30 results about "Gradient generator" patented technology

A system for perfusion and diffusion MR imaging of a portion of patient anatomy includes an RF (Radio Frequency) signal generator for generating RF excitation pulses in anatomy and enabling subsequent acquisition of associated RF echo data. A magnetic field gradient generator generates anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition in a three dimensional (3D) anatomical volume. The RF signal generator and the gradient generator acquire within a single MR imaging scan, perfusion image data of the 3D volume, at least partially in the presence of contrast agent, and diffusion image data of the 3D volume.

Low-cost and portable microfluidic systems are needed for cell migration research and Point of Care (POC) testing. This study introduces a low-cost and portable USB Microscope Microfluidic Chemotaxis Analysis System (UMCAS) for rapid analysis of cell chemotaxis studies. A standalone microfluidic gradient generator is also developed for rapid generation of chemical gradient in microfluidic device without need of any peripheral perfusion apparatus. A smart phone based application program was developed for the real-time remote monitoring of the migration data. This system is validated by observing the neutrophil migration in three different conditions: 1) medium control, 2) uniform IL-8 control, and 3) IL-8 gradient. The results show that neutrophils exhibit random migration in both medium and uniform IL-8 control experiments, while they show strong directional migration to the IL-8 gradient. These results successfully validated the developed UMCAS system.

A system for fat signal suppression in MR imaging comprises an RF signal generator for generating RF pulses in an MR pulse sequence using one or more RF pulses for echo signal formation including, an RF excitation pulse and an RF refocusing pulse subsequent to said RF excitation pulse. A magnetic field slice select gradient generator generates first and second different slice select magnetic field gradients for corresponding use with the RF excitation pulse and the RF refocusing pulse, respectively, the first and second different slice select magnetic field gradients having substantially different amplitudes. An MR imaging control unit directs acquisition of MR imaging data having fat signal substantially suppressed using the generated RF pulses and different slice select magnetic field gradients.

A system uses multiple RF coils in MR imaging and an RF (Radio Frequency) signal generator generates RF excitation pulses in anatomical regions of interest and enables subsequent acquisition of associated RF echo data. A magnetic field gradient generator generates anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition. The RF signal generator and the gradient generator substantially concurrently acquire first and second volumes of first and second different anatomical regions by providing, a first RF pulse having a first asymmetric shape followed by a successive second RF pulse substantially having the first asymmetric shape but reversed in time, to substantially reduce echo time (TE) differences between acquisition of the first and second volumes and a phase encoding magnetic field gradient prepares for acquisition of data representing the first and second volumes.

A system acquires MR image data of a portion of patient anatomy associated with spin lattice relaxation time in a rotating frame using an RF (Radio Frequency) signal generator and a magnetic field gradient generator. The RF (Radio Frequency) signal generator generates RF excitation pulses in anatomy and enables subsequent acquisition of associated RF echo data. The magnetic field gradient generator generates anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition in a three dimensional (3D) anatomical volume. The RF signal generator and the gradient generator use in order, a saturation pulse, a T1 spin lattice relaxation rotating frame preparation pulse sequence and a spoiler gradient, in acquiring image data of the 3D volume showing luminance contrast associated with T1 spin lattice relaxation in a rotating frame.

The invention discloses an improved two-inlet concentration gradient generator and a design method thereof. The concentration gradient generator is processed by a soft lithography method, and structurally comprises two inlets, one outlet, a main channel, and a series of splitter plates that are subjected to special structure design and parallel to the main channel. Repeated separation and mixing of a fluid can be realized through the splitter plates, so that a certain concentration gradient is set up at the downstream of the splitter plates. The finally formed concentration gradient is determined by the structural position of the splitter plates, and the concentration gradient resolution of the splitter plate outlets is determined by the series of the splitter plates, the more the series is, the higher the resolution is. The number of the splitter plates contained at each level increases exponentially. The concentration gradient generator can realize concentration gradient establishment of arbitrary monotonic function, and only needs two fluid inlets. The structure is compact, the generated concentration gradient is stable, and the concentration gradient generator can be used for microbial chemotaxis research, drug screening and other biology, pharmacy and medical engineering fields.

