NZ728253A

NZ728253A - Medical temperature control apparatus

Info

Publication number: NZ728253A
Application number: NZ728253A
Authority: NZ
Inventors: Janisch Klaus
Original assignee: Hilotherm Holding Ag
Priority date: 2016-01-14
Filing date: 2017-01-12
Publication date: 2022-01-28
Also published as: ES2961335T3; EP3192476B1; ZA201700008B; DE102016000345A1; BR102017000487A2; EP3192476A1; BR102017000487A8; AU2017200221A1

Abstract

The invention relates to a medical temperature control apparatus comprising a housing, at least one fluid supply device, one temperature control device 2, 3 for the fluid, one fluid outflow device 27 and one pump device 31 for the fluid. The medical temperature control apparatus is particularly provided for the connecting of a temperature-control cuff applied to areas of a patient’s body for heat treatment or cold treatment. The pump device 31 is configured as a displacement pump, preferably as a gear pump, and a pressure limiting device 19, 35 is provided which keeps the pressure of the fluid flowing out of the housing within a predetermined range. The pressure limiting device is a throttle device and comprises a throttle line which is fluidly coupled to the pump device at one end and to the fluid supply device at the other end. This thereby prevents excessive pressure from developing in the fluid outflow device 27 which might damage the cuff.

Description

DEVICE FOR MEDICAL THERMOTHERAPY BACKGROUND TO THE INVENTION The therapeutic effect of heat treatment and cold treatment on human and animal bodies has long been known. While simple temperature control devices such as ice packs or hot water bottles are still used as household remedies, the professional medical therapy field has realized that the treatment success of such measures is significantly improved when a specific, largely constant temperature is applied to the relevant area of the body. One such therapeutic measure which has been very successful in treating traumatized or inflamed joints is, for example, an even cooling to 15°C.

In order to attain this temperature control, a temperature-control cuff having a number of flow channels for water is applied to the afflicted area of the body. A device for medical thermotherapy of the type under consideration here then supplies the cuff with cooled water so that the desired temperature can be kept substantially constant over the treatment period or can be adjusted to desired temperature changes respectively.

Known medical thermotherapy devices are used both in clinical as well as in private settings. In private use, the patient either acquires such a device himself or rents it for the length of the treatment period.

It has become evident that especially when used in a home setting where they need to be operated by laypersons, the known devices do not always function with the desired reliability.

It is therefore the task of the present invention to increase the reliability of such a medical thermotherapy device.

SUMMARY OF THE INVENTION A device for medical thermotherapy of the type under consideration here comprises at least one housing, at least one fluid supply device for supplying a fluid into the housing, at least one temperature control device arranged in the housing which controls the temperature of the fluid flowing through the housing, at least one fluid outflow device through which the fluid can be channeled out of the housing at a substantially predetermined temperature, and at least one pump device arranged within the housing which pressurizes the fluid flowing through the housing.

A fluid supply device is hereby to be understood as a device which ensures that a sufficient quantity of fluid is always provided during the operation of the thermotherapy device or enables the user of the thermotherapy device to do so, particularly via suitable means for supplying and/or refilling the fluid.

A temperature control device is to be understood as a device for heating and/or cooling the fluid, preferably by converting electrical energy into thermal energy or by using electrical energy to extract thermal energy respectively, and preferably comprises a heat exchanger for transferring generated heat to the fluid or, respectively, extracting heat from the fluid.

According to the invention, the at least one pump device is configured as a displacement pump and provided with a pressure limiting device which ensures that the pressure of the fluid flowing out of the housing is kept within a predetermined range.

The displacement pump is preferably configured as a gear pump. Such pumps can be of compact design, are largely maintenance-free and economical to manufacture.

The fluid is preferably water, in particular tap water, but it can, however, also be distilled water, water with specific additives or a different fluid other than water, particularly oil.

