Patent Application
20120022620
This present invention relates generally to a method and apparatus for performing warming therapy on medical patients. More particularly, the present invention relates to a method and apparatus for heating a mattress in a warming therapy device, wherein the heating apparatus is X-ray transparent, and wherein the heating system includes an oxygen monitoring system for providing control feedback to control the power applied to the heating apparatus.
Conventional warming therapy devices achieve patient warming through the use of air pumps and convective and radiant heaters. Some existing devices also use a conductive method of warming therapy, or a heated mattress. One such device (which is manufactured by the present assignee and sold under the name Babytherm®) utilizes an electric resistive heater attached to a metal plate which supports a thermally conductive gel mattress. The metal plate design provides some degree of uniform temperature distribution across the surface of the mattress, however, it is also non-transparent to X-rays. So, an X-ray cassette can only be placed over the mattress support containing the metal plate, which may interfere with the care of the patient disposed on the mattress. Other conventional warming devices including conductive warming utilize X-ray transparent carbon fiber material instead of a metal plate.
For example, U.S. Pat. Nos. 6,814,889 and 6,974,935, the disclosures of which are hereby incorporated by reference into this application, discuss a heated mattress device 1 which includes a conductive layer 3 with carbon particles. Carbon fiber is electrically conductive, and thus allows a similar distribution of heat as provided by the metal plate, and also permits the placement of an X-ray cassette below the carbon fiber layer. However, such structures often leaves artifacts on the X-ray image due to non-X-ray transparent temperature control sensors, buses and connecting wires disposed in the area around the carbon fiber layer.
The above-described metal plate design is also not usable in ‘oxygen rich’ environments because it consumes more power than is acceptable under current International Electrotechnical Commission (EC) guidelines. Oxygen rich environments could include, for example, environments where the oxygen level was four percent (4%) or more above ambient, as per IEC guidelines. For example, current IEC guidelines place an upper limit of 15 Volt-Amperes (VA) per circuit in oxygen rich environments, and the above-described metal plate design exceeds those limits.
Existing carbon fiber beaters are similarly unusable in ‘oxygen rich’ environments because of the above-described IEC guidelines. Although the above-referenced patents described temperature sensors for controlling heating, such sensors do not operate to maintain power consumption levels below IEC guidelines for oxygen rich environments. Rather, they assist only in achieving and maintaining a desired temperature for the mattress, with regard to the surrounding environment.
The present invention overcomes the deficiencies of conventional warming therapy devices through the use of a heated mattress assembly. In particular, conventional warming therapy devices are unable to maintain a desired temperature distribution at the interface between the mattress and the patient. The present invention solves this problem by using temperature sensors to measure the temperature at the interface between mattress and the patient, and using the temperature measurements to control specific heating elements in order to achieve a desired temperature at the interface between mattress and baby. In addition, the present invention avoids the above-described artifact problem experienced by warming therapy devices including carbon fiber structures within the mattress support by utilizing temperature sensors, buses and supply wires comprised of non-metallic radiolucent conductive materials, such as carbon nanotubes.
Further, in one exemplary embodiment, the present invention utilizes a segmented heated mattress assembly including an Oxygen control Device (OCD). In particular, conventional warming therapy devices are unable to achieve and maintain different temperatures depending on the presence or absence of oxygen in the surrounding environment. The present invention solves this problem by using the OCD to control the power supplied to one or more heating segments of a mattress, so as to achieve a desired temperature at the interface between mattress and baby and to also avoid power levels which exceed IEC guidelines.
Accordingly, there is presently a need for a warming therapy device that permits efficient heating of patients in oxygen rich environments, and simultaneously allows for simple and effective X-ray examinations to be performed in the same environment.
An exemplary embodiment of the present invention comprises an apparatus including a patient support assembly and at least one heating element coupled to the patient support assembly, the at least one heating element formed of a plurality of heating cells.
An exemplary embodiment of the present invention also comprises an apparatus including a patient support assembly and at least one heating element coupled to the patient support assembly, the at least one heating element formed of an insulating layer and first and second support layers, such that the insulating layer is disposed between the first and second support layers.
An exemplary embodiment of the present invention also comprises a heating element including a first support layer, a heater layer coupled to the first support layer, an insulating layer coupled to the heater layer, a grid layer coupled to the insulating layer, and a second support layer coupled to the grid layer.
An exemplary embodiment of the present invention also comprises an apparatus including a patient support assembly and at least one heating element coupled to the patient support assembly, the at least one heating element formed of a plurality of heating segments.
