Patent Description:
Outpatient treatment for such conditions typically includes instructing the patient on a therapeutic regimen to be followed at home. The apparatus of the present invention provides a portable heat/cold therapy unit for that purpose, among others.

There are many devices on the market for managing thermal treatment of injuries. These include electric blankets, pads, and body part shaped garments, chemical and inert products bagged for the freezer and microwave, and traditional hot water bottles and ice bags.

Perhaps the most commonly used modality is application of ice bags. These are very inexpensive and subject to shifting, dripping, and losing coldness during use. Ice bags thus need to be re-frozen and re-placed frequently in order to maintain peak thermal advantage. Ice bag therapy, to be at its most effective, must therefore be heavily supervised.

There are commercial products that require less supervision, including products having cooled water circulating through body part wraps, such as a foot wrap or elbow wrap. These can be an improvement but still do not maintain a peak thermal regimen.

Meanwhile, more robust products that are able to provide features such as temperature control, length of treatment timers, or other thermal add-ons, have not previously been portable and have been too expensive to be sent home with a patient even if possible.

There are also sophisticated and more costly devices such as those used by hospitals and surgical care physicians. However, devices that are large, expensive, and/or complex are not desirable for the therapy conditions contemplated herein.

Peltier devices, known as thermoelectric modules (TEMs), have also been on the market for a number of years. These devices have been aimed at replacing the refrigerant and heating element technology but have primarily been applied to industrial cooling applications and small coolers. TEMs in the medical device industry have been for creating cooling or heating fluids for circulation through a fitted "garment", pad or blanket for thermal treatment of injuries or post-surgery.

TEM technology eliminated the need for refrigeration and heating elements but still required a fluid reservoir and pumping system. These units have temperature sensors to control the temperature but, with a large mass of fluid to control, the unit can have significant temperature fluctuation. The temperature is controlled by turning the current on and off as well as alternating the polarity of the current to the TEM based on the temperature sensor's reading. Due to the volume of fluid needed to reach the desired temperature and the potential for heat exchange (loss or gain) through the insulated garment, it takes significant time for the fluid in the reservoir to reach and maintain the temperature.

One of the critical issues related to thermal treatment is ensuring that treatment is carried out as prescribed by the professional recommending treatment. For injuries such as strains, sprains, and minor tears, many trainers and other professionals recommend cycling <NUM> to <NUM> minutes of ice treatment followed by <NUM> to <NUM> minutes off of ice treatment continuously during waking hours for the first <NUM> to <NUM> hours after injury, depending on the severity of the injury and the patient's individual recovery rate. Very few patients maintain consistency in the process because of the continuous changes required but also because such therapy is not practical with ice-based technology.

Improved systems are needed that overcome the disadvantages of prior technologies.

<CIT> discloses a heating/cooling garment is provided that comprises a microclimate system, as well as methods of manufacturing and using same.

<CIT> discloses a control unit coupled to a thermal therapy device, a compression therapy device and DVT therapy devices. The thermal therapy device includes a fluid bladder for delivering hot and/or cold therapy to a patient. The compression therapy device includes an gas bladder for providing compression to a patient. The DVT therapy devices provide pulsed compression in coordination with the compression therapy device.

<CIT> discloses thermal contrast therapy devices, treatment methods for providing thermal contrast therapy, and systems for providing and managing thermal contrast therapy treatments. The thermal contrast therapy devices are configured to provide a sequence of alternating cooling periods and heating periods to one or more areas of a patient's body. A thermal contrast therapy device may comprise a source of hot fluid, a source of cold fluid, and one or more pumps configured to circulate fluid through one or more treatment pads in fluid communication with the device. The thermal contrast therapy devices are configured to rapidly and efficiently transition between alternating cooling periods and heating periods.

<CIT> discloses a device for efficiently cooling a fluid, such as drinking water. It comprises a stack of thermoelectric cooling modules which are oriented with the hot sides of adjacent modules facing each other, and with the cold sides also facing each other. Positioned between each pair of modules is an elastomeric spacer which forms a leakproof seal with each module. The spacer defines a fluid channel between the sides of the adjacent modules and also has a fluid inlet and a fluid outlet. The fluid to be cooled is circulated through those spacers which are positioned between the cold sides of the thermoelectric modules. A coolant is circulated through those spacers which are positioned between the hot sides of the thermoelectric modules.

<CIT> discloses a sequential compression and temperature therapy blanket with a plurality of air chambers. The air chambers are filled and released by a valve assembly that may be separate from or integrated within the blanket. The temperature therapy blanket includes a fluid bladder for delivering hot and/or cold therapy to a patient. The temperature therapy blanket may also include an air bladder for providing compression.

The present invention provides a device for providing therapeutic thermal compression when used in association with a patient garment according to claim <NUM>. The medical device of the present invention can be used to provide both analgesic and thermal treatment for use with acute injuries, post-surgical use, and medical conditions where cryotherapy or heat therapy, or a cycling of each, are recommended. The device provides timed controlled temperature and compression along with optional treatments of DVT prophylaxis.

