Digital operation of magnetic resonance systems

Abstract

It provides digital operation for magnetic resonance systems. [Solution] In a general embodiment, a magnetic resonance system performs magnetic resonance measurements. In some examples, the magnetic resonance system includes a data processing unit and a superheterodyne spectrometer system. The data processing unit generates digital intermediate frequency (IF) signal information based on a pulse profile. The digital IF signal information is configured to suppress image sidebands in the magnetic resonance control signal. The superheterodyne spectrometer generates a magnetic resonance control signal based on the digital IF signal information.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 489,834, filed on 13 March 2023, entitled “Digital Operation of a Magnetic Resonance System.” The priority document referenced above is incorporated herein by reference in its entirety. [Background technology]

[0002] The following description pertains to the digital operation of magnetic resonance systems.

[0003] Magnetic resonance systems are used to investigate various types of samples and phenomena. In some magnetic resonance applications, the spin of a sample is polarized by a static external magnetic field, and the resonator manipulates the spin by creating a magnetic field at a frequency near the spin's resonance frequency. Examples of magnetic resonance applications include electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and magnetic resonance imaging (MRI). [Brief explanation of the drawing]

[0004] [Figure 1] This is a schematic diagram illustrating an exemplary magnetic resonance system. [Figure 2A] This is a schematic diagram illustrating an exemplary magnetic resonance system. [Figure 2B] This is a schematic diagram illustrating an exemplary magnetic resonance system. [Figure 3A] This is a schematic diagram of an exemplary signal processing unit for a magnetic resonance system. [Figure 3B] Figure 3A is a schematic diagram of the exemplary data format of the FIFO buffer device in the exemplary signal processing unit. [Figure 4] This is a flowchart illustrating an exemplary process. [Figure 5A] This figure shows the time series of amplitude and phase of the pulse interval. [Figure 5B] This graph shows the digital IF signal value as a function of time, based on the time series of pulse amplitude and phase in Figure 5A. [Figure 5C] This figure shows the amplitude and phase time series of an exemplary pulse similar to the one shown in Figure 5A and the pulse recovered by demodulating the digital IF signal value in Figure 5B. [Figure 6A] This figure shows the time series of pulse amplitude and phase in an exemplary pulse profile, as well as the first and second digital IF signal values. [Figure 6B] This figure shows the Fourier component of the first output signal of the IQ mixer model. [Figure 6C] This figure shows the Fourier component of the third output signal of the IQ mixer model. [Figure 7A] This figure shows the time series of amplitude and phase of the first exemplary pulse in the pulse sequence. [Figure 7B] This figure shows the time series of amplitude and phase of a second exemplary pulse in a pulse sequence. [Figure 7C] Figures 7A and 7B are graphs showing the digital IF signal values ​​determined based on the time series of amplitude and phase of the first and second exemplary pulses. [Figure 7D] This figure shows the time series of amplitude and phase of the pulse sequence and the reconstructed pulse sequence. [Figure 7E] Figures 7A and 7B are graphs showing the digital IF signal values ​​determined based on the time series of amplitude and phase of the first and second exemplary pulses. [Figure 7F] This figure includes graphs showing the time series of amplitude and phase of the pulse sequence and the reconstructed pulse sequence. [Figure 7G] This figure includes graphs showing enlarged views of the digital IF signal values ​​in Figure 7C and Figure 7E, respectively, for the time window of 1465 to 1485 ns. [Figure 7H]A graph showing an enlarged view of the time series of the phases of two restored pulse sequences shown in FIGS. 7D and 7F between time windows 1475 to 1600 ns. [Figure 7I] A graph showing the time series of the amplitude of the second exemplary pulse shown in FIG. 7B and the time series of the phase of the second exemplary pulse before and after applying a phase shift to correct for the effect from the time delay. [Figure 8] A figure including a graph of a subset of the digital 1F signal values of the corresponding pulses in the pulse sequence. [Figure 9A] A graph and corresponding table of an exemplary hardware control sequence. [Figure 9B] A graph and corresponding table of an exemplary hardware control sequence. [Figure 10] A graph showing exemplary ADC data as a function of time. [Figure 11A] A figure including a graph showing the amplitude envelopes and phase envelopes of the first and second pulses in the pulse sequence. [Figure 11B] A figure including a graph showing a first subset of digital IF signal values generated based on the amplitude envelope and phase envelope of the first pulse shown in FIG. 11A, a graph showing a second subset of digital IF signal values generated based on the amplitude envelope and phase envelope of the second pulse shown in FIG. 11A, a graph showing a third subset of digital IF signal values generated by overlapping the first and second subsets of digital IF signal values, and a graph showing the Fourier transform of the third subset of digital IF signal values. [Figure 11C] A figure including a graph showing the amplitude envelopes and phase envelopes of the first pulse and the first restored pulse obtained by demodulating the third subset of digital IF signal values at the first intermediate frequency, and a graph showing the amplitude envelopes and phase envelopes of the second pulse and the second restored pulse obtained by decomposing the third subset of digital IF signal values at the second intermediate frequency. [Figure 12A]This figure includes graphs showing the amplitude envelope and phase envelope of the first pulse in a pulse sequence, graphs showing the amplitude envelope and phase envelope of the second and third pulses in the pulse sequence, and graphs showing the amplitude envelope and phase envelope of the fourth pulse in the pulse sequence. [Figure 12B] The figure includes a graph showing the configuration of a first set of digital IF signal values, which includes three subsets of digital IF signal values; a graph showing the configuration of a second set of digital IF signal values, which also includes three subsets of digital IF signal values; a graph showing a third set of digital IF signal values ​​generated by superimposing the first and second digital IF signals; and a graph showing the corresponding Fourier transform of the third set of digital IF signal values. [Figure 12C] This figure includes graphs showing the amplitude envelope and phase envelope of the original pulse sequence and the first restored pulse sequence obtained by demodulating a third set of digital IF signal values ​​shown in Figure 12B at a first intermediate frequency of 150 MHz, as well as graphs showing the amplitude envelope and phase envelope of the original pulse sequence and the second restored pulse sequence obtained by demodulating a third set of digital IF signal values ​​shown in Figure 12B at a second intermediate frequency of 250 MHz. [Modes for carrying out the invention]

