Soft shell venous reservoir

• US 6,337,049 B1
• Filed: 08/28/1998
• Issued: 01/08/2002
• Est. Priority Date: 08/28/1998
• Status: Expired due to Term

• Current Assignee: Yehuda Tamari
• Original Assignee: Yehuda Tamari
• Inventors: Tamari, Yehuda
• Primary Examiner(s): Sykes, Angela D.
• Assistant Examiner(s): BIANCO, PATRICIA
• Application Number:
  US09/141,960
• Time in Patent Office: 1,229 Days
• Field of Search: 604/4.01, 604/6.15, 604/317, 604/327, 604/403-411, 604/5.01, 604/319-21, 604/322, 128/DIG.3, 128/24
• US Class Current: 422/44
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 1/3667 with assisted venous return
• CPC Class Codes: Y10S 128/03 Heart-lung

Abstract

The venous reservoir accommodates variations in the total volume of blood circulating in the extracorporeal circuit during cardiopulmonary bypass (CPB). It is connected between the patient and the arterial pump and serves as a compliance chamber. Venous drainage by gravity alone provides an inadequate rate of blood return during procedures such as minimally invasive cardiac surgery and bypass via femoral cannulation. In these cases the resistance of the venous cannula limits the maximum achievable flow. Vacuum augmented venous drainage (VAVD) is a technique that overcomes flow limitations by applying suction to the hard shell reservoir thereby increasing the pressure difference between the venous site and venous reservoir. VAVD allows for a decrease in the inner diameter of the venous line, thereby reducing prime volume, as well as the use of a smaller cannula that translates to an easier insertion, a better surgical view, and a smaller surgical incision. VAVD precludes the use of the safer, soft-shell closed venous reservoir (bag) unless a more expensive and complicated two-pump system is used. The present invention describes a soft-shell venous reservoir that allows VAVD using a single pump. The invention describes a soft shell reservoir that is sealed within a, preferably, clear rigid housing. A gas port connected to the space between the bag and rigid housing is used to adjust the pressure within that space: it allows the user to adjust the “atmospheric” pressure about the external walls of the soft-shell reservoir. Another aspect of the invention improves gas bubble removal.

Claims

1. The combination of a disposable blood reservoir and a rigid housing for vacuum assisted venous drainage, in a sterile extracotporeal circuit, said combination comprising:

a) said disposable blood reservoir having a first wall and a second wall, said first wall having a first periphery, said first wall having an inner blood side and an external side, said second wall having a second periphery, an inner blood side and an external side, said first wall being a flexible wall, said first wall sealed along its first periphery to said second wall along said second periphery thereby forming a blood chamber having at least one flexible wall, said blood chamber adapted to contain a physiological liquid at a first pressure,

b) said disposable blood reservoir having an inlet tube, an outlet tube, and a gas purge tube to provide fluid communication between said blood chamber and said extracorporeal circuit,

c) at least a first and a second rigid structure that when combined form said rigid housing,

d) at least one of said rigid structures being disposable and integrated with said disposable blood reservoir,

e) a gas port formed in one of said rigid structure, said port adapted to be in fluid communication with a vacuum source,

f) at least one of said inlet, outlet or purge tubes passing through and is sealed within said disposable rigid structure,

wherein said rigid structures are combined to form said rigid housing that seals said flexible wall of said blood chamber within said rigid housing, with said gas port providing a second pressure within said rigid housing when said housing is sealed, said second pressure being transmitted across said at least one flexible wall to affect the first pressure of said physiological liquid in said blood chamber, said combination formed by an end user without compromising the sterility of said extracorporeal circuit.

2. The combination of a blood reservoir, and a rigid housing, as claimed in claim 1, wherein the second wall is flexible, with said first and second flexible walls of said blood chamber sealed within said rigid housing.

3. The combination of a blood reservoir and a rigid housing, as claimed in claim 1 wherein said inlet and said outlet tubes pass through and are sealed within said disposable rigid structure.

4. The combination of a disposable blood reservoir and a rigid housing for vacuum assisted venous drainage, in a sterile extracorporeal circuit, said combination comprising:

a) said disposable blood reservoir having a first wall and a second wall said first wall having a first periphery, said first wall having an inner blood side and an external side, said second wall having a second periphery, an inner blood side and an external side, said first wall being a flexible wall, said first wall sealed along its first periphery to said second wall along said second periphery thereby forming a blood chamber having at least one flexible wall, said blood chamber adapted to contain a physiological liquid at a first pressure,

b) said disposable blood reservoir having an inlet tube, an outlet tube, and a gas purge tube to provide fluid communication between said blood chamber and said extracorporeal circuit,

c) at least a first and a second rigid structure that when combined form said rigid housing, said first and second rigid structures being nondisposable,

d) a gas port formed in one of said first or said second rigid structures, said port adapted to be in fluid communication with a vacuum source,

wherein said rigid structures form a clamshell like rigid housing that seals said flexible wall of said blood chamber within said rigid housing, with said gas port providing a second pressure within said rigid housing when said housing is sealed, said second pressure being transmitted across said at least one flexible wall to affect the first pressure of said physiological liquid in said blood chamber, said combination formed by an end user without compromising the sterility of said extracorporeal circuit.

5. The combination of a blood reservoir and a rigid housing, as claimed in claim 4 wherein said nondisposable rigid structures form a clamshell like rigid housing and are connected to each other with a hinge along a common side.

6. The combination of a disposable blood reservoir and a rigid housing for vacuum assisted venous drainage, in a sterile extracorporeal circuit, said combination comprising:

a) said disposable blood reservoir having a first flexible wall and a second rigid wall said first wall having a first periphery, said first wall having an inner blood side and an external side, said second wall having a second periphery, an inner blood side and an external side, said first wall sealed along its first periphery to said second wall along said second periphery thereby forming a blood chamber having at least one flexible wall, said blood chamber adapted to contain a physiological liquid at a first pressure,

b) said disposable blood reservoir having an inlet tube, an outlet tube, and a gas purge tube to provide fluid communication between said blood chamber and said extracorporeal circuit,

c) at least a first rigid structure that when combined with said second rigid wall form said rigid housing,

d) a gas port formed in said second rigid structures, said port adapted to be in fluid communication with a vacuum source,

wherein said first rigid structure and said second rigid wall are combined to form said rigid housing that seals said flexible wall of said blood chamber within said rigid housing, with said gas port providing a second pressure within said rigid housing when said housing is sealed, said second pressure being transmitted across said at least one flexible wall to affect the first pressure of said physiological liquid in said blood chamber, said combination formed by an end user without compromising the sterility of said extracorporeal circuit.

7. The combination of a blood reservoir and a rigid housing, as claimed in claim 6, wherein said inlet tube, said outlet tube, and said gas purge tube are connected respectively to an inlet port, an outlet port and a gas purge port formed in said second rigid wall, said ports providing fluid communication between said blood chamber and said extracorporeal circuit.