The invention will be described herein using the example of a thermotherapy device for use with a temperature-control cuff through which water flows which is applied to the afflicted area of the patient’s body. This, however, does not constitute a limitation; the inventive medical thermotherapy device can also be used for other applications, for example for use with a temperature control element inserted into an orifice of the patient’s body.

The present invention signifies a departure from the previous principles of such thermotherapy devices operated with flow pumps, in particular centrifugal pumps. Even when the use of such flow pumps, for example as circulator pumps in heaters, etc,. has a wide range of advantages, their pumping characteristics have proven disadvantageous when used for medical thermotherapy devices.

In order to keep the thermoregulation process as comfortable as possible for the patient, relatively light tubes need to be used for the supply line from the thermotherapy device to the cuff. However, such tubes, especially when used by laypersons in a home setting, are at risk of kinking, twisting or otherwise having their flow cross-section constricted.

The same also applies to the cuff. In order to optimally adapt to the body shape, the cuff has to be of relatively flexible design. This is again coupled with the risk of constricting the flow.

A pump operating on the displacement principle has the fundamental advantage of being able to – depending on drive power – generate high pressure.

If the flow through the supply tubes or through the cuff is obstructed, the pressure in the supply line increases accordingly and sufficient fluid can be conducted into the cuff despite the flow obstruction. The desired therapeutic success is thereby also ensured in these cases.

In one preferential implementation of the invention, the fluid supply device comprises a fluid inflow device through which the fluid is fed into the housing from the outside.

The fluid inflow device is thereby preferably provided for supplying at least a portion of the fluid into the housing which the fluid outflow device conducts out of the housing so that there is at least partial fluid circulation.

Preferably, the fluid fed into the housing by the fluid inflow device is at a different temperature, and in fact preferably a lower temperature (in the case of the thermotherapy device being used for heat treatment) or, respectively, a higher temperature (in the case of the thermotherapy device being used for cold treatment), and/or a different, preferably lower, pressure than the fluid conducted out of the housing by the fluid outflow device.

In a further preferential implementation of the invention, the fluid supply device comprises a fluid reservoir arranged within the housing. This thus makes it convenient for the user to fill the thermotherapy device with fluid when starting it.

In a further preferential implementation of the invention, the fluid inflow device is fluidly coupled to the fluid reservoir. In so doing, the fluid reservoir can be integrated into the fluid circulation system and thereby serve as a buffer for the circulating volume of fluid, whereby fluid which has been lost, for example due to leakage or evaporation, will be automatically offset.

The invention further proposes combining the provided displacement pump with a pressure limiting device which keeps the pressure of the fluid flowing out of the housing within a predetermined range.

This thus prevents the pressure in the supply lines and/or in the cuff from rising high enough to cause the connections between the housing and the supply lines, or between the supply line and the cuff respectively, to leak or even disengage, and prevents excessive pressure from damaging the supply lines and/or the cuff.

It is common to configure such pressure limiting devices as pressure relief valves. In so doing, a ball is, for example, pressed onto a spring in a closure area of a flow channel. If the pressure becomes too high, the spring is accordingly further compressed and the ball lifts out of its seat, with the fluid then passing through that flow channel.

A typical pressure limiting device of this type can also be used in conjunction with the present invention. However, in one preferential embodiment, the invention proposes a differently designed pressure limiting device of particularly reliable functioning and which can be of simple design.

Such an advantageous pressure limiting device is configured as a throttle device having a specific higher flow resistance. As soon as the pressure in the system rises, the volumetric flow through the pressure limiting device increases and accordingly relieves the pressure.

In a further preferential implementation of the invention, the throttle device comprises a throttle line which is fluidly coupled to the pump device at one end. The throttle line is preferably connected in parallel to the pump device; i.e. designed as a so-called "bypass." At its remote end from the pump device, the throttle line is preferably fluidly coupled to the fluid supply device, in particular to a fluid reservoir or to a fluid inflow device. Thus, both the fluid flowing through the throttle line for pressure equalization, as well as leakage fluid resulting from such a pressure control device also allowing passage of small volumes of fluid within the normal range of pressure, remain within the flow circulation.

