Title of Invention

AN IMPROVED CATHETER FOR HEATING OF BODY CAVITIES

Abstract

An improved circulating fluid type catheter for heating a body cavities is described. Such catheters in prior art incorporate side-by-side inlet and outlet passages for fluid circulation. In the catheter of this invention the passages are made concentric to each other while keeping cross-sectional areas, the same, thus reducing the effective outer diameter of catheter. This makes the catheter thinner and thus easier to insert in the body. Secondly, as the circulating hot fluid heats all parts of catheter, even non-targeted parts of body receive the undesired heating. To avoid this, a third concentrial tube is fitted coaxially over the inlet and outlet tubes. The air gap formed by the third tube serves as insulation between hot fluid and other body parts. To further improve the insulation a simple evacuating arrangement is described. As an alternative embodiment this air gap can be sealed and permanently evacuated like a vacuum flask.

Full Text

FORM - 2 THE PATENT ACT 1970 (39 OF 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION [See Section 10 and rule 13] AN IMPROVED CATHETER FOR HEATING OF BODY CAVITIES Vartak Taraprakash Prabhakar 87/1/C, Parvati, Sahakamagar No.2, Swanand Society, PUNE-411009 The following specification particularly describes the invention and the manner in which it is to be performed. This invention relates to an improved catheter used for heating of body cavities to effect ablation or fomentation of the area to be treated. Catheters used for such therapies can be classified in two major types. One type of catheter has heating elements situated within the catheter while the second type has externally heated fluid circulating in and out of the catheter. This invention relates to the second i.e. circulating type of catheter. All such catheters known in prior art have two passages side by side, one for inlet of fluid and the other for outlet. Following patents describe such catheters US Patent no. 2.077.453 US Patent no. 5.084.044 Indian Patent no. 187488 Since they are required to be inserted into the body, the catheters have to be as small as possible in diameter. Non-circulating type of catheters have only one passage while the circulating type need atleast two passages. Thus the circulating type catheter having passages side by side result into larger diameter. This is the first shortcoming of the catheters in prior art. A second shortcoming in prior art is that the circulating hot fluid heats all parts of catheter. When inserted into the target body cavity, other non targeted body parts also receive the heat e.g. vagina and cervix in case of endometrial ablation. Present invention overcomes the abovementioned shortcomings of prior art. Firstly to reduce the diameter of the catheter, the inlet and outlet passages are made co-axial instead of usual side-by-side configuration (fig.-1). Referring to Figure 1, the side-by-side tube configuration has inlet tube (21) and outlet tube (22), while co-axial configuration has inlet tube (23) and outlet annular gap (24). : 2 : Simple calculations show that for equal inlet and outlet cross section the outer dimension of the co-axial- tube configuration is smaller than side-by-side-tube configuration. The smaller diameter of catheter is particularly advantageous in endometrial ablation because the required dilation of cervix is smaller. Secondly, to avoid heat injury to non targeted body parts, a third co-axial tube (25) is provided in the present invention (see fig. 1). The air-gap (26) between the third outer tube (25) and middle tube serves as heat insulation. To further improve the insulation this gap can be partially or fully evacuated with help of known devices. A detailed description of the improved catheter as per present invention is given below with reference to figure 2. Three coaxially mounted tubes (1), (2) and (3) are separated by spacers (not shown) at distal end of catheter. A flexible balloon (4) is attached to the tube (3). Hot pressurised fluid coming in from the innermost tube (1), distends the flexible balloon, the fluid then exits from middle tube (2). The air gap (5) between outer tube (3) and the middle tube (2) serves as thermal insulation between hot middle tube and patient's body parts. At the proximal end of the improved catheter of this invention, a manifold with three chambers (6), (7), & (8) is provided. These chambers are hydraulically isolated from each other by spacers (9), (10) (11). Connectors (12), (13) and (14) are provided to the chambers for connecting to external tubing. Hot fluid enters at (14), travels through the chamber (8) and via inner tube to the balloon, returns via middle tube to chamber (7) and exits through connector (13). : 3 : Connector (12) can be connected to a device to create partial or full vacuum in the airgap (5) of catheter. A simple device as shown in figure 3 to create this vacuum can be attached