Low pressure measurement devices in high pressure environments

• US 20030122095A1
• Filed: 12/09/2002
• Published: 07/03/2003
• Est. Priority Date: 12/07/2001
• Status: Active Grant

• Current Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Original Assignee: ACIST Medical Systems Incorporated (Bracco SPA)
• Inventors: McPeak, Thomas, Wilson, Robert F., Gabbard, Mark, Duchon, Douglas J., Mohiuddin, Khader
• Granted Patent: US 7,389,788 B2
• Time in Patent Office: Days
• US Class Current: 251/12
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: A61M 5/007 for contrast media
• CPC Class Codes: F16K 15/1402 having an integral flexible member cooperating with a plurality of seating surfaces
• CPC Class Codes: F16K 15/144 the closure elements being fixed along all or a part of their periphery
• CPC Class Codes: F16K 15/147 the closure elements having specially formed slits or being of an elongated easily collapsible form
• CPC Class Codes: Y10T 137/0318 Processes
• CPC Class Codes: Y10T 137/2567 Alternate or successive inflows
• CPC Class Codes: Y10T 137/784 Integral resilient member forms plural valves
• CPC Class Codes: Y10T 137/7843 Integral resilient member forms plural valves
• CPC Class Codes: Y10T 137/7879 Resilient material valve
• CPC Class Codes: Y10T 137/7881 Apertured plate
• CPC Class Codes: Y10T 137/87676 With flow control
• CPC Class Codes: Y10T 29/49405 Valve or choke making

Abstract

The present invention presents various novel approaches to solving the problems inherent in measuring biological pressures in high pressure systems. Thus, to protect a pressure transducer exposed to fluid flows at higher pressures than its overpressure rating, a novel valve is used that closes a protected leg in which the transducer is located. The various exemplary embodiments of such valves each have a high pressure input, one or more low pressure inputs, and an output. In operation, when a high pressure fluid flow occurs at a high pressure input, such valves automatically close the low pressure inputs. Alternatively, a novel transducer system is presented, which automatically limits the effective pressure sensed by a transducer to a certain maximum.

Claims

1. A fluid valve comprising:

a first input port;

one or more second input ports; and

an output port;

where, when a high pressure liquid flows through the first input port, any path from a second input port to the output port is blocked, and where a portion or all of the valve is an elastomere material.

2. The valve of claim 1, where the high pressure flow is injected into the first input port.

3. The valve of claim 1, where the valve is injection molded in one piece.

4. The valve of claim 1 where any path from a second output port to the output port is blocked due to a change in shape of an elastomeric portion of the valve.

5. The valve of claim 4, where there is a minimum cracking pressure necessary for the elastomeric portion to change its shape.

6. The valve of claim 5, where the cracking pressure is a function of a durometer and/or an elasticity of the elastomeric portion.

7. The valve of claim 6, where variation of the durometer and/or the elasticity allow for specification of the cracking pressure.

8. The valve of claim 1, further comprising:

a first tapered cavity provided in front of the first input port so as to receive fluid flow therefrom;

a second tapered cavity provided behind the output port so as to provide fluid flow thereto; and

an elastomeric disc portion between the first and second tapered cavities.

9. The valve of claim 8, where said elastomeric disc has an opening, which opens when a fluid in the first tapered cavity has a certain cracking pressure.

10. The valve of claim 9, where said opening comprises one or more slits.

11. The valve of claim 10, where said one or more second input ports open into said second tapered cavity.

21. The valve of claim 1, further comprising a transducer location, where, when when a high pressure liquid flows through the first input port, any path from said transducer locaiton to the output port is blocked.

12. A fluid valve, comprising:

a disc holder;

an elastomeric valve disc with a slit;

a valve body;

a first input port;

a set of one or more second input ports; and

an output port;

where, when the valve disc is in a closed state the first input port is isolated from the output port and the second input port; and

where, when the valve disc is in an open state the second input port is isolated from the output port and the first input port.

13. The valve of claim 12, where the state of the valve disc is determined by a pressure applied to it by a fluid flowing into the valve via the first input port.

14. The valve of claim 13, where the valve disc has at least one opening which open(s) when it enters the open state.

15. A bidirectional fluid valve, comprising:

a first input/output port;

one or more second input ports; and

a third input/output port;

where, when a high pressure liquid flows through the first input/output port, any path from a second input port to the third input/output port is blocked, and where all or a portion of the valve is elastomeric.

16. The valve of claim 15, where flow into the third input/output port and out of the first input/output port can only occurr when such flow is at or above a backflow pressure.

17. The valve of claim 16, where the valve is injection molded in one piece.

18. The valve of claim 15 where any path from a second input port to the third input/output port is blocked due to a change in shape of an elastomeric portion of the valve.

19. The valve of claim 16 where the backflow pressure causes a change in shape of an elastomeric portion of the valve.

20. A method of accurately measuring biological pressures in an environment where much higher pressures are also experienced, comprising:

exposing a low pressure sensor to biological pressures;

protecting said low pressure sensor from higher pressures,

where said protection comprises at least one of;

(a) isolating the low pressure sensor from fluid contact with high pressures; and

(b) limiting the pressure that can be applied to the sensor by high pressure flow.

22. A fluid pressure transducer, comprising:

a pressure sensor;

a sensor contact; and

a sensor contact limiter;

where in biological pressure regimes the pressure sensor measures the actual pressure, and in high pressure regimes the contact limiter causes the pressure sensor to see a fixed pressure which is less than the actual pressure.

23. The transducer of claim 30, further comprising an insertion assembly for insertion into high pressure tubing.

24. The transducer of claim 23, where said insertion assembly comprises a pressure transmission member, and an outer housing, where the outer housing protrudes into a tube, and the pressure transmission member is enclosed in the outer housing.

25. The transducer of claim 24, where the outer housing comprises an electrically conductive material.

26. The transducer of claim 25, further comprising an electrical contact, in electronic communication with the outer housing.

27. A method of accurately measuring biological pressures in an environment where much higher pressures are also experienced, comprising:

exposing a low pressure sensor to biological pressures;

protecting said low pressure sensor from higher pressures,

where said protection comprises isolating the low pressure sensor from fluid contact with high pressures, and where such isolation si achieved by at leat one of a rotary seal valve, a rotary seal valve with air pocket, a rotary seal valve with compressible material, a sleeve valve with orifice, or a shuttel valve with an additoinal sample/aspiration port.