Thermal bimetallic actuators for use in non-magnetic medical devices

Abstract

Described herein are non-magnetic, thermally controlled bimetallic valves having active and passive members with different thermal expansion coefficients, and systems implementing such valves, which find particular application in the field of patient care associated with magnetic resonance ("MR") environments, such as environments with strong electromagnetic fields produced by MR imaging equipment.

Description

[Technical field]

[0001] The present disclosure relates generally to thermal actuators and systems implementing such actuators, and more particularly to non-magnetic thermal bimetallic valves for use in environments exposed to strong magnetic fields. [Background technology]

[0002] In many technology fields, advances often drive the design of increasingly miniaturized components and subsystems. At the same time, within the medical device field, there is an equally important need for safety management and risk mitigation. This need is especially heightened in specialized medical environments where patients are exposed to strong electromagnetic fields, such as magnetic resonance ("MR") environments.

[0003] Strong magnetic fields make the MR environment quite different from other treatment areas. In particular, the electromagnetic fields generated in the MR environment by powerful magnets can significantly affect the operation of nearby objects, including medical devices. General-purpose medical devices (or components thereof) can not only degrade the quality of the treatment provided, but also jeopardize the safety and health of the patient and those nearby. Because additional care must be taken to design and manufacture medical devices and components of those medical devices intended for use in the MR environment, these devices and components can often be more expensive than general-purpose accessories.

[0004] When designing for high magnetic field strengths, components and materials that can function in these high fields are limited. One example of a device that must be specifically designed, engineered and manufactured to meet the challenges of this MR environment includes fluid valves (e.g., for air, gas, liquid, etc.) used in various medical devices and patient monitoring systems. Summary of the Invention [Problem to be solved by the invention]

[0005] A typical valve uses a coil spring mechanism to actuate a plunger to open and close the valve. This coil is usually made of a magnetic material so that a high magnetic field attracts the valve, either opening or closing it, preventing the valve from doing the opposite.

[0006] Current approaches to such valves include incorporating piezoelectric technology and / or shape memory alloy (SMA) designs, however, other valve actuators that function in extreme magnetic fields, have minimal overall dimensions, and do not compromise the quality of treatment or patient safety are desired. [Means for solving the problem]

[0007] The present disclosure relates generally to inventive thermal actuators and valves, such as thermal bimetallic actuators, intended for use in magnetic resonance ("MR") environments. The present disclosure is further directed to systems implementing such actuators and valves.

[0008] According to one embodiment of the present disclosure, there is provided a non-magnetic thermally controlled valve having a valve housing having an inlet, an outlet, and an open interior volume, and a bimetallic actuator disposed within the open interior volume of the valve housing and forming a fluid-tight seal with at least one of the inlet and outlet, the bimetallic actuator including an active member and a passive member, where the active member can be physically joined to the passive member.

[0009] According to one aspect of the disclosure, the active member can include a first non-magnetic metal and / or metal alloy and have a first coefficient of thermal expansion.

[0010] According to one aspect of the disclosure, the passive component can include a second non-magnetic metal and / or metal alloy and have a second coefficient of thermal expansion.

[0011] According to one aspect of the disclosure, the first coefficient of thermal expansion can be greater than the second coefficient of thermal expansion.

[0012] According to one aspect of the disclosure, the first non-magnetic metal and / or metal alloy can include at least one of magnesium, manganese, nickel, titanium, copper, and the like.

[0013] According to one aspect of the present disclosure, the second non-magnetic metal and / or metal alloy can include at least one of magnesium, manganese, nickel, titanium, copper, and the like.

[0014] According to one aspect of the disclosure, the first non-magnetic metal and / or metal alloy may be substantially free of at least one of iron, nickel, cobalt, steel, or the like.

[0015] According to one aspect of the present disclosure, the second non-magnetic metal and / or metal alloy may be substantially free of at least one of iron, nickel, cobalt, steel, or the like.

[0016] According to one aspect of the disclosure, the ratio of the first coefficient of thermal expansion to the second coefficient of thermal expansion can be from about 11:10 to about 100:1.

[0017] According to one aspect of the disclosure, the active member may be at least one of a cantilever beam, a disk, and a plunger.

[0018] According to one aspect of the disclosure, the passive member may be at least one of a cantilever beam, a disk, and a plunger.

