Device and method for detecting irregular placement of an extracorporeal vascular access needle

• US 8,974,394 B2
• Filed: 01/07/2013
• Issued: 03/10/2015
• Est. Priority Date: 07/30/2001
• Status: Active Grant

• Current Assignee: Henry Ford Health System
• Original Assignee: Henry Ford Health System
• Inventors: Frinak, Stanley, Zasuwa, Gerard, Yee, Jerry, Besarab, Anatole, Kennedy, John B., Curry, Douglas S., Hirschman, Helen Kimball
• Primary Examiner(s): D'Angelo, Michael
• Assistant Examiner(s): JANG, CHRISTIAN YONGKYUN
• Application Number:
  US13/735,421
• Publication Number:
  US 20140024954A1
• Time in Patent Office: 792 Days
• Field of Search: 600/485, 340/573.1, 604 401- 616
• US Class Current: 600/485
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3641 Pressure isolators
• CPC Class Codes: A61M 1/3653 Interfaces between patient blood circulation and extra-corporal blood circuit
• CPC Class Codes: A61M 1/3655 Arterio-venous shunts or fistulae
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 5/16836 by sensing tissue properties at the infusion site, e.g. for detecting infiltration detecting tissue temperature for diagnostic purposes A61M39/0247

Abstract

A device and method for determining intravascular pressure and irregular needle placement in a hemodialysis procedure include analyzing means for automatically deriving venous access pressure (VAP) at a location of venous needle insertion into the patient and determining a ratio of VAP to mean arterial pressure, where the analyzing means determines multiple VAP values over multiple time periods and determines multiple ratios, one for each VAP value. Detecting means compare each ratio to a predetermined standard ratio derived from a moving average of prior VAP ratios, where the detecting means detects irregular needle placement when elevation of the ratio above the standard ratio is indicated.

Claims

1. A device for determining intravascular pressure and irregular placement of a vascular access needle retained within a vascular access site of a patient during a hemodialysis procedure, the device comprising:

an analyzer for automatically determining venous access pressure (VAP) at a location of venous needle insertion into the vascular access site of the patient and determining a ratio of VAP to mean arterial pressure, where the analyzer determines multiple VAP values over multiple time periods and determines multiple ratios, one for each VAP value; and

a comparator for comparing each ratio to a predetermined standard ratio derived from a moving average of prior VAP ratios, where the comparator indicates irregular placement of the retained vascular access needle within the vascular access site of the patient when the ratio is elevated above the standard ratio.

2. The device of claim 1, further comprising an alarm for communicating a warning when the comparator indicates irregular placement of the retained vascular access needle.

3. The device of claim 1, wherein the analyzer corrects VAP based on a relative height of a drip chamber and for a viscosity of blood.

4. The device of claim 1, wherein the comparator indicates irregular placement of the retained vascular access needle when the ratio is elevated at least two standard deviations above the standard ratio.

5. A device for detecting irregular placement of a vascular access needle retained within a vascular access site of a patient during a hemodialysis procedure using a dialysis machine, the device comprising:

an analyzer for automatically and continuously determining at an access pressure and at a location of needle insertion into the vascular access site of the patient and determining a ratio of access pressure to mean arterial pressure, where the analyzer determines multiple access pressure values over multiple time periods and determines multiple ratios, one for each access pressure value, respectively; and

a comparator for comparing the ratio during a current dialysis session for the patient to a moving average and normal variance of access pressure from at least one previous dialysis session, where the comparator indicates irregular placement of the retained vascular access needle within the vascular access site of the patient when the current ratio is outside of the normal variance.

6. The device of claim 5, wherein the access pressure includes a venous access pressure and the access pressure ratio includes a venous access pressure ratio.

7. The device of claim 5, wherein the access pressure includes an arterial access pressure and the access pressure ratio includes an arterial access pressure ratio.

8. The device of claim 5, further comprising an alarm for communicating a warning when the comparator indicates irregular placement of the retained vascular access needle.