An exemplary embodiment of the present invention also comprises an apparatus including a patient support assembly and at least one heating element coupled to the patient support assembly, the at least one heating element including power rails disposed on opposing sides thereof, and at least one temperature sensor coupled thereto.
An exemplary embodiment of the present invention also comprises a control system including at least one heating element, a system controller coupled to the at least one heating element, and at least one oxygen sensor coupled to the system controller, wherein the at least one oxygen sensor and the system controller operate to control the power applied to the at least one heating element.
An exemplary embodiment of the present invention also comprises a method of providing warming therapy to a patient, the method including providing at least one heating element in proximity to a patient, and selectively activating the at least one heating element, so that the patient is heated to a predetermined level.
The present invention relates to a warming therapy device (e.g., incubator, warmer, etc.) including a heated mattress tray assembly. In particular, the warming therapy device includes a resistive or radiolucent heater disposed within a mattress tray assembly for providing heating of a patient disposed on the mattress tray assembly in one embodiment. In another embodiment, the warming therapy device includes a segmented carbon fiber heater coupled to an oxygen control device and disposed within a mattress tray assembly for providing heating of a patient situated on the mattress tray assembly.
The mattress tray 41 may be made rotatable within the support base 42 up to three hundred and sixty degrees (360°).
The warming therapy device 10 may optionally include a backplane 50, to which ventilation hoses and other devices may be coupled through, for example, interconnection nozzles 51. The backplane 50 may also include one or more oxygen sensors disposed therein for sensing an oxygen level inside the hood 45, as explained in detail below.
The resistive heating element 60 may be formed of a substantially flat member or plurality of substantially flat members (segments) which extend through some or all of the mattress 42. For example, if the mattress 42 is substantially rectangular in shape as shown in
As mentioned above, non-metallic conductive materials may be used for the resistive heating element 60. For example, materials using carbon nanotubes may be utilized to achieve an increase in electrical and thermal conductivity. Materials such as graphene may also be used for the resistive heating element 60. Graphene in particular shows electrical conductivity even as one (1) atom layer thick film, and is virtually undetectable by microscope. Conductive plastics, such as optically transparent vacuum metallized polyethylene, may also be used for the resistive heating element 60. However, in order to insure effective X-ray imaging of the patient 70, any material used for the resistive heating element 60 should be X-ray transparent, which is the case for some conductive plastics and thin metal cloth. Those of ordinary skill will realize that the X-ray cassette 75 is not a necessary element of the above-described exemplary embodiment, and in cases where X-ray capacity is not needed the resistive heating element 60 may be formed of materials which are not necessarily X-ray transparent.
The thermal capacity of the mattress 42 may be made sufficiently large so as to allow continued warming of the patient 70 even after the electric heating element 60 is turned off. Certain gels, such as polyurethane and silicone gels, may be used for the forming the entirety, or a portion of die mattress 142 as they have a high thermal capacity. The previously-mentioned Babytherm® product manufactured by the present assignee includes such a gel within the mattress. However, those of ordinary skill in the art will realize that other materials (e.g., thermally conductive plastic foam) are also suitable for forming the mattress 42, or some portion thereof.
The warming therapy device 110 includes a mattress tray assembly 140, including a mattress tray 141 and mattress 142, which are disposed on a patient support assembly 130. As opposed to the warming therapy device 10, an electric resistive heating element 160 is disposed on the mattress tray 141, for providing heat to a patient 170 disposed on the mattress 142. A utility tray 180 may be disposed beneath the mattress tray 141, and may house an X-ray cassette 175. The X-ray cassette 175 may be used, for example, in performing X-ray examinations of the patient 170, as is well known in the art.
The resistive heating element 160 may be a substantially flat member which extends through some or all of the mattress tray 141. For example, if the mattress tray 141 is substantially rectangular in shape as shown in
As with the resistive heating element 60 discussed above, non-metallic conductive materials may be used for the resistive heating element 160. For example, materials using carbon nanotubes may be utilized to achieve an increase in electrical and thermal conductivity. Materials such as graphene may also be used for the resistive heating element 160. Graphene in particular shows electrical conductivity even as one (1) atom layer thick film, and is virtually undetectable by microscope. Conductive plastics, such as optically transparent vacuum metallized polyethylene, may also be used for the resistive heating element 160. However, in order to insure effective X-ray imaging of the patient 170, any material used for the resistive heating element 160 should be X-ray transparent, which is the case for some conductive plastics and thin metal cloth. Those of ordinary skill will realize that the X-ray cassette 175 is not a necessary element of the above-described exemplary embodiment, and in cases where X-ray capacity is not needed the resistive heating element 160 may be formed of materials which are not necessarily X-ray transparent.