[0019] According to another embodiment of the present disclosure, a magnetic resonance system is provided having a magnetic resonance device, a fluid flow device having a non-magnetic thermal control valve with a bimetallic actuator, and a valve controller operably connected to the non-magnetic thermal control valve, where the valve controller is configured to actuate the bimetallic actuator of the non-magnetic thermal control valve. The non-magnetic thermal control valve includes a valve housing having an inlet, an outlet, and an open interior volume, and a bimetallic actuator disposed within the open interior volume of the valve housing and forming a fluid-tight seal with at least one of the inlet and the outlet, where the bimetallic actuator includes an active member and a passive member. According to the present disclosure, the active member can be physically joined to the passive member.

[0020] According to one aspect of the disclosure, the active component can include a first non-magnetic metal and / or metal alloy and have a first coefficient of thermal expansion, and the passive component can include a second non-magnetic metal and / or metal alloy and have a second coefficient of thermal expansion, where the first coefficient of thermal expansion can be greater than the second coefficient of thermal expansion.

[0021] According to one aspect of the disclosure, the ratio of the first coefficient of thermal expansion to the second coefficient of thermal expansion can be from about 11:10 to about 100:1.

[0022] According to one aspect of the disclosure, the first non-magnetic metal and / or metal alloy can include at least one of magnesium, manganese, nickel, titanium, copper, and the like.

[0023] According to one aspect of the present disclosure, the second non-magnetic metal and / or metal alloy can include at least one of magnesium, manganese, nickel, titanium, copper, and the like.

[0024] According to one aspect of the disclosure, the first non-magnetic metal and / or metal alloy may be substantially free of at least one of iron, nickel, cobalt, steel, or the like.

[0025] According to one aspect of the present disclosure, the second non-magnetic metal and / or metal alloy may be substantially free of at least one of iron, nickel, cobalt, steel, and the like.

[0026] These and other aspects of various embodiments will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief description of the drawings]

[0027] In the drawings, like reference numbers generally refer to the same parts throughout the different views and the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments. [Figure 1A] FIG. 1A is a side cross-sectional view of a non-magnetic thermal bimetallic valve system according to one embodiment of the present disclosure. [Figure 1B] FIG. 1B is a side cross-sectional view of a non-magnetic thermal bimetallic valve system according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is an exploded view of a first non-magnetic thermal bimetallic valve system with a circular disk actuator according to one embodiment of the present disclosure. [Diagram 3] FIG. 3 is an exploded view of a second non-magnetic thermal bimetallic valve system with a circular disk actuator according to one embodiment of the present disclosure. [Figure 4] FIG. 4 is a side cross-sectional view of the first non-magnetic thermal bimetallic valve system shown in FIG. [Diagram 5] FIG. 5 is a schematic diagram illustrating an embodiment of a non-magnetic thermal bimetallic valve in a strong magnetic field according to one aspect of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] This disclosure describes various embodiments of non-magnetic, thermally controlled bimetallic valves and systems implementing such valves, including patient monitoring systems for use in magnetic resonance ("MR") environments. As used herein, the term "non-magnetic" refers to the ability of a material, such as a metal or metal alloy, to be non-ferromagnetic and to exhibit little or no movement or heating in the presence of a strong magnetic field when used in thermally controlled bimetallic valves and valve systems according to the present disclosure.

[0029] 1A and 1B, the basic principles of operation of a non-magnetic bimetallic valve 100 are illustrated. In accordance with the present disclosure, the bimetallic valve 100 can include a housing 102 that includes one or more fluid communication openings 104 (e.g., inlet and / or outlet) and defines an interior volume or portion 106 of the valve 100. The fluid communication openings 104 allow a flow of fluid (e.g., gas or aqueous solution) through the valve 100. In certain embodiments, the pressure and flow rate of the fluid flow depends on the composition and / or purpose of the fluid flow. For example, but not limited to, the fluid flow can include room air and can have a flow rate of about 1 L / min at about 300 mmHg, or the fluid flow can include CO2, O2, and / or anesthesia and can have a flow rate of about 200 mL / min at about 100 mmHg.

