Position determination system

• US 9,310,207 B2
• Filed: 10/20/2011
• Issued: 04/12/2016
• Est. Priority Date: 10/20/2010
• Status: Active Grant

• Current Assignee: Sonitor Technologies AS
• Original Assignee: Sonitor Technologies AS
• Inventors: Booij, Wilfred Edwin, Olsen, ysten Haug
• Primary Examiner(s): Tweel, Jr., John A
• Application Number:
  US13/880,928
• Publication Number:
  US 20130307696A1
• Time in Patent Office: 1,636 Days
• Field of Search: 340/686.6, 340/573.17, 340/539.12
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0026 characterised by the transmission medium
• CPC Class Codes: A61B 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: A61B 5/1117 Fall detection
• CPC Class Codes: A61B 5/6801 specially adapted to be attached to or worn on the body surface
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01C 5/06 by using barometric means
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/02585 at least one of the measurements being a non-radio measurement
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G08B 21/043 detecting an emergency event, e.g. a fall
• CPC Class Codes: G08B 21/18 Status alarms G08B21/02 takes precedence
• CPC Class Codes: H04W 48/04 : based on user or terminal location or mobility data, e.g. moving direction, speed
• CPC Class Codes: H04W 64/00 : Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A position determination system is provided comprising one or more fixed base units and one or more mobile units, wherein the system is arranged to determine the horizontal position of a mobile unit based on the proximity of said mobile unit to at least one base unit and wherein the system is arranged to determine the height of said mobile unit based on the air pressure sensed at the mobile unit and the air pressure sensed at one or more of the base units. The use of pressure sensors to determine height reduces the complexity of the infrastructure required for 3D positioning. The invention finds particular benefit in patient care and monitoring environments and in object tracking and inventory systems. The invention also extends to mobile units for use in the system, intelligent buildings fitted with the system and to methods of determining the position of mobile units.

Claims

1. A position determination system comprising one or more fixed base units and one or more mobile units, wherein the system is arranged to determine the position in the horizontal plane of a mobile unit using ultrasound and based on the proximity of said mobile unit to at least one base unit and wherein the system is arranged to determine the height of said mobile unit based on the air pressure sensed at the mobile unit and the air pressure sensed at one or more of the base units.

2. The position determination system as claimed in claim 1, wherein the system comprises a plurality of base units and wherein the system is arranged to determine a reference air pressure based on an average of the air pressures sensed at each of the plurality of base units.

3. The position determination system as claimed in claim 1, wherein the system comprises at least one height reference base unit and wherein the system is arranged such that when a mobile unit is determined to be within a certain proximity of said height reference base unit the system determines that the mobile unit is at a predetermined mobile unit reference height.

4. The position determination system as claimed in claim 3, wherein in response to said proximity determination, the system instructs the mobile unit to perform a calibration based on the mobile unit reference height.

5. The position determination system as claimed in claim 1, wherein the system comprises a height calibration zone, said height calibration zone comprising a plurality of base units positionally arranged so as to be capable of determining the height of a mobile unit based on the proximity of said mobile unit to each of said plurality of base units.

6. The position determination system as claimed in claim 5, wherein in response to said height determination, the system instructs the mobile unit to perform a calibration based on the determined height.

7. The position determination system as claimed in claim 1, wherein the system is arranged to raise an alarm based on one or more criteria being met by a mobile unit.

8. The position determination system as claimed in claim 7, wherein one criterion is based on the current height of said mobile unit.

9. The position determination system as claimed in claim 7, wherein one criterion is based on a detected change in height of said mobile unit.

10. The position determination system as claimed in claim 7, wherein the alarm is arranged to indicate an identification of said mobile unit and a current position of said mobile unit.

11. The position determination system as claimed in claim 7, wherein the alarm criteria depend on the current position of said mobile unit.

12. The position determination system as claimed in claim 1, wherein said base unit and said mobile unit are arranged to communicate via ultrasound.

13. The position determination system as claimed in claim 1, wherein said base unit and said mobile unit are arranged to communicate via radio communication.

14. The position determination system as claimed claim 1, wherein the height determination of the mobile unit based on pressure data is combined with height determination based on proximity to the base units.

15. The position determination system as claimed in claim 1, wherein a stationary mobile unit is arranged to act as an additional base unit.

20. The position determination system as claimed in claim 1, comprising a mobile unit as claimed in claim 16.

21. A building comprising a position determination system as claimed in any of claim 1, said building comprising one or more monitoring zones for positioning mobile units, wherein at least one monitoring zone comprises only one base unit.

22. The building as claimed in claim 21, wherein one or more monitoring zones each correspond to a room within the building.

23. The building as claimed in claim 21, wherein said position determination system is adapted to receive data from one or more sensors within said building, said sensors including at least one of a light switch sensor, a motion sensor, a door sensor and a telephone activity sensor.

24. The building as claimed in claim 23, wherein the position determination system as adapted to raise an alarm based on one or more criteria being met by a mobile unit and based on the output of said building sensors.

16. A mobile unit for use in a position determination system, said mobile unit comprising an ultrasound transmitter or an ultrasound receiver for determining position in the horizontal plane, an air pressure sensor and a transmitter adapted to transmit data from said air pressure sensor to said system.

17. The mobile unit as claimed in claim 16, wherein said mobile unit comprises a receiver and wherein said unit is adapted to transmit position data including at least data from said pressure sensor.

18. The mobile unit as claimed in claim 17, wherein said mobile unit is adapted to receive a calibration instruction and in response to said calibration instruction said mobile unit is adapted to calibrate said pressure sensor.

19. The mobile unit as claimed in claim 18, wherein said calibration instruction includes at least a reference pressure or a reference height.

25. A method of determining the position of a mobile unit relative to one or more fixed base units, comprising:

measuring the air pressure at the position of said mobile unit;

measuring the air pressure at the position of said base units;

measuring the proximity of the mobile unit to said base units using ultrasound;

determining the position in the horizontal plane of said mobile unit based on said proximity measurements; and

determining the height of said mobile unit based on said air pressure measurements.