Introducer sheath with electrodes for use in bleed detection

• US 9,700,216 B2
• Filed: 06/10/2015
• Issued: 07/11/2017
• Est. Priority Date: 01/04/2008
• Status: Active Grant

• Current Assignee: Texas Heart Institute
• Original Assignee: Texas Heart Institute
• Inventors: Arevalos, Christopher Alexander, Razavi, Mehdi, Brewer, Maurice Alan
• Primary Examiner(s): Ghafoorian, Reza
• Application Number:
  US14/735,523
• Publication Number:
  US 20150272451A1
• Time in Patent Office: 762 Days
• CPC Class Codes: A61B 5/02042 Determining blood loss or bleeding, e.g. during a surgical procedure
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/07 Endoradiosondes
• CPC Class Codes: A61B 5/6851 Guide wires
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61M 25/0662 Guide tubes

Abstract

An introducer includes a sheath for introducing a catheter into a blood vessel at an insertion site and a plurality of electrodes on the sheath. The introducer also includes an impedance assessment unit connected to the electrodes. The impedance assessment unit includes a power source and a wireless transceiver and is configured to inject one of a predetermined current or voltage across a first pair of electrodes and to measure the other of the current or voltage across a second pair of electrodes. The impedance assessment unit also is configured to perform at least one: wirelessly transmit current and voltage values to an external apparatus for detection of a bleed, and compute an impedance based on the current and voltage and wirelessly transmit the computed impedance to the external apparatus for detection of the bleed.

Claims

1. An introducer, comprising:

a sheath for introducing a catheter into a blood vessel at an insertion site;

a plurality of electrodes on the sheath; and

an impedance assessment unit connected to said electrodes, said impedance assessment unit includes a power source and a wireless transceiver and is configured to;

inject one of a predetermined current or voltage across a first pair of electrodes and to measure the other of the current or voltage across a second pair of electrodes; and

perform at least one;

wirelessly transmit current and voltage values to an external apparatus for detection of a bleed, and compute an impedance based on the current and voltage and wirelessly transmit the computed impedance to the external apparatus for detection of the bleed.

2. The introducer of claim 1 wherein the impedance assessment unit is configured to serially inject the predetermined current or voltage at multiple predetermined frequencies.

3. The introducer of claim 1 wherein the wireless transceiver in the impedance assessment unit is a bi-directional wireless transceiver.

4. The introducer of claim 3 wherein the impedance assessment unit is configured to receive a command via the wireless transceiver to initiate injection of the predetermined current or voltage.

5. The introducer of claim 3 wherein the impedance assessment unit is configured to receive a command via the wireless transceiver to program an amplitude or frequency of the current or voltage.

6. The introducer of claim 1 wherein the impedance assessment unit is configured to compute multiple impedance values and average the multiple impedance values together.

7. The introducer of claim 1 wherein the impedance assessment unit is configured to compute multiple impedance values and compare the multiple impedance values to a previously computed impedance value.

8. The introducer of claim 1 wherein the impedance assessment unit is configured to compute multiple impedance values and compute a time rate of change of the computed impedance values relative to a previously computed impedance value.

9. An apparatus, comprising:

an introducer usable to insert a catheter into a blood vessel, said introducer comprising a hollow sheathe to receive the catheter when inserting the catheter into the blood vessel;

a first electrode provided on the sheathe;

a second electrode; and

a measuring device to which the first and second electrodes are coupled, the measuring device to detect a blood clot by measuring the impedance or conduction velocity between the first electrode on the sheathe and the second electrode.

10. The apparatus of claim 9, wherein the sheath comprises a tubular member and the first electrode is provided on a surface of the tubular member.

11. The apparatus of claim 10, wherein the measuring device is to detect a blood clot within the tubular member by measuring the impedance or conduction velocity between the first electrode and the second electrode.

12. The apparatus of claim 9, wherein the second electrode is provided on the sheathe.

13. The apparatus of claim 9, wherein the measuring device is to detect a blood clot by comparing the impedance or conduction velocity to a threshold.