Inflow and outflow control of a closed cooling system

Abstract

A microwave ablation antenna assembly (10) includes a coaxial cable (14) terminating in a radiating portion (16), a first tubular member (18) surrounding and spaced apart from the coaxial cable (14) to allow fluid flow therebetween, and a second tubular member (20) surrounding and spaced apart from the first tubular member (18) to allow fluid flow therebetween. The microwave ablation antenna assembly (10) further includes a hub (26) configured to receive the coaxial cable (14), the first tubular member (18), and the second tubular member (20), including a fluid inflow chamber (36) and a fluid outflow chamber (38), an integrated hub divider (40) and hub cover (28) separating the fluid inflow chamber (36) from the fluid outflow chamber (38) and preventing fluid flow between the inflow chamber (36) and the outflow chamber (38) except through the gaps between the coaxial cable (14) and the first tubular member (18) and between the first tubular member (18) and the second tubular member (20).

Description

[0001] This application is a divisional application of the invention patent application entitled "Inflow and Outflow Control of a Closed Cooling System", filed March 13, 2017, International Application No. PCT / CN2017 / 076392, National Application No. 201780088346.3. TECHNICAL FIELD

[0002] The present disclosure relates to a water-jacketed microwave ablation antenna assembly, and more particularly to a device for sealing the inflow and outflow of cooling media in the manifold portion of a microwave ablation antenna assembly. BACKGROUND

[0003] Microwave ablation antennas are a well-known mechanism for treating cancerous lesions and tumors in the body. For example, treatment of liver tumors is often accomplished by placing one or more microwave ablation antennas near the tumor and then treating with microwave radiation at power levels reaching and exceeding 150 W for a duration sufficient to coagulate and kill the tumor tissue and some of the marginal healthy tissue.

[0004] Some microwave ablation antennas are cooled using compressed or liquefied CO2 gas that absorbs energy from the antenna and, in particular, heat from the coaxial cable during expansion to help limit damage to healthy tissue near the radiating section that is typically formed on the distal portion of the antenna. The actual heat sink for this device is typically separate from the cooling gas flow.

[0005] In an alternative construction, a circulating fluid, typically saline or deionized water, is pumped through the microwave ablation antenna assembly. One such construction is described in detail in commonly-assigned U.S. Patent No. 9,119,650 to Brannan et al., entitled "Microwave Energy-Delivery Device and System", the entire contents of which are incorporated herein by reference. Figure 1 A microwave ablation antenna assembly 10 is depicted that is constructed for circulation of fluid therethrough. As shown in FIG. 1, the antenna assembly 10 includes a coaxial cable 12 that is connected to a microwave generator 14. The coaxial cable 12 is connected to a proximal end of a distal antenna 16 that is formed of a dielectric material, such as ceramic or glass, and is configured to radiate microwave energy in a pattern that is shaped to treat a tumor or other lesion in the body. Figure 1As shown, the microwave ablation assembly 10 includes a transition 12 that is connected by a coaxial cable to a microwave ablation generator (not shown). The transition 12 allows for a 90° change in direction of the coaxial cable entering the transition 12 to the coaxial cable 14 of the microwave ablation assembly 10. The coaxial cable 14 extends perpendicularly from the transition 12 and ends at a radiating section 16. The radiating section 16 can take a variety of forms, including monopole, dipole, symmetric and asymmetric configurations. The coaxial cable 14 extends through a first tubular member 18, which is itself housed within a second tubular member 20. A first fluid passageway 22 is located between the coaxial cable 14 and the first tubular member 18 while a second fluid passageway 24 is located between the first tubular member 18 and the second tubular member 20. The transition 12 is housed within a first end of a hub 26, a hub cap 28 is housed at a second end of the hub 26, and is itself designed to receive and secure the second tubular member 20. O-rings 30 and 32 formed on the hub cap 28 and the transition 12 form seals to create a water-tight compartment 34 between the hub cap 28 and the transition 12.

