FLUID DELIVERY SYSTEM AND FLOW CONTROL THEREFOR

• US 20080255502A1
• Filed: 03/21/2008
• Published: 10/16/2008
• 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
• Granted Patent: US 8,672,876 B2
• Time in Patent Office: Days
• US Class Current: 604/67
• 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 pulsatile flow profile 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 and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel, the flow sensor comprising a positive displacement flow sensor; and

a controller for controlling the pump, the controller causing adjustments to the output rate of the pump as a function of the flow rate signal such that the output flow rate has a generally pulsatile characteristic corresponding to the desired pulsatile flow profile.

2. A system as set forth in claim 1 wherein the controller provides a flow rate status signal and further comprising a status monitoring device providing an indication of an operating status of the desired pulsatile flow profile in response to the flow rate status signal.

3. A system as set forth in claim 1 wherein the flow rate status signal comprises a signal indicative of a blockage in the delivery channel and wherein the indication of the operating status of desired flow rate comprises an indication identifying that the delivery channel has a blockage.

4. A system as set forth in claim 1 wherein the pump is a peristaltic pump, a piezoelectric pump or a valve pump.

5. A system as set forth in claim 1 wherein the controller provides a closed-loop control path with the pump.

6. 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 and for generating a flow rate signal indicative of a rate of flow of the fluid in the delivery channel, the flow sensor comprising a positive displacement flow sensor; and

a controller for controlling the pump, the controller providing a flow rate status signal indicative of a blockage in the delivery channel when the flow rate signal indicates the rate of flow of fluid in the delivery channel is less than a blockage threshold.

7. A system as set forth in claim 6 further comprising a status monitoring device responsive to the flow rate status signal for providing an alarm to a user and a communication channel for transmitting the flow rate status signal from the controller to the status monitoring device.

8. A system as set forth in claim 7 wherein the communication channel comprises a wireless spread spectrum communication channel operating in an unlicensed frequency band.

9. A system as set forth in claim 7 wherein the alarm comprises an audible alarm.

10. A system as set forth in claim 7 wherein the alarm comprises a visual alarm.

11. A system as set forth in claim 7 wherein the alarm comprises a vibrating alarm.

12. A method of detecting a blockage in a medical fluid delivery system arranged for delivering a medical fluid to a delivery point associated with a patient at a desired flow rate, the method comprising:

operatively connecting a reservoir to a delivery mechanism, the reservoir containing the medical fluid to be delivered to the delivery point;

operatively connecting the delivery mechanism to an administration tube, the administration tube being in fluid communication with the delivery point, the delivery mechanism receiving the medical fluid from the reservoir and supplying the medical fluid to the delivery point via the administration tube at an output flow rate;

sensing the output flow rate of the medical fluid in the administration tube;

determining if the sensed output flow rate is indicative of a blockage in the administration tube; and

providing an alarm signal if it is determined that the sensed output flow rate indicates that the administration tube is blocked.

13. A method as set forth in claim 12 wherein determining if the sensed output flow rate is indicative of a blockage in the administration tube comprises comparing the sensed output flow rate to a blockage threshold such that the alarm signal is provided if the output flow rate is less than the blockage threshold.

14. A method as set forth in claim 13 wherein determining if the sensed output flow is indicative of a blockage in the administration tube comprises averaging the sensed output flow rate of the medical fluid in the administration tube over a time period and comparing the averaged sensed output flow rate to a blockage reference such that the alarm signal is provided if the averaged sensed flow rate is less than the blockage reference.

15. A method as set forth in claim 12 further comprising receiving the alarm signal at a status monitoring device associated with the medical fluid delivery system and providing an indication of the alarm signal at the status monitoring device.

16. A method as set forth in claim 15 wherein the indication of the alarm signal comprises an audible alarm.

17. A method as set forth in claim 15 wherein the indication of the alarm signal comprises a visual alarm.

18. A method as set forth in claim 15 wherein the indication of the alarm signal comprises a vibrating alarm.