In some embodiments, the temperature, time, pressure, and DVT prophylaxis is managed by an onboard microprocessor in an attached controller using a touch screen or other input devices.

One key object of the present invention is to provide a controlled application of professionally recommended thermal treatment including time, temperature, compression, and number of cycles with specified cycle duration. This is achieved by controlled tracking of actual usage compared to recommended treatment. In some embodiments, the device also maintains the history of actual usage and details of number of cycles completed for output to a display for the user's records.

Another object of the present invention is to provide rapid transitions between temperatures for the most effective hot/cold cycle treatment. Once the desired temperature is reached, another object of the invention is to maintain the temperature without fluctuations or slow degradation.

In some embodiments, the device is lightweight, preferably under <NUM> kgs (<NUM> lbs). excluding the power supply. It is preferably a single assembly that contains the controller, display, fan, TEM, thermal plate, and housing.

Certain embodiments of the invention are described below. It should be understood that the invention is not limited to these exemplary embodiments, but by the scope of the appended claims.

First describing the parts of system <NUM> generally, as seen in <FIG>, the system comprises a combination thermal compression and deep vein thrombosis prophylaxis compression device <NUM>. Device <NUM> has a housing <NUM>, preferably including an integrated top handle <NUM>. Housing <NUM> includes a front section and a rear section and, as seen in <FIG>, front section bears a screen <NUM>, connection ports 18A, 18B, and <NUM>, DVT ports 20a and 20b, and a USB port <NUM>. USB port <NUM> is currently designed to charge a user's phone or other device, but could have multiple future applications. Further technologies may supplement or supplant a USB port without change to the scope of this patent application.

Note that connection port <NUM> is connected to the air pressure control system <NUM> to provide a garment with air pressure, thus providing the opportunity to provide both temperature and pressure therapy with a single garment. Housing <NUM> further includes a pair of sides bearing side vents <NUM>, and rear section bearing a fluid tank cap <NUM> and an electrical cord port <NUM> into which a desktop power supply cord <NUM> may be inserted.

System <NUM> also has a thermal connection hose <NUM> that is connectable to thermal garments <NUM>, and DVT lines <NUM> that are connectable to separate DVT-only compression garments <NUM>.

Thermal connection hose <NUM>, as shown in <FIG>, has a device connector end <NUM> and a garment connector end <NUM>. <FIG> shows that hose <NUM> contains conduits 30A, 30B, and <NUM> corresponding, respectively, to connection ports 18A, 18B, and <NUM>. Conduits 30A and 30B transport fluid to and from garment <NUM>, while conduit <NUM> provides air to inflate garment <NUM>. Conduits 30A, 30B, and <NUM> are contained within an insulating sheath <NUM> that minimizes temperature changes to fluid contained in conduits 30A, 30B by way of ambient temperature.

As can be seen in <FIG>, device connector end <NUM> has a shell <NUM>, preferably made of a heavy duty plastic, through which conduits 30A, 30B, and <NUM> connect with device <NUM>. Shell <NUM> has a front end <NUM> with connection mounts <NUM> extending therefrom, an aperture <NUM> through which a disconnect button <NUM> extends, and a thumb structure <NUM>.

Connection mounts <NUM> are retained in connection ports 18A, 18B, and <NUM> by way of corresponding retention tabs <NUM> and retention catches <NUM> (not shown in present draft drawings) that connect with one another by inserting shell <NUM> into ports 18A, 18B, and <NUM>, optionally using thumb structure <NUM> to assist in a firm connection. To disconnect, pressing button <NUM> retracts retention tabs <NUM> so that shell <NUM> may be removed from ports 18A, 18B, and <NUM>.

Garment connector end <NUM> terminates in a garment connection shell <NUM> constructed of a hard plastic material or the like. Shell <NUM> contains fluid conduit outlets 74A and 74B as well as air outlet <NUM>.

On the garment side, as shown in <FIG>, garment inlet shell <NUM>, again preferably constructed of a durable material such as hard plastic, contains inlets 76A, 76B, and <NUM> corresponding to conduits 74A, 74B, and <NUM>. Accordingly, garment connection shell <NUM>, when properly coupled with garment inlet shell <NUM>, establishes a mating communication between outlets 74A, 74B, <NUM> and inlets 76A, 76B, <NUM>.

The connection between shell <NUM> and inlet shell <NUM> is firmly established by way of a mechanical catch (not shown) and is releasable by a release button <NUM>.

Note that DVT pressure can be applied without temperature treatment. As seen in <FIG>, a set of ports 20a, 20b is provided apart from thermal connection hose <NUM> and its associated ports 18a, 18b, <NUM>.