[0030] The bimetallic valve 100 further includes a bimetallic actuator 108 disposed within the open interior volume 104 of the valve 100 and forming a fluid-tight seal 110 with at least one of the fluid communication openings 104. The bimetallic actuator 108 may be mechanically secured to the housing 102 by, for example, but not limited to, heat staking, screwing, overmolding, etc. In some embodiments, the bimetallic valve 100 may also include one or more gaskets 118 disposed within seats associated with the one or more fluid communication openings 104 of the housing 102 to aid in forming the fluid-tight seal 110.

[0031] According to the present disclosure, the bimetallic actuator 108 can include a first or active member 112 and a second or passive member 114. Each of the active member 112 and the passive member 114 can include a metal and / or a metal alloy. In certain embodiments, the metal and / or metal alloy of the active member 112 and the passive member 114 are non-magnetic and different such that the active member 112 has a different coefficient of thermal expansion than the passive member 114. In certain embodiments, the active member 112 can include a first non-magnetic metal and / or metal alloy. For example, but not limited to, the first non-magnetic metal and / or metal alloy can include at least one of magnesium, manganese, nickel, titanium, copper, and the like. In certain aspects, the first non-magnetic metal and / or metal alloy can include Nitinol (NiTi). Similarly, the passive member 114 can include a second non-magnetic metal and / or metal alloy. For example, without limitation, the second non-magnetic metal and / or metal alloy can comprise at least one of magnesium, manganese, nickel, titanium, copper, etc. In certain embodiments, the second non-magnetic metal and / or metal alloy can comprise Nitinol (NiTi). In other embodiments, the active member 112 and / or the passive member 114 can be substantially free of at least one of iron, nickel, steel, cobalt, or other magnetic metals. As used herein, the active member 112 and the passive member 114 are substantially free of magnetic metals when the magnetic metal is less than 0.1 wt%.

[0032] 1A and 1B, the active members 112 and the passive members 114 are physically joined to one another. In particular, the active members 112 and the passive members 114 are joined to one another using one or more restraining devices 116. For example, but not limited to, the restraining devices 116 can be mechanical restraining devices or methods such as, for example, welded joints, brazed joints, and rivets. In other words, the active members 112 and the passive members 114 are welded, brazed, and / or riveted.

[0033] As discussed above, the bimetallic actuator 108 may be configured to form a fluid-tight seal 110 with at least one of the fluid communication openings 104 of the valve 100, as shown in FIG 1A. However, as shown in FIG 1B, the bimetallic actuator 108 may be operable to release the fluid-tight seal 110 with the at least one fluid communication opening 104 and allow the flow of fluid, such as, for example, a gas or aqueous solution, into and through the open interior volume 106 of the valve 100. In an alternative embodiment, rather than being configured to release the fluid-tight seal 110 upon operation, the bimetallic actuator 108 may be operable to form a fluid-tight seal 110 with at least one of the fluid communication openings 104 upon actuation.

[0034] As used herein, operating and / or actuating the bimetallic actuator 108 refers to changing the temperature of at least the active member 112 of the bimetallic actuator 108. In certain embodiments, this can be accomplished using one or more methods, such as, for example, by directly heating and / or passing an electrical current through at least the active member 112. Because the active member 112 has a different coefficient of thermal expansion than the passive member 114, the active member 112 and the passive member 114 deform by different amounts, thereby engaging or disengaging from the fluid-tight seal 110. In some embodiments, the active member 112 has a first coefficient of thermal expansion that is greater than the second coefficient of thermal expansion of the passive member 114. In certain embodiments, the bimetallic actuator has a ratio between the first coefficient of thermal expansion and the second coefficient of thermal expansion that is about 11:10 to about 100:1. In further embodiments, the ratio of the first coefficient of thermal expansion to the second coefficient of thermal expansion is at least about 15:10, at least about 2:1, at least about 5:1, at least about 10:1, at least about 25:1, at least about 50:1, or at least about 75:1.

[0035] 2-4, two embodiments of a non-magnetic thermal control valve according to various aspects of the present disclosure are illustrated.

