Infusion pump

An infusion pump for administering fluid from a fluid source through an outlet to a patient at a controlled average volumetric flow rate comprising:

• (a) pump means for pumping fluid from said fluid source through said outlet at an average volumetric flow rate proportional to the average rate of movement of said pump means;
• (b) electric motor means for moving said pump means;
• (c) control means for controlling the average rate at which said electric motor means moves said pump means, said control means comprising time-based means for repeatedly initiating motor-driving electric energy at a predetermined time rate, and position-based means for repeatedly terminating said energy in response to the advancement of said motor means beyond respective predetermined positions after respective initiations of said energy, said respective predetermined positions being separated by identical increments of movement of said motor means;
• and
• (d) comparator means for sensing whether or not said motor means has advanced beyond one of said increments of movement within a predetermined time period after an initiation of said energy.

An infusion pump for administering fluid from a fluid source through an outlet to a patient, comprising:

• (a) fluid pump means connected to said fluid source and said outlet for pumping fluid from said fluid source through said outlet at a predetermined average volumetric flow rate;
• (b) electric motor means for driving said pump means;
• (c) sensor means for sensing the average rate of movement of said motor means;
• (d) means responsive to said sensor means for transmitting an error signal when the average rate of movement of said motor means, as sensed by said sensor means, is below a predetermined rate;
• and
• (e) means for controllably varying the time-averaged magnitude of electric current driving said motor means, so as to controllably vary the maximum pressure of said fluid pumped through said outlet, independently of the magnitude of said predetermined average volumetric flow rate so as to maintain said predetermined average volumetric flow rate in case of a partial occlusion tending to reduce said volumetric flow rate.

An infusion pump for administering fluid from a fluid source through an outlet to a patient at a controlled average volumetric flow rate comprising:

• (a) pump means for pumping fluid from said fluid source through said outlet at an average volumetric flow rate proportional to the average rate of movement of said pump means;
• (b) electric motor means for moving said pump means;
• and
• (c) control means for controlling the average rate at which said electric motor means moves said pump means, said control means comprising time-based means for repeatedly initiating motor-driving electric energy at a predetermined time rate, position sensor means for sensing the position of said motor, and position-based means responsive to said position sensor means for repeatedly terminating said energy, said position-based means including means for terminating said energy concurrently with the advancement of said motor means beyond respective predetermined positions after the most recent initiation of said energy irrespective of the time elapsed since said most recent initiation, successive ones of said respective predetermined positions being separated by identical increments of movement of said motor means;
• and
• (d) said means comprising reciprocative piston and cylinder means for pumping fluid through said outlet at said controlled average volumetric flow rate while simultaneously drawing fluid from said fluid source at said controlled average volumetric flow rate.

An infusion pump for administering fluid from a fluid source through an outlet to a patient, comprising:

• (a) fluid pump means connected to said fluid source and said outlet for pumping fluid from said fluid source through said outlet at a predetermined average volumetric flow rate;
• (b) electric motor means for driving said pump means;
• (c) sensor means for sensing regressive movement of said motor means in a direction opposite to that in which said motor means drives said pump means;
• and
• (d) control means responsive to said sensor means for initiating motor-driving electrical energy opposing said regressive movement in response to the sensing by said sensor means of said regressive movement.