Abstract: Some aspects comprise a tuning system configured to tune a radio frequency coil for use with a magnetic resonance imaging system comprising a tuning circuit including at least one tuning element configured to affect a frequency at which the radio frequency coil resonates, and a controller configured to set at least one value for the tuning element to cause the radio frequency coil to resonate at approximately a Larmor frequency of the magnetic resonance imaging system determined by the tuning system. Some aspects include a method of automatically tuning a radio frequency coil comprising determining information indicative of a Larmor frequency of the magnetic resonance imaging system, using a controller to automatically set at least one value of a tuning circuit to cause the radio frequency coil to resonate at approximately the Larmor frequency based on the determined information.

Abstract: A method, computer program product, and system are provided to calibrate a sensor array with a plurality of sensors. The method can include sweeping a voltage of a reference electrode from a first voltage to a second voltage, where the reference electrode is in fluid communication with the sensor array. The output voltage of each of the plurality of sensors can be monitored at one or more voltages within the first and second voltages. An overall average gain of the plurality of sensors can be calculated at each of the one or more voltages. Further, an acquisition window for the sensor array can be determined. The acquisition window can include a maximum distribution of sensors that provides a maximal overall average gain at a particular reference electrode voltage.

Abstract: Methods and apparatus for reducing noise in RF signal chain circuitry for a low-field magnetic resonance imaging system are provided. A switching circuit in the RF signal chain circuitry may include at least one field effect transistor (FET) configured to operate as an RF switch at an operating frequency of less than 10 MHz. A decoupling circuit may include tuning circuitry coupled across inputs of an amplifier and active feedback circuitry coupled between an output of the amplifier and an input of the amplifier, wherein the active feedback circuitry includes a feedback capacitor configured to reduce a quality factor of an RF coil coupled to the amplifier.

Abstract: A radio-frequency (RF) coil for use in a low-field magnetic resonance imaging system and methods of making the same are provided. The RF coil may include a substrate having a first and second side and a conductor. The conductor may include a first portion wound around the substrate from the first side to the second side at a first plurality of locations spaced between the first side and the second side and a second portion wound around the substrate from the second side to the first side at a second plurality of locations spaced between the first side and the second side, wherein the first plurality of locations alternate with the second plurality of locations spaced between the first side and the second side.

Abstract: Methods and apparatus for reducing noise in RF signal chain circuitry for a low-field magnetic resonance imaging system are provided. A switching circuit in the RF signal chain circuitry may include at least one field effect transistor (FET) configured to operate as an RF switch at an operating frequency of less than 10 MHz. A decoupling circuit may include tuning circuitry coupled across inputs of an amplifier and active feedback circuitry coupled between an output of the amplifier and an input of the amplifier, wherein the active feedback circuitry includes a feedback capacitor configured to reduce a quality factor of an RF coil coupled to the amplifier.

Abstract: According to some aspects, a low-field magnetic resonance imaging system is provided. The low-field magnetic resonance imaging system comprises a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, the magnetics system comprising, a B0 magnet, a plurality of gradient coils, and at least one radio frequency coil, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a power connection configured to connect to a single-phase outlet to receive mains electricity and deliver the mains electricity to the power system to provide power needed to operate the magnetic resonance imaging system.

Abstract: Aspects relate to providing radio frequency components responsive to magnetic resonance signals. According to some aspects, a radio frequency component comprises at least one coil having a conductor arranged in a plurality of turns oriented about a region of interest to respond to corresponding magnetic resonant signal components. According to some aspects, the radio frequency component comprises a plurality of coils oriented to respond to corresponding magnetic resonant signal components. According to some aspects, an optimization is used to determine a configuration for at least one radio frequency coil.

Abstract: Methods and apparatus for reducing noise in RF signal chain circuitry for a low-field magnetic resonance imaging system are provided. A switching circuit in the RF signal chain circuitry may include at least one field effect transistor (FET) configured to operate as an RF switch at an operating frequency of less than 10 MHz. A decoupling circuit may include tuning circuitry coupled across inputs of an amplifier and active feedback circuitry coupled between an output of the amplifier and an input of the amplifier, wherein the active feedback circuitry includes a feedback capacitor configured to reduce a quality factor of an RF coil coupled to the amplifier.