[0036] 2, an exploded perspective view of a non-magnetic thermal control valve 200 is illustrated. The non-magnetic thermal control valve 200 includes a valve housing 202 formed from a non-magnetic material, such as, for example, plastic. The valve housing 202 can include at least a first fluid communication opening or outlet 204A and a second fluid communication opening or inlet 204B. Additionally, as shown, the valve housing 202 can have two or more components, such as a first portion 220 and a second portion 222, that join to define an open interior volume or portion 206 within the housing 202. Although the fluid communication openings 204A, 204B are shown as part of the second portion 222 of the valve housing 202, other embodiments of the housing 202 are contemplated, such as, for example, where the first portion 220 of the housing 202 has one or more of the fluid communication openings 204A, 204B. Additionally, the valve system 200 is not limited to only two fluid communication openings 204A, 204B, but the valve system 200 can include more than two fluid communication openings, for example, two or more outlets 204A and two or more inlets 204B.

[0037] The non-magnetic thermal control valve 200 also includes a bimetallic actuator having an active member 212 and a passive member 214. As shown in FIG. 2, the active member 212 and the passive member 214 of the bimetallic actuator are disk-shaped rather than cantilever-shaped as shown in FIG. 1. The active member 212 can include a first surface 224 and an opposing second surface 226, and the passive member 214 can include a first surface 228 and an opposing second surface 230, where the active member 212 and the passive member 214 are constrained together at the first surface 224 of the active member 212 and the adjacent second surface 230 of the passive member 214. Additionally, the active member 212 or a portion thereof (e.g., the second surface 226) can engage a gasket 218 disposed within a portion of the opening 204A to form a fluid-tight seal. In certain embodiments, the bimetallic actuator similarly engages one or more additional fluid communication openings 204 A, 204 B and is operable to engage or disengage additional fluid tight seals in the valve housing 202 .

[0038] As discussed above, the bimetallic actuator of the non-magnetic thermally controlled valve 200 can be actuated to engage or disengage one or more fluid-tight seals by at least heating the active member 212 of the bimetallic actuator. As shown in FIG. 2, this can be accomplished using a heating lead 232 operably connected to the active member 212. The heating lead 232 can have a material suitable for transferring heat to the active member 212. For example, without limitation, the heating lead 232 can have the same material used to form the active member 212 or can have copper wire. In certain embodiments, the heating lead 232 of the active member 212 extends through a cutout 234 in the passive member 214 and a receiving opening 236 in the valve housing 202, such as the receiving opening 236 in the first portion 220 of the valve housing 202. Although the heating lead 232 is shown centrally disposed in the active member 212, the heating lead 232 can be disposed in alternative locations. Regardless, as shown in FIG. 4, the heating lead 232 can form a fluid-tight seal with a receiving opening 236 in the valve housing 202 .

[0039] In certain embodiments, the heating leads 232 can be operably connected to an external valve controller (not shown) configured to operate the bimetallic actuator and / or a heat source (not shown) configured to electrically and / or thermally regulate the temperature of at least the active member 212. In some embodiments, the heat source is further connected to a valve controller and / or the external valve controller comprises the heat source. The external valve controller can operate the bimetallic actuator by using the heating leads 232 to heat the active member 212 of the bimetallic actuator, for example, by either directly heating the heating leads 232 and / or by passing an electric current through the heating leads 232. As described herein, the valve controller can be formed of one or more modules and can be configured to operate the valve 200 in response to input, such as, for example, input obtained via a user input device or from one or more sensors within the device. The controller can include, for example, a processor and a memory, and can optionally include a connection module. The processor may take any suitable form including, but not limited to, a microcontroller, multiple microcontrollers, a circuit, a single processor, or multiple processors. The memory may take any suitable form including non-volatile memory and / or RAM. The non-volatile memory may include a read-only memory (ROM), a hard disk drive (HDD), or a solid state drive (SSD). The memory may store, among other things, an operating system and sensor data from sensors. The RAM is used by the processor for temporary storage of data. According to some embodiments, the operating system may include code that, when executed by the valve controller, controls the operation of the hardware components of the valve system 200.

[0040] 3, another non-magnetic thermal control valve 300 according to the present disclosure is illustrated. Here, the valve 300 includes a bimetallic actuator having an active member 312 and a passive member 314. However, the active member 312 and the passive member 314 of the bimetallic actuator are arranged such that the passive member 314 or a portion thereof engages with a gasket 318 disposed within a portion of the fluid communication opening 304A to form a fluid-tight seal with the valve housing 302 (or a portion thereof, such as housing portion 322). Thus, the active member 312 can have a first surface 324 and a second surface 326, the passive member 314 can have a first surface 328 and a second surface 330, and the active member 312 and the passive member 314 can be joined at the second surface 326 of the active member 312 and the first surface 328 of the passive member 314. In some of these embodiments, the heating lead 332 of the active member 312 does not pass through the passive member 314 but may still engage with a receiving opening 336 (or a portion thereof, such as the first portion 320 ) of the valve housing 302 .