[0005] In some embodiments relating to the subject matter described herein, the magnetic resonance system includes a computer system and a superheterodyne spectrometer system. In some embodiments, a controller unit (which may be implemented, for example, on a field-programmable gate array (FPGA) or another type of programmable digital control unit) controls the superheterodyne spectrometer system to perform pulse transmission and signal detection. Digital pulse generation using an FPGA or another type of controller unit can offer considerable improvements and advantages, for example, by avoiding noise and fluctuations associated with analog electronics, thereby enhancing the signal-to-noise ratio and amplitude / phase stability. In some cases, spin control methods utilizing the capabilities of a fast arbitrary waveform generator (AWG) can improve control bandwidth and robustness to errors, while also providing a framework for developing novel experiments that take advantage of the dynamics of precisely designed spin systems.

[0006] In some cases, intermediate frequency (IF) pulse signals are generated digitally and detected by a superheterodyne spectrometer system, which enables precise AWG transmission of phase-coherent pulses over arbitrary time periods. Advanced quantum-controlled pulses and sequences that improve the sensitivity and fitness of electron paramagnetic resonance (EPR) measurements are implemented with high fidelity, thereby enabling demanding experiments to be performed with greater accuracy and precision.

[0007] In some embodiments, the methods and systems presented herein enable the precise execution of arbitrary and high-speed shaping pulses with multiplexing capabilities, AWG capabilities with nanosecond resolution, preservation of phase coherence over arbitrary time, large control bandwidth and dynamic range, or a combination of these and other advantages. In some cases, the methods and systems presented herein can enable multiplexed pulses at multiple distinct frequencies (e.g., double resonance experiments, triple resonance experiments, or more). In some cases, the methods and systems presented herein can enable the elimination or reduction of filter devices and other hardware components to increase control and detection bandwidth. In some cases, the methods and systems presented herein can be implemented without causing amplitude or phase dips.

[0008] In some cases, the methods and systems presented herein allow for the maintenance of single-sideband (SSB) behavior in any sequence and avoidance of local oscillator (LO) signal leakage. Local oscillator (LO) leakage generally refers to the leakage of the LO signal to the output of a mixer device, which can cause unwanted excitation of the spin system and degrade the performance of magnetic resonance system components (e.g., switches and amplifiers). In some cases, the control techniques described herein can reduce (e.g., block or eliminate) LO leakage without the addition of filters, shielding, or other modifications to the spectrometer system. For example, a DC offset may be applied to the digital IF signal to reduce or eliminate LO leakage.

[0009] In some cases, the methods and systems presented herein can enable the incorporation of image sideband suppression into a digital IF signal. Image sideband suppression reduces or removes unwanted sidebands that, if not incorporated, would appear in a radio frequency (RF) or microwave signal through signal conversion (e.g., mixing with the LO signal). In a mixer, the LO signal is mixed with the IF signal to create new frequencies, which typically include sum and difference frequencies, and possibly other harmonics. One frequency range (e.g., a sideband corresponding to the sum of the mixed frequencies) typically contains the desired output signal, while unwanted image signals appear in other frequency ranges (unwanted sidebands). In some cases, the unwanted signals may interfere with operation, so the goal is to remove signals in the unwanted sidebands using image sideband suppression. In some cases, the control techniques described herein can provide image sideband suppression (e.g., reduction or removal of unwanted sideband signals) without the addition of filters, shielding, or other modifications to the mixer or spectrometer system. For example, a digital IF signal may be configured such that when the IF signal is converted by a mixer device (e.g., by applying a phase offset to the digital IF signal), only a single sideband (containing the desired frequency range) is produced, so that unwanted sidebands can be reduced or removed at the digital IF stage.