The invention provides a high-throughput tumor-targeted drug concentration screening microfluidic device, which is composed of a cell sampling layer, a pneumatic film layer and a cell control layer. The cell sampling layer includes a multi-cell sampling channel and a valve control channel, which can realize simultaneous sampling of various cells. The cell control layer has a "two-stage parallel" structure, the first-stage parallel structure is a concentration gradient generator module, and the second-stage parallel structure is a cell culture module. Among them, the concentration gradient generator module can realize the uniform mixing of granular tumor-targeted drugs and generate drug concentrations in various ratios; the multi-cell culture module can provide a dynamic, uniform and stable fluid flow microenvironment for cell culture, and achieve Environment-independent culture of multiple cell types for targeted drug action. The microfluidic device provides a new technical platform for high-throughput cell culture, tumor-targeted drug screening and cell-drug experiments.

The invention relates to a functional micro-channel unit module, a fluid concentration gradient generator and a flow resistance measurer. The micro-channel unit module relates to a fluid-shunting module, a fluid-converging module, a fluid variable resistance module, a fluid-collecting module, a fluid speed-adjusting module, and the like. Suitable micro-channel unit modules can be selected as required to construct different micro-flow network systems, such as the flow resistance measurer for measuring the flow resistance of fluid, a fluid linearity concentration gradient generator for operating the fluid and generating a concentration gradient of the fluid, a fluid arbitrary concentration gradient generator, and the like, thereby greatly shortening the preparation time of a concentration gradient device, lessening the reliance on micro-processing equipment, randomly replacing a damaged module in a modularized system and keeping the stability of the system. The invention can be widely applied to physical, chemical and biological fields.

The invention discloses a three inlet concentration gradient generator and a power function concentration gradient generation method. The concentration gradient generator comprises three inlets, an outlet, a main passage and a series of flow distribution plates parallel to the main channel, and is prepared through a soft lithography method. The area where the flow distribution plates are located is a mixing area with fluid in different concentrations, and comprises three stages, wherein the first stage of the area comprises two flow distribution plates, the second stage of the area comprises four flow distribution plates, and the third stage of the area comprises eight flow distribution plates; the part, at the downstream of the flow distribution plates, of the main passage is the formation area of concentration gradient. Through control of flow and concentration of the three inlets, establishment of concentration gradient of different target power functions is realized. The concentration gradient generator is compact in structure, adjustable in concentration gradient and simple and feasible in adjustment method, and can be widely applied to the fields of cell directed migration, cell culture and the like in biology, pharmacy, medical engineering and the like.

The invention relates to a system for fat suppression in obtaining of MR image, comprising: an RF signal generator for generating the RF pulses in an MR pulse sequence, including an RF excitation pulse and an RF re-focusing pulse after the RF excitation pulse, using one or more RF pulses for an echo signal structure. A magnetic field slice selection gradient generator generates two different slice selection magnetic field gradients to be used together with the RF excitation pulse and the RF re-focusing pulse correspondingly, wherein the first and second slice selection magnetic field gradients are substantially different in amplitude. An MR imaging control unit controls the obtaining of MR imaging data substantially suppressed in fat signal using the generated RF signals and the differentslice selection magnetic field gradients.

The invention discloses a microfluidics cell drug concentration gradient generator. The microfluidics cell drug concentration gradient generator comprises four groups of liquid inlet holes which are communicated through microchannels so as to form drug and culture medium laminar flow combinations of different volume proportions in the microchannels; one group of microchannels with micro-mixing function can ensure that drug and culture medium laminar flow combinations of different volume proportions can be fully mixed to finally form different concentrations which can form nine concentration gradients together with liquid concentrations in two channels led out from a liquid inlet directly; one group of chambers are connected with the micro-mixed channels for cell culturing and drug interaction research, and nine chambers are independent from one another. The concentration gradient generator is hardly influenced by liquid inlet rate during the generation of concentration gradients, good linear concentration gradients can be formed, and the concentration gradient generator has a simple structure and provides a brandnew platform for screening and detection of cell drugs.