DVT lines <NUM>, which are preferably made of polyurethane but can be constructed of any other appropriate material, and may be connected to DVT ports 20a, 20b by way of a press fit or any other appropriate connection type. As seen in the drawings, a press fit is accomplished using an O-ring or the like (not shown) within DVT ports 20a, 20b or on the outer diameter of DVT lines <NUM>.

Either a single port may be connected to provide compression therapy via a single DVT garment <NUM>, or both of ports 20a, 20b may be used simultaneously or cyclically in connection with two compression garments <NUM>. In the embodiment shown in <FIG>, only one DVT line <NUM> is shown connected to either port 20a or 20b, either of which may be used without the other.

Turning to <FIG>, screen <NUM> displays messages relating to the programming and status of device. For example, as seen in <FIG>, at the start of a thermal cycle, screen <NUM> may provide cycle or program choices. During a cycle, device status error messages could appear. An exemplary error message might read: "ALERT! Garment or hose is not firmly attached. Rewrap garment and reattach hose connection until a 'click' is heard.

As shown in <FIG> and <FIG>, system <NUM> of the present invention includes a chiller block <NUM> that is comprised of a stack of three plates <NUM> arranged atop one another rather than within the same plane. This arrangement provides for increased thermal performance and requires no external cooling fins or other structures reliant on ambient air.

System <NUM> further comprises a pair of thermoelectric modules (TEMs) <NUM>. TEMs are solid-state heat pumps composed of two ceramic substrates that serve as electrically insulating materials and house P-type and N-type semiconductor elements. Heat is absorbed at the cold junction by electrons as they pass from a low-energy level in the P-type element onto a higher energy level in the N-type element. At the hot junction, energy is expelled to a thermal sink as electrons move from a high energy element to a lower energy element.

When DC current flows through the TEMs, heat transfer creates a temperature differential across the ceramic surfaces. As such, one side of the TEM is cold while the other side is hot. Reversing the polarity of the current changes the direction of heat transfer thus reversing the cold side to the hot side and vice versa.

In the present invention, TEMs <NUM> are used to heat or cool the fluid of system <NUM> by arranging plates <NUM> and TEMs <NUM> in an alternating fashion to create chiller block <NUM>. As seen in <FIG>, plates <NUM> are stacked one on the other with the center plate 102b being rotated <NUM>° from the top and bottom plates 102a, 102c. Not seen are TEMs <NUM> located between plates <NUM>. However, the chiller block is stacked as follows: top plate 102a, first TEM 104a, center plate 102b, second TEM 104b, and bottom plate 102c.

Plates <NUM> are preferably made of aluminum for cost and weight reduction. They are also preferably identical to one another to reduce machining costs.

In the present embodiment, each of plates <NUM> has <NUM> bores <NUM> passing through its width. Bores <NUM> have a preferred inner diameter of <NUM>" and are created by a process utilizing drilling, electrical discharge machining, or any other suitable process. Naturally, the number and size of bores <NUM> can vary without changing the scope of the invention whatsoever.

Plates <NUM> have a top face <NUM> and bottom face <NUM>, an inlet/outlet cap <NUM>, and an endcap <NUM>. Thumb screws <NUM> are provided for attaching caps <NUM>, <NUM> to chiller block <NUM>. Plates <NUM> have identical sides <NUM>. Each of inlet/outlet cap <NUM> and endcap <NUM> has an opening <NUM> for a hex nut connection. A screw <NUM> and hex nut (not shown) are used to firmly connect plates 102a, 102b, 102c of chiller block <NUM>.

As seen in <FIG>, each of plates 102a, 102b, and 102c is stacked axially with top plate 102a and bottom plate 102c facing in one direction, and center plate 102b turned <NUM> degrees axially from the orientation of the top and bottom plates 102a, 102c. A <NUM> degree turn could also be employed.

Turning to <FIG>, each inlet/outlet cap <NUM> bears a pair of nipples <NUM> which deliver fluid to and from an associated plate <NUM> of chiller block <NUM>. The fluid is directed through the plate <NUM> so that it is required to pass through bores <NUM>, extending the width of plate <NUM>, four times. This gives plates <NUM> and bores <NUM> adequate exposure to the heat or cold provided by TEM <NUM> so that the fluid is likewise heated or cooled. Multiple passes through plate <NUM> provides efficient adjustment of fluid to the desired temperature.

Specifically, referring to <FIG>, thermal conduits 22A and 22B attach to nipples 122A and 122B via friction fit. Nipples 122A deliver fluid of the system into inlet/outlet cap <NUM> through openings 112A. Openings 112a are surrounded by a raised perimeter creating a first chamber (C1). The fluid passes through chamber C1 through connected bores <NUM>. The fluid exits the bores <NUM> of chamber C1 at a second chamber C2 of endcap <NUM>, and is redirected back toward inlet/outlet cap <NUM> via return bores <NUM>. The fluid then enters and subsequently exits chamber C3, flows back to endcap <NUM> to chamber C4, and then to chamber C5 where it returns to system <NUM> via nipple 122B.

