Surgical cooling device

Surgical cooling may be implemented by various systems, processes, and techniques. In certain implementations, a surgical cooling device includes a shaft, a cooling assembly, and a mechanical control system. The shaft includes a pair of axial cooling channels extending through its interior. The cooling assembly includes a pair of arms pivotally attached to the shaft and a foldable thermal exchanger coupled to the pair of arms and fluidly coupled to the pair of axial cooling channels. The mechanical control system is adapted to unfold the cooling assembly from a closed position to an open position to allow a coolant to flow through a first of the pair of axial cooling channels, through one or more thermal exchange channels, and out a second of the pair of cooling channels.

BACKGROUND

This invention relates to the field of medicine and more particularly to a surgical cooling device. The present invention is useful for cooling organs attendant to surgery. For example, in partial nephrectomies, the kidney is often cooled prior to performing the surgery. This specification describes a novel surgical cooling device useful in surgeries where organ cooling is desired. It may be applied in any setting by any approach (open, laparoscopic, robotic and/or any minimally invasive approach) on any organ where surface hypothermia is desired.

SUMMARY OF THE INVENTION

The present invention is a surgical cooling device for cooling organs attendant to surgery. When the surgical cooling device is in use, a coolant circulates inside the device to cool the organ.

An embodiment of the present surgical cooling device comprises a body having a handle and a shaft having a pair of axial cooling channels extending through the interior of the shaft; a cooling assembly comprising a pair of arms pivotally attached to the shaft and a foldable thermal exchanger mounted on the pair of arms and fluidly coupled to the pair of axial cooling channels, the thermal exchanger comprising an inlet port, an outlet port, and one or more exchange channels fluidly connecting the inlet port to the outlet port; and a mechanical control system for opening and closing the cooling assembly, the mechanical control system comprising a rotatable knob with a male threaded end, a plunger with a female threaded opening and an opening adapted to receive a rod, the rod engaging the plunger and a pair of wing connectors, the wing connectors attached to the rod and the pair of arms; wherein the cooling assembly unfolds from a closed position to an open position and folds from the open position to the closed position in response to rotation of the knob; and wherein a coolant flows through a first of the pair of axial cooling channels, through the one or more exchange channels, and out a second of the pair of cooling channels.

An alternative embodiment of the present surgical cooling device comprises (A) a body including a handle, a shaft adjacent to the handle, a pair of shoulders adjacent to the shaft, and a pair of axial cooling channels extending through the interiors of the handle and the shaft, each of the pair of axial cooling channels having at least one inflow and one outflow port; and (B) a cooling assembly including a pair of arms pivotally attached to the pair of shoulders, a pair of fasteners attaching the pair of arms to the pair of shoulders, and a foldable thermal exchanger mounted on the pair of arms and engaging the pair of axial cooling channels; the thermal exchanger comprising an inlet port, an outlet port, one or more exchange channels fluidly connecting the inlet port to the outlet port, and a pair of sleeves at two edges of the thermal exchanger adapted to slip onto the pair of arms; wherein the cooling assembly unfolds from a closed position to an open position and folds from the open position to the closed position; and wherein a cooling media flows into a first of the pair of cooling channels, through the one or more exchange channels, and out a second of the pair of cooling channels.

A surgical cooling device will now be described with more particular reference to the attached drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a surgical cooling system1comprising one or more surgical cooling devices200, a chiller/pump system510, and one or more pairs of hoses or tubes410. Each pair of tubes410comprises an inlet tube for conveying coolant from the chiller/pump system510to a surgical cooling device200and an outlet tube for conveying coolant from the surgical cooling device200to the chiller/pump system510. Each tubing pair410fluidly connects one cooling device200to the chiller/pump system510. The one or more pairs of tubes410may be detachably engaged to the one or more cooling devices200or the chiller/pump system510.

