Abstract: There is provided a method of measuring the distance between a first device and a second device, the method comprising performing a time-of-flight-based distance measurement to measure the distance between the first device and the second device, wherein the length of the signals transmitted and/or the number of time-of-flight measurements obtained during the time-of-flight-based distance measurement is determined according to an accuracy level required for the distance measurement.

Abstract: The present invention relates to a medical needle which comprises an elongate tube and at least one optical fiber, e.g. two fibers, arranged within the elongate tube, for making optical measurements at the distal end of the needle. The optical fibers(s) has a beveled distal end surface, wherein a plane touching the beveled distal end surface and a longitudinal extension axis of the optical fiber forms a bevel angle which is 30°-35°. Such needle is advantageous for providing a medical needle which is reliable and long term stable, can be manufactured in low cost using known optical fiber materials, thus allowing it to form part of disposable medical kits. Still, the bevel angle of 30°-35° provides a needle which is easy to insert and which provides a low tendency to cause tissue sticking. Especially, the elongate tube and the optical fiber end(s) have the same beveled angle within the range 30°-35°, thus allowing a smooth front surface of the needle.

Abstract: A system (10) and a method (150) track a tracking device (14). A radio frequency (RF) receiver (52) is configured to receive a periodic beacon signal originating at the tracking device (14). The periodic beacon signal is received with a directional antenna (36) at multiple bearings over time. An estimator (70) is configured to estimate a bearing to the tracking device (14) as the bearing of the multiple bearings in which a time of flight (ToF) of the periodic beacon signal is lowest. The RF receiver (52) can further be configured to simultaneously receive multiple instances of the periodic beacon signal with the directional antenna (36) at a bearing of the multiple bearings. In such instances, the RF receiver (52) is further configured to correlate the instances to identify which of the instances has a lowest ToF.