Plates <NUM> of the preferred embodiment, as well as related parts and functions, have been described herein. However, numerous variations on each of these details are possible and all should be considered within the scope of the invention.

The other primary components of chiller block <NUM> are a pair of thermoelectric modules (TEMs) <NUM>. One of each TEM <NUM> is placed between top plate 102a and center plate 102b, and the other between center plate 102b and bottom plate 102c.

TEMs are frequently used with a control mechanism to regulate the temperature of a medium being heated or cooled. Control mechanisms include pulse width modulation (PWM) of the power to the device, changing the DC voltage the TEM is driven by, or a simple on/off power control.

PWM control comprises or consists of changing the percent of time in each cycle that the device is either on or off. For example, with a <NUM> frequency, the device can be turned on anywhere from <NUM> to <NUM>% duty cycle to control the amount of heat energy the device moves, up to the limit the TEM achieves on direct current.

Using a PWM duty cycle less than <NUM>% has the same effect on the TEM as lower DC voltage. As such, PWM is an effective control strategy, when used with temperature feedback, to control the temperature of the medium that is heated or cooled.

The disadvantage of using PWM is that it generates a high level of radio frequency (RF) noise since the TEM current is switched on and off many times per second. Such high RF noise is unacceptable in medical devices, particularly in life-maintaining medical devices, in which RF noise can interfere with proper operation.

Changing the TEM power supply DC voltage, used in conjunction with temperature feedback, is also an effective control strategy. This gives fine control over the medium temperature, since the TEM is primarily a resistive device and responds to changes in supply voltage. However, controlling the voltage output of a DC power supply also normally involves changing the PWM switching internal to the supply itself at a very high frequency. This also generates a high level of RF noise.

True analog control DC power supplies that do not use PWM for voltage control are normally reserved for laboratory use since they are very big, bulky, and expensive to manufacture.

Simple on and off control of the power to the TEM at a slow (less than <NUM> second cycle time) rate does not generate high levels of RF noise, but can shorten the life of the TEM from thermal fatigue. It also gives a highly inaccurate temperature control scheme with under- and overages. As such, it is not suitable for applications with fine control requirements such as medical devices.

Since the TEM current required at a fixed voltage is also dependent on the temperature differential across the TEM, the on/off method requires more electrical power from the power supply to be able to supply the high current requirements every time the TEM is turned on and off. Turning the TEM on and off at a slow rate allows the temperature differential built from operation to dissipate, causing the subsequent turn on to require more starting power and thermally fatigues the TEM.

The method described herein comprises a method of controlling a device in which more than one TEM is utilized. Multiple TEMs can either be connected in a series or parallel configuration, depending on the application and the specific power supply.

One example of keeping power supply voltages and TEM characteristics the same comprises using a parallel connection. The main supply voltage is applied to both TEM elements and doubles the current requirement from the power supply.

Series connection divides the supply voltage to each TEM in half, and also essentially doubles the resistance of the load and cuts the power supply current delivery in half.

Thus, in a parallel connection arrangement, each TEM works at "full power" in a parallel connection arrangement, and moves the maximum amount of heat energy. In a series connection arrangement however, each TEM works at half power and moves a lesser amount of heat. Providing a means for the TEMs to change the electrical connections from series to parallel "on the fly" provides a means for control over the heat flux from the device. It is practical to do this both with mechanical relays or using solid-state switches.

In another example, two double pole double throw relays can be used in concert to enable switching circuit connections between two TEMs from a control signal from a microprocessor.

<FIG> is chart illustrating test data that shows the advantages that a series/parallel circuit can provide, both from the standpoint of current supply and RF noise.

The solid line curve shows the startup power required of two TEMs connected to a 15V power supply in parallel. It can be seen that the peak current rises immediately on startup, since there is no temperature differential at that point and the "back EMF" (electromotive force) or "Seebeck Effect" is zero until a temperature delta across TEM is built from TEM operation. After startup, the Seebeck Effect begins to build and increases the effective resistance to the flow of current through the TEM, so the current goes down.

The broken line curve shows the startup power required of two TEMs connected to the same <NUM> V power supply, this time starting in series connection, then switched to parallel after <NUM> minute. Startup current is very low, and after <NUM> seconds there is enough temperature difference between the two sides of the TEM to decrease the power requirements to allow a switch to parallel, now requiring <NUM>% less power from the power supply. This in effect allows reduction of the power supply size by <NUM>% peak capacity.

The reverse strategy is also true. After running the TEMs in parallel to achieve maximum cooling and upon reaching the target temperature, the switch can again be made to series connection. This drops the cooling power of the TEMs while still keeping them active, so dramatically reduces temperature overage without turning them completely off and inducing thermal shock when turning them back on again. Switching back and forth from series to parallel across the temperature target thus allows for good temperature control without generating excessive RF energy and without causing undue thermal shock on the module.