The surgical cooling system is a closed, self-contained system, with coolant circulating from the chiller/pump system510, through an inlet tube of a tubing pair410, through a surgical cooling device200, through an outlet tube of a tubing pair410, and back into chiller/pump system510. The chiller/pump system510circulates chilled fluid or other coolant, either continuously or in an intermittent manner, for cooling an organ to a desired temperature. Off-the-shelf equipment may be used for the chiller/pump system510, such as Tek-Temp Instruments, Inc.'s LK-10 Light Capacity Chiller. The coolant flow rate and type of coolant may be varied according to the cooling needs of the specific surgery.

As shown inFIG. 1, the surgical cooling device200may comprise a body220and a cooling assembly210. Body220may include a handle assembly221, a shaft222, and a knob223, all of which may be constructed of stainless steel, durable plastic, or other materials known in the art. Referring toFIG. 2, the cooling assembly210may comprise a pair of arms211and a thermal exchanger212. The total length of the surgical cooling device200may be about 300 millimeters (mm), but the total length may be varied as needed for placement of the cooling assembly210on the target organ. The surgical cooling device200may be capable of being deployed laparoscopically or in open surgeries. For example, the surgical cooling device200may be inserted into a trocar during use, so the diameter of shaft222and cooling assembly210(in the closed position) may be 12 mm or sized as needed to enter standard trocars.

Referring toFIG. 2, the cooling assembly210comprises a pair of arms211and a thermal exchanger212. The thermal exchanger212may be connected to the pair of arms211. The design and properties of thermal exchanger212may be similar to the design and properties of thermal exchanger112, described in further detail below. In particular, the thermal exchanger212may be formed of foldable plastic containing a pattern of channels. The pair of arms211may be pivotally attached to the shaft222and will open into a generally V-shaped cooling surface. The pair of arms211may be mounted on an internal protrusion241in shaft222, with one arm mounted directly above the other, or mounted with a pin or fastener. Each arm of the pair of arms211may be about 150 millimeters in length. However, the pair of arms211need not be identical in length and may be sized as needed for the procedure.FIG. 2shows the pair of arms211in an open position. In the open position, the angle of separation between the pair of arms211may be about 90 degrees; however, this angle may be more or less as appropriate for the specific cooling application.FIG. 1shows the pair of arms211in a closed position, wherein the pair of arms211are approximately parallel. The pair of arms211may open either symmetrically or asymmetrically about the axis of body220. The pair of arms211may be made of the same material as body220or of a different suitable material.

Shaft222contains a pair of axial cooling channels. The cooling channels may have cross-sections that are circular in shape, preferably about 5 to 6 mm in diameter. Although each of the cooling channels preferably possesses the same shape and cross-sectional area, the cooling channels may possess dissimilar shapes or cross-sectional areas. The axial cooling channels convey the coolant between the tubing pair410and the cooling assembly210. The thermal exchanger212is fluidly coupled to the pair of axial cooling channels within shaft222.

The cooling device200further comprises a plunger224, a rod225, a shaft cover226, and a pair of arm connectors227. The knob223has a male-threaded section that engages a female-threaded opening within plunger224. Knob223additionally comprises a rotation plate, which holds knob223in its axial position within the handle assembly221while allowing the knob223to rotate. The plunger of224moves axially in response to the rotation of knob223. One end of the rod225is connected to the plunger224, typically in a small opening opposite the threaded female opening of the plunger224. The opposite end of rod225connects to the pair of arm connectors227, typically using a pin or other fastener. The rod225passes through an axial rod channel in the shaft222. The shaft222contains a locking plate having a 90 degree cut-out, which holds the shaft222in its axial position within the handle assembly221and prevents rotation of the shaft222. One end of each of the pair of arm connectors227is connected to the rod225and the opposite end is connected to one of the arms221, typically using a pin or other fastener. The shaft cover226is attached to the shaft222.FIG. 3,FIG. 4,FIG. 5,FIG. 6, andFIG. 7show further aspects of surgical cooling device200. Surgical cooling device200may be used in a manner similar to the use of surgical cooling device100, as described below.