[0041] Regardless of whether the active members 212, 312 or the passive members 214, 314 form a fluid-tight seal with one or more of the fluid communication openings 204A, 304A, each of the active members 212, 312 and passive members comprises a non-magnetic metal and / or metal alloy such that the active members 212, 312 have a coefficient of thermal expansion greater than the coefficient of thermal expansion of the passive members 214, 314. Thus, when the active members 212, 312 are no longer active, the passive members 214, 314 operate to pull the active members 212, 312 back to their original position (engaging or disengaging from the fluid-tight seal).

[0042] 4, a non-magnetic thermally controlled valve 400 is shown comprising an active member 412 forming a fluid-tight seal with a gasket 418 over a fluid communication opening 404A. According to various aspects of the disclosure, the valve 400 includes a valve housing having a first housing portion 420 and a second housing portion 422, a first fluid communication opening 404A, a second fluid communication opening 404B, and an open interior volume / portion 406 defined by the first housing portion 420 and the second housing portion 422. A bimetallic actuator passive member 414 is joined to the active member 412 and is positioned over the active member 412 such that a heating lead 432 of the active member 412 extends through a receiving opening 436 formed by the first portion 420 of the valve housing.

[0043] Also disclosed herein is a magnetic resonance ("MR") system implementing a non-magnetic thermal control valve for use in environments with strong magnetic fields, such as the magnetic resonance system 500 illustrated in FIG. 5. A magnetic resonance device, such as an MR scanner 526, can generate a strong magnetic field 528, such as a static main magnetic field, magnetic gradient fields, radio frequency ("RF") pulses, etc. In certain embodiments, the non-magnetic thermal control valve 502 can be used to regulate the delivery of a fluid, such as an anesthetic gas, to a subject 530, monitoring gas exhaled by the subject 530, and monitoring the blood pressure of the subject 530. As shown, two medical devices capable of delivering a flow of fluid and equipped with the non-magnetic thermal control valve 501 are shown, including, by way of example and not limitation, an anesthesia device 522 and a non-invasive blood pressure (NIBP) measuring device 524.

[0044] It should be understood that all combinations of the above concepts and additional concepts discussed in more detail below (provided that such concepts are not mutually inconsistent) are considered to be part of the inventive subject matter disclosed herein. In particular, the claimed subject matter at the end of this disclosure is considered to be part of the inventive subject matter disclosed herein. It should also be understood that the terminology explicitly used in this specification, where any disclosure incorporated by reference appears, shall be given the meaning most consistent with the particular concept disclosed herein.

[0045] All definitions, as defined and used herein, should be understood to control for any dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meaning of the defined terms.

[0046] In the specification and claims, unless clearly indicated to the contrary, a plurality is to be understood to mean "at least one" even when not stated. The term "and / or" as used in the specification and claims should be understood to mean "either" or "both" of the conjoint elements, i.e., elements that are present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" should be construed in the same manner, i.e., "one or more" of the conjoint elements. Other elements than those specifically identified by the "and / or" clause may optionally be present, whether related or unrelated to the specifically identified elements.

[0047] In the specification and claims, "or" should be understood to have the same meaning as "and / or" defined above. For example, when separating listed items, "or" or "and / or" should be interpreted as inclusive, i.e., including at least one, but also including two or more of the plurality or listed elements, and optionally items not listed. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or "consisting of" when used in the claims, refer to the inclusion of exactly one of the plurality or listed elements. In general, the term "or" in this specification, when followed by an exclusive term, such as "either," "one of," "only one of," or "exactly one of," should be interpreted merely as indicating exclusive alternatives (i.e., one or the other, but not both).

[0048] In the specification and claims, when referring to a list of one or more elements, the term "at least one" should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed in the list of elements, and not excluding any combinations in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the "at least one" clause refers, whether related or unrelated to the specifically identified elements.

[0049] In the claims, as well as in the above specification, all transitional phrases such as, for example, "having," "including," "carrying," "having," "containing," "involving," "holding," "comprising," and the like, are to be understood to be in open-ended form, i.e., to mean inclusive but not limited to. Only the transitional phrases "consisting of" or "consisting essentially of" are closed or semi-closed transitional phrases, respectively.