Generally speaking, the heating/cooling fluid system of the present invention comprises a radiator loop <NUM> and a garment loop <NUM>, each of which is connected to chiller block <NUM>. Essentially, radiator loop <NUM> controls the temperature of the chiller block <NUM>, which in turn controls the temperature of the garment loop <NUM>.

Both loops <NUM>, <NUM> share a single fluid tank <NUM> for keeping both loops full of liquid as required for proper function of the device <NUM>. A shared tank <NUM> is advantageous over two individual tanks for numerous reasons, one of which is that it takes up less space, another of which is simplicity of design.

Schematic views of embodiments of radiator loop <NUM> are shown in <FIG> and <FIG>. Radiator loop <NUM> can be said to begin with tank <NUM>, which has one or more vapor separators <NUM> as seen in <FIG>. Referring to <FIG>, which shows an embodiment according to the invention, a first vapor separator 204A is provided for radiator loop <NUM> and second vapor separator 204B for garment loop <NUM>. Each of separators <NUM> has a nipple <NUM> or multiple nipples <NUM> that lead to one of the radiator and garment loops <NUM>, <NUM>.

Radiator loop <NUM> has a straight tube <NUM> extending into a volume of fluid contained in tank <NUM>, which is in fluid communication with separator 204A. Separator 204A then channels the fluid through a filter <NUM> or the like if desired, then to a pump <NUM>, then to chiller block <NUM>. Chiller block <NUM>, depending on the thermal settings chosen, either heats or chills the fluid by reversing polarity of the TEMs <NUM>. The fluid then passes through a pair of radiator/fan assemblies <NUM> in sequence to correct and dissipate fluid temperature, and returns to fluid tank <NUM>.

Note that the arrangement of chiller block <NUM> and TEMs <NUM> in radiator loop <NUM> permits dissipation of excess heat without need for traditional finned heat sinks. The principle advantage to this is that it allows fluid to heat or cool more rapidly and to higher or lower temperatures than traditional TEM arrangements. Another advantage is the reduction in expense and space that the arrangement of the present invention affords over traditional heat sinks.

Referring now to garment loop <NUM>, an elbow tube <NUM> extends from within tank <NUM> to vapor separator 204B. Elbow tube <NUM> extends above the surface of the volume of fluid in tank <NUM> into an air reservoir. Since new garments <NUM> must be filled with fluid on first use, air residing in the garment must be flushed out to fully fill the garment with fluid. Air is either pushed out of radiator loop <NUM> and into the reservoir by the bolus of fluid or is entrained in the fluid and released into the reservoir during while fluid passes through the loop <NUM>.

Occasionally tank <NUM> must be filled by the operator, depending on how often new garments are filled. Radiator loop <NUM> could theoretically be filled only once when the device is new, and kept filled for the life of the machine by sealing the passages. But practically, over several years a portion of the fluid is lost by way of permeability of the material of the hoses and imperfect seals. This can be minimized by proper hose and other material selections, but cannot be eliminated completely.

However, radiator loop <NUM> must be kept full of fluid in order to maximize heat transfer. As such, eventually tank <NUM> must be refilled.

Garment loop <NUM> can also be said to begin with tank <NUM>, which is in fluid connection with vapor separator 204B. Fluid passes through filter <NUM> before entering and subsequently exiting chiller block <NUM>. Fluid then passes through a temperature sensor <NUM>, a pump <NUM>, and a pressure sensor <NUM> before entering garment <NUM>.

Pressure sensor <NUM> measures average fluid pressure to assess whether there is an overly low pressure such that additional fluid is needed in tank <NUM>. A relief valve <NUM> is also provided between the ingress of fluid into garment <NUM> and the egress of fluid away from garment <NUM>. This is so that in the case of overly high fluid pressure, excess fluid is prevented from entering garment <NUM> and is directed instead back toward tank <NUM>.

Additionally, relief valve <NUM> opens when device <NUM> is turned on but no garments are attached. This prevents pump <NUM> from running continually in an attempt to fill a non-existent garment, thus potentially damaging the pump.

One feature of the present disclosure is testing the system coolant level in the tank and garment loop system using fast Fourier transforms (FFTs). The system, not shown, uses a piston pump, tubing, and a pressure transducer. These could be a Topsflo™ piston pump, <NUM>/<NUM><NUM>, <NUM>/<NUM><NUM> Ark-Plas® urethane tubing, and a <NUM> PSI Honeywell® pressure transducer.

When the piston pump is activated it runs at approximately <NUM>. This creates a pressure signature that travels through the tubing and can be read by the pressure transducer. As shown in Fig. XX (a coordinate grid illustrating a sufficient pressure signature), when an FFT is done to transform this time domain signal into a frequency domain signal, a strong signal can be seen between <NUM>-<NUM>.