FIG. 8shows a surgical cooling device100in a surgical cooling system2. The surgical cooling system comprises one or more surgical cooling devices100, a chiller/pump system500, a graphical user interface600, and one or more hoses or tubes400. The one or more hoses or tubes400are coupled to the chiller/pump system500and detachably engage the one or more surgical cooling device100. The chiller/pump system500maintains coolant at the desired temperature and continuously pumps coolant into the one or more surgical cooling devices100. The coolant flow rate and coolant may be varied according to the specific surgery. The surgical cooling system is a closed, self-contained system with coolant circulating out of the chiller/pump system500, through the one or more hoses or tubes400, through the one or more surgical cooling devices100, back through the one or more hoses or tubes400, and into chiller/pump system500. The surgical cooling device100is capable of being deployed laparoscopically or in open surgeries, and may be reusable or disposed after a single-use.

FIG. 9discloses an embodiment of a surgical cooling device100. The surgical cooling device100comprises a cooling assembly110and a body120. Surgical cooling device100is Y-shaped when in the open position as shown inFIG. 9. Body120may include a handle121, a shaft122, and a pair of shoulders123, all of which are preferably made of plastic. Handle121, shaft122, and pair of shoulders123may be integrally manufactured, welded together, or coupled with fasteners such as screws. The total length of the surgical cooling device100is preferably about 300 millimeters (mm). However, the total length of surgical cooling device100may be optimized to allow precise extension to the target organ based on the application.

When in use, the surgical cooling device100is capable of being inserted into and engaging a 12 mm diameter trocar. Accordingly, the diameter of body120is preferably at least 12 mm. Referring now toFIG. 10, body120further comprises typically a pair of axial cooling channels125running through handle121and shaft122. Each of the pair of cooling channels125has at least one inflow and one outflow port. The cooling channels125may have cross-sections that are circular in shape, preferably about 5.5 mm in diameter. Although each of the cooling channels125preferably possesses the same shape and cross-sectional area, the cooling channels125may possess dissimilar shapes or cross-sectional areas.

Referring back toFIG. 9, the cooling assembly110comprises a pair of arms111and a thermal exchanger112. The pair of arms111may be pivotally attached to the pair of shoulders123. Fasteners113, such as locking pins or screws, mount the pair of arms111to the pair of shoulders123. Each arm of the pair of arms111is preferably about 150 millimeters in length. However, the pair of arms111need not be identical in length.FIG. 9andFIG. 11shows the pair of arms111in an open position. In the open position, the angle of separation between the pair of arms111in a preferred embodiment is about 90°; however, this angle may be more or less as required for the specific cooling application.FIG. 12shows the pair of arms111in a closed position, wherein the pair of arms111are approximately parallel. The pair of arms111may open either symmetrically or asymmetrically about the axis of body120. The pair of arms111may be made of the same material as body120or of a different suitable material.

Thermal exchanger112may be triangular or sectoral in shape and includes an inlet port, an outlet port, one or more exchange channels fluidly connecting the inlet port to the outlet port, and typically a pair of sleeves adapted to slip onto the pair of arms111of the cooling assembly110. The pair of sleeves adapted to slip onto the pair of arms111are preferably positioned at or near the edges of thermal exchanger112. The inlet port and outlet port of thermal exchanger112may be permanently or removably secured to or integrated with the cooling channels125of the body120. Alternatively, the inlet port and outlet port may include a fitting or connector adapted to detachably engage the cooling channels125of the body120. Such fittings or connectors may be standard fluid fittings, such as Luer lock fittings, barbed fittings, or proprietary fittings.

The one or more exchange channels of thermal exchanger112connect the inlet port to the outlet port, preferably without overlapping sections of exchange channel. For example, a single exchange channel may follow a generally zigzag or serpentine path from the inlet port to the outlet port without overlapping sections. A generally circular flow path may also be created without overlapping sections of channel. Alternatively, one or more sections of the one or more exchange channels may overlap within thermal exchanger112. The total cross-sectional area of the exchange channels of thermal exchanger112is preferably (A) constant along the length of the exchange channels and (B) equal to the cross-sectional area of one of the pair of axial cooling channels125. As the number of exchange channels increases, the cross-sectional area of each individual exchange channel may be decreased, keeping the total cross-section area of the one or more exchange channels constant.