[0010] In some embodiments, the pulse sequence to be performed in the magnetic resonance system includes pulses and time delays. A computer system or other data processing device (e.g., running computer software or firmware) can analyze the pulse sequence and construct appropriate digital IF signal values ​​to maintain phase coherence, single-sideband operation, and LO suppression. The computer system can also generate a hardware control sequence corresponding to the pulse sequence and store individual pulses in memory units (e.g., DAC memory, buffer memory, etc.) according to the pulse sequence. The superheterodyne spectrometer system can read the hardware control sequence and trigger hardware operations (e.g., digital-to-analog conversion (DAC), analog-to-digital conversion (ADC), digital input / output (DIO), and possibly others) according to the hardware control sequence. In some embodiments, the hardware control sequence enables synchronization of DAC, ADC, and DIO channels and enables signal averaging and other processes. The superheterodyne spectrometer system may further include a microwave or radio frequency transceiver unit that applies the pulse sequence to the spin system (e.g., via the resonator unit) and receives the resulting spin signals from the resonator unit.

[0011] Embodiments of the systems and techniques described herein can be adapted to various types of magnetic resonance systems. For example, computer systems, programmable controllers, and other hardware components can be adapted to nuclear magnetic resonance (NMR) systems, electron paramagnetic resonance (EPR) systems, or other types of magnetic resonance systems. As another example, the systems and techniques described herein can be deployed in magnetic resonance systems that include probes within probeless magnetic resonance systems. In some cases, magnetic resonance systems can be adapted to operate with liquid samples, solid samples, liquid crystal samples, spin-labeled protein samples, biological samples (e.g., blood samples, urine samples, saliva samples, etc.), or other types of samples that will be measured or otherwise analyzed by the magnetic resonance system. As yet another example, a magnetic resonance system may include components that operate in cryogenic environments (e.g., other cryogenic temperatures lower than 77K, 4K, or 273K), or a magnetic resonance system may operate at non-cryogenic temperatures, including room temperature.

[0012] In some cases, the systems and techniques described herein may be compatible with multiple different types of resonators, cryogenic systems, probe configurations, and other components of various magnetic resonance systems. For example, the control techniques may be designed to be compatible with non-superconducting resonators and superconducting resonators fabricated from various superconducting materials. The resonator may be, for example, a microstrip, air gap, coil, waveguide, or another type of resonator for magnetic resonance systems. Furthermore, the resonator may be, for example, a rectangular air gap resonator, a cylindrical air gap resonator, a dielectric resonator, a loop gap resonator, or any lumped element resonator. In some cases, the control techniques presented herein may be developed in conjunction with various cryogenic systems, such as compact closed-cycle systems, open-cycle systems, and liquid cryogenic systems. In some cases, the control techniques presented herein may be developed in conjunction with various probes, including compact probe designs that can enable the use of low-noise cryogenic receiver amplifiers in various configurations without interfering with sample exchange methods. In some cases, a combination of these advantages, and possibly other advantages, and improvements can be obtained.

[0013] In some cases, the techniques and systems described herein may be developed in conjunction with continuous wave (CW) magnetic resonance (e.g., using CW ESR spectroscopy or CW NMR spectroscopy techniques), pulsed magnetic resonance (e.g., using pulsed ESR spectroscopy or pulsed NMR spectroscopy techniques), or combinations of these and other MR regions. In a typical continuous wave (CW) spectroscopy experiment, the resonator applies a low-power continuous excitation field (e.g., a radio frequency or microwave frequency driven field) to the sample over a relatively long period (e.g., relative to a characteristic relaxation time) to bring the spin ensemble to a stable state. The resonance frequency of the spins is swept over a range (by sweeping the main magnetic field), and the resulting absorption spectrum is measured. In a typical pulsed spectroscopy experiment, while the main magnetic field is kept constant, the resonator applies a series of strong, high-power pulses (e.g., radio frequency or microwave pulses) to the sample. The obtained spin state can then be observed, for example, by acquiring free induction decay (FID) or spin echo, and then a spectrum can be obtained by performing a Fourier transform on it.

[0014] The systems and techniques described herein can be adapted to various types of applications. For example, the systems and techniques described herein can be used for structural biological measurements to measure the structural properties of proteins or protein complexes in biological samples (e.g., blood samples, urine samples, or other types of biological samples). Such measurements may be useful in understanding the structure and function of membrane proteins in clinical applications, such as diagnosis, therapy, and drug discovery / development, as well as in other applications.

[0015] Figure 1 is a schematic diagram showing an embodiment of an exemplary magnetic resonance system 100. Generally, the exemplary magnetic resonance system 100 may be an EPR system, an NMR system, or another type of magnetic resonance system. The exemplary magnetic resonance system 100 includes a data processing unit 102, a signal processing unit 104, a spectrometer 106, and a resonator unit 108. The data processing unit 102 includes one or more processor units 112, one or more memory units 114, and other computer elements. The signal processing unit 104 includes a controller unit 122, one or more digital-to-analog converter (DAC) devices 124, one or more analog-to-digital converter (ADC) devices 126, and a digital input / output (DIO) unit 128. The spectrometer 106 includes a transmitter unit 122 for processing magnetic resonance control signals transmitted to the resonator unit 106 and a receiver unit 124 for processing magnetic resonance detection signals received from the resonator unit 106. In some examples, each unit of the magnetic resonance system 100 may include associated electronic circuits and other components such as housings and ports.