However, if the fluid in the machine is low, the pump will not run consistently at that frequency. Rather, air pockets will develop and, as seen in Fig. XX (a coordinate grid illustrating an insufficient pressure signature), there will be no peak at the FFT in this region. By using this discrepancy between the <NUM> FFTs in the <NUM>- <NUM> range it is possible to determine whether or not there is a sufficient supply of fluid in the system using only a single transducer.

This method is an improvement over designs in which a single pressure threshold is used to determine whether the fluid level is sufficiently high. These designs are not as reliable as the FFT detection method because of variation is native pressures of different garments. Using an FFT to determine the magnitude of activity at a given frequency eliminates this problem.

Note that this inventive feature is not limited to use with the apparatus of the present invention. Rather it is applicable anywhere a piston pump or other rhythmic device is acting on a fluid that has potential to be reduced in quantity. Not only is it very reliable in determining fluid level in a closed system, it requires the use of only a single pressure transducer and the capability to perform FFTs.

Air pressure control system <NUM> comprises a system of solenoids and air chambers to create, control, and vent air pressure in device <NUM>. Control system <NUM> provides at least three different pressurized chambers - a chamber <NUM> for a thermal garment <NUM>, a chamber <NUM> for a first DVT garment 36a, and a chamber <NUM> for a second DVT garment 36b. Each of chambers <NUM>, <NUM>, <NUM> sustains pressures of up to <NUM> Hg and is pressurized using pump <NUM> of system <NUM>.

Referring to <FIG>, a schematic of air pressure control system <NUM> shows an air supply pump <NUM>, an initial air pathway <NUM>, an air pressure sensor <NUM>, and four solenoid operated switch assemblies S1, S2, S3, and S4, each of which is normally open as shown.

Switch assembly S1 controls the air pressure level in a thermal garment <NUM>. When the thermal garment <NUM> is not in use, a first solenoid of 310a switch S1 remains closed, preventing air from entering the garment. When the thermal garment is in use, a second solenoid 310b of switch S1 will open and first solenoid 310a will close as pump <NUM> turns on. This allows air pressure to begin building up within thermal garment <NUM>.

A similar solenoid assembly is present in each of switch assemblies S2, S3, and S4. Switch assembly S2 controls air pressure in system <NUM> at large by permitting the release of excess air from the system entirely. Each of switch assemblies S3 and S4 are directed to individual DVT units.

The pressure in the DVT chambers is intended to alternate such that when one pressure is at the cycle maximum, the other is near zero. Thus, when the first chamber is being pressurized, solenoids <NUM>, <NUM>, and <NUM> will be closed and <NUM> will be open. When the second chamber is being pressurized, solenoids <NUM>, <NUM>, and <NUM> will be closed and <NUM> will be open. Once these chambers have reached the requisite pressure, their respective solenoids will be closed until the software calls for them to be vented. At venting, the solenoid attached to the chamber to be vented, as well as solenoid <NUM>, will be opened.

All chambers are preferably pressurized by the single air pump within the system, which has a direct line to all chambers. The single sensor will measure all pressures within the system, using the solenoids to seal off the chambers when the correct pressure has been reached.

Many DVT prophylaxis cycles have variance in the level of compression they provide to the foot or calf over the duration of their cycles. This is primarily due to the fact that a DVT cycle alternates from fully compressed to empty to encourage blood flow to and from the region to which the DVT garment is applied.

All DVT cycles essentially have an "on" state in which the garment is compressed, and an "off" state in which it does not hold pressure. In the present invention, during the "on" period the pressure provided by the DVT garment will alternate between its maximum pressure and approximately <NUM>% of its maximum pressure every <NUM> seconds as shown in <FIG>.

User testing has concluded that users prefer this type of pulsed cycle over a more traditional cycle that does not pulse in the "on" position. Increased patient comfort during treatment yields elevated DVT prophylaxis efficacy through increased patient compliance. Not surprisingly, this is more likely to lead to better long-term clinical outcome<NUM>.

Additionally, user feedback has indicated that the pulsed DVT prophylaxis leads to temporary relief of chronic localized pain. This is possibly related to a phenomenon known as "gate control theory" which posits that that painful stimuli can be mitigated by the activation of Af3 fibers. Af3 fiber activation promotes inhibitory
<NUM> <NPL>. interneurons, which in turn inhibit the propagation of the pain signals<NUM>. This process is illustrated in <FIG>. When Af3 fibers are activated by "innocuous, tactile sensation", such as is provided by a pulsing DVT treatment, the perception of pain may be mitigated<NUM>.

System <NUM>, and more particularly air pressure control system <NUM>, is controlled by software code to initiate a first pulse of air on initiation of inflation. In a preferred embodiment, the code directs a first pulse of air to all three garments (thermal garments <NUM> and DVT garments <NUM>) to jump-start the filling process.

Air pressure control system <NUM> allows operation of device <NUM> as a thermal garment only, a thermal garment with a first DVT garment, or a thermal garment with first and a second DVT garments.

