the returned, reflected, signal is monitored. As ice formed on the internal surface of the receptacle, the reflected signal differs from that received when no ice has formed, thereby indicating that ice is created on the internal surface of the receptacle. It may also be possible to determine the thickness of the ice formation using the system. A single acoustic emitter and corresponding receiver may be used; however, it is preferable that a plurality is used so that various points on the receptacle can be monitored. Using a plurality of emitters and receivers can also check the uniformity of the ice formation. The emitters and receives may be set out in a two-dimensional array or in a one-dimensional array, depending upon the position(s) on the receptacle that require monitoring. The heating and cooling of the receptacle may be controlled by a temperature control element which may be in the form of a single element that can be used to both cool and heat the receptacle, for example a fluid-containing conduit. Alternatively, it may be in the form of two or more elements in which one of the elements is used to cool the receptacle and another is used to warm the receptacle. For example, a thermoelectric cooling module may be used for cooling the receptacle and a heater element, which may be electric may be used for heating the receptacle. It will be appreciated that the use of electrical components may be disadvantageous in an ice bath where water and condensation may be present. The temperature control element, in one arrangement, may be an evaporator for use in a refrigeration process. It will be appreciated that “heat”, “cold” and similar words herein are used as relative terms. Thus, “heat” and “cold” are relative to the temperature of the water inside the ice bath and / or the temperature of the receptacle wall. As such, whilst “heat” may flow to the receptacle wall through the temperature control element, it may be that the flow is only a degree or two warmer than the temperature of the receptacle wall or relative to the water within the receptacle. In some arrangements, it may be desirable to have the warm flow at a temperature significantly more than the temperature of the water and / or receptacle. A valve may be connected to the temperature control element and the valve is further connected to both: the refrigeration module; and the heating module, wherein the heating module comprises a heat storage unit; and wherein, in a first state, the valve allows the movement of heat away from the temperature control element to decrease the temperature of the receptacle section; and, in a second state, the valve allows the movement of heat from the heat storage unit into the temperature control element to increase the temperature of the receptable section. The heat storage unit is, preferably, a condenser that can be used as part of the refrigeration process. In such an arrangement, rather than having a separate heat storage unit, heat is accumulated in the condenser, which would normally be provided with heat from the refrigeration process. The heat can be retained within the condenser, or the heat therefrom can be used to heat a separate vessel via a heat exchanger. The heat stored can then be used in the second state by drawing the heat down from the condenser via the valve. In a particularly advantageous embodiment, when the ice bath is in its first state, heat passes from the temperature control module to the heat storage unit. The heating module may be in the form of a heat storage unit and, as the receptacle is chilled by the refrigeration module, the heat that is generated during the first state in chilling the water, through a refrigeration process, may be stored in the heat storage unit. Thus, the heat removed from the system can be directed into the heat storage unit for use later on, thereby making the arrangement more efficient than having a separate heating element. When the ice layer is at the desired thickness, the heat in the heat storage unit can be used to warm the receptacle in order to detach the ice layer. Again, “heat storage” reflects the relative temperature differences of the receptacle and / or water and the movement of warmer gas, liquid or conducted warmth, which may only be slightly warmer. In an alternative arrangement, ambient air may be taken into the heat storage unit. Thus, whilst it is preferred that the heat storage unit receives heat from the refrigeration process, heat may be obtained from another source. The heat storage unit may be provided with uplift means, which is means for heating the fluid therein. Whilst it is envisaged that the heat stored within the heat storage unit should be of a sufficient temperature to release the ice from the receptacle wall, there may be circumstances in which the fluid therein would benefit from being heated further before discharge. Therefore, a warming element can be provided to heat fluid within the heat storage unit. A heat exchanger may be used to warm fluid in the heat storage unit. The ice bath may further have a third state in which the temperature control element is neither cooled nor heating. This may be a dormant state in which the ice bath can be in a neutral mode and the water, and any ice therein, is left without heating or cooling. In a preferred arrangement, the valve is a solenoid valve. The use of a solenoid valve provides a quick and reliable switching between the two states of the ice bath. Furthermore, a default safety position can be established so that should there be a power failure, the device can be placed into a default state, which is, preferably, the second state, but could be the first state to keep the water in the ice bath cool for as long as possible. Whilst a mechanical valve may be employed, a solenoid valve provides a quick and efficient response to the changing states of the ice bath. Advantageously, the temperature control element comprises a conduit through which fluid passes. The use of a fluid conduit allows a reliable heating a cooling conduit through which liquid or gas can pass to heat and cool the receptacle. In one arrangement, copper pipe is employed and is connected to the valve so that the refrigeration unit can readily cool the receptacle using fluid. Similarly, fluid can be stored in the heat storage unit and that can flow through the valve and into the fluid conduit, when required. Clearly, other materials may be used for the cooling conduit, for example, other metals or thermally conductive