[0006] Further, as Figure 1 shown, the water-tight compartment 34 is divided into an inflow chamber 36 and an outflow chamber 38 by a hub divider 40. The hub divider 40 receives the first tubular member 18 and maintains it in alignment with the second tubular member 20. The hub divider 40 is formed of an elastomeric material and forms a seal around the first tubular member 18 that, in combination with a compression fit within the hub 26, restricts fluid in the inflow chamber 36 from flowing out to the first fluid passageway 22 and prevents fluid that passes through the second fluid passageway 24 from returning and entering the inflow chamber 36. Figure 1 Also shown in FIG. 1 is an inflow port 42 that is connected to the inflow chamber 36 and an outflow port 44 that is connected to the outflow chamber 38. A wire 48 is depicted as extending through the hub 26 and the inflow chamber 36 and into the first tubular member 18 where it will terminate proximate the radiating section 16 and include a thermocouple (not shown) to detect the temperature of the microwave ablation assembly 10. Once assembled, the entire hub 26, hub cap 28 and transition 12 are placed within a handle assembly 46 for ease of gripping and other ergonomic considerations.

[0007] While the microwave ablation antenna assembly 10 has been commercially successful and is currently sold as the EMBLINT® TM ablation system by Medtronic, improvements are always needed. SUMMARY

[0008] This disclosure relates to a microwave ablation antenna assembly. According to one aspect of this disclosure, the assembly includes a coaxial cable terminating in a radiating section, a first tubular member surrounding and spaced therefrom the coaxial cable to allow fluid flow therebetween, and a second tubular member surrounding and spaced therefrom the first tubular member to allow fluid flow therebetween. The assembly further includes: a manifold configured to receive the coaxial cable, the first tubular member, and the second tubular member, the manifold including a fluid inlet chamber and a fluid outlet chamber; a manifold separator separating the fluid inlet chamber and the fluid outlet chamber; and an inlet tube insert attached to the inlet tube member and interacting with the manifold separator to form a seal that prevents fluid flow between the inlet and outlet chambers unless fluid passes through a gap between the coaxial cable and the first tubular member and a gap between the first and second tubular members.

[0009] According to another aspect of this disclosure, the microwave ablation antenna assembly includes a wall extending from the assembly and intersecting with an assembly separator to prevent movement of the assembly separator. Fluid flow is directed from the fluid inflow chamber into a gap formed between the coaxial cable and the inner tubular member, and the fluid flow can extend into the radiating section. Furthermore, the fluid flow can return from the radiating section in the gap between the outer and inner tubular members. The microwave ablation antenna assembly may also include an assembly cover configured to receive the outer tubular member and be housed within the assembly to form an outflow chamber.

[0010] Another aspect of this disclosure relates to a microwave ablation antenna assembly comprising a coaxial cable terminating in a radiating section, a first tubular member surrounding and spaced therefrom the coaxial cable to allow fluid flow therebetween, and a second tubular member surrounding and spaced therebetween the first tubular member to allow fluid flow therebetween. The assembly includes a manifold configured to receive the coaxial cable, the first tubular member, and the second tubular member, the manifold including a fluid inflow chamber and a fluid outflow chamber. Further, the assembly includes an integrated manifold separator and a manifold cover that separate the fluid inflow chamber from the fluid outflow chamber and prevent fluid from flowing between the inflow and outflow chambers unless fluid passes through a gap between the coaxial cable and the first tubular member and a gap between the first and second tubular members.

[0011] According to another aspect of the invention, a microwave ablation antenna assembly includes at least one rib formed on the inner surface of a manifold and engaging with at least one groove formed on an integrated manifold separator and a manifold cover. The assembly may also include at least one O-ring that, in combination with the integrated manifold separator and manifold cover, forms a seal to prevent fluid flow between a fluid inflow chamber and a fluid outflow chamber. Fluid flow is directed from the fluid inflow chamber into a space formed between a coaxial cable and an inner tubular member. The fluid flow may extend into a radiating section and may return from the radiating section in the gap between the outer and inner tubular members.

[0012] The integrated manifold separator and manifold cover may include a window that fluidly connects the gap between the outer tubular member and the inner tubular member and the outflow chamber. A proximal portion of the inner tubular member may be attached to a proximal portion of the integrated manifold separator and manifold cover, and a proximal portion of the outer tubular member may be attached to a distal portion of the integrated manifold separator and manifold cover.