In use as a thermal garment only, the dedicated thermal garment is used the same as in connection with other functions. That is, the thermal garment is inflated to apply and maintain heat more effectively to the selected body part, for example, a user's lower back.

When in use with a single DVT garment, the dedicated DVT garment is inflated to apply pressure to a different body part, for example a user's right leg, and after inflation performs a therapeutic pulsing cycle.

If a second DVT garment is in use, the first DVT garment is deflated and the second DVT garment is inflated to apply pressure to yet another body part, for example a user's left leg. A therapeutic pulsing cycle is
<NUM> <NPL>. <NUM> <NPL>. then performed with the second DVT garment.

A representation of this cycle profile is shown in <FIG>. As can be seen, in the event the device is being used only as a thermal garment, the cycle begins with "check thermal". Pressure at the thermal garment will, at this point, be low, so the decision step "is DVT-<NUM> active? divide by <NUM> count" is engaged. Since DVT-<NUM> in this scenario is not active, the step of inflation of all connected garments is performed and the thermal garment pressure is again examined.

Once the thermal garment pressure reaches its defined pressure point, a second decision point is engaged, i.e. "is DVT-<NUM> active?" Again, the first DVT garment in this scenario is inactive, so a third decision point, "is DVT-<NUM> active?" is reached, and, the answer being no, the system returns to "check thermal.

When a first DVT garment is employed with the thermal garment, at the "is DVT-<NUM> active? divide by <NUM> count" decision point, the DVT-<NUM> garment is active and the "divide by <NUM> count" step is engaged. Because this is the beginning of the first cycle, there have been zero full cycles, and zero divided by three is zero. Whenever the answer to the question is anything other than zero, inflation is not allowed. However, because the answer in this case is zero, all attached devices are allowed to be inflated as needed.

Again, once the thermal garment pressure reaches its defined pressure point, the decision "is DVT-<NUM> active?" is reached, but now the first DVT garment is active, so all pressure to DVT-<NUM> is dumped. In this scenario, there is no pressure at DVT-<NUM> because it is not being employed. DVT-<NUM> is uninflated, so pressure will be low such that DVT-<NUM> is inflated until the appropriate pressure is reached. The therapeutic pulse cycle is ensues after which, since DVT-<NUM> is not active, the system returns to the check thermal step.

This time at the "is DVT-<NUM> active? divide by <NUM> count" decision point, since one cycle has been completed, the "divide by <NUM> count" answer is one divided by three, i.e. not zero. As such, inflation of all attached device is not allowed and the cycle continues from there.

Only after the 3rd cycle will the answer to "divide by <NUM> count" be zero again, at which point all attached devices will be allowed to inflate again.

Naturally, each of the thermal garment and first and second DVT garments can be used in the same therapy session as well. This iteration differs only slightly from the thermal garment + single DVT garment scenario, except that at "is DVT-<NUM> active?" the answer is yes and the DVT-<NUM> garment cycle is performed. This includes dumping pressure at the DVT-<NUM>, inflating and/or deflating the DVT-<NUM> pressure as needed, and performing an additional therapeutic pulse step.

Many medical professionals recommend different treatments for injuries during different periods of injury recovery. For instance, immediately after an injury occurs most professionals will recommend cooling and compressing the injured area to prevent secondary injury and mitigate swelling. However, after a period of time has passed, most will recommend a change of treatment to a warm thermotherapy cycle for its analgesic effect and encouragement of blood flow to an area.

Advantageously, as seen in Fig. XX, the cryotherapy device of the present invention is capable of having multiple cycle programs that run automatically based on a clock internal to the device. This permits the pre-programming of prescribed cycles, typically by a medical professional, so that even in outpatient care the preferred treatment regimen can be followed automatically.

To ensure proper use of the device for the best thermal outcome, as well as to prevent misuse of the device, a password may be required in order to modify the preprogrammed therapy instructions.

Methods of tracking patient compliance are contemplated so that care providers know not only what regimen of therapy was prescribed but also what therapy was actually performed throughout the patient's therapy history. This information can useful for the provider who may be receiving mistaken or only partial information about therapy performance.

To this end, a USB port can be provided for relaying system information, including therapy history, to an external device such as a computer. The history can be added to a patient's file for future reference. For the researcher, such a record of therapy, when aggregated with numerous other patient histories, presents a useful dataset. Such information could direct improvements for future treatment protocol.

As previously noted however, in the present embodiment USB port <NUM> is a convenience enabling a user to charge a phone or the like while device <NUM> is powered.

Referring to thermal garment <NUM> as described herein passim, an internal fabric layer 400a and an external fabric layer 400b are presented as well as a thermal contact layer 400c. Fabric layers 400a, 400b may be constructed of any suitable material.

Contact layer 400c comprises a bladder, preferably constructed of a puncture resistant but flexible material. The patient contact side of contact layer 400c may further be provided with a plurality of protrusions <NUM> that provide even closer contact between layer 400c and the patient body part.