In the case of the fluid supply device comprising a fluid reservoir, the fluid communication between the throttle line and the fluid supply device is preferably comprised substantially of a through-hole in a wall of the fluid reservoir.

Such a through-hole is simple and economical to produce.

The inner diameter of the through-hole is thereby preferably smaller than the inner diameter of the throttle line, preferably half the size at most, further preferably a third the size at most, and even further preferably, no more than a fourth the size. This thus makes it just as simple as it is economical to dimension the force of the throttling action.

In a further preferential implementation of the invention, the throttle line also serves as a vent line for the pump device. This function is particularly advantageous in the start-up phase of the pump device configured as a displacement pump since the chambers of the displacement pump can still be partly or completely filled with air during this phase, resulting in reduced or even no pumping capacity. The pumping action does not start until the air is purged from the displacement pump’s chambers. The throttle line which is already provided anyway thus eliminates the need for a separate vent line.

BRIEF DESCRIPTION OF THE DRAWINGS The following will reference the drawings in describing the invention by way of example embodiments. Shown are: Fig. 1: a frontal view of a thermotherapy device according to the invention; Fig. 2: a side view of the inventive thermotherapy device from Fig. 1; Fig. 3: a side sectional view of the inventive thermotherapy device along the A-A line in Fig. 1 as well as a magnified view of detail X; Fig. 4: the inventive thermotherapy device from Fig. 1 as seen from above.

The individual views in Figs. 1 to 4 in each case depict the same embodiment of the device for thermotherapy. Accordingly, identical reference numerals in the figures also denote identical elements of this embodiment.

Therefore, the following will not discuss the figures individually but rather just the embodiment depicted in the figures as a whole.

DESCRIPTION OF PREFERRED EMBODIMENT The thermotherapy device according to the invention comprises a pump unit 30, a fluid reservoir 23 as well as a temperature control device having a first temperature control unit 2 and a second temperature control unit 3 as its fundamental components.

The pump unit 30 comprises a gear pump 31, via which the fluid is pressurized, and an electric pump motor 32 for driving the gear pump 31. The pump motor 32 preferably operates at a relatively low voltage, approximately 5 V in the example embodiment, as opposed to the otherwise customary approx. 6 to 14 V operating voltages for gear pumps. Correspondingly, the gear pump 31 preferably operates at a relatively low rotational speed, approximately 2570 min in the example embodiment, whereby a relatively high maximum fluid pressure can be generated.

The gear pump 31 substantially comprises two plastic gearwheels driven by a reduction gear of the pump motor 32 and can thereby be inexpensively manufactured.

The thermotherapy device comprises a first temperature control unit 2 and a second temperature control unit 3 enclosed by a common housing 1. The housing 1 can thereby be of two-piece design so that the temperature control units 2, 3 can be inserted into the housing 1.

The two temperature control units 2, 3 are configured as so-called "liquid-to-air modules." In the example embodiment, the temperature control units 2, 3 are structurally identical. They can, however, also be configured differently.

The temperature control units 2, 3 each comprise a Peltier element 4, which is in each case arranged between a cooling element 6, 7 and a heat exchanger 8, 9, its respective opposite sides being in flat contact with these elements.

The Peltier elements 4, 5 generate a difference in temperature between the respective heat exchanger 8, 9 and respective cooling element 6, 7 during the operation of the thermotherapy device, whereby the fluid which flows through the heat exchanger 8, 9 is either cooled or heated depending on the specific application of the thermotherapy device. Two fans in housing 1, of which only one fan 14 is depicted in Fig. 1, draw heated air off from the cooling elements 6, 7, or supply heated air to the cooling elements 6, 7 respectively, in order to even further increase the temperature difference produced by the Peltier elements 4, 5. In the example embodiment, the generated temperature difference amounts to approximately 11 Kelvin.