to connector (12). This device is a Y connector on one leg of which is a elastic bulb (15) with a one way valve (16) as shown. The second leg of 'Y' connector is open to air and has another one way valve (17) as shown. When the blub is pressed by hand the air in the balloon is forced out only through valve (17). When the pressure on bulb is released the elastic bulb attains its original shape and the air from air gap (5) gets sucked in the bulb thus creating at least partial vacuum in the catheter air gap. As an alternative embodiment the outer tube (3) instead of connecting to chamber (6) can be sealed to middle tube as shown in figure 4. The space between outer and middle tube can be permanently evacuated like a vacuum flask, thus serving as a permanent heat insulation. The manifold gets heated due to hot fluid and to avoid injury to the person performing the therapy a jacket (18) of insulating material, preferably of a suitable polymer plastic, is provided (figure 2). The improved catheter of this invention thus takes care of the shortcomings of the catheters of prior art. : 4 : 1. A catheter for heating mammalian body cavity comprising, co-axially mounted tubes (1),(2) ,(3) ,Fig.(2) for fluid circulation having an inlet and outlet tubes are separated at distal end of the catheter, a flexible balloon (4) fig,(2) ,is attached to the tube (3), for insulating untargeted body parts from fluid heat, a hot pressurized fluid coming from the inner most tube (1) which distends the flexible balloon the fluid then exits from the middle tube (2) , air gap (5) between outer tube (3) and middle tube (2) serves as thermal insulation between hot middle tube and patients body parts, an hydraulically isolated chambers (6),(7),& (8),are provided at the proximal end of the catheter, the said chambers are isolated from each other by spaces (9),(10),(11), a connector (12),(13),(14),are provided to the chambers for connecting external tubing, a hot fluid enters at (14) travels through the chamber (8) via inner tube to the balloon and returns via middle tube to chamber (7) exists through connector(13), 2. A catheter as claimed in claim 1, wherein the tubes for inlet and outlet of fluid are mounted co axially on each other and maintained co axially by spacers both at proximally and at distal ends , 3. A catheter as claimed in claim 1, wherein a third tube is mounted coaxially on the outlet tube and maintained coaxially by spacers both at proximal and distal ends so as to form a uniform air gap over middle tube, 4. A catheter as claimed in claims 1 or 2, wherein a distendable balloon is attached to distal end of the outermost coaxial tube such that openings on the inlet and outlet tubes are located within the balloon, 5. A catheter as claimed in claims 1 to 3, wherein the proximal ends of the three coaxially maintained tubes are fixed in a manifold, 6. A catheter as claimed in claims 1 or 5, wherein the manifold has three chambers hydraulically isolated from each other by spacers each chamber having a connector protruding from the manifold, 7. A catheter as claimed in claim 7, wherein each coaxial tube ends in a separate chamber of the manifold, 8. A catheter as claimed in claim 6, wherein an external source of pressurized hot fluid is connected to the protruding connectors so as to achieve circulation to and from the inlet and outlet tubes, 9. A catheter as claimed in claim 6, wherein the suction device is connected to the connector of the chamber having the outermost coaxial tube 10. A catheter as claimed in claim 9, wherein the suction device is in form of a "Y" connector having an elastic bulb and two one way valves , : 5 : 11. A catheter as claimed in the above claims, wherein the distal and proximal ends of outermost coaxial tube is sealed to the outer surface of the outlet so that the enclosed air gap formed by outlet tube and the outer most tube is evacuated or filled with insulation and sealed to create permanent vacuum, 12. A catheter as claimed in claims 1 and 5, wherein a heat insulating jacket is provided on the manifold, 13. A catheter for heating, of mammalian body cavity, such as herein described with reference to an accompanying drawings,

Documents:

1197-mum-2005-abstract(23-01-2007).doc

1197-mum-2005-abstract(23-01-2007).pdf

1197-mum-2005-claims(granted)-(23-01-2007).doc

1197-mum-2005-claims(granted)-(23-01-2007).pdf

1197-MUM-2005-CORRESPONDENCE(11-7-2012).pdf

1197-mum-2005-corrospondence(23-02-2007).pdf

1197-mum-2005-corrospondence(ipo)-(24-02-2006).pdf

1197-mum-2005-drawing(23-01-2007).pdf

1197-mum-2005-form 1(26-03-2006).pdf

1197-MUM-2005-FORM 15(11-7-2012).pdf

1197-mum-2005-form 18(26-02-2005).pdf

1197-mum-2005-form 19(23-01-2007).pdf

1197-mum-2005-form 2(granted)-(23-01-2007).doc

1197-mum-2005-form 2(granted)-(23-01-2007).pdf

1197-mum-2005-form 6(23-01-2007).pdf

1197-mum-2005-form 9(23-01-2007).pdf

1197-mum-2005-form 9(26-09-2003).pdf

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