[0016] The data processing unit 102 may include one or more application-specific devices. The data processing unit 102 may be implemented as a single computer device (e.g., a laptop computer, workstation, desktop computer, or server) or by multiple computer devices. In some cases, the data processing unit 102 may be located in the same position as the signal processing unit 104, the spectrometer 106, and the resonator unit 106 within the magnetic resonance system 100, and may be directly connected to other units and components of the magnetic resonance system 100, for example, by cables (e.g., coaxial cables, network cables, waveguides, etc.) or other types of local communication channels. In some cases, all or part of the data processing unit 102 may be located far away from the signal processing unit 104, the spectrometer 106, and the resonator unit 106, and may be directly connected to units and components of the magnetic resonance system 100, for example, by a network (e.g., the Internet, a virtual private network, a wide area network, etc.) or other types of telecommunication channels. Some embodiments of the data processing unit 102 may be deployed within or otherwise within a cloud computing environment. In some embodiments, the data processing device 102 includes one or more user interfaces, such as a touchscreen, pointing device, keyboard, and microphone, which enable a user to interact with the data processing device 102 and provide input to the data processing device 102. In some embodiments, the data processing device 102 includes one or more output devices that enable the data processing device 102 to present information and data for display to the user (e.g., a graphical user interface).

[0017] The processor unit 112 of the data processing device 102 may include, for example, a central processor unit (CPU) or another type of general-purpose processor that runs software. The processor unit 112 may include, for example, a graphics processing unit (GPU), a cryptographic processor unit, or another type of dedicated coprocessor unit. In some cases, the processor unit 112 of the data processing device 102 may be configured to perform digital signal processing and signal averaging. In particular, the processor unit 112 may be configured to identify a pulse sequence for a magnetic resonance experiment, generate a set of digital intermediate frequency (IF) signal information by modulating each pulse of the pulse sequence at an intermediate frequency, generate a hardware control sequence based on the pulse sequence, transmit the digital IF signal information and hardware control sequence to the signal processing unit 104, receive a digitized magnetic resonance detection signal from the signal processing unit 104, demodulate the digitized magnetic resonance detection signal at an intermediate frequency for phase-sensitive detection, and display the data. In some cases, the processor unit 112 may be configured to perform other operations. For example, the processor unit 112 may be configured to generate multiple resonance pulses by modulating pulses in a pulse sequence at different intermediate frequencies and superimposing the modulated pulses, for example, in order to perform multiple magnetic resonance measurements. In this case, the processor unit 112 may also be configured to demodulate the digitized magnetic resonance detection signal at multiple intermediate frequencies. In some cases, the processor unit 112 may be controlled by software to execute a pre-configured program stored in the memory unit 114.

[0018] In some cases, the digital IF signal information includes the digital IF signal value, one or more phase shifts based on a time series of phases specified by the pulse profile (e.g., the phase time series 502 in Figure 5A), and possibly other information. For example, the digital IF signal value may include a time series of I-quadrature phase signal values ​​and a time series of Q-quadrature phase signal values. In some embodiments, the processor unit 112 is configured to modify the digital IF signal value by applying a phase shift to the time series of Q-quadrature phase signal values ​​relative to the time series of I-quadrature phase signal values. In some embodiments, the processor unit 112 is configured to modify the digital IF signal value by applying a DC offset to the time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values. In some embodiments, the phase shift and DC offset applied to the time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values ​​are configured to suppress image sidebands in the magnetic resonance control signal and to suppress LO leakage. In some embodiments, the processor unit 112 generates digital IF signal information by performing operations 402, 404 of the exemplary process 400, or by using other types of processes.

[0019] In some cases, the memory unit 114 is used to store a pre-configured program, pulse sequence information related to pulse sequences, digital IF signal values ​​for DAC waveform reproduction, hardware control sequences, digitized magnetic resonance detection signals, demodulated magnetic resonance detection signals, and other information.

[0020] In some cases, the signal processing unit 104 communicates with the data processing unit 102 and other units / components of the magnetic resonance system 100. The signal processing unit 104 is configured to generate an analog IF electrical signal based on a digital IF signal value according to a hardware control sequence, transmit the analog IF electrical signal to the transmitter unit 122, receive a magnetic resonance detection signal from the receiver unit 124, and digitize the magnetic resonance detection signal. In some cases, the signal processing unit 104 may be configured to perform other operations.