Abstract: Described herein are techniques to reduce or remove the impact of secondary path photons and/or charge carriers on storage bins of an integrated device to improve noise performance, and thus, sample analysis. Some embodiments relate to optical rejection techniques such as including an optical barrier positioned to block at least some photons from reaching the storage bins. Some embodiments relate to electrical rejection techniques such as including an electrical barrier configured to block at least some charge carriers from reaching the storage bins along at least one secondary path. Some embodiments relate to an integrated device in which at least one storage bin is shaped and/or positioned relative to the photodetector to facilitate receipt of some charge carriers (e.g., fluorescent emission charge carriers) and/or photons and to impede receipt of other charge carriers (e.g., noise charge carriers) and/or photons.

Abstract: Methods and apparatus for reducing noise in RF signal chain circuitry for a low-field magnetic resonance imaging system are provided. A switching circuit in the RF signal chain circuitry may include at least one field effect transistor (FET) configured to operate as an RF switch at an operating frequency of less than 10 MHz. A decoupling circuit may include tuning circuitry coupled across inputs of an amplifier and active feedback circuitry coupled between an output of the amplifier and an input of the amplifier, wherein the active feedback circuitry includes a feedback capacitor configured to reduce a quality factor of an RF coil coupled to the amplifier.

Abstract: Methods, compositions, systems, apparatus, and kits are provided for depositing samples onto surfaces. The samples can include one or more particles, and the surface can include one or more reaction chambers. In some embodiments, the depositing can include the use of companion particles in combination with sample particles.

Abstract: A method of modeling a background signal when sequencing a polynucleotide strand using sequencing-by-synthesis includes: flowing a series of nucleotide flows onto a reactor array having multiple reaction confinement regions, one or more copies of the polynucleotide strand being located in a loaded reaction confinement region of the reactor array, the loaded reaction confinement region being located in a vicinity of one or more neighboring reaction confinement regions that may or may not be loaded; receiving output signals from the reactor array; and modeling a background signal for the loaded reaction confinement region using the received output signals and a model adapted to account at least for an exchange of ions between the one or more neighboring reaction confinement regions and a headspace adjacent the loaded reaction confinement region and the one or more neighboring reaction confinement regions.

Abstract: According to some aspects, a portable magnetic resonance imaging system is provided, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging. The magnetics system comprises a permanent B0 magnet configured to produce a B0 field for the magnetic resonance imaging system, and a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a base that supports the magnetics system and houses the power system, the base comprising at least one conveyance mechanism allowing the portable magnetic resonance imaging system to be transported to different locations.

Abstract: Aspects relate to providing radio frequency components responsive to magnetic resonance signals. According to some aspects, a radio frequency component comprises at least one coil having a conductor arranged in a plurality of turns oriented about a region of interest to respond to corresponding magnetic resonant signal components. According to some aspects, the radio frequency component comprises a plurality of coils oriented to respond to corresponding magnetic resonant signal components. According to some aspects, an optimization is used to determine a configuration for at least one radio frequency coil.

Abstract: Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.

Abstract: In one implementation, a method is described. The method includes determining an operational characteristic of sensors of a sensor array. The method further includes selecting a group of sensors in the array based on the operational characteristic of sensors in the group. The method further includes enabling readout of the sensors in the selected group. The method further includes receiving output signals from the enabled sensors.

Abstract: A method, computer program product, and system are provided to calibrate a sensor array with a plurality of sensors. The method can include sweeping a voltage of a reference electrode from a first voltage to a second voltage, where the reference electrode is in fluid communication with the sensor array. The output voltage of each of the plurality of sensors can be monitored at one or more voltages within the first and second voltages. An overall average gain of the plurality of sensors can be calculated at each of the one or more voltages. Further, an acquisition window for the sensor array can be determined. The acquisition window can include a maximum distribution of sensors that provides a maximal overall average gain at a particular reference electrode voltage.

Abstract: According to some aspects, a portable magnetic resonance imaging system is provided, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging. The magnetics system comprises a permanent B0 magnet configured to produce a B0 field for the magnetic resonance imaging system, and a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals, a power system comprising one or more power components configured to provide power to the magnetics system to operate the magnetic resonance imaging system to perform image acquisition, and a base that supports the magnetics system and houses the power system, the base comprising at least one conveyance mechanism allowing the portable magnetic resonance imaging system to be transported to different locations.

Abstract: In some aspects, a method of operating a magnetic resonance imaging system comprising a B0 magnet and at least one thermal management component configured to transfer heat away from the B0 magnet during operation is provided. The method comprises providing operating power to the B0 magnet, monitoring a temperature of the B0 magnet to determine a current temperature of the B0 magnet, and operating the at least one thermal management component at less than operational capacity in response to an occurrence of at least one event.

Abstract: Methods and apparatus relating to FET arrays including large FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by-synthesis reactions. Some methods provided herein relate to improving signal (and also signal to noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.