[0013] Another aspect of this disclosure relates to a microwave ablation antenna assembly comprising a coaxial cable terminating in a radiating section, a first tubular member surrounding and spaced therefrom the coaxial cable to allow fluid flow therebetween, and a second tubular member surrounding and spaced therebetween the first tubular member to allow fluid flow therebetween. The assembly further comprises: a manifold configured to receive the coaxial cable, the first tubular member, and the second tubular member, the manifold including a fluid inflow chamber and a fluid outflow chamber; and an integrated manifold separator and manifold cover separating the fluid inflow chamber from the fluid outflow chamber and preventing fluid flow between the inflow and outflow chambers unless fluid passes through a gap between the coaxial cable and the first tubular member and a gap between the first and second tubular members.

[0014] According to another aspect of this disclosure, the assembly includes at least one rib formed on the inner surface of the manifold and engaging at least one groove formed on the integrated transition cover and manifold separator. The assembly may also include at least one O-ring that, in combination with the integrated transition cover and manifold separator, forms a seal to prevent fluid flow between a fluid inlet chamber and a fluid outlet chamber, wherein the fluid flow is directed from the fluid inlet chamber to the space formed between the coaxial cable and the inner tubular component.

[0015] According to another aspect of this disclosure, fluid returns to the manifold outlet chamber in the gap between the outer tubular member and the inner tubular member. Furthermore, the integrated transition cover and manifold separator may include a window that allows the gap between the inner tubular member and the coaxial cable to communicate with the fluid inflow chamber. Further, a proximal portion of the inner tubular member may be attached to a manifold separator portion of the integrated transition cover and manifold separator. Attached Figure Description

[0016] The objects and features of this disclosure will become apparent to those skilled in the art when the description of various embodiments of the invention is read with reference to the accompanying drawings, in which:

[0017] Figure 1 This is a cross-sectional view of a known microwave ablation antenna assembly;

[0018] Figure 2 This is a partial cross-sectional view of a microwave ablation antenna assembly according to aspects of this disclosure;

[0019] Figure 3 This is a partial cross-sectional view of a microwave ablation antenna assembly according to another aspect of this disclosure;

[0020] Figure 4 This is a partial cross-sectional view of a microwave ablation antenna assembly according to another aspect of this disclosure. Detailed Implementation

[0021] Figure 2 A first embodiment of this disclosure is depicted. Handle assembly 46 is shown as an encapsulated assembly 26. Note that common numbering conventions are used wherever possible in all embodiments of this disclosure. Assembly 26 mates at a first end with transition 12, which connects a coaxial cable extending to a microwave generator (not shown) at a 90° angle to a second coaxial cable 14. Transition 12 mates with assembly 26 using an O-ring 32. A conductor 48 extends upward through an opening in handle assembly 46 for receiving the first coaxial cable, extending into assembly 26 and terminating in a thermocouple (not shown) for sensing the temperature of microwave ablation assembly 10, more specifically sensing the radiation segment 16 (…). Figure 1 The temperature near ).

