MEDICATION INJECTION DEVICE

• US 3,858,581 A
• Filed: 07/02/1973
• Issued: 01/07/1975
• Est. Priority Date: 07/02/1973
• Status: Expired due to Term

• Current Assignee: Baxter Travenol Laboratories Incorporated
• Original Assignee: Dean Kamen
• Inventors: Kamen, Dean
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/375,955
• Time in Patent Office: 554 Days
• Field of Search: 128/2R,2.5R,218R,218A,214E,214F,DIG.1,234,236
• US Class Current: 604/155
• CPC Class Codes: A61M 5/1456 with a replaceable reservoir comprising a piston rod to be moved into the reservoir, e.g. the piston rod is part of the removable reservoir
• CPC Class Codes: Y10S 128/01 Motorized syringe

Abstract

A medication-administering device controlled for repetitive delivery, by intravenous injection or otherwise, of predetermined syringe volumes of said medication at present time intervals, wherein the syringe plunger medication injection stroke is achieved using a powering motor, and the control exercised over the mode of operation of the device is related to the rotational traverses of said motor. This minimizes non-uniform performance and other shortcomings which characterize prior art medication injection devices in which the performance of the powering motors are vulnerable to variances due to varying line voltage, changing work loads (i.e. medication with different viscosities) and the like.

Claims

1. A medication injection device comprising a syringe for dispensing medication in accordance with linear displacement of a plunger thereof, means secured to said syringe for connection to a patient for dispensing said medication to said patient, a rotatively mounted lead screw with threads of uniform pitch disposed in substantially parallel relation to the linear displacement path of said syringer plunger, pushing means mounted on said lead screw for advancement therealong in pushing engagement with said syringe plunger, a motor operatively arranged to power said lead screw in rotation to cause advancement oF said pushing means and corresponding linear displacement of said syringe plunger, a radially oriented striker mounted on said lead screw, a pulse-emitting switch located adjacent said lead screw in the path of the rotational traverse of said striker so as to be engaged thereby to cause an emission of an electrical pulse during each rotation of said lead screw, and a pulse-counting means electrically connected to receive the transmission of each aforesaid pulse and operatively connected to permit the operation of said motor for the duration of the transmission thereto of a selected number of said ppulses, whereby medication is dispensed in accordance with the linear displacement of said syringe plunger as a function of the number of rotational traverses of said lead screw as counted by said pulse-counting means.

2. A medication injection device as defined in claim 1 including an additional timing means operatively connected to said motor to cause the commencement of the operation thereof after a selected interval of non-operation, whereby said medication is dispensed by said device in accordance with a selected schedule of successive intervals of operation and non-operation of said motor.

3. A medication injection device as defined in claim 2 including a clutch interposed in the drive connection between said motor and said lead screw, and including means mounting said lead screw for selected limited linear movement for disengaging the same from said clutch to thereby terminate the powering rotation of said lead screw by said motor, whereby said dispensing of medication by said device is capable of being terminated in an emergency situation.

4. A medication injection device as defined in claim 2 wherein said additional timing means is of the type operated by pulses transmitted to it as is also said pulse-counting means, and further including a visual signaling device connected to be operated by each pulse being transmitted to said additional timing means and to said pulse-counting means, whereby the operation of said visual signal device is effective in indicating the working condition of said medication injection device.

5. A medication injection device as defined in claim 4 including a scale calibrating linear displacement of said syringe plunger with an ascending number of pulses produced during said rotational operation of said motor, whereby the volume of medication to be dispensed can be readily related to a selected number of pulses as counted by said pulse-counting means.