Magnetic enhancement in determination of physiological blood parameters

• US 9,326,684 B2
• Filed: 11/08/2011
• Issued: 05/03/2016
• Est. Priority Date: 11/08/2011
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Wood, Lockett E.
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Liu, Chu Chuan (JJ)
• Application Number:
  US13/291,751
• Publication Number:
  US 20130116519A1
• Time in Patent Office: 1,638 Days
• Field of Search: 600/309, 600/310, 600/322, 600/323, 600/324, 600/326, 600/328, 600/333, 600/340, 600/344, 600/473, 600/476, 600/407, 600/421, 600/410, 356/41
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/6816 Ear lobe
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6828 Leg

Abstract

Systems and methods for measuring a physiological parameter of blood in a patient are provided herein. An example method includes establishing with a magnetic array, an first magnetic field along tissue of the patient inserted into the magnetic array and a second magnetic field perpendicular to the tissue, emitting optical signals into further tissue of the patient during at least a first alignment of the magnetic array around the tissue, detecting characteristics of the optical signals, and identifying a value of a physiological parameter based on at least the characteristics of the optical signals.

Claims

1. A system for measuring a physiological parameter of blood in a patient, the system comprising:

a magnetic array having an opening therein configured to have tissue of the patient inserted therein and simultaneously establish in the tissue an axial magnetic field and a radial magnetic field perpendicular to the axial magnetic field;

an emitter configured to emit a first optical signal into the tissue during a first angular configuration between the emitter and the magnetic array, and emit a second optical signal into the tissue during a second angular configuration between the emitter and the magnetic array the second angular configuration being different from the first angular configuration;

a detector configured to detect characteristics of the first optical signal and the second optical signal;

a user interface; and

a processing module configured to;

calculate a differential of the characteristics of the first and the second optical signals;

identify a value of a physiological parameter from the differential; and

display the physiological parameter on the user interface.

2. The system of claim 1, wherein the magnetic array comprises a central hole configured to have the tissue of the patent inserted therein, and wherein the axial magnetic field and the radial magnetic field are established within the central hole.

3. The system of claim 1, wherein the physiological parameter comprises a total hemoglobin parameter of the blood of the patient.

4. The system of claim 1, wherein the characteristics of the first optical signal and the second optical signal comprise an amplitude of the first optical signal and the second optical signal after scattering through the tissue.

5. The system of claim 1, wherein the magnetic array comprises a composite array of permanent magnets forming a central hole, wherein the permanent magnets are organized so both the axial magnetic field and the radial magnetic field are observed in the central hole.

6. The system of claim 1, wherein the tissue comprises a digit of the patent, and wherein the digit is inserted to a first distance into a central hole of the magnetic array for application of the axial magnetic field and the radial magnetic field at the first distance along the digit, and wherein the first optical signal and the second optical signal are each applied at a second distance along the digit.

7. The system of claim 1, wherein the first angular configuration between the emitter and the magnetic array is correlated to a first intensity of the first optical signal and a second intensity of the second optical signal, wherein the second angular configuration between the emitter and the magnetic array is correlated to a second intensity of the first optical signal and a first intensity of the second optical signal, and wherein the first intensity is greater than the second intensity.

8. The system of claim 1, wherein the emitter is configured to emit the first optical signal and the second optical signal over an optical fiber into the tissue, and wherein the detector is configured to detect the characteristics of the first optical signal and the second optical signal over optical sensors arranged on the tissue.

9. A method for measuring a physiological parameter of blood in a patient, the method comprising:

simultaneously establishing within tissue of the patient inserted into a magnetic array an axial magnetic field and a radial magnetic field perpendicular to the axial magnetic field;

emitting optical signals into the tissue during at least a first angular configuration and a second angular configuration between the magnetic array and the optical signals;

detecting characteristics of the optical signals at both the first and second angular configurations between the magnetic array and the optical signals;

identifying a differential using at least the characteristics of the optical signals which vary when measured in the first and second angular configurations between the magnetic array and the optical signals;

identifying a value of a physiological parameter using the differential; and

in a user interface, receiving the value of the physiological parameter and displaying the value of the physiological parameter.

10. The method of claim 9, wherein the magnetic array comprises a central hole configured to have the tissue of the patent inserted therein, and wherein the axial magnetic field and the radial magnetic field are established within the central hole.

11. The method of claim 9, wherein the physiological parameter comprises a total hemoglobin parameter of the blood of the patient.

12. The method of claim 9, wherein the characteristics of the optical signals comprise an amplitude of the optical signals after scattering through the tissue.

13. The method of claim 9, wherein the magnetic array comprises a composite array of permanent magnets forming a central hole, wherein the permanent magnets are organized so both the axial magnetic field and the radial magnetic field are observed in the central hole.

14. The method of claim 9, wherein the tissue comprises a digit of the patent, and wherein the digit is inserted to a first distance into a central hole of the magnetic array for application of the axial magnetic field and the radial magnetic field at the first distance along the digit, and wherein the optical signals are applied at a second distance along the digit.

15. The method of claim 9, wherein emitting the optical signals into the tissue comprises emitting a first optical signal into the tissue at a first position and emitting a second optical signal into the tissue at a second position, wherein the first position and the second position are oriented orthogonally along the tissue.

16. The method of claim 9, wherein emitting the optical signals into the tissue comprises emitting the optical signals over optical fibers into the tissue, and wherein detecting the characteristics of the optical signals comprises detecting the characteristics of the optical signals over optical sensors arranged on the tissue.

17. A system for measuring a physiological parameter of blood in a patient, the system comprising:

a magnetic array comprising an central hole configured to have a digit of the patient inserted therein, the magnetic array configured to simultaneously establish within the central hole a first magnetic field along the length of an inserted digit and a second magnetic field perpendicular to the inserted digit;

a transceiver module configured to emit a first optical signal into tissue of the digit during an initial alignment of the magnetic array around the inserted digit, and emit a second optical signal into the tissue of the digit during a rotated alignment of the magnetic array around the inserted digit, the rotated alignment being different from the initial alignment;

the transceiver module configured to detect characteristics of the first optical signal and the second optical signal through the tissue of the digit;

a processing module configured to;

identify a differential using at least the characteristics of the first optical signal and the characteristics of the second optical signal which vary when measured in the initial alignment and the rotated alignment of the magnetic array around the inserted digit; and

identify a value of a physiological parameter using the differential; and

a user interface configured to receive the value of the physiological parameter and display the value of the physiological parameter.