SYSTEM AND METHODS FOR MANAGING BLOOD LOSS OF A PATIENT

• US 20190008427A1
• Filed: 04/02/2018
• Published: 01/10/2019
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: Gauss Surgical, Inc. (Stryker Corporation)
• Original Assignee: Gauss Surgical, Inc. (Stryker Corporation)
• Inventors: SATISH, Siddarth, ZANDIFAR, Ali, MILLER, Kevin J
• Granted Patent: US 10,863,933 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 5/0082 adapted for particular medical purposes
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• CPC Class Codes: A61B 5/02042 Determining blood loss or bleeding, e.g. during a surgical procedure
• CPC Class Codes: A61B 5/14535 for measuring haematocrit
• CPC Class Codes: A61B 5/4848 Monitoring or testing the effects of treatment, e.g. of medication
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• 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: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01N 2015/1472 with colour
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: G16H 30/40 for processing medical images, e.g. editing

Abstract

One variation of the method for managing blood loss of a patient includes: receiving an image of a physical sample; extracting a feature from an area of the image corresponding to the physical sample; estimating a blood volume indicator of the physical sample according to the extracted feature; estimating a patient blood loss based on the blood volume indicator; estimating a euvolemic patient hematocrit based on an estimated patient blood volume and the estimated patient blood loss; receiving a measured patient hematocrit; and generating a volemic status indicator based on a comparison between the measured patient hematocrit and the estimated euvolemic patient hematocrit.

Claims

1-17. -17. (canceled)

18. A method for managing blood loss of a patient, comprising:

tracking a quantity of a fluid administered to the patient intravenously;

receiving an image of a physical sample;

extracting a feature from an area of the image correlated with the physical sample;

estimating a red blood cell content of the physical sample based on the extracted feature;

estimating an extracorporeal blood content of the physical sample based on the estimated red blood cell content of the physical sample; and

estimating a hematocrit of the patient based on a previous hematocrit of the patient, the quantity of the fluid administered to the patient, and the estimated extracorporeal blood content of the physical sample.

19. The method of claim 18, wherein tracking the quantity of the fluid administered to the patient intravenously comprises tracking the quantity of a known composition administered to the patient according to a transfusion rate, wherein estimating hematocrit of the patient comprises estimating the hematocrit of the patient further based on the known composition of the fluid.

20. The method of claim 18, wherein extracting the feature from the area of the image correlated with the physical sample comprises extracting a subset of pixels from a set of pixels within the area of the image.

21. The method of claim 20, wherein receiving the image of the physical sample comprises receiving an image of a surgical sponge gauze and correlating a time stamp of the image with a time of use of the surgical sponge gauze, wherein estimating the extracorporeal blood content of the physical sample comprises converting the estimated red blood cell content of the physical sample into an extracorporeal blood volume according to a patient hematocrit estimated at a time approximate the time of use of the surgical sponge gauze.

22. The method of claim 18, wherein receiving the image of the physical sample comprises receiving a set of sequential images of a surgical suction canister, wherein estimating the extracorporeal blood content of the physical sample comprises estimating the extracorporeal blood content of the surgical suction canister according to estimates of the volume of the surgical suction canister based on each image in the set of sequential images, estimated hematocrits of the patient based on each image in the set of sequential images, and estimated red blood cell contents of the surgical suction canister based on each image in the set of sequential images over time.

24. The method of claim 20, wherein estimating the red blood cell content of the physical sample comprises matching the subset of pixels with a template image in a library of template images.

25. The method of claim 24, wherein the template images include pixels tagged with known hemoglobin or red blood cell content.

26. The method of claim 20, wherein extracting the feature from the area of the image comprises extracting at least one feature of the subset of pixels, and estimating the red blood cell content of the physical sample comprises transforming the at least one feature into a red blood cell content of the physical sample according to a parametric model.

27. The method of claim 26, wherein the parametric model relates the at least one extracted feature to a hemoglobin concentration value correlatable to an estimated red blood cell content.

28. The method of claim 18, wherein the extracted feature is a color-related value.

29. The method of claim 18, wherein estimating the extracorporeal blood content comprises estimating an extracorporeal blood volume based on the estimated red blood cell content and a static patient hematocrit value.

30. The method of claim 18, wherein estimating the extracorporeal blood content comprises estimating a blood volume based on the estimated red blood cell content and a dynamic patient hematocrit value.

31. The method of claim 18, further comprising tracking the estimated hematocrit of the patient over time.

32. The method of claim 18, further comprising triggering an alarm in response to the estimated hematocrit of the patient being outside a predefined range.

33. The method of claim 18, further comprising tracking total estimated extracorporeal blood content across multiple physical samples.

34. The method of claim 33, further comprising triggering an alarm in response to the total estimated extracorporeal blood content being outside an acceptable range.

35. The method of claim 18, further comprising displaying the estimated hematocrit of the patient.

23. (canceled)