[0022] like Figure 2 As shown, assembly 26 has with Figure 1The internal configurations shown differ. One difference lies in the formation of a wall 50 separating the inflow chamber 36 from the outflow chamber 38. According to this embodiment of the present disclosure, the inflow tube insert 52 is received within the manifold separator 40. The inflow tube insert 52 includes a flange 54 formed at one end. The flange 54 forms a surface on which fluid in the inflow chamber 36 acts, and when the inflow chamber 36 is pressurized, the flange 54 compresses the manifold separator 40, thereby forming a watertight seal. Due to this seal between the flange 54 and the manifold separator 40, circulating fluid is forced into the gap between the first tubular member 18 and the coaxial cable 14. After flowing to the distal portion of the microwave ablation assembly 10, the fluid flows back in the gap between the first tubular member 18 and the second tubular member 20, in accordance with... Figure 1 The device shown releases fluid into the outflow chamber 38 in a substantially similar manner. The inflow tube insert 52 can be attached or bonded (e.g., with a binary adhesive) to the first tubular member 18, thereby effectively securing the first tubular member 18 within the handle assembly 46. In addition to the pressure applied to the flange 54 to form a seal between the inflow tube insert 52 and the manifold separator 40, the opening in the manifold separator 40 through which the inflow tube insert 52 passes can be sized such that its inner diameter is smaller than the outer diameter of the inflow tube insert 52. Furthermore, the outer diameter of the manifold separator 40 can be larger than the space 56 within the manifold 26 that receives the manifold separator 40. The manifold separator 40, made of an elastomeric material, is compressed to be contained within this space and compressed again to receive the inflow tube insert 52. In this way, fluid is prevented from flowing from the inflow chamber 36 to the outflow chamber 38 without first passing through the lengths of the first tubular member 18 and the second tubular member 20, respectively. The manifold cover 28 further secures the second tubular member 20 within the manifold 26, and an O-ring 30 can be used to prevent fluid from flowing out of the manifold 26 instead of out of the outlet 44. Ribs 57 formed on the manifold 26 facilitate securing the manifold cover 28 by engaging with corresponding grooves 58 formed in the manifold cover 28.

[0023] Figure 3 A second embodiment of this disclosure is described. Figure 3 The embodiments are the same as those described above. Figure 2 The main difference between the embodiments described lies in the internal structure of assembly 26. Figure 2 The implementation methods differ, in Figure 2 In this embodiment, wall 50 separates the inflow chamber 36 from the outflow chamber 38. Figure 3 In this configuration, the separation is formed by an integrated manifold separator and a manifold cover 60. The integrated manifold separator and manifold cover 60 have a distal portion 62, which is substantially similar to... Figure 2The manifold cover 28 is shown. The distal portion 62 is attached to the second tubular member 20 and, together with the manifold 26, forms a seal with ribs 57 and grooves 58 on the manifold 26 and the distal portion 62. To ensure the watertight integrity of the seal, an O-ring 30 is used in addition to the grooves 58 and ribs 57. The proximal portion of the second tubular member 20 terminates at the intermediate portion 64 of the integrated manifold separator and manifold cover 60. The intermediate portion 64 has one or more openings or windows 65 formed therein, thereby allowing fluid to flow from the gap between the outer tubular member 20 and the inner tubular member 18 into the outlet 44.

[0024] The integrated manifold separator and the middle portion 64 of the manifold cover 60 are connected to the proximal portion 66. The proximal portion 66 is secured in the manifold 26 by such that ribs 68 formed on the inner surface of the manifold 26 mate with grooves 70 formed in the proximal portion 66. Figure 3 As shown, the O-ring 72 forms a seal between the proximal portion 66 and the manifold 26, which effectively separates the inflow chamber 36 from the outflow chamber 38. The proximal portion 66 is attached to the outer surface of the first tubular member 18 and engages with the remaining portion of the integrated manifold separator and manifold cover 60 to secure the inner tubular member 18.

[0025] Figure 4 Another embodiment of this disclosure is depicted. A key difference is also the shape of the manifold 26. As shown, the shape of the manifold 26 completely eliminates the manifold cover 28. The outer tubular member 20 can be received and attached to a hole 27 formed in a portion of the manifold 26. At the opposite end of the handle assembly 46, an integrated transition cover and manifold separator 74 are connected to the transition portion 14 and help retain the coaxial cable 14 in the transition portion 12. The integrated transition cover and manifold separator 74 are formed by three integrated parts. The first part is the transition cover 75 as described above, which secures the coaxial cable 14 in the transition portion 12. Figure 1 and Figure 2 The embodiments also include a transition cover that performs a similar function but does not separate the inflow chamber 36 from the outflow chamber 38, and therefore was not described above. As shown, the transition cover 75 is secured to the manifold 26 by ribs 76 formed on the manifold 26, the ribs 76 being received in grooves 78 formed on the transition cover 75. An O-ring 80 prevents fluid from flowing from the fluid inflow chamber 36 out of the handle assembly 46.