[0050] It should also be understood that, unless expressly indicated to the contrary, in any method claimed in this specification that includes two or more steps or actions, the order of the steps or actions of the method is not necessarily limited to the order in which the steps or actions of the method are recited.

[0051] While several inventive embodiments have been described and illustrated herein, those skilled in the art will readily envision various other means and / or configurations for performing the functions described herein and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the particular application for using the teachings of the present invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. Thus, the embodiments described above are presented by way of example only, and it should be understood that within the scope of the appended claims and their equivalents, the inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, product, material, kit, and / or method described herein. In addition, any combination of two or more of the above features, systems, articles of manufacture, materials, kits, and / or methods is included within the inventive scope of the present disclosure, if such features, systems, articles of manufacture, materials, kits, and / or methods are not mutually inconsistent.

Claims

1. a valve housing having an outlet, an inlet, and an open interior volume; and a bimetallic actuator disposed within the open interior volume of the valve housing and forming a fluid-tight seal with at least one of the inlet and the outlet; A non-magnetic thermal control valve having: the bimetallic actuator has an active member and a passive member; the active member is physically joined to the passive member; the active member comprises a first non-magnetic metal and has a first coefficient of thermal expansion; the passive member includes a second non-magnetic metal and has a second thermal expansion coefficient; the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion; Non-magnetic thermal control valve.

2. 10. The non-magnetic thermal control valve of claim 1, wherein the first non-magnetic metal comprises at least one of magnesium, manganese, nickel, titanium, and copper.

3. 3. The non-magnetic thermal control valve of claim 1, wherein the second non-magnetic metal comprises at least one of magnesium, manganese, nickel, titanium, and copper.

4. 10. The non-magnetic thermal control valve of claim 1, wherein the first non-magnetic metal is substantially free of at least one of iron, nickel, cobalt, and steel.

5. 5. The non-magnetic thermal control valve of claim 1, 2 or 4, wherein the second non-magnetic metal is substantially free of at least one of iron, nickel, cobalt and steel.

6. 10. The non-magnetic thermally controlled valve of claim 1, wherein the bimetallic actuator has a ratio of the first coefficient of thermal expansion to the second coefficient of thermal expansion that is from about 11:10 to about 100:

1.

7. 10. The non-magnetic thermal control valve of claim 1, wherein the active member is at least one of a cantilever beam, a disk, and a plunger.

8. The non-magnetic thermal control valve of claim 1 , wherein the passive member is at least one of a cantilever beam, a disk, and a plunger.

9. magnetic resonance imaging, A fluid flow device having a non-magnetic thermal control valve; and a valve controller operably connected to the non-magnetic thermal control valve; 1. A magnetic resonance system comprising: The non-magnetic thermal control valve is a valve housing having an inlet, an outlet, and an open interior volume; and a bimetallic actuator disposed within the open interior volume of the valve housing and forming a fluid-tight seal with at least one of the inlet and the outlet; Including, the bimetallic actuator includes an active member and a passive member; the active member is physically joined to the passive member; the valve controller is configured to operate the bimetallic actuator of the non-magnetic thermal control valve. Magnetic resonance system.

10. the active member comprises a first non-magnetic metal and has a first coefficient of thermal expansion; the passive member comprises a second non-magnetic metal and has a second coefficient of thermal expansion; and the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion; 10. The magnetic resonance system of claim 9.

11. 11. The magnetic resonance system of claim 10, wherein the bimetallic actuator has a ratio of the first coefficient of thermal expansion to the second coefficient of thermal expansion that is from about 11:10 to about 100:

1.

12. 12. The magnetic resonance system of claim 10, wherein the first non-magnetic metal comprises at least one of magnesium, manganese, nickel, titanium, and copper.

13. The magnetic resonance system of claim 10 , wherein the second non-magnetic metal comprises at least one of magnesium, manganese, nickel, titanium, and copper.

14. The magnetic resonance system of claim 10 , wherein the first non-magnetic metal is substantially free of at least one of iron, nickel, cobalt, and steel.

15. The magnetic resonance system of claim 10 , wherein the second non-magnetic metal is substantially free of at least one of iron, nickel, cobalt, and steel.

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