US 7,553,294 B2Granted

Syringe plunger sensing mechanism for a medical injector

AssigneeMedrad, Inc.

InventorsFrank A. Lazzaro, Dennis P. Hack

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Abstract

Embodiments of an injector, syringe, syringe interface, syringe adapter, and piston/plunger assembly for an injector (of contrast medium, for example) are described. Preferably, the syringe is adapted to engage a syringe interface mechanism such that the syringe may be connected to an injector without regard to any particular orientation of the syringe to the injector or to the piston/plunger assembly. The injector piston or drive member includes a sensing pin positioned at a forward end thereof to sense contact with the syringe plunger during advancement of the piston or drive member to contact the plunger. The piston can be advanced automatically upon connection of, for example, the syringe to the injector, or piston advance can be automated to occur after operator initiation. The injector may include or be adapted to accommodate two syringes, which for example provide for simultaneous injection of fluid into separate injection sites on a patient.

Claims24

Dependent claims

An injector system for injecting fluid from at least one syringe mounted thereon, the syringe having a plunger slidably disposed therein, the injector system comprising:

a housing;
at least one drive member at least partially disposed within the housing and operable to engage the plunger of the syringe;
a controller in operative connection with the drive member;
at least one syringe retaining mechanism associated with the housing, the syringe retaining mechanism adapted to releasably engage the syringe;
and
a first sensing pin positioned at a forward end of the drive member and extending forward of a forward surface of the drive member to sense contact of the first sensing pin with an inner surface the syringe plunger upon forward advancement of the drive member to engage the syringe plunger prior to contact of the forward surface of the drive member with the syringe plunger, the first sensing pin being forced rearward upon with contact with the inner surface of the syringe plunger without causing forward movement of the syringe plunger, the rearward motion of the first sensing pin causing data of proximity of the inner surface of the syringe plunger and the forward surface of the drive member to be transmitted to the controller before contact of the forward surface of the drive member with the inner surface of the syringe plunger to control forward advancement of the drive member,
wherein the forward surface of the drive member is shaped to conform to the inner surface of the plunger.

4 more elements

An injector system comprising:

a housing;
a first drive member at least partially disposed within the housing and operable to engage a plunger of a first syringe mounted on the housing;
a second drive member at least partially disposed within the housing and operable to engage a plunger of a second syringe mounted on the housing;
a controller in operative connection with the first drive member and the second drive member;
a first mechanism comprising a first movable element disposed on a forward end of the first drive member and extending forward of a forward surface of the first drive member, the first mechanism being adapted to sense when the first movable element contacts an inner surface of the first syringe plunger upon forward advancement of the first drive member to engage the first syringe plunger prior to contact of the forward surface of the first drive member with the first syringe plunger, the first movable element being forced rearward upon contact with the first syringe plunger without causing forward movement of the first syringe plunger, the rearward motion of the first movable element causing data of proximity of the inner surface of the first syringe plunger and the forward surface of the first drive member to be transmitted to the controller before contact of the forward surface of the first drive member with the inner surface of the first syringe plunger;
and
a second mechanism comprising a second movable element disposed on a forward end of the second drive member extending forward of a forward surface of the second drive member, the second mechanism being adapted to sense when the second movable element contacts an inner surface of the second syringe plunger upon forward advancement of the second drive member to engage the second syringe plunger prior to contact of the forward surface of the second drive member with the second syringe plunger, the second movable element being forced rearward upon with contact with the second syringe plunger without causing forward movement of the second syringe plunger, the rearward motion of the second movable element causing data of proximity of the inner surface of the second syringe plunger and the forward surface of the second drive member to be transmitted to the controller before contact of the forward surface of the second drive member with the inner surface of the second syringe plunger.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/159,592Filed 30 May 2002
Published: US 2004/0064041 A11 Apr 2004
Granted: 30 Jun 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

A61M 5/14546
Pressurised by means of pistons: front-loading type injectors
A61M 5/14566
Pressurised by means of pistons: with a replaceable reservoir for receiving a piston rod of the pump
A61M 5/1458
Pressurised by means of pistons: means for capture of the plunger flange
A61M 5/172
Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters: electrical or electronic