Programmable infusion pump

A fluid dispensing cartridge assembly comprising:

• a housing;
• at least one flexible compartment for containing fluid, each compartment being connected by an access tube to an outlet for expelling fluid;
• a pressure roller movable within said housing to compress said at least one flexible compartment, said pressure roller including means extending from said housing for engagement with a drive mechanism;
• position indicating markings arranged along the length of said housing in the direction of movement of said pressure roller;
• and
• flow restrictor means for adjustably compressing each said access tube to regulate the flow of fluid therethrough, said flow restrictor means including:
• a compression member for contacting and pressing against each said access tube;
• a spring located adjacent said compression member so that said spring may exert force against said compression member;
• a rotatable threaded cylindrical member;
• and
• a non-rotating member having a threaded hole engaged by said cylindrical member, said non-rotating member being adjacent said spring opposite said compression member so the rotation of said cylindrical member adjusts the force exerted by said non-rotating member on said spring and consequently adjusting the force exerted by said spring on said compression member.

A fluid dispensing cartridge assembly comprising:

• a housing having a resilient base;
• at least one flexible compartment formed on said resilient base for containing fluid, each compartment being connected by an access tube to an outlet for expelling fluid;
• a roller for compressing said at least one compartment against said resilient base to squeeze fluid out through the outlets of said at least one compartment;
• means for holding said roller against said base to prevent fluid from leaking within any of said at least one compartments between said roller and said base;
• and
• flow restrictor means for adjustably compressing each said access tube to regulate the flow of fluid therethrough, said flow restrictor means including:
• a compression member for contacting and pressing against each said access tube;
• a spring located adjacent said compression member so that said spring may exert force against said compression member;
• a rotatable threaded cylindrical member;
• and
• a non-rotating member having a threaded hole engaged by said cylindrical member, said non-rotating member being adjacent said spring opposite said compression member so that rotation of said cylindrical member adjusts the force exerted by said non-rotating member on said spring and consequently adjusting the force exerted by said spring on said compression member.

A programmable pump comprising:

• a housing;
• a sliding member within said housing;
• means for applying a substantially constant force to said slidable member;
• means for detecting the position of said slidable member within said housing;
• a motor;
• means, coupled to said motor, for regulating a flow restrictor;
• and
• programmable controller means responsive to said position detecting means for operating said motor to regulate the flow restrictor such that said slidable member moves through said housing to provide a preprogrammed volume of flow per the time duration of the infusion.

An infusion pump comprising:

• a pump housing for receiving at least one fluid containing compartment;
• a constant force spring having a free end at the exterior of a coil, said coil mounted within said housing so as to be prevented from translational movement;
• means for applying pressure coupled to the free end of said constant force spring such that said pressure applying means is pulled against said at least one compartment for pushing fluid therefrom;
• and
• flow restrictor means for regulating the flow of fluid out of said at least one compartment;
• a motor on said pump housing;
• and
• gear means connected to said motor for adjusting said flow restrictor means.

An infusion pump comprising:

• a pump housing for receiving at least one fluid containing compartment located on a cartridge insertable into said pump housing;
• a constant force spring having a free end at the exterior of a coil, said coil mounted within said housing so as to be prevented from translational movement;
• a slidable member connected to the free end of said constant force spring;
• and
• a roller engaged by said slidable member so that said roller is pulled against said at least one compartment for squeezing fluid therefrom, wherein said roller includes an engagement means extending through slots of said cartridge for engaging said slidable member such that when said cartridge is loaded into said pump housing said engagement means engages said slidable member to unwind said constant force spring.

A programmable infusion pump comprising:

• a pump housing for receiving a cartridge housing, said cartridge housing containing at least one flexible fluid containing compartment each compartment having an access tube through which fluid can be expelled;
• a substantially constant force spring having a free end on the exterior of a coil, said coil mounted within said pump housing so as to be prevented from translational movement;
• a slidable member connected to the free end of said spring;
• a roller carried in said cartridge housing and engaged by said slidable member for compressing said at least one compartment to squeeze fluid out through the access tubes of said at least one compartment;
• flow restrictor means for restricting the flow of fluid out through the access tubes;
• a motor coupled to said flow restrictor means for regulating said flow restrictor means;
• means for detecting the position of said roller;
• and
• programmable controller means responsive to said position detecting means for operating said motor to regulate the flow restrictor such that as said roller is pulled through said cartridge housing by said slidable member, a preprogrammed volume of fluid flows out of said at least one flexible compartment per time duration of the infusion.

A method for maintaining a predetermined infusion rate comprising the steps of:

• providing infusion apparatus having a fluid containing compartment and a movable member for pushing fluid out of said compartment;
• counting the amount of time for which said infusion apparatus is being used during the infusion;
• determining the time it takes said movable member to move from a first position to a second position;
• determining the volume of fluid infused between the first position and the second position;
• dividing the volume of fluid infused between the first position and the second position by the amount of time it took to move from the first position to the second position to determine the current infusion rate;
• comparing the current infusion rate with the predetermined infusion rate;
• and
• adjusting the rate of fluid flow from said infusion apparatus by adjusting a flow restrictor means to vary the size of an outlet from said compartment when said current infusion rate differs from said predetermined infusion rate by more than a predetermined tolerance.

A method of infusing a predetermined volume of fluid over a predetermined infusion time period comprising the steps of:

• providing infusion apparatus having a fluid containing compartment and a means for expelling fluid from said compartment;
• counting the time as said infusion apparatus is used during an infusion;
• determining the time it takes to infuse a sample volume of fluid, said sample volume being smaller than said predetermined volume;
• dividing the sample volume by the amount of time it took to infuse said sample volume to determine the current infusion rate;
• determining a rate error as a function of the current infusion rate and a desired rate which will result in the infusion of the predetermined volume of fluid at the end of the predetermined infusion time period;
• determining the total volume of fluid infused between the start of the infusion and the end of the infusion of said sample volume;
• determining a volumetric error as a function of the total volume of fluid infused and a desired volume which is the product of the predetermined volume of fluid and the rate of the time elapsed between the start of infusion and the end of the infusion of said sample volume to the predetermined infusion time period;
• and
• adjusting the flow of fluid from said infusion apparatus by adjusting a flow restrictor means to vary the size of an outlet from said compartment when either said rate error exceeds a predetermined rate tolerance or said volumetric error exceeds a predetermined volume tolerance.