According to some embodiments, a method implemented in electronic circuitry includes: receiving a first signal having a sinusoidal waveform; receiving a second signal having a sinusoidal waveform; generating a composite signal responsive to the first and second signals; determining an orthogonality adjustment coefficient based on a duty cycle of the composite signal; and applying the orthogonality adjustment coefficient to generate an adjusted second signal that is substantially orthogonal to the first signal.

A chopping technique, and associated structure, is implemented to cancel the magnetic 1/f noise contribution in a Tunneling Magnetoresistance (TMR) field sensor. The TMR field sensor includes a first bridge circuit including multiple TMR elements to sense a magnetic field and a second circuit to apply a bipolar current pulse adjacent to each TMR element. The current lines are serially or sequentially connected to a current source to receive the bipolar current pulse. The field sensor has an output including a high output and a low output in response to the bipolar pulse. This asymmetric response allows a chopping technique for 1/f noise reduction in the field sensor.

A Hall sensor circuit includes a first Hall sensor, a second Hall sensor, a first preamplifier circuit, a second preamplifier circuit, a subtractor circuit, and a duty cycling circuit. The first preamplifier circuit includes an input and an output. The input is coupled to the first Hall sensor. The second preamplifier circuit includes a first input, a second input, and an output. The first input is coupled to the second Hall sensor. The subtractor circuit includes a first input coupled to the output of the first preamplifier circuit, a second input coupled to the output of the second preamplifier circuit, and an output coupled to the second input of the second preamplifier circuit. The duty cycling circuit is coupled to the second preamplifier circuit and the second Hall sensor.

In the present disclosure, there is provided a permeability measurement jig including a first waveguide, wherein a signal line of the first waveguide comprises an excited magnetic part at one end side, and a magnetic field is generated at the excited magnetic part by an excitation signal, and a second waveguide, wherein a signal line of the second waveguide comprises a detection part at one end side, a detection signal is induced at the detection part due to an action of the magnetic field generated at the excited magnetic part to a measurement sample, and the detection part is placed on the excited magnetic part to face the excited magnetic part at a predetermined distance. A permeability measurement device having the permeability measurement jig and a permeability measurement method are disclosed.

An electronic circuit for measuring an angle and an intensity of an external magnetic field, includes: first and second magnetic field sensing units having sensing axes substantially orthogonal to each other; a voltage generator supplying a synchronization signal, a first voltage waveform to the first magnetic field sensing unit and a second voltage waveform to the second magnetic field sensing unit; a signal conditioning unit configured for adding the first and second sensing output signals and outputting a conditioned signal. The first and second voltage waveforms have substantially the same amplitude and frequency and are phase shifted by about 90° with respect to each other. The conditioned signal and the synchronization signal are inputted into a magnetic field angle detection unit configured for measuring a phase shift between the conditioned signal and the synchronization signal and for determining the angle of the external magnetic field from the measured phase shift.

Provided are a detection method, a detection apparatus and a detection process. The detection method includes: using a sensor for idle scanning to obtain a first output electrical signal, and performing feedback correction on the first output electrical signal to eliminate a noise to obtain first correction data; using the sensor to scan a correction specimen page to obtain a second output electrical signal, and performing the feedback correction on the second output electrical signal to eliminate a noise to obtain second correction data; calculating according to the first correction data, the second correction data and an electrical signal predetermined value to obtain third correction data; using the sensor to scan a to-be-detected object to obtain a third output electrical signal; and correcting the third output electrical signal according to the first correction data and the third correction data. In the detection method obtains an accurate detection result.

Disclosed herein is a detection device comprising sensors with spin torque oscillators (STOs), at least one fluidic channel configured to receive molecules to be detected, and detection circuitry coupled to the sensors. At least some of the molecules to be detected are labeled by magnetic nanoparticles (MNPs). The presence of one or more MNPs in the vicinity of a STO subjected to a bias current changes the oscillation frequency of the STO. The sensors are encapsulated by a material, such as an insulator, separating the sensors from the at least one fluidic channel. A surface of the material provides binding sites for the molecules to be detected. The detection circuitry is configured to detect changes in the oscillation frequencies of the sensors in response to presence or absence of one or more MNPs coupled to one or more binding sites associated with the sensors.

Disclosed are methods and devices for detecting retained surgical items or other objects having a magnetic signature within a corpus of a patient. The device can comprise a handle, a shaft extending from the handle, and a distal sensing portion positioned distally of the shaft. The distal sensing portion can comprise one or more gradiometers comprising a plurality of magnetometers. The device can further comprise one or more output components configured to generate a user output to alert a user of a detected object.

Disclosed are methods and devices for detecting retained surgical items or other objects having a magnetic signature within a corpus of a patient. The device can comprise a handle, a shaft extending from the handle, and a distal sensing portion positioned distally of the shaft. The distal sensing portion can comprise one or more gradiometers comprising a plurality of magnetometers. The device can further comprise one or more output components configured to generate a user output to alert a user of a detected object.

Disclosed is a contactless magnetic sensing system. Proposed is a sensing system in which multiple magnetic sensors are disposed at the center of a rotating magnet and rotation angles of the magnetic sensors disposed around a center point at intervals of an angle of 90 degrees can be extracted.