Aspiration system having pressure-controlled and flow-controlled modes

• US 5,380,280 A
• Filed: 11/12/1993
• Issued: 01/10/1995
• Est. Priority Date: 11/12/1993
• Status: Expired due to Term

• Current Assignee: Medical Instrument Development Laboratories, Inc.
• Original Assignee: Medical Instrument Development Laboratories, Inc.
• Inventors: Peterson, Erik W.
• Primary Examiner(s): Rosenbaum, C. Fred
• Assistant Examiner(s): WILKENS, FRANK
• Application Number:
  US08/150,715
• Time in Patent Office: 424 Days
• Field of Search: 604/31, 604/35, 604/65-67, 604/118, 604/119, 604/73, 604/246, 604/317-320
• US Class Current: 604/65
• CPC Class Codes: A61F 9/00736 Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments A61F9/008 takes precedence
• CPC Class Codes: A61M 1/74 Suction control underwater drainage A61M1/61
• CPC Class Codes: A61M 1/742 by changing the size of a vent A61M1/7411 takes precedence
• CPC Class Codes: A61M 1/743 by changing the cross-section of the line, e.g. flow regulating valves A61M1/7413 takes precedence
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes

Abstract

An aspiration system (10) having pressure-controlled and flow-controlled modes comprises connective plumbing (26), a collector (14), a pump (12), a variable flow resistor (20), a pressure sensor (18), and a control circuit (24). The connective plumbing (26) includes a conduit (28) which communicates with the surgical site from which fluid is to be aspirated and delivered to the collector (14). The pump (12) induces flow from the surgical site to the collector (14). The variable flow resistor (20) and the pressure sensor (18) are in fluid communication with the conduit (28) by the connective plumbing (26). In the pressure-controlled mode, the variable flow resistor (26) is adjusted to maintain a pre-selected pressure according to an output signal (50) from the pressure sensor (18). In the flow controlled mode, the pump (12) is adjusted to maintain a preselected flow according to a pressure differential in the connective plumbing across the variable flow resistor (20). The system (10 ) further includes a gas source (22) which is inputted into the variable flow resistor (20) to provide a known pressure against which the pressure in the remainder of the connective plumbing is compared to establish the pressure differential. The connective plumbing (26) further includes a flow director (16) permitting flow only in one direction to avoid contamination of certain portions of the connective plumbing (26). The contaminated portions of the connective plumbing (26) are discarded.

Claims

1. A surgical aspiration system comprising:

(a) a first conduit having a first end and a second end, the first end and the second end being in fluid communication and the first end communicating with the surgical site from which fluid is to be aspirated;

(b) a second conduit having a first end and a second end, the first end of the second conduit and the second end of the second conduit being in fluid communication, the second end of the first conduit and the first end of the second conduit meeting at a juncture which permits fluid communication therethrough;

(c) a collector which is in fluid communication with the second end of the second conduit, the collector receiving aspirated fluid;

(d) a pump which induces flow of aspirated fluid through the second conduit, and into the collector;

(e) a third conduit having a first end and a second end, the first end of the third conduit and the second end of the third conduit being in fluid communication, the first end of the third conduit meeting at the juncture such that it is in fluid communication with the second end of the first conduit and the first end of the second conduit;

(f) a flow director having an input and an output, the output being located at the second end of the third conduit and being in fluid communication with the second end of the third conduit, the flow director permitting flow of gas into the third conduit and preventing the flow of liquid to the input of the flow director.

(g) a fourth conduit having a first end and a second end, the first end of the fourth conduit and the second end of the fourth conduit being in fluid communication, the second end of the fourth conduit being in fluid communication with the input of the flow director;

(h) a proportional valve having a first port and a second port, the first port being in fluid communication with the first end of the fourth conduit;

(i) a gas source being in fluid communication with the second port of the proportional valve;

(j) a pressure sensor which is in fluid communication with the fourth conduit and which produces a signal proportional to the pressure in the fourth conduit;

(k) operator input means which produce a signal proportional to the desired pressure level; and

(l) control means which control the proportional valve to maintain the pressure in the fourth conduit as indicated by the signal produced by the pressure sensor approximately equal to the desired pressure level as indicated by the signal produced by the operator input means.

2. The system of claim 1 wherein the flow director is a one-way valve.

3. The system of claim 1 wherein the flow director is a hydrophobic membrane.

4. The system of claim 1 wherein the pump is a peristaltic pump.

5. The system of claim 1 wherein the gas source is the atmosphere.

6. The system of claim 1 wherein the fourth conduit further communicates with an orifice disposed between the fourth conduit and the gas source.

7. A surgical aspiration system comprising:

a conduit which communicates with a surgical site from which fluid is to be aspirated;

a first portion of connective plumbing disposed in fluid communication with the conduit;

a second portion of connective plumbing disposed in fluid communication with the first section;

a flow director connecting in fluid flowing relation the first and second portions of connective plumbing, and wherein the flow director permits fluid movement in the direction from the second portion to the first portion;

a collector for receiving aspirated fluid from the conduit and which is connected in fluid flowing communication with the first portion of the plumbing;

a pump for inducing the flow of aspirated fluid from the conduit to the collector, and which is disposed in fluid communication with the first portion of the connective plumbing;

a pressure sensor disposed in fluid flowing relation relative to the second portion of the connective plumbing;

a variable flow resistor disposed in fluid flowing relation relative to the second portion of the connective plumbing;

a gas source connected in fluid flowing relation relative to the variable flow resistor to provide a known pressure against which pressure in the remainder of the connective plumbing is compared to establish a pressure differential;

operator input means which produces a signal proportional to a user selected pressure level; and

control means for adjusting the variable flow resistor and the pump for use in first and second modes of operation, and wherein the control means is disposed in signal receiving relation relative to the pressure sensor, and wherein in the first mode of operation, the variable flow resistor is adjusted to maintain a preselected pressure conveyed by the conduit which is approximately equal to the preselected pressure level as indicated by the operator input means, and in the second mode of operation the control means adjusting the pump to maintain a predetermined flow according to the pressure differential as established in the connective plumbing.

8. A surgical aspiration system as claimed in claim 7, and wherein the flow director is a one-way valve.

9. A surgical aspiration system as claimed in claim 7, and wherein the flow director is a hydrophobic membrane.

10. A surgical aspiration system as claimed in claim 7, and wherein the pump is a peristaltic pump.

11. A surgical aspiration system as claimed in claim 7 and wherein the gas source is the atmosphere.

12. A surgical aspiration system as claimed in claim 7, and wherein the first portion of the plumbing is detachable from the second portion.