Apparatus and methods for purging catheter systems

Abstract

Apparatus and methods for providing controlled pressure-flow pulses which purge a catheter system with turbulent flow flushing. Accomplishment of such controlled pressure-flow pulses is provided by a variety of inventive devices including a special plunger rod for a conventional syringe, other interactive parts for conventional syringes, an in-line catheter attachable device which automatically generates the controlled pressure-flow pulses and also single pulse, digitally operated devices.

1 . An apparatus which provides controlled and consistent push-pause pulsatile flow of sufficiently turbulent flushing pressure and flow within a catheter system to substantially purge the line of unwanted residue, said apparatus comprising:
 a source of flush fluid;   a container for retaining a predetermined volume of the fluid,   a valve mechanism interconnected for controllably interrupting fluid flow communication between the container and the catheter system;   a sensing actuator which controls opening and closing said valve mechanism, said sensing actuator opening said valve mechanism at a given predetermined pressure which yields the sufficiently turbulent flow of fluid from the container, said sensor actuator further having an operating hysteresis such that the valve mechanism is closed at another predetermined pressure which is lower than the opening pressure;   an implement for providing at least enough fluid force to engender the pressure within the container necessary to open the valve mechanism; and   a memory element which stores energy received from action of the implement and releases the stored energy upon valve opening to provide the turbulent flushing fluid pressure and flow for a a period dependent upon time pressure within the container is above the other pressure.   
     
     
         2 . The apparatus according to  claim 1  wherein:
 (i) said source comprises fluid contained within a barrel of a syringe;   (ii) said container comprises a housing comprising the distal portion of the barrel of the syringe and a plunger affixed to a plunger rod which are disposed for slideable displacement within said barrel, said barrel further comprising a retention ring on the proximal end thereof and said plunger comprising a proximally disposed entry disk associated with said plunger, said entry disk and retention ring cooperating to provide a tactilely discernable stop which prevents inadvertent removal of the plunger from the barrel;   (iii) said plunger rod further comprising at least one sensing actuator comprising a valve actuating disk proximally disposed relative to said plunger and entry disk, said valve actuating disk being sized and shaped to require controlled and consistent force upon displacement past the retention ring to produce pressure required for turbulent flow when the valve actuating disk is forced through the retention ring;   (iv) said implement comprising said plunger rod which comprises a proximally disposed button upon which force is manually applied to provide sufficient force to displace the actuating disk past the retention ring; and   (v) said memory element comprising continuing reflexive force resulting from force manually applied for displacing the actuating disk past the retention ring.   
     
     
         3 . The apparatus according to  claim 1  wherein:
 (i) said source comprises a fluid receptacle which has a volume for liquid containment which is generally greater than the volume of a single push-pause pulse of fluid for purging an associated catheter system;   (ii) said container comprising a hollow cylindrical vessel comprising a communication pathway via a one-way valve from the source receptacle and another communicating pathway through a second one-way valve to the catheter system;   (iii) said valve mechanism comprising a plunger sized, shaped and disposed to displace fluid within the vessel, either a liquid drawn from the source or dispensed into the catheter system;   (iv) said sensor actuator comprising a retention ring disposed at a proximal end of the plunger and plunger rod and associated manual activator button disposed for manually displacing the plunger, a valve actuating disk proximally disposed relative to said plunger and which is disposed proximal to the retention ring until forced there through, said retention ring retarding displacement of the plunger until force upon the plunger yields the pressure which provides the sufficiently turbulent flow of fluid from the container to the catheter system; and   (v) said implement comprises a button associated with the plunger which is manually depressed to dispense fluid from the vessel, said implement further comprising a memory element which stores energy of plunger displacement during dispensing to return plunger and valve actuating disk to refill the vessel and reset the sensor actuator for a following pressure pulse cycle.   
     