The fluid reservoir 23 serves in the supplying of fluid into the thermotherapy device as well as in the storing of fluid in the thermotherapy device. The fluid reservoir 23 has a fluid filling hole 24 at its top through which fluid can be filled as well as a fluid drain hole 25 at its bottom through which fluid can be drained from the fluid reservoir 23 – e.g. in the event of the device being taken out of operation or to completely replace the fluid.

The fluid preferably circulates during the operation of the inventive thermotherapy device as follows: The fluid coming from and pressurized by the pump unit 30 first flows through a connecting piece 22 by means of which the gear pump 31 is connected to a branching piece 20. A throttle line 19, which will be described in greater detail below, branches off from the branching piece 20.

The fluid circulation continues with a fluid line 15 which leads to the connection 11 of the second temperature control unit 3. There, the fluid enters into the heat exchanger 9 of the second temperature control unit 3, is to some extent subject to thermoregulation there, and then exits the heat exchanger 9 again at connection 13. The fluid then flows through connecting line 17 to the first temperature control unit 2. There, the fluid enters into the heat exchanger 8 of the first temperature control unit 2, is likewise subject to some extent of thermoregulation there, and then exits the heat exchanger 8 again at connection . Thus, the fluid coming from the pump device 30 is fully temperature- controlled.

The fluid thereafter flows through the fluid line 16 to a manifold 21 to which a hose connector 27 is attached. A tube 29 can be connected to the hose connector 27. Said tube preferably leads to a temperature-control cuff to be applied to a part of a patient’s body, particularly a hand, knee or another part of the body requiring thermoregulation. Thermal energy is released to this body part, or thermal energy drawn therefrom respectively, depending on whether the patient is undergoing hot or cold treatment.

A cuff to be connected to the thermotherapy device typically has a fluid capacity of up to 0.5 liter. Preferably, only one cuff is attached to the thermotherapy device. By appropriately designing the thermotherapy device, however, multiple cuffs can also be attached. To this end, although not used in the example embodiment, another connection for a further hose connector is provided on the manifold 21.

The fluid preferably flows back from the cuff into the fluid reservoir 23 through a tube 28 connected to same. Due to the decreased pressure effected by the cuff, the fluid is only at low pressure and, due to the heat loss or absorption in the cuff, is also almost back to its initial temperature again. Generally speaking, the larger the cuff is, the greater the drop in pressure in the cuff and the heat loss/absorption in the cuff will thereby also be.

The fluid within the fluid reservoir 23 is drawn through a further fluid line 18, which is connected to an opening at the bottom of the fluid reservoir 23, by the gear pump 31, again subjected to pressure there, and the described fluid circulation begins anew. Of course, the individual devices involved in the circulation can also be arranged in a different order.

Should the fluid flow be obstructed in the cuff, and the pressure in the thermotherapy device and in the cuff thus rise, the thermotherapy device is equipped with a throttle line 19, in which the flow cross-section is significantly reduced at least at one point, as a pressure limiting device. When the pressure in the fluid circulation system rises, the volumetric flow through the throttle line 19 increases and correspondingly relieves such "pressure spikes" or even increased pressure lasting for a longer period of time.

In the example embodiment, the fluid pressure is typically limited to 0.5 to 0.9 bar so as to virtually eliminate a risk of scalding even at higher fluid temperatures.

The throttle line 19 branches off from the described fluid circulation system after the gear pump 31 at branching piece 20 and leads directly to the fluid reservoir 23 in the form of a "bypass." In so doing, the fluid introduced into the throttle line 19 for limiting the pressure flows into the fluid reservoir 23 and thus directly back into the fluid circulation system, whereby leakage and thus fluid loss is eliminated.

The point of reduced flow cross-section in the throttle line 19 is preferably in the form of a hole 35 of small diameter at the bottom of the fluid reservoir 23 through which the fluid at the end of throttle line 19 flows into the fluid reservoir 23. In the example embodiment, the hole 35 has a diameter of approximately 1 mm, while the rest of throttle line 19 has an inner diameter of approximately 4 mm. The hole 35 constitutes a simple hydraulic resistance to the fluid and the pressure in the fluid circulation system is limited in an equally simple manner.