materials. It is preferable that the conduit is arranged in a predefined manner, for example, with a plurality of substantially parallel sections. By having a predefined and known shape of the conduit, the cooling of the receptacle can be undertaken in a way in which ice is formed in a known manner. Thus, a particular shape of ice sheet can be formed. It is beneficial that a central processing unit is provided to control the ice bath and the state thereof, and, preferably, sensors are provided, and those sensors provide feedback to the central processing unit. The use of a central processing unit, or “CPU”, allows the ice bath to be controlled automatically. Thus, the central processing unit can be used to monitor various parameters that can be detected by the sensors, for example, the sensors can monitor at least one parameter from a group comprising: ambient air temperature; water temperature; and ambient humidity. The information received from the sensors can be used to determine a temperature to which the receptacle, and optionally the water, can be chilled. Similarly, the sensors and CPU can be used to determine a time for which the ice bath should be in the first state and a time for which the ice bath should be in the second state. Therefore, it is useful that the ice bath is also provided with a timing module. The ice bath can be put into the first state for a known period of time and then either switched to the second state or put into a dormant state. In one embodiment, a wireless transmitter and / or a wireless receiver is provided. This allows the ice bath to be controlled and updated remotely and / or for information from the ice bath, for example the parameters detected by any sensors, to be received. This allows the ice bath to be adapted for changes to the way in which the device operates and for updating of system software. The transmitted and / or receiver can send and receive information relating to the control of the ice bath. The immersion ice bath can be operated by: a) having liquid within the receptacle of the ice bath; b) placing the ice bath into the first state and chilling the receptacle until the ice detection system detects that a layer of ice, or a layer of ice of a predetermined thickness, has formed on an internal surface of the receptacle; and c) placing the ice bath into the second state and heating the receptable to release the layer of ice from the internal surface of the receptacle. The heating of the receptacle may be undertaken for a for a predetermined amount of time, or until the ice detection system determines that the layer of ice is no longer present on the internal surface of the receptacle. A method of operating the ice bath includes the steps of filling the ice bath with water and then operating it according to further steps. Such operation includes placing the bath into the first state so that the receptacle is chilled to create ice. Ideally, the heat from the refrigeration process is stored and then it can be re-used when the ice bath is placed into the second state. When the ice bath is in its first state, a layer of ice is created on the internal surface of the receptacle of the ice bath. Upon the ice reaching a certain thickness, which can be calculated by the ice detection system, for example by way of optical or capacitive sensors, the layer of ice can be detached from the receptacle wall by placing the ice bath into the second state. The ice is then free to float to the surface of the water. A third state may be provided in which the ice bath is neither in the first state or the second state. The third state may be a rest state in which the receptacle is not provided with further chilling, and it is not heated, but instead it is left dormant. The time in which the ice bath is placed into the second, warming, state can be determined by calculating how long the ice layer will take to release from the receptacle surface when the water is of a known temperature. Thus, the water temperature may also be monitored. Additionally, or alternatively, the sensor may determine when the ice layer has been released. It is preferable that the ice is created with a waveform profile on at least one surface and wherein the thickness of the ice on a narrow part of the waveform may be a maximum of up to 50mm. Thus, at least one surface of the ice layer has a sinusoidal, or corrugated, profile. The thickest section is, preferably, less than 30mm, and the thinnest section is less than that. The corrugated profile allows the ice easier to break into smaller pieces through natural flow and currents within the water. The profile may be created by way of chilling elements, or conduits, being placed in a particular pattern or configuration. The pattern may comprise substantially parallel chilling elements or concentric chilling elements to create a layer of ice that has a particular profile. It will be appreciated that the position of any ice detection sensor will need to take into account the profile of the ice layer. For example, the ice detection system could be placed in a position where a narrow part of the profile is formed, or a thick part of the wave profile. The sensed reading will need to take this into account and adapted accordingly. Preferably, further sensors are provided that feed into the central processing unit. For example, the sensors may monitor at least one variable parameter, such as the ambient temperature, ambient humidity and / or water quality. The processor can adjust the cooling and heating requirements of the ice bath depending upon the received signals. