Blood compatible heat exchanger

Claim 2

A blood compatible heat exchange apparatus for cooling or heating blood which comprises: (a) an outer, elongate, longitudinally cylindrical, optically clear polycarbonate tube (20); (b) an inner, elongate, longitudinally cylindrical tube (30) disposed within said outer tube for providing a transverse thermally conductive path for coolant or heating fluid passing longitudinally through said tube (30), the inner tube (30) having a plurality of helical, radially outward extensions along the longitude thereof; and (c) an inlet cap (40I) at one longitudinal end of said tubes (20, 30) and an outlet cap (40E) at the opposite ends, each end cap having a shoulder (45) which abuts the outer tube (20), an end bore (46) through which the inner tube (30) passes and a transverse aperture (42) for providing fluid communication for introducing blood from the outside of the apparatus into the space (60) between the inner surface of the outer tube (20) and the outer helical surface of the inner tube (30) to facilitate thermal exchange between fluid in the inner tube and blood in the space (60) between the inner and outer tubes.

Claim 3

The heat exchanger according to claim 1, wherein said end caps (40I,E) retain the inner and outer tubes (20, 30) in a fixed, spaced apart relationship, thereby forming a heat transfer region (60) between the outer surface of the inner tube and the inner surface of the outer tube.

Claim 4

The heat exchanger according to claim 1 or claim 2, wherein the transverse aperture (42I) of said end caps allows blood to enter the inlet cap, and to exit through the transverse aperture in the outlet cap after flow through the spaced apart heat exchange region.

Claim 5

The heat exchanger according to claim 1, 2 or 3, wherein the outer tube (20) extends along the entire fluid pathway from the inlet cap (40I) to the outlet cap (40E).

Claim 6

The heat exchanger according to any of claims 1 to 4, wherein the helical, radially outward extensions on the inner tube (30) are in contact with the inner surface of the outer tube (20), thereby creating a series of helical flow paths in the heat transfer region (60) of the apparatus.

Claim 7

The heat exchanger according to any of claims 1 to 5, which is capable of (a) maintaining a continuous pressure between the inner tube and the outer tube of 10 psi (0.69 bar), and/or (b) being ETO sterilised and/or (c) maintaining sterility in a closed system for an indefinte time period.

Claim 8

The heat exchanger according to any of claims 1 to 6, wherein said inner tube (30) is constructed of thermally conductive metal such as aluminium, for example aluminium with a natural hardcoat finish.

Claim 9

A heat exchange apparatus which comprises: (a) an outer, elongate, cylindrical tube (20); (b) an inner elongate, cylindrical tube (30), optionally made of metal, disposed within said outer tube and having a pair of circumferential grooves (30) about the periphery, one adjacent each end; (c) a pair of flexible torroidal gaskets (50), one each being disposed in said groove (31) at each end of said inner cylindrical tube; and, (d) an inlet cap (40I) at one longitudinal end of said tubes and an outlet cap (40E) at the opposite end, each having a first shoulder (41) which abuts the corresponding gasket (50) and a second shoulder (45) which abuts the outer tube, either or both of the caps (40I, E) being for example made of plastic.

Claim 10

A heat exchange apparatus which comprises: (a) an outer, elongate, cylindrical tube (20); (b) an inner elongate, cylindrical tube (30), optionally made of metal, disposed within said outer tube and having a pair of circumferential grooves (30) about the periphery, one adjacent each end; (c) a pair of flexible torroidal gaskets (50), one each being disposed in said groove (31) at each end of said inner cylindrical tube; and, (d) an inlet cap (40I) at one longitudinal end of said tubes and an outlet cap (40E) at the opposite end, each having a first shoulder (41) which abuts the corresponding gasket (50) and a second shoulder (45) which abuts the outer tube, either or both of the caps (40I, E) being for example made of plastic.

Claim 11

The apparatus according to claim 8, wherein the end caps (40I, E) retain the inner and outer tubes (20, 30) in a fixed, spaced apart relationship forming a heat transfer region (60) between the outer surface of the inner tube and the inner surface of the outer tube.

Claim 12

The apparatus according to claim 8 or claim 9, wherein the end caps each have a transverse bore (43) with an inner diameter which enables the end cap to slide over a gasket (50) and compress it.

Claim 13

The apparatus according to claim 8, 9 or 10, wherein the end caps each have a transverse aperture (42) allowing a fluid to enter the inlet cap and to exit the outlet cap after flowing through a heat exchange region (60) between the tubes (20, 30).

Claim 14

A heat exchanger according to any of claims 8 to 11, wherein each end cap is sealed to a respective end of said outer tube (20).

Claim 15

A heat exchange apparatus which comprises: (a) an outer tube (20); (b) an inner tube (30) disposed within said outer tube and having a pair of circumferential grooves (31) about the periphery, one adjacent each end; (c) a pair of gaskets (50) disposed one in each of the said grooves (31) of the inner tube; and (d) an inlet cap (40I) at one longitudinal end of said tubes and an outlet cap (40E) at the opposite end, each having a bore (43) with an inner diameter which permits the respective cap to slide over and compress the associated gasket, an outer shoulder (41) on each said cap which abuts the gasket (50) and an inner shoulder (45) which abuts the outer tube (20), said end caps serving to retain the tubes in a fixed, spaced apart relationship, and each of said end caps further having an aperture allowing a fluid to enter the inlet end cap, flow through the spaced apart region and exit the aperture in the outlet end cap.

Claim 16

A heat exchange apparatus which comprises: (a) an outer tube (20); (b) an inner tube (30) disposed within said outer tube and having a pair of circumferential grooves (31) about the periphery, one adjacent each end; (c) a pair of gaskets (50) disposed one in each of the said grooves (31) of the inner tube; and (d) an inlet cap (40I) at one longitudinal end of said tubes and an outlet cap (40E) at the opposite end, each having a bore (43) with an inner diameter which permits the respective cap to slide over and compress the associated gasket, an outer shoulder (41) on each said cap which abuts the gasket (50) and an inner shoulder (45) which abuts the outer tube (20), said end caps serving to retain the tubes in a fixed, spaced apart relationship, and each of said end caps further having an aperture allowing a fluid to enter the inlet end cap, flow through the spaced apart region and exit the aperture in the outlet end cap.

Claim 17

A heat exchange apparatus according to any of claims 8 to 13, which comprises an outer, elongate, cylindrical tube consisting essentially of a blood compatible, polycarbonate resin; an inner, elongate, cylindrical tube consisting essentially of blood compatible aluminium in the circumferential grooves of whcih are seated the said gaskets (50) which consist essentially of medical grade, silicone rubber, and the said caps (40I, 40E) each consist essentially of a blood compatible, polycarbonate resin and have a longitudinal, transverse bore (43) sized to permit the end cap to slide over an associated gasket and compress it, an outer shoulder (41) on each said end cap to abut the gasket and an inner shoulder (45) to abut the outer tube and prevent it from entering the entire length of the transverse bore in the end cap, said end caps serving to retain the inner and outer tubes (20, 30) in a fixed, spaced apart relationship forming a heat transfer region between the outer surface of the inner tube and the inner surface of the outer tube, each of said end caps further having a transverse aperture (42) allowing a fluid to enter the inlet cap, flow through the heat exchange region (60) between the spaced apart tubes and exit the transverse aperture in the outlet cap, and the said end caps being tightly and rigidly sealed to the outer peripheral surface of the outer tube adjacent each end thereof.