As can particularly be seen in detail X in Fig. 3, the throttle line 19 is fit onto a connector 33 formed on the bottom of the fluid reservoir 23 and secured by a hose clamp 34.

The throttle line 19 furthermore serves in ventilation for the gear pump The fluid lines 15 to 18 are preferably configured as tubes, particularly of polyurethane, but can, however, also be rigid tubes, particularly of plastic or metal.

The terms "comprises", "comprising", "including", and "having", and variations thereof are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

List of reference numerals 1 housing 2 first temperature control unit 3 second temperature control unit 4, 5 Peltier element 6, 7 cooling element 8, 9 heat exchanger -13 fluid line connections 14 fan -18 fluid lines 19 throttle line -22 connecting pieces 23 fluid reservoir 24 fluid filling hole fluid drain hole 26, 27 hose connector 28, 29 tube pump unit 31 gear pump 32 pump motor 33 connector 34 hose clamp hole

Claims

CLAIMS 1.:

1. A device for medical thermotherapy comprising at least one housing, at least one fluid supply device for supplying a fluid into the housing, at least one temperature control device arranged within the housing which controls the temperature of the fluid flowing through the housing, at least one fluid outflow device through which the fluid can be channeled out of the housing at a substantially predetermined temperature, at least one pump device arranged within the housing which pressurizes the fluid flowing through the housing, wherein the at least one pump device is configured as a displacement pump, preferably as a gear pump, and that a pressure limiting device is provided which keeps the pressure of the fluid flowing out of the housing within a predetermined range.

2. The device for medical thermotherapy according to claim 1, wherein the fluid supply device comprises a fluid inflow device through which the fluid is fed into the housing from the outside.

3. The device for medical thermotherapy according to claim 2, wherein the fluid inflow device is provided to supply at least a portion of the fluid into the housing which the fluid outflow device conducts out of the housing so that there is at least partial fluid circulation, wherein the fluid fed into the housing by the fluid inflow device is at a different, preferably lower, further preferably higher, temperature and/or a different, preferably lower, pressure than the fluid conducted out of the housing by the fluid outflow device.

4. The device for medical thermotherapy according to any one of the preceding claims, wherein the fluid supply device comprises a fluid reservoir arranged within the housing.

5. The device for medical thermotherapy according to claims 2 and 4, wherein the fluid inflow device is fluidly coupled to the fluid reservoir.

6. The device for medical thermotherapy according to any one of the preceding claims, wherein the pressure limiting device is a throttle device.

7. The device for medical thermotherapy according to claim 6, wherein the throttle device comprises a throttle line which is fluidly coupled to the pump device at one end.

8. The device for medical thermotherapy according to claim 7, wherein the throttle line is fluidly coupled to the fluid supply device at its remote end from the pump device.

9. The device for medical thermotherapy according to one of claims 4 or 5 and claim 8, wherein the fluid communication between the throttle line and the fluid supply device is comprised substantially of a through-hole in a wall of the fluid reservoir.

10. The device for medical thermotherapy according to claim 9, wherein the inner diameter of the through-hole is smaller than the inner diameter of the throttle line, preferably half the size at most, further preferably a third the size at most, and even further preferably, no more than a fourth the size.

11. The device for medical thermotherapy according to any one of claims 7 to 10, wherein the throttle line also serves as a vent line for the pump device.

12. A method for operating a device for medical thermotherapy according to any one of the preceding claims comprising the steps of: − the at least one fluid supply device supplying a fluid, − the at least one pump device pressurizing the fluid flowing through the housing, − the at least one temperature control device controlling the temperature of the fluid flowing through the housing, − the at least one fluid outflow device channeling the fluid out of the housing, wherein the pressure of the fluid flowing out of the housing is kept within a predetermined range by the pressure limiting device. HILOTHERM HOLDING AG WATERMARK INTELLECTUAL PROPERTY PTY LTD P42568NZ00