Drive system for an infusion pump
First Claim
1. A liquid delivery system comprising:
- a housing which accommodates a syringe containing the liquid;
a motor carried by the housing; and
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a rotatable gear;
a threaded rotatable shaft, the shaft including a fitting configured for permanent engagement with the rotatable gear;
a piston drive member which linearly advances the piston, the drive member defining a threaded portion which engages threads of the shaft, the piston drive member advancing linearly as the shaft rotates; and
a guide element adapted to telescopically receive the piston drive member and inhibit rotation of the piston drive member during linear advancement of the piston drive member.
6 Assignments
0 Petitions
Accused Products
Abstract
A pump system for an infusion system includes a linear drive (36, 36′) which minimizes the space occupied by the pump components in a portable housing (10, 10′). A motor (34) and a motor drive shaft (42) are arranged in parallel with, and adjacent to a syringe (14, 14′) and lead screw (94, 94′). A gear box (54) connects the drive shaft and lead screw to transfer rotational movements between them. A piston driving member, such as a cone (116) or drive nut (116′) converts the rotational movement of the lead screw into linear motion of a syringe piston (24). Sensors (150, 152) detect when the piston or cone is in a “home” position and in an “end” position, respectively. Optionally, a proximity sensor (170) is used to ensure that the cone and the piston (24) are abutting during dispensing. Alternatively, a clamping member (350) selectively clamps the lead screw (94′) against linear motion in at least a dispensing direction.
452 Citations
24 Claims
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1. A liquid delivery system comprising:
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a housing which accommodates a syringe containing the liquid;
a motor carried by the housing; and
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a rotatable gear;
a threaded rotatable shaft, the shaft including a fitting configured for permanent engagement with the rotatable gear;
a piston drive member which linearly advances the piston, the drive member defining a threaded portion which engages threads of the shaft, the piston drive member advancing linearly as the shaft rotates; and
a guide element adapted to telescopically receive the piston drive member and inhibit rotation of the piston drive member during linear advancement of the piston drive member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A liquid delivery system comprising:
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a housing which accommodates a syringe containing the liquid;
a motor carried by the housing;
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a threaded rotatable shaft; and
a piston drive member, which linearly advances the piston, the drive member defining an interior threaded portion which engages exterior threads of the shaft, and an exterior threaded portion which engages interior threads of the piston drive member thereby advancing the piston linearly as the shaft rotates; and
a clamping member which selectively clamps the shaft against linear advancement, relative to the housing, in at least a dispensing direction, while permitting the shaft to rotate relative thereto. - View Dependent Claims (13, 14, 15)
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16. A liquid delivery system comprising:
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a housing which accommodates a syringe containing the liquid;
a motor carried by the housing; and
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a threaded rotatable shaft; and
a piston drive member, which linearly advances the piston, the drive member defining an interior threaded portion which engages exterior threads of the shaft, and an exterior threaded portion which engages interior threads of the piston drive member thereby advancing the piston linearly as the shaft rotates, wherein the housing defines an opening for receiving the syringe therethrough, the opening defining threads for engaging threads on the syringe barrel to lock the syringe to the housing.
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17. A liquid delivery system comprising:
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a housing which accommodates a syringe containing the liquid;
a motor carried by the housing;
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a threaded rotatable shaft; and
a piston drive member, which linearly advances the piston, the drive member defining an interior threaded portion which engages exterior threads of the shaft, and an exterior threaded portion which engages interior threads of the piston drive member thereby advancing the piston linearly as the shaft rotates;
a proximity sensor which senses occurrence of at least one of two states;
(a) the piston drive member abutting the piston, and (b) the piston drive member not abutting the piston; and
a microprocessor which receives a signal from the proximity sensor and alerts a user of the delivery system of the occurrence of at least one of state (a) and state (b);
wherein the piston drive member defines a first flange and the piston defines a second flange, at least a portion of the proximity sensor being associated with at least one of the first and second flanges.
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18. A liquid delivery system comprising:
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a housing which accommodates a syringe containing the liquid;
a motor carried by the housing;
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a threaded rotatable shaft; and
a piston drive member, which linearly advances the piston, the drive member defining an interior threaded portion which engages exterior threads of the shaft, and an exterior threaded portion which engages interior threads of the piston drive member thereby advancing the piston linearly as the shaft rotates;
a first position sensor which detects when at least one of the piston and the piston drive member is in a first position; and
a second position sensor which detects when the at least one of the piston and the piston drive member is in a second position, linearly spaced from the first position. - View Dependent Claims (19)
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20. A liquid delivery system comprising:
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a housing which accommodates a syringe containing the liquid;
a motor carried by the housing;
a drive system, operatively connected with the motor, which advances a piston of the syringe to expel liquid from a barrel of the syringe, the drive system including;
a threaded rotatable shaft; and
a piston drive member, which linearly advances the piston, the drive member defining an interior threaded portion which engages exterior threads of the shaft, and an exterior threaded portion which engages interior threads of the piston drive member thereby advancing the piston linearly as the shaft rotates;
a cap, which selectively connects the syringe to the housing, the cap including;
a first threaded portion which threadably engages a threaded portion on the syringe; and
a second threaded portion which threadably engages a threaded portion on the housing.
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21. An infusion system comprising:
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a housing which receives a cartridge, the housing defining an opening for receiving the cartridge therethrough;
a threaded shaft which is selectively drivingly coupled with a piston of the cartridge, the threaded shaft linearly advancing the piston as the shaft rotates to expel a liquid from a barrel of the cartridge; and
a clamping member which is selectively actuated to engage the shaft and thereby inhibit linear advancement of the shaft, relative to the barrel. - View Dependent Claims (22, 23, 24)
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Specification