Fluid delivery system and flow control therefor

• US 7,879,025 B2
• Filed: 01/17/2006
• Issued: 02/01/2011
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Yardimci, Atif, Jacobson, James D., Slepicka, James S., Garchow, Stephen R., Bui, Tuan
• Primary Examiner(s): Sirmons; Kevin C
• Assistant Examiner(s): GRAY, PHILLIP A
• Application Number:
  US11/333,594
• Publication Number:
  US 20060142692A1
• Time in Patent Office: 1,841 Days
• Field of Search: 604/48, 604 65- 67, 604155-157, 604/890.1, 604/131, 604118-121
• US Class Current: 604/890.1
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2205/0294 Piezoelectric materials
• CPC Class Codes: A61M 5/14236 Screw, impeller or centrifugal type pumps
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: G05D 7/0676 by action on flow sources G05D7/0688, G05D7/0694 take precedence

Abstract

A fluid delivery system having a closed-loop control process for delivering a medical fluid to a patient. A fluid infusion system includes a pump for delivering a fluid to a patient via an administration tube. A flow sensor associated with the administration tube provides an indication of the actual flow rate of fluid in the administration tube. Such a flow sensor may comprise a positive displacement flow sensor constructed using micro-fabrication and/or micro-molding techniques. A reader reads the actual flow rate signal and provides an indication to a controller for controlling the pump. The flow rate information can also be used for providing status information, such as the existence of a blockage in the fluid delivery system.

Claims

1. A system for delivering a fluid at a desired flow rate from a reservoir to a delivery point associated with a patient, the system comprising:

a delivery channel between the reservoir and the delivery point through which the fluid is delivered to the patient;

a pump associated with the delivery channel for operatively delivering the fluid to the delivery point at an adjustable output rate;

a flow sensor located along the delivery channel for sensing a flow of the fluid in the delivery channel, the flow sensor comprising a positive displacement flow sensor, the flow sensor comprising;

a housing having an inlet port and an outlet port, the ports being operatively connected to the delivery channel;

a first rotor positioned within the housing between the inlet port and the outlet port;

a second rotor positioned within the housing between the inlet port and the outlet port, the second rotor being positioned adjacent to the first rotor, the first and second rotors being constructed and arranged to rotate in response to a flow of medical fluid in the delivery channel; and

a clear cover enclosing the housing;

a controller for controlling the pump;

an optical reader associated with the flow sensor for generating a flow rate signal; and

a wireless communication channel between the reader and the controller, the reader configured for providing the flow rate signal indicative of the flow rate via the wireless communication channel to the controller and the controller configured for receiving the flow rate signal via the wireless communication channel and causing adjustments to the adjustable output rate of the pump in response thereto.

2. A system as set forth in claim 1, wherein the communication channel comprises a wireless spread spectrum communication channel operating in an unlicensed frequency band.

3. A system as set forth in claim 1, wherein the flow sensor is located entirely within the delivery channel.

4. A system as set forth in claim 1, wherein the flow sensor is selected from the group consisting of a MEMS device, an assembly of micromolded components, a deep reactive ion etching device and a UV-LIGA device.

5. A system as set forth in claim 1, wherein the housing and the first and second rotors are fabricated from a process selected from the group consisting of:

a micro-fabrication process;

from one or more molds made via a UV-LIGA process; and

a deep reactive ion etching (RIB) process.

6. A system as set forth in claim 1, wherein the pump comprises a syringe pump.

7. A system for delivering a fluid at a desired flow rate from a reservoir to a delivery point associated with a patient, the system comprising:

an infusion pump for pumping the fluid to the delivery point at an adjustable output rate;

a delivery channel between the pump and the delivery point through which the fluid is delivered to the patient;

a flow sensor located outside the pump and along the delivery channel for sensing a flow rate of the fluid in the delivery channel, the flow sensor comprising a positive displacement flow sensor having;

a housing having an inlet port And an outlet port, the ports being operatively connected to the delivery channel;

a first rotor positioned within the housing between the inlet port and the outlet port;

a second rotor positioned within the housing between the inlet port and the outlet port, the second rotor being positioned adjacent to the first rotor, the first and second rotors being constructed and arranged to rotate in response to a flow of medical fluid in the delivery channel; and

a clear cover enclosing the housing;

a controller for controlling the pump; and

a wireless communication device for communicating between the flow sensor and the controller, the device providing a flow control signal indicative of the flow rate to the controller, wherein the controller is configured for causing adjustments to the flow rate as a function of the flow control signal whereby the desired flow rate is substantially achieved.

8. The system of claim 7, further comprising a reader operatively connected to the flow sensor for generating a flow rate signal to the device.

9. The system of claim 7, wherein the infusion pump is a syringe pump.

10. The system of claim 8, wherein the reader is an optical reader.