[0026] An intermediate portion 82 of the integrated transition cover and manifold separator 74 extends from the transition cover 75. The intermediate portion 82 includes one or more openings or windows 84 that allow fluid to enter the integrated transition cover and manifold separator 74 and reach the gap between the coaxial cable 14 and the inner tubular member 18. A proximal portion of the inner tubular member 18 terminates near the window 84. In one embodiment, a parallel flange 86 forms a proximal portion of the manifold separator portion 88 of the integrated transition cover and manifold separator 74. The inner tubular member 18 may adhere to the inner surface of an orifice 90 formed in the manifold separator portion 88 of the integrated transition cover and manifold separator 74. The manifold separator portion 88 is secured to the manifold 26 by ribs 92 formed on the inner surface of the manifold 26 and grooves 94 formed in the manifold separator portion 88. An O-ring 96 forms a seal between the inflow chamber 36 and the outflow chamber 38.

[0027] According to this disclosure, there are examples of multiple manifold separators (e.g., 40, 88, and proximal portion 66). Each of these examples is formed of an elastomeric material and can be adhered to the inner tubular member 18 or the inflow tube insert 52 using one or more adhesives. The inner tubular member 18 and the inflow tube insert can be formed of a variety of materials, including glass fiber, carbon fiber, stainless steel, thermoplastics, other extruded and unextruded materials, etc. Adhesives can be selected based on the adhesive properties of the chosen materials and their heat resistance, since the coaxial cable 14 will become hot during use. Similar materials and adhesives can be used for the manifold cover 28 and the outer tubular member 20. Furthermore, although the manifold 26 is formed of a harder and more durable medical-grade plastic, in Figure 4 In some embodiments, an adhesive may be selected to connect the assembly 26 to the outer tubular member 20. Similarly, Figure 2 In the embodiments, the inflow pipe insert 52 can be adhered to the wall 50 of the manifold 26 by selecting a suitable adhesive.

[0028] While several embodiments of the present disclosure have been shown in the accompanying drawings, it is not intended to limit the disclosure thereto, as the specification is intended to be read as broadly as permitted in the art. Any combination of the above embodiments is also contemplated, and such combinations are within the scope of the appended claims. Therefore, the above description should not be construed as limiting, but merely as examples of particular embodiments. Other modifications within the scope of the appended claims will be contemplated by those skilled in the art.

Claims

1. A microwave ablation antenna assembly, comprising: Coaxial cable terminating at the radiating section; A first tubular member surrounds the coaxial cable and has a first gap between the first tubular member and the coaxial cable; A second tubular member surrounds the first tubular member and has a second gap between the second tubular member and the first tubular member; A manifold configured to receive the coaxial cable, the first tubular member, and the second tubular member, the manifold including a fluid inflow chamber and a fluid outflow chamber; as well as An integrated manifold separator and manifold cover separate the fluid inflow chamber from the fluid outflow chamber and prevent fluid from flowing between the fluid inflow chamber and the fluid outflow chamber unless fluid flows through a first gap between the coaxial cable and the first tubular member and a second gap between the first tubular member and the second tubular member, the integrated manifold separator and manifold cover comprising: The proximal section separates the fluid inflow chamber from the fluid outflow chamber; The distal portion, which is located distal to the proximal portion; and The intermediate portion extends through the fluid outflow chamber and interconnects the proximal and distal portions, the intermediate portion contacting at least one of the first tubular member or the second tubular member.

2. The microwave ablation antenna assembly of claim 1, further comprising at least one rib formed on the inner surface of the assembly and engaging at least one groove formed on the integrated assembly separator and assembly cover.

3. The microwave ablation antenna assembly according to claim 1, further comprising at least one O-ring, the O-ring being combined with the integrated manifold separator and manifold cover to form a seal between the fluid inflow chamber and the fluid outflow chamber.

4. The microwave ablation antenna assembly according to claim 1, wherein, The radiating section is in fluid communication with the fluid inflow chamber and the fluid outflow chamber.

5. The microwave ablation antenna assembly according to claim 1, wherein, The radiating portion is in fluid communication with the fluid inflow chamber via a first gap and with the fluid outflow chamber via a second gap.

6. The microwave ablation antenna assembly according to claim 1, wherein, The middle portion of the integrated manifold separator and manifold cover includes a window that fluidly connects the fluid outflow chamber to the second gap.

