METHOD AND SYSTEM FOR MEASURING CHEST PARAMETERS, ESPECIALLY DURING CPR

• US 20120191014A1
• Filed: 11/09/2010
• Published: 07/26/2012
• Est. Priority Date: 11/11/2009
• Status: Active Grant

• Current Assignee: Laerdal Medical AS (Laerdal Medical Corporation)
• Original Assignee: Laerdal Medical AS (Laerdal Medical Corporation)
• Inventors: Fossan, Helge
• Granted Patent: US 9,649,251 B2
• Time in Patent Office: Days
• US Class Current: 600/587
• CPC Class Codes: A61H 31/004 Heart stimulation
• CPC Class Codes: A61H 31/005 with feedback for the user

Abstract

This invention relates to a system for monitoring the position of a measuring unit when placed on a person, especially on the chest of a person, the system comprising a drive unit generating a magnetic field oscillating at a predetermined frequency adapted to be positioned on the opposite side of the person, e.g. chest to back dimensions, and the measuring unit being adapted to measure the magnetic field strength, the system including calculating means for calculating the distance between the measuring unit and the drive unit.

Claims

1. A system for monitoring position of a measuring unit when placed on a person, the system comprising:

a drive unit generating a magnetic field oscillating at a predetermined frequency adapted to be positioned on an opposite side of the person, wherein the measuring unit is adapted to measure a magnetic field strength;

calculating means for calculating a distance between the measuring unit and the drive unit, wherein the drive unit includes a secondary magnetic field sensor measuring a the generated field strength; and

adjustment means adjusting an input to the drive unit until the generated field strength obtains a the predetermined strength at the secondary magnetic field sensor, thereby reducing influences of metal objects in the surroundings.

2. The system according to claim 1, wherein the drive unit is a backboard for positioning beneath a patient during CPR and the system being adapted to monitor the CPR compression depth based on a sequence of said position measurements.

3. The system according to claim 2, wherein said calculating means is adapted to compare the monitored compression depths with known recommended compression depths and generate a response indicating the quality of the compressions.

4. The system according to claim 2, wherein the system is adapted to measure the static distance between compressions.

5. The system according to claim 1, wherein the drive unit comprises a coil coupled to an AC current source.

6. The system according to claim 1, wherein the magnetic field variation is in the frequency range of 50-100 kHz thus avoiding absorption in water between the measuring unit and drive unit.

7. The system according to claim 6, wherein the drive frequency is the resonance frequency of the drive unit.

8. The system according to claim 1, wherein the secondary magnetic field sensor is a coil.

9. The system according to claim 1, wherein the measuring unit comprises an orientation measuring device measuring the tilt relative to the magnetic field.

10. The system according to claim 9, wherein the orientation measuring device is an accelerometer.

11. The system according to claim 1, further comprising a communication unit for varying amplitude of the varying magnetic field transmitted by the drive unit, the measuring unit being adapted to receive a communicated signal by detecting the varying amplitude.

12. The system according to claim 1, wherein the measuring unit comprising an energy storage means for extracting energy from said varying magnetic field and storing it in said unit.

13. The system according to claim 1, wherein the measuring unit comprising an energy storage means and coupling means for coupling to a charger adapted to charge the energy storage means when coupled to a corresponding charger.

14. The system according to claim 1, wherein the calculation means comprises analyzing means for comparing information of said distance before and after chest compressions, so as to detect chest collapse or molding.

15. Use of the system according to claim 1 for measuring the depth of the chest of a by measuring the distance between the measuring unit and the drive unit.