Method and apparatus for locating a person who has been buried alive

#This application claims priority of European Application No. 05015558, filed Jul. 18, 2005.

#The present invention relates to a method and to an apparatus for locating a person who has been buried while alive, in particular one who has been covered in snow by an avalanche.

#A method of finding such buried people, which has become standard in particular for locating avalanche victims, is to search according to the transmitter-receiver principle. That is, a wireless transmitter carried by the buried person sends out signals that are received by a searcher, or a group of searchers, by means of a wireless receiver. To achieve a high degree of compatibility between an arbitrary number of transmitters and receivers, a standardized signal characteristic is employed. In the case of avalanche searches, for example, a frequency of 457 kHz is used.

#FIG. 1 is a diagram of an exemplary embodiment of an appliance with which to search for people buried by avalanches, with a display device.

#FIG. 2 shows a first way to represent locality information for display in the display device of FIG. 1, where the search apparatus is in a point-localization phase of operation and the apparatus is moving further away from a buried transmitter.

#FIG. 3 shows a second way to represent locality information for display in the display device of FIG. 1, where the search apparatus is in the point-localization phase of operation and the apparatus is moving closer to the buried transmitter.

#FIG. 1 is a schematic representation of an embodiment of an apparatus of the present invention which serves to locate a person who has been buried alive. In particular, this drawing represents a search appliance 10 for locating people buried by avalanches. This search appliance 10 has a display device 20 for displaying at least one item of locality information which aids a user of the search appliance 10 in finding the buried person. The search appliance 10 also has a receiver 11 with a directional characteristic to receive signals transmitted from a transmitter (not shown) carried by a buried person. A processing device 12 is provided for analyzing the received signals and determining from the signals current locality information, including at least a current target distance and preferably the directionality of the signal with respect to the search appliance 10. A control means 21 drives the display device 20, which presents information relating to the location of the buried person with respect to the search appliance 10. The search appliance 10 also has a storage device 13 having an addressable memory for storing at least one previously acquired item of locality information in memory. The memory preferably has the capacity to store at least the current target distance, the smallest target distance observed to date, and data needed to establish a symbolic comparison of the current target distance to a recent prior observed distance. The search appliance 10 also has a deletion device 14 for deleting at least one previously acquired item of locality information. The deletion device 14 may take the form of hardware, and be operated manually, or alternatively, and preferably, is automatically operated with software. When software is employed, one can delete previous data by reinitializing the storage location containing the data. The search appliance 10 is provided with a discrimination means 22 that analyzes signal strength with respect to a predetermined threshold value and, based on this analysis, the search appliance 10 enters a search phase or a point-localization phase, processing the received signals according to the phase in which the search appliance 10 is operating and providing an appropriate display according to the phase in which the search is being conducted. It is preferred to incorporate an actuation device 23 with which to manually input commands such as turning the search appliance 10 on or off.

#The display device 20 shows representations of locality information such as can be seen in FIGS. 2-9. The display device 20 can also, when appropriate software is provided for the search appliance 10, show additional information, such as a current temperature, a current altitude, a time of day, a search time, current battery condition, or any other information that may be desired.

#The search appliance 10 shown in FIG. 1 can operate in either a search phase or in a point-localization phase, and the discrimination means 22 determines which phase is appropriate at any given time. The search phase is suitable for determining the approximate position of the buried person, while the point-localization phase serves to specify the exact position of the buried person. The determination of which phase the search appliance 10 operates in is discussed below and, in particular, with regard the discussion of FIGS. 10 and 11.