A DVT garment <NUM>, which fills with compressed air but not fluid, does not require internal fluid structures, only an internal air bladder <NUM> connected to an air supply. Garment <NUM> has inner and outer fabric layers 412a, 412b.

As shown in <FIG>, a number of garment configurations are possible to provide heat therapy proximate to the body part requiring treatment. These include but are not limited to the configurations shown for use with a patient's foot, ankle, knee, lower back, and elbow.

<FIG>, <FIG>, and <FIG> illustrate DVT-only garments, again designed to provide therapy to the targeted body part.

<FIG> and <FIG> show additional thermal garments, including features such as elbow/knee openings <NUM>, body straps <NUM>, sling straps <NUM>, and adjustment/closure patches <NUM>.

When the circulating liquid through a thermal garment <NUM> for application to a patient's joints, such as elbows and ankles, garment <NUM> itself must be able to conform to the joints. Fold lines <NUM> are provided to ease wrapping of garment <NUM> around a joint.

In addition, bending the liquid conduit around a body part can crimp the conduit. This stops the flow of the liquid that would normally circulate through the entire garment, creates back pressure in the garment, and, naturally, limits the effectiveness of garment. One design uses hollow tubing embedded in the areas where the garment has a tendency to become kinked. The tubing provides a rigid structure that prevents a patient's arm, for instance, from pinching off the liquid to the bladder even when the patient bends the arm. Proper flow ensures that the patient receives uncompromised treatment.

Also, when cooled or heated fluid is circulated within garment <NUM> at a desired therapeutic temperature, the fluid temperature is normalized by the atmospheric temperature, raising or lowering the fluid temperature accordingly. The effectiveness of the therapeutic regimen can therefore be negatively impacted by the external temperature.

To avoid temperature degradation of the fluid, the garment may include an insulated layer system within the design of garment <NUM>. Specifically, a three-fabric layer system is envisioned in which insulating layers 404a, 404b are provided over the front and rear sides of contact layer 400c. The fluid is therefore provided with more insulation against the effects of ambient air, leading to more effective treatment.

For patients with diabetes, lymphedema, high blood pressure, or other conditions that cause edema (foot swelling due to fluid buildup), DVT compression of the feet is of particular importance.

Whether the edema is caused by standing for long hours, such as is required in a number of professions, or simply from sitting at a desk all day, DVT compression of the feet is beneficial.

To provide such patients with an option that would allow DVT compression cycles while standing or sitting, but also allow for quick removal of a DVT garment when walking is required, slip-on foot garments are envisioned. 48a, 48b, 48c. For example, a desk worker could remove his or her shoes once seated and insert them into a DVT foot garment located under his or her desk. When the patient needs to get up, he or she simply removes his or her feet from the slip-on DVT garment and back into his or her shoes.

A person standing behind a counter, such as a cashier, could likewise remove shoes and slip feet into a DVT foot garment, replacing his or her shoes when not behind the counter. Even a person who is usually in motion could readily and rapidly employ such a garment during scheduled breaks.

A number of garments are envisioned. For example, a DVT insert might be provided for a pair of store-bought slippers, or a slipper having integral DVT chambers could be made. A single unit having a single DVT foot chamber or two individual chambers are also envisioned. Other garments that could provide slip-on convenience for foot DVT are likewise considered, as are other slip-on or other easy-on, easy-off configurations for other parts of the body. In addition, the foot DVT could be manufactured complete or made to be adapted to commercially available foot accessories.

Safety concerns regarding sanitation, as codified in FDA regulations, prevent multiple users from using the same garment. One way to address this is to provide reusable garment covers to each patient with a single insert. However, a garment cover invariably reduces the ability of the insert to heat or cool the intended body part. Further, the garment covers themselves are, at least at present, almost as expensive as the garment itself.

Claim 1:
A device for providing therapeutic thermal compression when used in association with a patient garment, said device (<NUM>) comprising:
a temperature system, a compression system, and a control system, wherein said temperature system comprises a heating/cooling assembly (<NUM>) having an upper plate (102a), a center plate (102b), and a lower plate (102c), and a first and second thermoelectric module (TEM) (104a, 104b), said first TEM (104a) being interposed between said upper and center plates and said second TEM (104b) being interposed between said center plate and said lower plate
a coolant tank (<NUM>);
the garment (<NUM>);
a garment loop (<NUM>) for filling the patient garment, said garment loop including a fluid pump (<NUM>) and being fluidly connected to said heating/cooling assembly (<NUM>) and said coolant tank (<NUM>), wherein said garment loop is fluidly connected to said coolant tank with a first vapor separator (204b); and
a radiator loop (<NUM>) including a fluid pump (<NUM>), said radiator loop fluidly connected to said heating/cooling assembly (<NUM>) and said coolant tank (<NUM>), said radiator loop fluidly connected to said coolant tank with a second vapor separator (204a).