Thermal performance optimization in a thermal therapy device
A rapid contrast therapy system can provide cold, heat/hot/warm (hereafter referred to as “hot”), and/or rapid contrast therapy, which involves rapidly alternating between cold therapy and hot therapy. The system can circulate cold or hot fluid, such as water, through a hose, into a therapy wrap, and then back to the fluid reservoirs of the system. The system can utilize a vapor compression system or other chiller technology to cool the cold water reservoir, and immersion heaters can be used to heat the hot water reservoir.
1 . A system for providing rapid contrast therapy, the system comprising:
a cold reservoir configured to hold a cold liquid, the cold reservoir including a first liquid level sensor to measure a level of the cold liquid and a first temperature sensor to measure a temperature of the cold liquid;
a hot reservoir configured to hold a hot liquid, the hot reservoir including a second liquid level sensor to measure a level of the hot liquid and a second temperature sensor to measure a temperature of the hot liquid;
a return valve for directing return flow from a therapy device to the hot reservoir and the cold reservoir;
a return temperature sensor for measuring a temperature of the return flow from the therapy device; and
a controller directing operation of the return valve to control the return flow from the therapy device to the cold and hot reservoirs, wherein the controller is configured to:
responsive to determining that the level of the cold liquid and the hot liquid are within a target liquid level range, direct the return flow to one of the cold reservoir or the hot reservoir having a closest temperature with the temperature of the return flow, and
responsive to determining that the level of either the cold liquid or the hot liquid falls below a lower limit of the target liquid level range, direct the return flow to a corresponding one of the cold reservoir or the hot reservoir.
2 . The system of claim 1 , wherein the controller is further configured to:
responsive to determining that the level of either the cold liquid or the hot liquid exceeds an upper limit of the target liquid level range, direct the return flow to an opposite one of the cold reservoir or the hot reservoir.
3 . The system of claim 1 , further comprising:
a cold therapy supply valve in fluid communication with the cold reservoir, the cold therapy supply valve directing a flow of the cold liquid to a therapy device; and
a hot therapy supply valve in fluid communication with the hot reservoir, the hot therapy supply valve directing a flow of the hot liquid to the therapy device, wherein the controller directs operation of the cold therapy supply valve and the hot therapy supply valve.
4 . The system of claim 1 , further comprising:
a conduit extending between the cold reservoir and the hot reservoir, the conduit providing fluid communication therebetween; and
one or more cross-tank valves for controlling flow through the conduit, wherein:
the controller directs operation of the one or more cross-tank valves to control flow between the cold and hot reservoirs, and
the controller directs operation of the one or more cross-tank valves in response to a measured liquid level in each of the cold and hot reservoirs such that the level of the cold liquid in the cold reservoir and the level of the hold liquid in the hot reservoir do not exceed an upper limit or fall below the lower limit of the target liquid level range.
5 . The system of claim 4 , wherein the controller directs flow through the conduit:
from the hot reservoir to the cold reservoir when the first liquid level sensor measures a liquid level below the lower limit of the target liquid level range,
from the cold reservoir to the hot reservoir when the second liquid level sensor measures a liquid level below the lower limit of the target liquid level range,
from the cold reservoir to the hot reservoir when the first liquid level sensor measures a liquid level above the upper limit of the target liquid level range, or
from the hot reservoir to the cold reservoir when the second liquid level sensor measures a liquid level above upper limit of the target liquid level range.
6 . The system of claim 4 , wherein the system is not operating when at least one of the cold and hot liquids have not been provided to the therapy device for a predetermined off period and, when the system is not operating, the controller directs operation of one or more of the cross-tank valves to open fluid communication between the cold and hot reservoirs for a first time period.
7 . The system of claim 6 , wherein the predetermined off period that the system is not operating is between 5 and 20 seconds.
8 . The system of claim 6 , wherein the controller directs operation of one or more of the cross-tank valves to open fluid communication between the reservoirs until a difference between the measured liquid levels in the cold and hot reservoirs is within a predetermined deviation amount.
9 . The system of claim 6 , wherein the controller directs cycled operation of one or more of the cross-tank valves to open and close fluid communication between the reservoirs, such that during each open-close cycle the one or more of cross-tank valves is open for the first time period and closed for a second time period until a difference between the measured liquid levels in the cold and hot reservoirs is within a predetermined deviation amount.
