Single needle alternating flow blood pump system

Claim 2

A single needle alternating flow blood pump system for alternate removal of blood from a blood vessel and return to said blood vessel via a single needle, said system comprising: a blood flow path including a blood pump and tubing means communicating between said needle and said blood pump for withdrawing blood from said blood vessel, blood receiving means also in said blood flow path through which blood is circulated by said blood pump for subsequent return to said needle, valve means in said blood flow path by way of which the blood flow is returned to said needle, said valve means being normally closed for impeding the flow of blood to said needle as said pump operates to withdraw blood therefrom, and means operatively connected to both said pump and said valve means and responsive to a given cyclical condition of said blood pump during pumping operation thereof for cyclically interrupting operation of said blood pump to interrupt withdrawal of blood for predetermined time periods after said blood pump has withdrawn substantially equal quantities of blood and for opening said valve means to return said blood to said blood vessel through said needle, whereby blood is alternately withdrawn and returned via the same needle.

Claim 3

The system according to claim 1 wherein said blood receiving means is located in said blood flow path between the outlet side of said blood pump and said needle such that blood flows through said receiving means in returning to said needle, and wherein said valve means is disposed in said blood flow path between said blood receiving means and said needle.

Claim 4

A flow system for alternate removal of liquid from and return of liquid to a single passage comprising: a flow loop connected at either end thereof to said single passage for receiving liquid from said single passage and returning liquid to said single passage, a roller-and-flexible-tube pump having a tube thereof inserted in said loop for producing the transport of liquid along said loop, said pump including a rotor carrying rollers for bearing against a tube inserted in said loop, a guide for receiving said tube, and means for rotating said rotor to force liquid along said tube, a valve means located in said flow loop between the outflow side of said pump and said single passage for temporarily impeding the passage of liquid, and means operatively connected to both said pump and said valve means and responsive to a cyclical condition of said pump during pumping operation thereof, for temporarily opening said valve means and arresting operation of said pump for predetermined time periods while at least one roller of said pump engages the said tube in said pump.

Claim 5

A flow system for alternate removal of liquid from and return of liquid to a single passage comprising: a flow loop connected at either end thereof to said single passage for receiving liquid from said single passage and returning liquid to said single passage, a roller-and-flexible-tube pump having a tube thereof inserted in said loop for producing the transport of liquid along said loop, said pump including a rotor carrying rollers for bearing against a tube inserted in said loop, a guide for receiving said tube, and means for rotating said rotor to force liquid along said tube, a valve means located in said flow loop between the outflow side of said pump and said single passage for temporarily impeding the passage of liquid, and means operatively connected to both said pump and said valve means and responsive to a cyclical condition of said pump during pumping operation thereof, for temporarily opening said valve means and arresting operation of said pump for predetermined time periods while at least one roller of said pump engages the said tube in said pump.

Claim 6

The system according to claim 3 wherein said means for temporarily opening said valve means comprises actuating means responsive to rotational movement of the rotor of said pump, said valve means comprising a section of tubing normally closed by said actuating means until said pump reaches a predetermined pump rotor position, and timing means for returning said pump to a condition of rotor rotation after a predetermined period of time.

Claim 7

A flow system for alternate removal of liquid from and return of liquid to a single passage comprising: a flow loop connected at either end thereof to said single passage for receiving liquid from said single passage and returning liquid to said single passage, a roller-and-flexible-tube pump having a tube thereof inserted in said loop for producing the transport of liquid along said loop, said pump including a rotor carrying rollers for bearing against a tube inserted in said loop, a guide for receiving said tube, and means for rotating said Rotor to force liquid along said tube, a valve means located in said flow loop for temporarily impeding the passage of liquid, means, responsive to a cyclical condition of said pump, for temporarily opening said valve means and arresting operation of said pump while at least one roller of said pump engages the said tube in said pump, said means for temporarily opening said valve means comprising actuating means responsive to rotational movement of the rotor of said pump, said valve means comprising a section of tubing comprising a portion of said loop and normally closed by said actuating means until said pump reaches a predetermined pump rotor position, said actuating means comprising a spring-biased arm normally disposed in clamping relation to said section of tubing, said arm being positioned relative to the rotor of said pump so that rotation of said rotor to a predetermined position moves said arm against spring bias for unclamping said tubing, and timing means for returning said pump to a condition of rotor rotation after a predetermined period of time, said timing means comprising timed switching means having contacts for providing power to said pump after a predetermined time period whereby said arm acts to re-clamp said tubing after said predetermined time period.

Claim 8

A flow system for alternate removal of liquid from and return of liquid to a single passage comprising: a flow loop connected at either end thereof to said single passage for receiving liquid from said single passage and returning liquid to said single passage, a roller-and-flexible-tube pump having a tube thereof inserted in said loop for producing the transport of liquid along said loop, said pump including a rotor carrying rollers for bearing against a tube inserted in said loop, a guide for receiving said tube, and means for rotating said Rotor to force liquid along said tube, a valve means located in said flow loop for temporarily impeding the passage of liquid, means, responsive to a cyclical condition of said pump, for temporarily opening said valve means and arresting operation of said pump while at least one roller of said pump engages the said tube in said pump, said means for temporarily opening said valve means comprising actuating means responsive to rotational movement of the rotor of said pump, said valve means comprising a section of tubing comprising a portion of said loop and normally closed by said actuating means until said pump reaches a predetermined pump rotor position, said actuating means comprising a spring-biased arm normally disposed in clamping relation to said section of tubing, said arm being positioned relative to the rotor of said pump so that rotation of said rotor to a predetermined position moves said arm against spring bias for unclamping said tubing, and timing means for returning said pump to a condition of rotor rotation after a predetermined period of time, said timing means comprising timed switching means having contacts for providing power to said pump after a predetermined time period whereby said arm acts to re-clamp said tubing after said predetermined time period.

Claim 9

The system according to claim 5 wherein said means for temporarily opening said valve means and arresting operation of said pump further comprises a limit switch operated by movement of said arm, and means for connecting said limit switch in energizing relation to said pump so that operation of said limit switch disconnects said pump, said timed switching means being operated by said limit switch.

Claim 10

The system according to claim 5 wherein said arm is rotatable, having a forward portion on one side of the axis thereof engageable by the rotor of said pump, a clamping pin forming part of said valve means, said arm having a second portion on the opposite side of the axis thereof normally spring-biased against said clamping pin, said tubing being disposed between said clamping pin and said arm whereby said arm in its normally spring-biased position compresses said tubing against said clamping pin, and wherein said operation of said arm by rotation of said rotor to said predetermined position rotates said arm away from said clamping pin and allows liquid flow through said tubing.