Ultrasonic and optical tracking method and system for small animal research

A method of detecting the position of an animal, the method comprising:

• positioning at least one optical transmitter with known location within the animal position measurement field to generate an anisotropic light beam with different light intensities in different directions that is radially emitted from a localized source and can be moved through the animal position measurement field;
• positioning at least one strobe light source to generate a strobe pulse to illuminate said animal position measurement field;
• moving the anisotropic light beam through the animal position measurement field repeatedly along a known trajectory and with a known speed;
• illuminating the animal position measurement field by strobe pulse at a known time;
• attaching a mobile device to the animal;
• receiving, by the mobile device with the help of a light sensor, the light of the optical transmitter and the strobe pulse emitted by the strobe light source;
• determining the animal position using:
• the time difference between the mobile device receiving the anisotropic light beam from the optical transmitter with known location and the strobe pulse;
• information on the location of the optical transmitter at the time the mobile device receives the anisotropic light beam.

A method of detecting the position of a mobile device, comprising:

• positioning at least one optical transmitter with a known location within the mobile device position measurement field to generate an anisotropic light beam with different light intensities in different directions that is radially emitted from a localized source and can be moved through said mobile device position measurement field;
• positioning at least one ultrasonic emitter with a known location within the mobile device position measurement field to generate an ultrasonic signal propagating through said mobile device position measurement field;
• positioning at least one strobe light source to generate a strobe pulse to illuminate said mobile device position measurement field;
• moving the anisotropic light beam through said mobile device position measurement field repeatedly along a known trajectory and with a known speed;
• illuminating said mobile device position measurement field by strobe pulse at a known time;
• receiving, by the mobile device with the help of a light sensor, the light pulse of the anisotropic light beam emitted by the optical transmitter and the strobe pulse emitted by the strobe light source;
• receiving, by the mobile device at a receipt time, the ultrasonic signal emitted from the ultrasonic emitter;
• determining the mobile device position using:
• the time difference between the mobile device receiving the anisotropic light beam from the optical transmitter and the strobe pulse;
• the time difference between the mobile device receiving the ultrasonic signal and strobe pulse;
• information on the location of the optical transmitter at the time the mobile device receives the anisotropic light beam;
• information on the location of the ultrasonic emitter at the time of emission of the ultrasonic signal by the ultrasonic emitter.

A system for detecting the position of an animal comprising:

• a plurality of ultrasonic emitters with known locations, each of which is configured to generate an ultrasonic signal at a predetermined time, wherein the ultrasonic signal frequency is chosen to be higher than the frequency of possible animal vocalization;
• and
• a mobile device attached to the tracked animal, wherein the mobile device is configured to receive ultrasonic signals from at least part of the plurality of ultrasonic emitters with known location and to convert them to electrical signal;
• and
• a signal managing block separating the received ultrasonic signals from the vocalizations of the animal using differences in frequencies;
• and
• a processing module computing the time difference of ultrasonic signal arrivals to the mobile device in order to determine the position of the animal.

A system for detecting position of an animal comprising:

• at least one optical transmitter positioned within an animal position measurement field to generate an anisotropic light beam that is radially emitted from a localized source, means of moving said anisotropic light beam through the animal position measurement field along a known trajectory with known speed, and
• at least one strobe light source to generate a strobe pulse to illuminate said animal position measurement field;
• a mobile device attached to the tracked animal, wherein the mobile device is configured to receive illumination from the anisotropic light beam and the strobe pulse;
• and
• a processing module computing the time difference of the anisotropic light beam detection and the strobe pulse detection.

A mobile device position measurement system, comprising:

• at least one optical transmitter positioned within a mobile device position measurement field to generate an anisotropic light beam that is radially emitted from a localized source, means of moving said anisotropic light beam through the mobile device position measurement field along a known trajectory with known speed, and
• at least one strobe light source to generate a strobe pulse to illuminate said mobile device position measurement field;
• at least one ultrasonic emitter positioned within the mobile device position measurement field to generate an ultrasonic signal propagating through said mobile device position measurement field;
• a mobile device attached to a tracked object, wherein the mobile device is configured to receive illumination from the anisotropic light beam and the strobe pulse, and the ultrasonic signal;
• and
• a processing module computing the time difference of the anisotropic light beam detection and the strobe pulse detection, and the time difference of the ultrasonic signal detection and the strobe pulse detection.