[0021] In some embodiments, the controller unit 122 of the signal processing unit 104 transmits digital IF signal values ​​to the DAC unit 124 according to a hardware control sequence, receives a digitized magnetic resonance detection signal from the ADC unit 126 according to a hardware control sequence, and generates digital control signals for the hardware components of the transmitter and receiver units 132 and 134 according to a hardware control sequence. In some embodiments, the controller unit 122 is configured to perform operations including synchronizing the outputs of the DAC unit 124, the ADC unit 126, and the DIO unit 128 to an internal timer, and controlling the outputs of the DAC unit 124, the ADC unit 126, and the DIO unit 128 according to a hardware control sequence, and other operations. The controller unit 122 is configured to synchronize the phase and timing across the components in the magnetic resonance system 100 according to a hardware control sequence. In some cases, the controller unit 122 may be configured to perform other operations. In some cases, the controller unit 122 of the signal processing unit 104 may include a field-programmable gate array (FPGA) unit, a digital signal processing (DSP) unit, or another type of data processing device. In some cases, the signal processing unit 104 may include other signal processing devices.

[0022] The DAC unit 124 is configured to convert the digital IF signal value received from the controller unit 122 and generate an analog IF electrical signal. The analog IF electrical signal generated by the signal processing unit 104 may be implemented as a pulse sequence including amplitude, phase, and frequency modulation at intermediate frequencies. In various examples, the DAC unit 124 is configured to generate analog IF control signals (e.g., analog IF I - quadrature phase control signal and analog IF Q - quadrature phase control signal) from the digital IF signal value. In the example shown, the digital control signal from the DIO unit 128 and the analog IF electrical signal from the DAC unit 124 are delivered to the spectrometer 106.

[0023] The signal processing unit 104 can receive a magnetic resonance detection signal from the resonator device 106 via the receiver unit 124. The magnetic resonance detection signal includes a signal with amplitude, phase, and frequency modulation at an intermediate frequency and can be digitized by the operation of the ADC unit 126. The digitized magnetic resonance detection signal (e.g., spin signal) can be demodulated by the operation of the processor unit 112 for further processing (e.g., for measurement, pulse transient control, and correction).

[0024] The exemplary DIO unit 128 converts the digital control toggle signal from the controller unit 122 into a hardware control toggle signal (e.g., TTL, ECL, etc.) and transmits the digital control signals to the respective control components within the spectrometer 106. For example, the digital control signals can be delivered to a switching device (switching devices 232, 252 in Figures 2A-2B) or other digitally controlled electronic components. The digital control signals from the DIO unit 128 are time-locked to an accuracy of less than 4 ns with respect to the analog IF electrical signal generated by the DAC unit 124 and the digitized magnetic resonance detection signal output from the ADC unit 126.

[0025] In some cases, the transmitter unit 122 of the spectrometer 106 includes microwave or radio frequency hardware components (e.g., switches, mixers, amplifiers, attenuators, etc.) that generate and receive microwave or radio frequency signals. For example, the transmitter unit 122 may be configured to process single-sideband X-band (8-12 GHz) signals. In some embodiments, the transmitter unit 122 includes a low-phase-noise microwave synthesizer for generating a system master oscillator signal and an analog spectrometer local oscillator signal, and for upconverting the analog IF electrical signal to a single-sideband signal that can be applied to the resonator unit 106, as well as for local oscillator suppression and (

number

number

[0026] In some cases, the transmitter unit 122 can be controlled digitally by digital control signals from a signal processing unit. In some cases, the transmitter unit 122 may include one or more switching devices and high-power amplifier (HPA) devices. The transmitter unit 122 can be implemented as the transmitter unit 204 in Figure 2A or in other forms. In some embodiments, at least a portion of the transmitter unit 122 operates at an elevated temperature away from the cryogenic environment, for example, room temperature. In some cases, the transmitter unit 122 operates in a cryogenic environment, for example, the same or a different cryogenic environment where the resonator unit 108 is present. In some examples, the transmitter unit 122 may be digitally controlled to perform fast switching between pulse operation mode and continuous wave operation mode.

[0027] In some embodiments, the resonator unit 106 resides in a cryogenic environment at extremely low temperatures, for example, within a cryogenic maintenance device. The resonator unit 106 includes a resonator that generates an electromagnetic field (e.g., a drive field) in the sample region of the magnetic resonance system. The resonator unit 106 may also include signal wiring for transmitting microwave signals and digital control signals, cryogenic receiver components, and internal hardware for temperature setting and stabilization. In some cases, a data processing device 102 can also transmit control signals to the resonator unit 106.

[0028] In some cases, the receiver unit 124 includes an amplifier device (e.g., a cryogenic LNA device). In some embodiments, the receiver unit 124 transmits the magnetic resonance detection signal to the local oscillator frequency (f LO By mixing it with the intermediate frequency (f IF The receiver unit 124 further includes a mixer device for down-converting to f. The receiver unit 124 also includes a filter device to remove unwanted frequency components, for example, from the mixer device to f. LO ~f IFRemove frequencies near the frequency value and reduce the receiver bandwidth (±f IF The receiver unit 124 may also include a bandpass IF filter to suppress noise outside the specified frequency range. The receiver unit 124 may further include other components, such as an IF amplifier, a low-pass filter, and other circuit components. In some cases, the receiver unit 124 includes various stages of filtering and amplification to reduce the noise bandwidth. The exemplary receiver unit 124 shown in Figure 1 can accept both a low-level spin signal input and a high-level pulse transient digitization input. In some examples, the receiver unit 124 may be controlled to switch between operating modes, for example, between a magnetic resonance measurement mode and a pulse transient digitization / correction mode.