     
         4 . The apparatus according to  claim 1  wherein:
 (i) said source comprises a fluid receptacle upstream from a pressure providing device, which provides fluid dispensed at a predetermined pressure and flow;   (ii) said container comprises a vessel which communicates with said pressure providing device through a flow restrictor and with said catheter system through a selected pressure sensitive valve;   (iii) the valve mechanism comprising the pressure sensitive valve which opens for dispensing fluid from the container to the catheter system at the predetermined pressure and which closes at the other predetermined pressure;   (iv) said sensing actuator being that portion of the pressure sensitive valve which comprises a valve opening action at the predetermined pressure and which comprises a valve closing action at the other predetermined pressure;   (v) said implement comprising the pressure providing device, which provides fluid dispensed at a predetermined pressure and flow, acting through said flow restrictor to fill said container and raise pressure within the container to the predetermined pressure; and   (vi) said memory element comprising a compressible element disposed proximal to a plunger element which is displaced by pressure and flow from the pump through the flow restrictor to accrue controlled and consistent pressure and volume to thereby provide a desired pressure pulse for purging the catheter system.   
     
     
         5 . The apparatus according to  claim 4  wherein said device comprises a pump. 
     
     
         6 . The apparatus according to  claim 4  wherein said device comprises tubing which is manually squeezed as the implement to provide the predetermined pressure at which said valve is opened by said actuator to produce the push pause pulsatile flow. 
     
     
         7 . A method for providing controlled push-pause pulsatile flow of sufficiently turbulent flushing pressure and flow within a catheter system to purge the line of unwanted residue comprising the steps of:
 (a) providing an apparatus comprising:
 (i) a source of flush fluid; 
 (ii) a container for retaining a predetermined volume of the fluid, 
 (iii) a valve mechanism interconnected for controllably interrupting fluid flow communication between the container and the catheter system; 
 (iv) a sensing actuator which controls opening and closing said valve mechanism, said sensing actuator opening said valve at a given predetermined pressure which yields the sufficiently turbulent flow of fluid from the container, said sensor actuator further having an operating hysteresis such that the valve mechanism is closed at another predetermined pressure which is lower than the opening pressure; 
 (v) an implement for providing at least enough fluid force to engender the pressure within the container necessary to open the valve mechanism; and 
 (vi) a memory element which stores energy received from the implement and releases the stored energy from action of the implement upon valve opening to provide the turbulent flushing fluid pressure and flow for a a period dependent upon time pressure within the container is above the other pressure. 
   (b) filling container with fluid from the source;   (c) providing force via the implement to create a fluid opening pressure within the   (c) providing force via the implement to create a fluid opening pressure within the container thereby opening the valve at the given predetermined pressure;   (c) dispensing flushing fluid having predetermined turbulent pressure and flow for a predetermined period into the catheter system; and   (d) closing the valve once pressure within the container is reduced to a level below the other predetermined pressure.   
     
     
         8 . The method according to  claim 7  comprising the following specified steps associated with parts in use:
 (a) providing an apparatus wherein:
 (i) said source comprises fluid contained within a barrel of a syringe; 
 (ii) said container comprises a housing comprising the distal portion of the barrel of the syringe and a plunger affixed to a plunger rod which are disposed for slideable displacement within said barrel, said barrel further comprising a retention ring on the proximal end thereof and said plunger comprising a proximally disposed entry disk associated with said plunger, said entry disk and retention ring cooperating to provide a tactilely discernable stop which prevents inadvertent removal of the plunger from the barrel; 
 (iii) said plunger rod further comprises at least one sensing actuator comprising at least one valve actuating disk proximally disposed relative to said plunger and entry disk, said valve actuating disk being sized and shaped to require controlled and consistent force upon displacement past the retention ring to produce pressure required for turbulent flow when the valve actuating disk is forced through the retention ring; 
 (iv) said implement comprises said plunger rod which comprises a proximally disposed button upon which force is manually applied to provide controlled and consistent force required to displace the actuating disk past the retention ring; and 
 (v) said memory element comprises continuing reflexive force resulting from force manually applied for displacing the actuating disk past the retention ring; 
   (b) affixing the syringe comprising the barrel filled with flushing fluid to the catheter system; and   (c) applying sufficient force upon the plunger rod button to displace one valve actuating disk past the retention ring and reflexively continuing displacement of the plunger rod to provide the desired pressure pulse.   
     