7. The microwave ablation antenna assembly according to claim 1, wherein, The proximal portion of the first tubular member is attached to the proximal portion of the integrated manifold separator and manifold cover.

8. The microwave ablation antenna assembly according to claim 1, wherein, The proximal portion of the second tubular member is attached to the distal portion of the integrated manifold separator and manifold cover.

9. The microwave ablation antenna assembly of claim 1, wherein the proximal portion is configured to receive a first tubular member therethrough, and the proximal end of the second tubular member terminates in a fluid outflow chamber distal to the proximal portion.

10. The microwave ablation antenna assembly of claim 1, wherein the distal portion is configured to receive a first tubular member and a second tubular member passing through it.

11. The microwave ablation antenna assembly of claim 1, wherein the intermediate portion contacts the distal surface of the proximal portion and the proximal surface of the distal portion.

12. A microwave ablation antenna assembly, comprising: Coaxial cable terminating at the radiating section; A first tubular member surrounds the coaxial cable and has a first gap between the first tubular member and the coaxial cable; A second tubular member surrounds the first tubular member and has a second gap between the second tubular member and the first tubular member; A manifold configured to receive the coaxial cable, the first tubular member, and the second tubular member, the manifold including a fluid inflow chamber and a fluid outflow chamber; An integrated manifold separator and manifold cover separate the fluid inflow chamber from the fluid outflow chamber and prevent fluid from flowing between the fluid inflow chamber and the fluid outflow chamber, the integrated manifold separator and manifold cover comprising: The proximal section separates the fluid inflow chamber from the fluid outflow chamber; The distal portion, which is located distal to the proximal portion; and The intermediate portion extends through the fluid outflow chamber and interconnects the proximal and distal portions, the intermediate portion contacting at least one of the first tubular member or the second tubular member.

13. The microwave ablation antenna assembly according to claim 12, wherein, The assembly includes an inner surface and ribs formed on the inner surface, and the integrated assembly separator and assembly cover include at least one groove configured to engage the ribs.

14. The microwave ablation antenna assembly of claim 12, further comprising at least one O-ring, the O-ring being combined with the integrated manifold separator and manifold cover to form a seal between the fluid inflow chamber and the fluid outflow chamber.

15. The microwave ablation antenna assembly of claim 12, wherein the fluid outflow chamber is in fluid communication with the second gap between the first tubular member and the second tubular member.

16. The microwave ablation antenna assembly according to claim 12, wherein, The intermediate portion of the integrated manifold separator and manifold cover includes a window that fluidly connects the fluid outflow chamber to a second gap between the first tubular member and the second tubular member.

17. The microwave ablation antenna assembly according to claim 12, wherein, The proximal portion of the first tubular member is attached to the proximal portion of the integrated manifold separator and manifold cover.

18. A microwave antenna assembly comprising: A coaxial cable having a distal radiating portion configured to deliver energy to tissues; A first tubular member surrounds the coaxial cable and defines a first fluid passage between the first tubular member and the coaxial cable; A second tubular member surrounds the first tubular member and defines a second fluid passage between the second tubular member and the first tubular member; A manifold configured to receive the coaxial cable, the first tubular member, and the second tubular member, the manifold including a fluid inflow chamber and a fluid outflow chamber; as well as An integrated manifold separator and manifold cover, configured to fluid-tighten the fluid inflow chamber and the fluid outflow chamber, the integrated manifold separator and manifold cover comprising: The proximal portion separates the fluid inflow chamber from the fluid outflow chamber and is configured to receive the first tubular member passing through it; The distal portion, disposed distal to the proximal portion, is configured to receive a first tubular member and a second tubular member passing through it; and The intermediate portion extends through the fluid outflow chamber and interconnects the proximal and distal portions, the intermediate portion contacting at least one of the first tubular member or the second tubular member.

19. The microwave antenna assembly of claim 18, wherein the proximal end of the second tubular member terminates within the intermediate portion.

20. The microwave antenna assembly of claim 18, wherein the proximal portion is disposed on the proximal side of the proximal end of the second tubular member.

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