[0029] In some cases, the spectrometer 104 may be configured to process signals in single-sideband Ku-band (12–18 GHz), Q-band (33–50 GHz), W-band (75–110 GHz), or other microwave frequency bands. For example, the transmitter unit 122 and receiver unit 124 may include a single-stage upconversion (e.g., Figure 2A) or downconversion (e.g., as shown in Figure 2B) using a single microwave synthesizer device configured to generate LO signals in each microwave frequency band. In another example, the transmitter unit 122 and receiver unit 124 may include a two or more-stage upconversion or downconversion using two or more microwave synthesizers and two or more corresponding mixers.

[0030] In the example shown in Figure 1, the components of the spectrometer 106 are electromagnetically coupled to the resonator unit 106 (e.g., by coaxial cable, waveguide, etc.) and adapted to communicate with the resonator unit 106. For example, the transmitter unit 122 may be adapted to provide a voltage or current electrical signal to drive the resonator unit 106. In the example shown in Figure 1, the receiver unit 124 acquires magnetic resonance data based on the control signals delivered to the resonator unit 106. For example, the receiver unit 124 may receive a magnetic resonance detection signal generated by the interaction between the resonator unit 106 and the sample contained in the resonator unit 106, based on the magnetic resonance control signals received in the resonator unit 106.

[0031] In some embodiments, the magnetic resonance system 100 includes a superheterodyne spectrometer system. Generally, the superheterodyne spectrometer generates a magnetic resonance control signal by mixing an intermediate frequency (IF) signal with a local oscillator (LO) signal to produce a high-frequency (e.g., RF or microwave) signal, which may then be further processed and passed to a resonator unit 106. The superheterodyne spectrometer processes the high-frequency magnetic resonance detection signal (e.g., spin signal) from the resonator unit 106 by mixing the high-frequency signal with the LO signal to produce an IF signal, which may then be further processed and digitized for analysis by a data processing device 102. Among the advantages of superheterodyne operation, it can enable increased sensitivity, selectivity, and signal-to-noise ratio. In some cases, superior control and data processing can be achieved by generating control information and processing the detected signal at the IF frequency. Furthermore, by using one or more tunable local oscillators, the superheterodyne spectrometer can be tuned to multiple distinct spin resonance frequencies, thereby enabling the superheterodyne spectrometer to function as a multi-functional system.

[0032] In some examples, the exemplary magnetic resonance system 100 may include further or different components, which may be configured as shown or in other ways. For example, the exemplary magnetic resonance system 100 may include a temperature control unit (TCU) configured and operated to monitor and stabilize the temperature of the cryogenic environment in which the resonator unit 106 resides; a field control unit (FCU) configured and operated to monitor, stabilize, and vary the primary magnetic field of the magnetic resonance system 100; and an electromagnet power supply and Hall probe that interface with the FCU to receive control signals from the FCU and apply the appropriate current to the primary magnet system. In some cases, the exemplary magnetic resonance system 100 may include a cryogenic maintenance device cooled by helium or nitrogen that can maintain an extremely low temperature (e.g., below 1K or another extremely low temperature). In some cases, the cryogenic maintenance device of the exemplary magnetic resonance system 100 may include internal control hardware for temperature setting and stabilization.

[0033] In some embodiments of operation, the primary magnet system of the magnetic resonance system 100 generates a primary magnetic field within a controlled environment of the sample region of the magnetic resonance system 100. The primary magnetic field is typically applied to a sample in the sample region near the resonator apparatus 106. In various embodiments, the primary magnetic field may be uniform across the volume of the sample region. In some cases, a gradient system generates one or more spatially varying gradient magnetic fields across the sample region. Generally, the primary magnetic field generated by the primary magnet system quantizes the spin states and sets the Larmor frequency of the spin ensemble.

[0034] In some embodiments of operation, a spin ensemble within a sample interacts with the resonator apparatus 106. Control of spins within a sample can be achieved, for example, by a radio frequency or microwave magnetic field generated by the resonator apparatus. The driving frequency may be tuned to the resonant frequency of the spins, which is determined by the strength of the primary magnetic field and the gyromagnetic ratio of the spins. A spin can be an aggregate of particles having non-zero spin that magnetically interact with the applied magnetic field. For example, a spin ensemble can include nuclear spins, electron spins, or a combination of nuclear spins and electron spins. Examples of nuclear spins include hydrogen nuclei (1H) and carbon-13 nuclei (13C). In some embodiments, a spin ensemble is an aggregate of identical spin-1 / 2 free electron spins attached to an ensemble of larger molecules.