     
         9 . The method according to  claim 7  comprising the following specified steps associated with parts in use:
 (a) providing an apparatus wherein:
 (i) said source comprises a fluid receptacle which has a volume for liquid containment which is generally greater than the volume of a single push-pause pulse of fluid for purging an associated catheter system; 
 (ii) said container comprising a hollow cylindrical vessel comprising a communication pathway via a one-way valve from the source receptacle and another communicating pathway through a second one-way valve to the catheter system; 
 (iii) said valve mechanism comprises a plunger sized, shaped and disposed to displace fluid within the vessel, either a liquid drawn from the source or dispensed into the catheter system; 
 (iv) said sensor actuator comprises a retention ring disposed at a proximal end of the plunger and plunger rod and associated manual activator button disposed for manually displacing the plunger, a valve actuating disk proximally disposed relative to said plunger and which is disposed proximal to the retention ring until forced there through, said retention ring retarding displacement of the plunger until force upon the plunger yields the pressure which provides the sufficiently turbulent flow of fluid from the container to the catheter system; and 
 (v) said implement comprises a button associated with the plunger which is manually depressed to dispense fluid from the vessel, said implement further comprising a memory element which stores energy of plunger displacement during dispensing to return plunger and valve actuating disk to refill the vessel and reset the sensor actuator for a following pressure pulse cycle; 
   (b) affixing the container to the catheter system; and   (c) applying sufficient force upon the button to displace one valve actuating disk past the retention ring and reflexively continuing displacement of the plunger rod to provide the desired pressure pulse; and   (d) releasing the button to be displaced by the memory element to refill the vessel.   
     
     
         10 . The method according to  claim 7  comprising the following specified steps associated with parts in use:
 (a) providing an apparatus wherein:
 (i) said source comprises a fluid receptacle upstream from a pump; 
 (ii) said container comprises a vessel which communicates with said pump through a flow restrictor and with said IV line through a selected pressure sensitive valve; 
 (iii) the valve mechanism comprises the pressure sensitive valve which opens for dispensing fluid from the container to the catheter system at the predetermined pressure and which closes at the other predetermined pressure; 
 (iv) said sensing actuator is that portion of the pressure sensitive valve which comprises a valve opening action at the predetermined pressure and which comprises a valve closing action at the other predetermined pressure; 
 (v) said implement comprising the pump acting through said flow restrictor to fill said container and raise pressure within the container to the predetermined pressure; and 
 (vi) said memory element comprises a compressible element disposed proximal to a plunger element which is displaced by pressure and flow from the pump through the flow restrictor to accrue controlled and consistent pressure and volume to provide a desired pressure pulse for purging the catheter system; 
   (b) affixing the container to the catheter system; and   (c) initiating pumping to fill the container at a rate dependent upon pump output pressure and resistance of the restrictor to fill the vessel until the predetermined pressure is reached;   (d) opening the valve upon reaching the predetermined pressure to dispense fluid into the catheter system at a pressure and flow rate which purges the catheter system of undesired residue with a pressure pulse having a duration ended by closing of pressure sensitive valve at the other   (e) successively repeating steps c thru d until a desired number of pressure pulses has been delivered to the catheter system.   
     
     
         11 . A plunger rod which, in combination with an attached plunger of a syringe, is used to displace liquid within a syringe barrel which has a proximally disposed retention ring which provides opportunity for a tactile indication of a discernable stop to indicate a limit of proximal displacement of the plunger and plunger rod within the barrel, said plunger rod comprising:
 an elongated stem disposed between said plunger and a proximal end of the stem;   an entry disk proximally disposed relative to the plunger on said stem for interacting with the retention ring;   at least one valve actuating disk proximally disposed relative to said entry disk, said valve actuating disk being sized and shaped to require sufficient force upon displacement past the retention ring to produce pressure required for turbulent flow of liquid dispensed into an attached catheter when the valve actuating disk is forced through the retention ring.   
     
     
         12 . The plunger rod according to  claim 11  further comprising a second valve actuating disk disposed a more proximal distance from the at least one valve actuating disk to define a pressure pulse volume dispensed from the barrel as the plunger rod is displaced from contact by the at least one valve actuating disk with the retention ring to like contact by the second valve actuating disk.