The thermal capacity of the mattress 142 may be made sufficiently large so as to allow continued warming of the patient 170 even after the electric heating element 160 is turned off. Certain gels, such as polyurethane and silicone gels, may be used for the forming the entirety, or a portion of the mattress 142, as they have a high thermal capacity. The previously-mentioned Babytherm® product manufactured by the present assignee includes such a gel within the mattress. However, those of ordinary skill in the art will realize that other materials (e.g., thermally conductive plastic foam) are also suitable for forming the mattress 142, or some portion thereof.
Again, as with the resistive heating element 60 discussed above, the resistive heating element 160 may be formed as a matrix structure, as shown in
When, for example, a patient is disposed on or in close proximity to the heating element 260, the temperature directly below the patient (at the interface) increases due to the fact that heat dissipation to the ambient environment is at least partially blocked by the patient's body. The heating element 260 according to the second exemplary embodiment of the present invention overcomes this increased heating problem through the use of a thermocouple grid (i.e., temperature sensing array), as explained below.
As shown in
Although the mattress tray assemblies 40, 140 according to the first and second exemplary embodiments are shown and described above with reference to an associated warming therapy devices 10, 110 of specific configurations, those of ordinary skill in the art will realize that the mattress tray assemblies 40, 140 may be integrated into any suitable incubator, warmer, medical treatment device or other equivalent apparatus.
Each of the first and second segments 361, 362 of the heating element 360 may be power-limited according specific standards. For example, each of the segments 361, 362 may have an upper power limit of 15 VA, thereby permitting a total power of the heating element 360 to be up to 30 VA. As noted above, current IEC guidelines place an upper limit of 15 VA per circuit, and thus the heating element according to the third exemplary meets IEC guidelines.
The heating element 360 may also include an Oxygen Control Device (OCD) which controls the power supplied to the heating segments 361, 362 between lower and upper limits. For example, a lower power limit may be the IEC guideline for oxygen rich environments of 15 VA, and the upper limit may be greater than 50 VA (for environments which are not oxygen rich). The upper limit may be set so as to insure that the mattress surface temperature does not exceed 42° C. The OCD may additionally control the amount of oxygen supplied to the patient 70 disposed on the mattress 42 (when utilizing the heating element 360 in connection with the warming therapy device 10).
In operation, a user (e.g., health care professional) selects a desired mattress temperature (e.g., 39° C.), and the OCD controls the power supplied to the heating segments 361, 362, and the oxygen supply, so that the mattress (e.g. mattress 42) reaches the desired temperature in the shortest possible time given conditions. For example, if oxygen is not immediately required for the patient during warm up, the OCD would allow maximum power to be supplied to the heating segments 361, 362 (e.g., 70-100 VA) until the desired temperature was reached. Once the desired temperature was reached, the OCD would initiate supply of oxygen to the patient, and would maintain the temperature at the desired level through switching the power to the heating segments 361, 362 on and off at power levels at or below LEC limits (e.g., 15 VA or less). However, if oxygen is required for the patient during warm up, the OCD would regulate the power supplied to the heating segments 361, 362, so as not to exceed 15 VA per segment, which would necessarily increase the warm up time.
The first control line 611 may be coupled to the power rails or buses of the heating element 630 (e.g., buses 393, 394 of the heating element 360), to enable the controller 610 to supply power to the heating element. Similarly, the second control line 612 may be coupled to the backplane of a warming therapy device (e.g., backplane 51 of the warming therapy device 10), which may include one or more oxygen sensors (e.g., oxygen sensors 630) as noted above. The first sensor control line 631 may be coupled to a first sensor of the heating element 630 (e.g., sensor 391), and die second sensor control line 632 may be coupled to a second sensor of the heating element (e.g., sensor 392). The system controller 610 may be used to set a predetermined mattress temperature for monitoring purposes. Such a predetermined temperature may be set (and changed) by a health care professional using, for example, the display and control unit 640.
