Infusion pump
AssigneeBionica Pty. Limited
InventorsVladimir Feingold, Peter C. Allworth
Life of this patent
Estimating the term…
Abstract
A portable infusion pump assembly utilizing continuous drive propulsion means (8) to effect automatic and incremental displacement of a plunger (5) within a disposable syringe (3) so as to deliver accurately repeatable volumes of fluid from the syringe (3) over a predetermined period of time. Intermittent drive of the continuous drive propulsion means (8) is effected. Comparison of desired delivery rate with actual delivery rate is made by use of angular displacement signals received from a shaft encoder (10) attached to the shaft of the continuous propulsion means (8). This method of control also allows indirect measurement of fluid pressure in the syringe (3) without the need for a pressure sensor to be located in direct contact with the fluid being delivered.
Claims25
A method of controlling an infusion pump, said pump including a motor adapted to impart continuous rotary motion via an output shaft, said pump further including encoding means adapted to provide data indicative of rotational motion of said output shaft, said data being proportional to the angular displacement of said output shaft;
- said method comprising providing power to said motor only for a first period of time within a time window during which first data is produced from said encoding means;
- monitoring second data received from said encoding means during a second period of time immediately following said first period of time during said time window;
- comparing said first and second data with desired data corresponding to a predetermined volume feed rate of said infusion pump and, on the basis of said comparison, determining whether and for how long to energize said motor during subsequent window periods.
An infusion pump including a motor adapted to impart continuous rotary motion via an output shaft, said pump further including encoding means adapted to provide data indicative of rotational motion of said output shaft, said data being proportional to the angular displacement of said output shaft;
- said pump further including means to provide power to said motor only for a first period of time within a time window during which first data is produced from said encoding means;
- comparison means for comparing said first data and second data received from said encoding means during a second period of time immediately following said first period of time during said time window with desired data corresponding to a predetermined volume feed rate of said infusion pump;
- said comparison means determining whether and for how lng to energize said motor during subsequent window periods on the basis of the comparison.
A method of controlling an infusion pump, said pump including a DC motor connected by its output shaft to a reduction gearbox and thence to a rotary to linear motion converter, said converter imparting linear thrust to a syringe piston;
- said shaft of said DC motor also driving encoding means, said encoding means providing output pulses in proportion to angular displacement of said shaft;
- said method comprising:
- providing power to said DC motor only for a first period of time within a time window during which a first series of output pulses is produced from said encoding means;
- monitoring said output pulses (as said shaft of said DC motor returns to a stationary state) during a second period of time during said time window;
- comparing said pulses with a desired number of pulses corresponding to a predetermined volume feed rate and, on the basis of said comparison, determining whether and for how long to energize said DC motor during subsequent window periods.
An infusion pump, said pump including a DC motor connected by its upward shaft to a reduction gearbox and thence to a rotary to linear motion converter, said converter imparting linear thrust to a syringe piston;
- said shaft of said DC motor also driving encoding means, said encoding means providing output pulses in proportion to angular displacement of said shaft;
- said pump including control means to supply power to said DC motor only for a first period of time within a time window during which a first series of output pulses is produced from said encoding means;
- said control means monitoring said output pulses (as said shaft of said DC motor returns to a stationary state) during a second period of time during said time window;
- said control means comparing said pulses received during said first and said second periods and comparing said pulses with a desired number of output pulses corresponding to a predetermined volume feed rate and, on the basis of said comparison, determining whether and for how long to energize said DC motor during subsequent window periods.
Dependencies are inferred from the claim text.