10 . A method of operating a rapid contrast therapy device, the method comprising:
measuring liquid levels of both a cold liquid within a cold liquid reservoir and a hot liquid within a hot liquid reservoir of the rapid contrast therapy device;
determining whether the measured liquid levels are within a target liquid level range; and
controlling, via a return valve, a return flow of liquid from a therapy wrap of the rapid contrast therapy device to at least one of the cold liquid reservoir or the hot liquid reservoir to minimize thermal pollution of hot water from entering the cold liquid reservoir or cold water from entering the hot liquid reservoir upon return from the therapy wrap, wherein:
responsive to determining, by a controller, that the level of the cold liquid and the hot liquid are within a target liquid level range, the return flow is directed to one of the cold liquid reservoir or the hot liquid reservoir having a closest temperature with a temperature of the return flow, and
responsive to determining, by the controller, that the level of either the cold liquid or the hot liquid falls below a lower limit of the target liquid level range, the return flow directed to a corresponding one of the cold liquid reservoir or the hot liquid reservoir.
11 . The method of claim 10 , wherein responsive to determining, by the controller, that the level of either the cold liquid or the hot liquid exceeds an upper limit of the target liquid level range, the return flow is directed to an opposite one of the cold liquid reservoir or the hot liquid reservoir.
12 . The method of claim 10 , wherein the rapid contrast therapy device includes a conduit extend between the cold liquid reservoir and the hot liquid reservoir and a cross-tank valve for controlling flow through the conduit, the method further comprising:
operating the cross-tank valve to allow fluid to flow between the cold and hot liquid reservoirs such that the liquid level in either the cold and hot liquid reservoirs does not exceed an upper limit or fall below the lower limit of the target liquid level range.
13 . The method of claim 12 , the method further comprising operating the cross-tank valve to direct flow through the conduit:
from the hot liquid reservoir to the cold liquid reservoir when the level of the cold liquid falls below the lower limit of the target liquid level range,
from the cold liquid reservoir to the hot liquid reservoir when the level of the hot liquid falls below the lower limit of the target liquid level range,
from the cold liquid reservoir to the hot liquid reservoir when the level of the cold liquid exceeds the upper limit of the target liquid level range, or
from the hot liquid reservoir to the cold liquid reservoir when the level of the hot liquid exceeds the upper limit of the target liquid level range.
14 . The method of claim 12 , wherein the rapid contrast therapy device is not operating when at least one of the cold and hot liquids have not been provided to the therapy wrap for a predetermined off period, wherein, when the rapid contrast therapy device is not operating, the method further includes opening the cross-tank valve for a first time period.
15 . The method of claim 14 , wherein the predetermined off period that the rapid contrast therapy device is not operating is between 5 and 20 seconds.
16 . The method of claim 14 , wherein the cross-tank valve is held open until a difference between the measured liquid levels in the cold and hot liquid reservoirs is within a predetermined deviation amount.
17 . The method of claim 14 , further comprising:
cyclically operating the cross-tank valve to open and close fluid communication between the cold and hot liquid reservoirs, such that during each open-close cycle the cross-tank valve is open for the first time period and closed for a second time period until a difference between the measured liquid levels in the cold and hot liquid reservoirs is within a predetermined deviation amount.
18 . A controller for a rapid contrast therapy device, the controller comprising:
a processor; and
memory having instructions stored thereon that, when executed by the processor, cause the controller to:
measure liquid levels of both a cold liquid within a cold liquid reservoir and a hot liquid within a hot liquid reservoir of the rapid contrast therapy device;
determine whether the measured liquid levels are within a target liquid level range; and
control a return valve of the rapid contrast therapy device to direct a return flow of liquid from a therapy wrap of the rapid contrast therapy device to at least one of the cold liquid reservoir or the hot liquid reservoir, wherein responsive to determining, by a controller, that the level of the cold liquid and the hot liquid are within a target liquid level range, the return flow is directed to one of the cold liquid reservoir or the hot liquid reservoir having a closest temperature with the temperature of the return flow, and responsive to determining, by the controller, that the level of either the cold liquid or the hot liquid falls below a lower limit of the target liquid level range, the return flow is directed to a corresponding one of the cold liquid reservoir or the hot liquid reservoir.
19 . The controller of claim 18 , wherein if the level of either the cold liquid or the hot liquid exceeds an upper limit of the target liquid level range, the return flow is directed to an opposite one of the cold liquid reservoir or the hot liquid reservoir.
20 . The controller of claim 18 , wherein the instructions further cause the controller to:
control a cross-tank valve on a conduit extending between the cold liquid reservoir and the hot liquid reservoir of the rapid contrast therapy device to direct flow through the conduit such that the liquid level in either the cold and hot liquid reservoirs does not exceed an upper limit or fall below the lower limit of the target liquid level range.