[0035] Figure 2A is a schematic diagram showing an embodiment of an exemplary magnetic resonance system 200. The components of the exemplary magnetic resonance system 200 shown in Figure 2A are configured to generate and transmit magnetic resonance control signals to a resonator device. As shown in Figure 2A, the exemplary magnetic resonance system 200 includes a signal processing unit 202 and a transmitter unit 204. In some cases, the signal processing unit 202 and the transmitter unit 204 may be implemented as a controller unit 122 and a transmitter unit 122 in the exemplary magnetic resonance system 100 of Figure 1, or in a different form. In some examples, the exemplary magnetic resonance system 200 may include further or different components, which may be configured as shown or in a different form.

[0036] As shown in Figure 2A, the signal processing unit 202 includes a controller unit 212, two DAC units 214 and 216, and a DIO unit 218. In some cases, the controller unit 212 may be a field-programmable gate array (FPGA) module, which may include one or more buffer devices, digital signal processing devices, and other electronic devices. In some embodiments, the controller unit 212 is configured to transmit digital intermediate frequency (IF) signal values ​​to the first DAC unit 214 and the second DAC unit 216, and to control the DIO device 218 to transmit digital control signals according to a hardware control sequence. In some embodiments, the controller unit 212 is configured to receive and store digital IF signal values ​​representing the digital IF signals and a hardware control sequence for scheduling and synchronizing the output signals of the first and second DAC units 214 and 216, and the DIO device 218, so as to maintain temporal phase coherence. In some embodiments, the signal processing unit 202 may be implemented as the signal processing unit 300 in Figure 3 or in another form. In some embodiments, the signal processing unit 202 is configured to perform the operations in the exemplary process 400 shown in Figure 4.

[0037] In some embodiments, the first DAC unit 214 is configured to receive a first set of digital IF signal values ​​(e.g., digital I - quadrature phase signal values) according to a hardware control sequence from the controller unit 212 (e.g., an exemplary hardware control sequence shown in Figures 9A-9B), generate a first analog IF electrical signal (e.g., I - quadrature phase control signal), and transmit the first analog IF electrical signal to a first input port of the transmitter unit 204. Similarly, the second DAC unit 216 is configured to receive a second set of digital IF signal values ​​(e.g., digital Q - quadrature phase signal values) according to a hardware control sequence from the controller unit 212, generate a second analog IF electrical signal (e.g., Q - quadrature phase control signal), and transmit the second analog IF electrical signal to a second input port of the transmitter unit 204. The DIO device 218 is configured to receive digital control signal values ​​from the controller unit 212 and to transmit the digital control signal values ​​to the transmitter unit 204 (e.g., the switch device 232 of the transmitter unit 204, or other digitally controlled device). In some embodiments, the digital control signal is phase-locked to first and second analog IF electrical signals from first and second DAC units 214, 216. The transmitter unit 204 includes a superheterodyne spectrometer that mixes the first and second analog IF electrical signals with local oscillator (LO) electrical signals to generate and process a magnetic resonance control signal.

[0038] As shown in Figure 2A, the transmitter unit 204 includes low-pass filter devices 222A, 222B, microwave synthesizer device 224, mixer device 226, band-pass filter device 228, high-power amplifier (HPA) device 230, and switch device 232. In some cases, the transmitter unit 204 may include further microwave hardware components (e.g., switches, mixers, amplifiers, attenuators, etc.) for generating and receiving single-sideband X-band (8-12 GHz) signals, and the components of the transmitter unit 204 may be arranged in a different order.

[0039] As shown in Figure 2A, each of the low-pass filter units 222A and 222B has an input port connected to the input port of the transmitter unit 204 and an output port connected to the input port of the mixer unit 226. In some embodiments, the input port of the transmitter unit 204 can receive first and second analog IF electrical signals from the DAC units 214 and 216 of the signal processing unit 202, and the output port of the transmitter unit can provide a magnetic resonance control signal for transmission to the resonator device. The resonator device receives the magnetic resonance control signal and generates a control field (e.g., a drive field) in response to the received magnetic resonance control signal. In some cases, the magnetic resonance control signal is upconverted based on the analog IF electrical signal and the LO electrical signal.

[0040] The mixer unit 226 includes a third input port connected to a local oscillator unit 224 for receiving local oscillator electrical signals. The input port of the bandfilter unit 228 is coupled to the output port of the mixer unit 226. The HPA unit 230 includes an HPA input port and an HPA output port. The HPA input port is coupled to the output of the bandfilter unit 228. The input port of the switch unit 232 is coupled to the HPA output port of the HPA unit 230. The output port of the switch unit 232 is coupled to the output port of the transmitter unit 204. In some embodiments, the input and output ports of the components of the transmitter unit 204 are connected to each other via waveguides, coaxial cables, metal wires or feed lines, or other types of signal lines.