The heating element 460 is divided into a plurality of segments in the fourth exemplary embodiment, including a first segment 461, a second segment 462, and a third segment 463. As with the third exemplary embodiment, the first segment 461 may be coupled to a first sensor 491, the second segment 462 may be coupled to a second sensor 492, and the third segment 463 may be coupled to a third sensor 493 all for sensing the respective temperatures of the first through third segments, and providing control signals for use in regulating such temperatures to a system controller (e.g., system controller 610 shown in 13). The first through third segments 461, 462, 463 may also include respective power rails or buses 494, 495, 496 for receiving power from an external voltage or current source, which may be part of the system controller (e.g., system controller 610). As noted above, the first through third segments 461, 462, 463 are preferably radiolucent (e.g. X-ray transparent or translucent) and designed using primarily carbon fiber materials (e.g., carbon films, carbon nanotubes, etc.).
The heating element 460 according to the fourth exemplary embodiment further reduces the appearance of artifacts on an X-ray by routing the power rails 494, 495, 496 outside the X-ray area (i.e., the central portion of the heating element 460). Additionally, the heating element 460 provides three (3) times the heating power of a single segment heater, due to the presence of three independently controllable heating segments. Those of ordinary skill in the art will realize that this scalability concept may be expanded to increase heating power by increasing the number of segments in the heater. For example, a heater with four (4), five (5) or six (6) segments may be used to increase heating power.
The heating element 460 according to the fourth exemplary embodiment operates similarly to the heating element 360 according to the third exemplary embodiment, in that a user (e.g., health care professional) selects a desired mattress temperature (e.g., 39° C.), and the OCD controls the power supplied to the heating segments 461, 462, 463 and the oxygen supply, so that a mattress reaches a desired temperature in the shortest possible time given conditions. The main difference being that the OCD limits the power supplied to each of the heating elements 461, 462, 463 to 15 VA or less when oxygen is being supplied. However, the presence of three separate heating segments 461, 462, 463 permits a maximum power limit of 45 VA in oxygen rich environments (as opposed to 30 VA in the heating element 360).
The heating element 460 may be controlled by a control system 600 such as is shown in
Alternatively, from the heating elements 360 and 460, the heating element 560 according to the fifth exemplary embodiment is forted of a single segment 561. However, like the heating elements 360 and 460, the heating element 560 includes a first sensor 591 for sensing the temperature of the segment, and providing a control signal for use in regulating such temperature to a system controller (e.g., system controller 610 shown in
The heating element 560 according to the fifth exemplary embodiment operates similarly to the heating elements 360 and 460 described above, in that a user (e.g., health care professional) selects a desired mattress temperature (e.g., 39° C.), and the OCD controls the power supplied to the beating segment 561, and the oxygen Supply, so that a mattress reaches a desired temperature in the shortest possible time given conditions. The main difference being that the OCD limits the power supplied to the single heating element 561 to 15 VA or less when oxygen is being supplied. Thus, the heating element 560 permits a maximum power limit of 15 VA in oxygen rich environments (as opposed to 30 VA in the heating element 360 and 45 VA in the heating element 460).
The heating element 560 may be controlled by a control system 600 such as is shown in
Although sensors 391, 392 of the third exemplary embodiment, sensors 491, 492, 493 of the fourth exemplary embodiment, and sensor 591 of the fifth exemplary embodiment are shown in specific locations on the respective heating elements 360, 460, 560, those of ordinary skill will realize that such sensors may be disposed at any suitable location on or near the heaters, so long as accurate temperature readings can be obtained thereby. Further, although the beating elements 360, 460, 560 described above show heating segments of one, two and three portions, those of ordinary skill will realize that the present invention is not so limited, and that heaters with four or more segments are contemplated by the present invention. Finally, although the heating elements 360, 460, 560 according to the third through fifth exemplary embodiments are shown and described above with reference to associated warming therapy devices 10, 110 of specific configurations, those of ordinary skill in the art will realize that the heating elements 360, 460, 560 may be integrated into any suitable mattress, incubator, warmer, medical treatment device or other equivalent apparatus.
Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly to include other variants and embodiments of the invention which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention. This disclosure is intended to cover any adaptations or variations of the embodiments discussed herein.
This application claims priority to U.S. Provisional Application Ser. No. 61/161,184, filed Mar. 18, 2009, and U.S. Provisional Application Ser. No. 61/170,173, filed Apr. 17, 2009, the entire contents of both of which are hereby incorporated by reference, as if fully set forth herein.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2010/027379 | 3/16/2010 | WO | 00 | 7/27/2011 |
| Number | Date | Country | |
|---|---|---|---|
| 61161184 | Mar 2009 | US | |
| 61170173 | Apr 2009 | US |
