Abstract: A photodetector disclosed herein comprises an avalanche transistor having a reference junction structure in which temperature characteristics of a current amplification factor are about the same as those of an avalanche photodiode and which is reverse-biased, and a current injection junction structure which injects a reference current to the reference junction structure and which is forward-biased. Voltages to be applied to the avalanche photodiode and the reference junction structure are controlled so that the amplification factor of the reference current amplified in the reference junction structure is retained at a predetermined value, whereby the temperature characteristics of the photodetector utilizing an avalanche effect can be stabilized.

Abstract: A method for determining a position of a magnetic source includes measuring a magnetic field generated by the magnetic source and determining components of the three-dimensional magnetic flux density of the magnetic field at a plurality of points in space based on such measurement. The method also includes estimating a position of the magnetic source and determining components of a theoretical three-dimensional magnetic flux density at the plurality of points in space based on the estimated position. The position of the magnetic source may then be determined by minimizing the difference between the components of the measured and corresponding theoretical three-dimensional magnetic flux density components.

Abstract: A photodetector disclosed herein comprises an avalanche transistor having a reference junction structure in which temperature characteristics of a current amplification factor are about the same as those of an avalanche photodiode and which is reverse-biased, and a current injection junction structure which injects a reference current to the reference junction structure and which is forward-biased. Voltages to be applied to the avalanche photodiode and the reference junction structure are controlled so that the amplification factor of the reference current amplified in the reference junction structure is retained at a predetermined value, whereby the temperature characteristics of the photodetector utilizing an avalanche effect can be stabilized.

Abstract: A magnetic sensor array includes a first three-dimensional magnetic sensor secured to a substrate in a central location of the substrate. A number of second three-dimensional magnetic sensors are secured to the substrate at a first distance from the first magnetic sensor. Additionally, a number of one-dimensional magnetic sensors are secured to the substrate at a second distance from the first magnetic sensor greater than the first distance. Additional magnetic sensors of any dimension may also be included. The magnetic field sensitivity of the first and second three-dimensional magnetic sensors may be less than the magnetic field sensitivity of the one-dimensional magnetic sensors. The sensing range of the first and second three-dimensional magnetic sensors may be greater than the sensing range of the one-dimensional magnetic sensors. The magnetic sensor array may also include a processing circuit coupled to the magnetic sensors.

Abstract: A system that enables targeting of an instrument placed within a drill bushing aligns the axis of a drill bushing with the axis of a transverse hole in an intramedullary nail. The system includes a probe having an elongated member with a distal end, a magnet that is polarized along its longitudinal axis that is mounted perpendicularly to the distal end of the elongated member; and a processor executing programmed instructions to determine a position and orientation of the magnetic sensor array with respect to the targeting magnet.

Abstract: A magnetic sensor array includes a first three-dimensional magnetic sensor secured to a substrate in a central location of the substrate. A number of second three-dimensional magnetic sensors are secured to the substrate at a first distance from the first magnetic sensor. Additionally, a number of one-dimensional magnetic sensors are secured to the substrate at a second distance from the first magnetic sensor greater than the first distance. Additional magnetic sensors of any dimension may also be included. The magnetic field sensitivity of the first and second three-dimensional magnetic sensors may be less than the magnetic field sensitivity of the one-dimensional magnetic sensors. The sensing range of the first and second three-dimensional magnetic sensors may be greater than the sensing range of the one-dimensional magnetic sensors. The magnetic sensor array may also include a processing circuit coupled to the magnetic sensors.

Abstract: A magnetic sensor array includes a first three-dimensional magnetic sensor secured to a substrate in a central location of the substrate. A number of second three-dimensional magnetic sensors are secured to the substrate at a first distance from the first magnetic sensor. Additionally, a number of one-dimensional magnetic sensors are secured to the substrate at a second distance from the first magnetic sensor greater than the first distance. Additional magnetic sensors of any dimension may also be included. The magnetic field sensitivity of the first and second three-dimensional magnetic sensors may be less than the magnetic field sensitivity of the one-dimensional magnetic sensors. The sensing range of the first and second three-dimensional magnetic sensors may be greater than the sensing range of the one-dimensional magnetic sensors. The magnetic sensor array may also include a processing circuit coupled to the magnetic sensors.

Abstract: A system that enables targeting of an instrument placed within a drill bushing aligns the axis of a drill bushing with the axis of a transverse hole in an intramedullary nail. The system includes a probe having an elongated member with a distal end, a magnet that is polarized along its longitudinal axis that is mounted perpendicularly to the distal end of the elongated member; and a processor executing programmed instructions to determine a position and orientation of the magnetic sensor array with respect to the targeting magnet.