Cooling assembly110provides a flexible surface to facilitate heat transfer from the organ to the coolant. Thermal exchanger112typically folds and expands, accordion- or fan- like, as the pair of arms111move to the closed and open positions, respectively. Consequently, thermal exchanger112should be non-rigid, thermally conductive, and made from sufficiently strong material to withstand the pressure of the coolant circulating through surgical cooling device100. Generally, thermal exchanger112may be constructed of polymer film materials capable of handling the stress and pressure of the circulating coolant. Plastics, such as polyurethane film, are the preferred material for constructing thermal exchanger112. When polyurethane film is used, the one or more exchange channels of thermal exchanger112may be formed by radio-frequency welding two sheets of polyurethane in the desired exchange channel pattern. With respect to radio-frequency welding polyurethane sheets, although thermal exchanger112is initially empty, the one or more exchange channels will inflate with coolant as the coolant flows through the surgical cooling device100. To create a coolant-inflated exchange channel of approximately diameter D, the polyurethane film welds on the empty thermal exchanger112should be spaced approximately 1.57 D apart. An array of thermocouples may be embedded in or mounted on thermal exchanger112to measure the temperature distribution across all or part of thermal exchanger112.

When surgical cooling device100is used, the pair of arms111are first moved to the open position shown inFIG. 11, and cooling assembly110is positioned on the organ to be cooled. The cooling assembly110may be opened and closed by manually grasping the pair of arms111and opening or closing the arms111. Coolant then flows into a first of the cooling channels125, through the inlet port of thermal exchanger112, through the one or more exchange channels of thermal exchanger112, through the outlet port of thermal exchanger112, and out a second of the cooling channels125. Thus, flow through thermal exchanger112is unidirectional. As the coolant flows through the one or more exchange channels, it absorbs heat from the organ. The coolant may be a fluid that is safe for use during surgery, such as water, ice slurry, cold air, ideal gas, or a saline solution. The coolant is circulated at a temperature and flow rate such that the organ temperature is able to drop to at least 10 degrees Celcius as the coolant flows through the thermal exchanger112. To measure the heat transfer, surgical cooling device100may include a pair of thermocouples embedded (as by insert molding) in the cooling channels125at or near the thermal exchanger112, preferably with one thermocouple in each cooling channel. The wires for the thermocouples may be routed through the cooling channels125or may be embedded in the body120of surgical cooling device100.

FIG. 13shows another view of surgical cooling device100. In surgical cooling device100, the handle121of body120includes a rubber grip126to provide a better hold. The rubber grip126may be smooth or textured. Referring toFIG. 14, surgical cooling device100includes a pair of torsional springs127at the joint between the pair of shoulders123and the pair of arms111. One purpose of torsional springs127is to aid in keeping the pair of arms111in the closed position when the surgical cooling device100is inserted or retracted. Thus, the pair of torsional springs127are oriented so as to exert a force on the pair of arms111toward the closed position. The torsional springs127are preferably of sufficient strength to force the pair of arms111into the closed position when the arms are unrestrained.

To facilitate opening the pair of arms111, surgical cooling device100includes an opening mechanism, illustrated inFIG. 15,FIG. 16, andFIG. 17. The opening mechanism comprises a pair of axial rod channels in body120, a pair of rods128positioned inside and slidable within the rod channels, and a control lever attached to the pair of rods128. Each rod128is adapted to engage a hemispherical indentation114on a wedge115on one of the pair of arms111. The wedge115on each of the pair of arms111protrudes inwardly toward the opposite arm. The hemispherical indentation114is adapted to receive a rod.FIG. 16shows the direction the pair of rods128move when opening the pair of arms111.FIG. 17shows another view of a rod128engaging a hemispherical indentation114. When the pair of arms111are in the open position, the arm control mechanism may be locked, for example with a cap and lock system (not shown in the Figures). Rubber grip126may be operable to lock the pair of arms111in an open position.

While the subject of this specification has been described in connection with one or more exemplary embodiments, it is not intended to limit the claims to the particular forms set forth. On the contrary, the appended claims are intended to cover such alternatives, modifications and equivalents as may be included within their spirit and scope.