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which: Figure lisa diagram showing a first ice detection system in an immersion ice bath according to the present invention; Figure 2 is a diagram showing a second ice detection system in an immersion ice bath according to the present invention; Figure 3 is a diagram showing a third ice detection system in an immersion ice bath according to the present invention. Detailed Description of Exemplary Embodiments Figures 1 to 3 show an ice bath 10 according to the present invention. The ice bath 10 comprises a receptacle section 12 having a concave section and that contains water 14 within the concave section. The water is chilled using a refrigeration system that, preferable comprises conduits 16 arranged adjacent the external, or convex, surface of the receptacle section 12. The same conduits 16 can be used for releasing ice that forms on the internal surface of the receptacle section by providing warmed fluid therein, rather than the cooled fluid used to chill the receptacle 12. A central processing unit and appropriate circuitry is provided in the ice bath 10 to control the way in which the ice bath 10 is operated. In the first arrangement, shown in Figure 1, the ice detection system comprises a housing 18, in which is arranged a laser emitter 20 and an optical sensor 22 adjacent thereto. A reflector, in the form of a glass disc 24, is positioned on the base of the internal surface of the receptacle 12, with the reflector being arranged to reflect light emitted from the laser emitter 20 to the optical sensor 22. The laser emitter 20 and the optical sensor 22 are connected to the central processing unit so that that laser emitter 20 is controlled and operated thereby, when required, and the signal from the optical sensor 22 is provided to the central processing unit. Thus, the signal from the optical sensor 22 is monitored by the central processing unit to detect a change in the received signal, which will be indicative of a change in the light reflection. Such changes can be calibrated to identify where the change in the signal is attributed to ice forming over the glass disc 24. Thus, a predetermined threshold can be set, and when signal changes such that it crosses the threshold, the chilling function is stopped, and a warming function can be operated to release the layer of ice that is formed within the receptacle 12. The arrangement in Figure 2 has many features in common with that shown in Figure 1 and the common parts are numbered accordingly. The ice detection system in this embodiment comprises a capacitive sensor 30 embedded into the base of the receptacle 12. The capacitive sensor 30 is connected to the central processing unit to monitor the signal detected by the capacitive sensor 30. As ice forms in the receptacle 12, ice covers the capacitive sensor 30 and the measured capacitance changes significantly, thereby indicating that ice has formed. The signal received by the central processing unit from the capacitive sensor 30 is used to determine whether to cool or heat the receptacle 12, or to leave the heating / release system in a neutral, or off, state. The capacitive sensor 30 and optical reflector 24 may be arranged above the surface of the receptacle. Thus, the ice layer forms on the internal surface of the receptacle and only when it is of a known thickness does it change the detected reading from the optical sensor or the capacitive sensor. This may be advantageous for measuring when the ice layer is the required thickness. The arrangement shown in Figure 3 has features in comment with the previous arrangements; however, the ice detection system in this embodiment is an acoustic detection system. In this arrangement, a plurality of ultrasound emitters and receivers 32 are arranged on the base of the receptacle 12 and external thereof. When water 14 internal of the receptacle 12 is cooled, the ultrasound emitter 32 can be used to direct ultrasound to the receptacle 12 and to monitor the signal reflected therefrom. As ice forms within the receptacle 12, the returned signal changes, because the ice dampens the returned signal. The greater the ice adhesion to the internal surface of the receptacle 12, the more damping occurs and so the returned signal changes accordingly. The received signal is passed to the central processing unit and upon the signal passing a predetermined threshold, the cooling of the water 14 can be stopped, thereby stopping further ice formation until the cooling is restarted. The cooling, or refrigeration system, may be positioned on the base of the receptacle or on a side surface of the receptacle. The defrost system should be located in the same position to ensure that the arrangement is efficient, although it could be arranged in a different part of the ice bath in some arrangements. Other sensors, such as thermocouples or thermistors may be used in the ice detection system. It will be understood that the detection of temperature may not be an accurate indicator of ice formation and so the optical and / or capacitive sensors may be preferred. A temperature sensor may be provided at, or close to, the internal surface of the receptacle to monitor the temperature of the water at that point. This reading may be useful to knowing when the ice layer has detached from the receptacle wall. Additionally, or alternatively, the temperature information may be used in combination with any optical or capacitive reading to calculate the threshold reading at which the ice bath should change from the first state to the second state. Whilst a glass disc reflector is described, a different reflecting material may be used, depending upon the circumstances; however, the reflector material will need to be chosen to be one that is not significantly affected by changes in temperature. It is preferable that the conduits are arranged along the base of the receptacle, so that, when released, the ice layer will float upwards; however, it will be appreciated that the conduits may be placed adjacent a side wall, either in addition or as an alternative to the base. One or more features of one or more embodiments described herein may be incorporated 5 into other embodiments also described herein.

Claims

1. An immersion ice bath for a human or animal, the ice bath comprising a receptacle section for holding water and a refrigeration system for cooling the water, wherein the receptacle section can be chilled by the refrigeration system to create ice therein, and wherein the ice bath is provided with an ice detection system to detect ice formation within the ice bath, wherein the ice detection system comprises an acoustic emitter, a receiving sensor and a central processing unit, and wherein the acoustic emitter emits sound towards the receptacle and the receiving sensor receives the reflected signal, with the received signal from the sensor being provided to the central processing unit.

2. An immersion ice bath according to claim 2, Wherein when the signal received from the sensor of the ice detection system reaches a predetermined threshold, the central processing unit stops the refrigeration system.

3. An immersion ice bath according to claim 3, wherein the ice bath further comprises an ice release system and, when the refrigeration system is stopped, the ice release system can be started.

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