Universal connector means for transducer/monitor systems

• US 5,193,547 A
• Filed: 12/22/1986
• Issued: 03/16/1993
• Est. Priority Date: 07/16/1984
• Status: Expired due to Term

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Baxter International Inc.
• Inventors: Norman, Jacob J., Phillips, H. Don, Evans, George D. II
• Primary Examiner(s): Shay, David M.
• Application Number:
  US06/945,381
• Time in Patent Office: 2,276 Days
• Field of Search: 128/900, 128/902, 128/673, 128/675, 128/748, 128/668, 330/1 R, 323/911
• US Class Current: 600/481
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit
• CPC Class Codes: H03F 3/45479 characterised by the way of common mode signal rejection
• CPC Class Codes: H03F 3/45959 Controlling the input circuit of the differential amplifier

Abstract

A system for monitoring physiological conditions in humans and other animals includes a transducer for monitoring such conditions as blood pressure, a monitor for displaying or recording signals from such transducers, or both, and a connector for linking the transducer to the monitor and for transforming the impedance level of signals from such transducer to levels appropriate for such monitors and for drawing and adapting power from the monitor for effecting this impedance transformation. The connector may also include a mechanism for adjusting the offset or sensitivity of the signal from the transducer, a mechanism for detecting the absence of the transducer, and a mechanism for detecting an open circuit between the monitor and the transducer. A connector may also include a device for converting power drawn from a monitor to direct current where the power drawn from the monitor is, before conversion, either sine wave or pulsed; a mechanism for regulating the current from the monitor; and a mechanism for eliminating common-mode voltage errors from the transducer signal.

Claims

1. A system for use in environment having electromagnetic interference to monitor blood pressure in living tissue, comprising:

a transducer for converting a blood pressure into an electrical signal, said transducer exhibiting an electrical output impedance;

electrical signal monitoring means having an input electrical impedance different form said electrical output impedance; and

electrical amplifying means having an input connected to the transducer and an output connected to the monitoring means, said input of said amplifying means having an impedance acceptability range including the electrical output impedance of the transducer and said output of said amplifying means having an output impedance compatible with the input impedance of the monitoring means.

2. A system for use in an environment having electromagnetic interference to monitor blood pressure in living tissue, comprising:

blood pressure transducing means having an electrical output signal and a transducer output impedance;

monitoring means having a monitor input impedance for monitoring signals from said blood pressure transducing means;

means for interconnecting said blood pressure transducing means and said monitoring means, said interconnecting means including means for matching the output impedance of said transducer means to a value compatible with the input impedance of said monitoring means; and

means for drawing power from said monitoring means for effecting said impedance matching.

3. The system of claim 2 wherein said blood pressure transducing means produces an output signal having an offset, said interconnecting means includes means for adjusting the offset of said blood pressure transducing means electrical output signal.

4. The system of claim 2 wherein the interconnecting means further comprises means for eliminating or minimizing common-mode voltage.

5. The system of claim 2 wherein the impedance of said blood pressure transducing means is in the range of about 50 to 8,000 ohms.

6. The system of claim 2 wherein the impedance of said blood pressure transducing means is in the range of about 50 to about one million ohms.