초록 ▼

A system for locating objects in space, such as medical instruments within the body of a patient, based upon transmission of magnetic fields from coils in a fixed frame of reference to sensors on the object or visa-versa. The current supplied to the coils is adjusted to assure that the sensors recei

A system for locating objects in space, such as medical instruments within the body of a patient, based upon transmission of magnetic fields from coils in a fixed frame of reference to sensors on the object or visa-versa. The current supplied to the coils is adjusted to assure that the sensors receive fields within a preselected range of magnitudes regardless of the location of the object in space. This assures that the sensor operates within its optimum range, and permits use of compact transmitters and sensors.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for determining position comprising:(a) field generating means for producing a plurality of magnetic fields, each said field having parameters varying with location within a sensing volume according to a known pattern of variation, said patterns of variation bei

[ What is claimed is:] [1.] Apparatus for determining position comprising:(a) field generating means for producing a plurality of magnetic fields, each said field having parameters varying with location within a sensing volume according to a known pattern of variation, said patterns of variation being different for different ones of said fields;(b) at least one sensor adapted to detect one or more of said parameters of said fields generated by said field generating means prevailing at such sensor when said sensor is at an unknown location within said sensing volume and to provide one or more sensor signals representing said one or more parameters;(c) calculation means for determining a calculated location of said sensor based upon said sensor signals and said known patterns of variation; and(d) feedback control means for adjusting said field generating means to alter said known pattern of variation of at least one of said fields responsive to said sensor signals, said calculated location or both so as to maintain said parameters of each such altered field prevailing at said sensor within a preselected range.