An MPI imaging device for mapping an object to be examined in a sample volume, with a magnet arrangement which is designed to generate an MPI magnetic field with a gradient B1 and a field-free line in the sample volume, the magnet arrangement comprising a first pair of magnet rings with two magnet rings in a Halbach dipole configuration, which are arranged coaxially on a common Z axis that runs through the sample volume, wherein the magnet arrangement comprises a second pair of magnet rings with two further magnet rings in a Halbach dipole configuration, which is arranged coaxially in relation to the first pair of magnet rings, the magnet rings of both pairs being arranged rotatably with respect to one another about the Z axis. As a result, a variable MPI selection field can be generated by means of permanent magnets.

A sample analyzer according to an embodiment includes a magnetic field applier configured to apply a magnetic field to a cartridge containing a sample and magnetic particles which bond an object to be detected in the sample; a measurer configured to measure the magnetic particles in the cartridge; and an analyzing processor configured to analyze and process a result of a measurement by the measurer. In addition, the magnetic field applier includes an electromagnet disposed on a first side of the cartridge; a magnetic member configured to be magnetized by the electromagnet; and a moving actuator configured to move the magnetic member.

The invention relates to a measuring arrangement comprising: a coil arrangement for creating a magnetic field to measure a sample to be arranged in connection with it including at least one flat coil, the coil geometry of which is arranged to be changed in the direction of the plane defined by the coil arrangement, in order to create a spatially changing magnetic field having a known distance dependence for measuring the sample; and electronics connected to the coil arrangement for creating a magnetic field using the coil arrangement; and means for changing the position of the sample and the coil arrangement relative to each other in order to change the magnetic field affecting the sample and having the known distance dependence. In addition, the invention also relates to a method for measuring a sample.

A signal processing system used for GMR-based detection of a target analyte in a sample under test, comprising: a measurement circuit configuration unit configured to build a GMR sensor measurement circuit by routing in at least one GMR sensor, and to build a reference resistor measurement circuit by routing in at least one reference resistor; a magnetic field excitation unit configured to apply an AC magnetic field of frequency ω.sub.2 to the at least one GMR sensor; a carrier signal applying unit configured to apply a carrier signal of frequency ω.sub.1 to the GMR sensor measurement circuit, and apply carrier signals of frequency ω.sub.1, ω.sub.1+ω.sub.2, and ω.sub.1−ω.sub.2 to the reference resistor measurement circuit; a measurement signal pick-up unit coupled to the measurement circuits, configured to collect reference resistor measurement signals from the reference resistor measurement circuit and GMR sensor measurement signals from the GMR sensor measurement circuit; and a phase sensitive solution unit coupled to the measurement signal pick-up unit, configured to analytically solve for resistance change of the at least one GMR sensor based on both the reference resistor measurement signals from the reference resistor measurement circuit and the GMR sensor measurement signals from the GMR sensor measurement circuit.

A sensing device comprises a plurality of magnetoresistive (MR) sensors, at least one fluidic channel, and detection circuitry coupled to the MR sensors. Each MR sensor is configured to detect the presence of molecules (e.g., biologic molecules) labeled by magnetic nanoparticles (MNPs). The sensors are encapsulated by an insulating material that protects the sensors from the contents of the at least one fluidic channel. The insulating material has a surface within the fluidic channel that provides sites for binding the molecules to be detected. The detection circuitry is configured to detect (a) a characteristic of magnetic noise of each MR sensor, the characteristic being influenced by a presence or absence of one or more MNPs at each site, or (b) a change in resistance, current, and/or voltage drop of each MR sensor, wherein the change is influenced by the presence or absence of one or more MNPs at each site.

Electrically conductive proppant particles having non-uniform electrically conductive coatings are disclosed. The non-uniform electrically conductive coatings can have a thickness of at least about 10 nm formed on an outer surface of a sintered, substantially round and spherical particle, wherein less than 95% of the outer surface of the sintered, substantially round and spherical particle is coated with the electrically conductive material. Methods for making and using such electrically conductive proppant particles having non-uniform electrically conductive coatings are also disclosed.

A system for generating a traveling field free line, traveling along a propagation direction different from the orientation of said traveling field free line, said system comprising at least a first and a second coil assembly, wherein said first coil assembly is configured for generating a first stationary field free line at a first location when a current is flowing in the first coil assembly and the second coil assembly is current free, and wherein said second coil assembly is configured for generating a second stationary field free line at a second location, when a current is flowing in the second coil assembly and the first coil assembly is current free. The system further comprises a controller configured for driving the first and second coil assemblies with corresponding driving currents synchronized with each other, such that said traveling field free line travels along the propagation direction from a first location towards a second location.

Example embodiments of the present invention provide a magnetic relaxometry measurement apparatus, comprising: a magnetizing system configured to supply a pulsed magnetic fields to a sample; a sensor system configured to detect magnetic fields produced by induced magnetization of the sample after a magnetic field pulse from the magnetizing system; one or more compensating coils configured to suppress generation of eddy currents in an environment surrounding the apparatus due to the pulsed magnetic fields.

A system for detecting analytes in a test sample, and a method for processing the same, is provided. The system includes a cartridge reader unit that has a control unit and a pneumatic system, and a cartridge assembly that prepares the samples with mixing material(s) through communication channels. The assembly has a memory chip with parameters for preparing the sample and at least one sensor (GMR sensor) for detecting analytes in the sample. The assembly is pneumatically and electronically mated with the reader unit via a pneumatic interface and an electronic interface such that the parameters may be implemented via the control unit. The pneumatic system is contained within the unit and has pump(s) and valve(s) for selectively applying fluid pressure to the pneumatic interface of the assembly, and thus through the communication channels, to move the sample and mixing material(s) through and to sensor. The control unit activates the pneumatic system to prepare the sample and provide it to the sensor for detecting analytes, and also processes measurements from the sensor to generate test results.

Methods of detecting the presence of an analyte in a query sample include providing a sensor that includes biomolecules disposed on a polymer-coated surface of a giant magnetoresistance (GMR) sensor. Modes of operation remove or add magnetic beads from the vicinity of the sensor surface by interactions with the biomolecules. The methods feature detecting the presence of the analyte in the query sample by measuring resistance change of the GMR sensor based on determining resistance before and after passing magnetic particles over the sensor.