[0041] In some cases, the low-pass filter devices 222A and 222B each have 2f IF This is an anti-aliasing low-pass filter device having a cutoff frequency. In some cases, the low-pass filter devices 222A and 222B may be different types of low-pass filter devices having cutoff frequencies of different values. The filtered first analog IF electrical signal at the first input port of the mixer device 226 is a digitally generated analog IF-quadrature control signal, including amplitude, phase, and frequency modulation. In some cases, the first analog IF electrical

number

number

number

number

[0042] In some embodiments, the filtered second analog IF electrical signal at the second input port of the mixer device 226 is an analog IF Q-orthogonal phase control signal generated in a digital manner that includes amplitude, phase, and frequency modulation

Number

Number

Number

Number

Number

[0043] In some cases, the microwave synthesizer device 224 is a low-phase-noise microwave synthesizer device configured to generate a system master oscillator signal and an analog spectrometer local oscillator signal. In some cases, the microwave synthesizer device 224 may be a different type of microwave synthesizer device. In some cases, the mixer device 226 receives filtered first and second analog IF electrical signals and uses magnetic resonance control signals (e.g., single-sideband signals f) to resonate with the spin in the resonator device. res Upconverting to (

number

number

[0044] In some examples, the band filter device 228 of the transmitter unit 204 is configured to suppress noise from outside the spectrometer bandwidth and from other circuit components without reducing the pulse bandwidth. In some embodiments, the band filter device 228 is configured to suppress f0+f IF The center frequency is at , where f0 is the resonator frequency (e.g., 8-12 GHz in the X band, 12-18 GHz in the Ku band, 33-50 GHz and 75-110 GHz in the W band), and f IF This is the intermediate frequency, and the bandwidth is 4f IFIn some cases, the band filter device 228 has different center frequencies and bandwidths. In some cases, the HPA device 230 is configured to amplify the magnetic resonance control signal before transmitting it to the resonator device. In some embodiments, the magnetic resonance control signal transmitted to the resonator device includes a series of analog control pulses having frequencies in the microwave region. In some embodiments, the transmitter unit 204 may include other microwave hardware components (e.g., switches, mixers, amplifiers, attenuators, etc.) necessary to generate and receive single-sideband signals.

[0045] In some embodiments, the switch device 232 of the transmitter unit 204 includes a control port for receiving digital control signals from the DIO device 218 of the signal processing unit 202 and is digitally controlled to perform high-speed blanking of magnetic resonance control signals to the resonator device. In some cases, the transmitter unit 106 may include further or different switch devices, filter devices, and other devices. In some embodiments, the signal processing unit 202 and at least a portion of the transmitter unit 204 operate at elevated temperatures, such as room temperature, away from the cryogenic environment in which the resonator device exists. In some embodiments, the transmitter unit 204 operates at extremely low temperatures.

[0046] In some embodiments, the digital control signal generated by the signal processing unit 202 and received by the switch device 232 of the transmitter unit 204 may be a transistor-to-transistor logic (TTL) signal having two TTL logic levels. When the TTL signal is at a voltage in the range of 1.5 to 5 volts (V), the TTL logic level is digital "1" or at a logical high level, and similarly, when the TTL signal is at a voltage in the range of 0 to 0.7V, the TTL logic level is digital "0" or at a logical low level. In some cases, the TTL logic level may be in a different range, and the digital control signal may be a different type of digital signal. In some cases, the digital control signal received by the switch device 232 may be a different type of digital control signal.

[0047] In some embodiments, the input and output ports of a switch device may be selectively coupled or uncoupled depending on the state of the digital control signal. An input port of a switch device may be considered coupled to an output port of the switch device when the switch device is configured to transmit signals from the input port to the output port with no attenuation or with negligible attenuation. Similarly, an input port of a switch device may be considered uncoupled from an output port of the switch device when the switch device is configured to transmit signals from the input port to the output port of the switch device at a negligible level, for example, the switch device may completely block the signal or substantially attenuate the signal (e.g., at an attenuation level above a threshold value).

[0048] In some embodiments, the switch device 232 is configured to switch between a first state and a second state in response to a change in the state of a digital control signal at a control port. When the digital control signal received by the switch device 232 is in a first state (e.g., a high logic level), the switch device 232 is switched to a first state for coupling its input port to an output port, thereby enabling the magnetic resonance control signal to be delivered to the output port of the switch device 232 with little to no attenuation. When the digital control signal received by the switch device 232 is in a second state (e.g., a low logic level), the switch device 232 is in a second state for uncoupling its input port from its output port, thereby blocking the magnetic resonance control signal with considerable attenuation.

[0049] In some embodiments, the switch device 232 is a single-pole single-throw switch device. In some cases, the switch device 232 may be a different type of switch device. For example, the switch device 232 may have any number of poles, any number of throws, any number of input ports, output ports, and control ports. In some cases, the switch device 232 may have three or more states. In some cases, the control ports of the switch device 232 may interface with a 1-bit control line, a 2-bit control line, or other multi-bit control lines for receiving each type of digital control signal.

[0050] In some embodiments, the first and second analog IF electrical signals at the first and second input ports of the transmitter unit 204 and the digital control signals in the switching device 232 are synchronized by a hardware control sequence (e.g., exemplary hardware control sequences 900, 910 in Figures 9A-9B). For example, during continuous wave magnetic resonance (SMR) measurements or pulsed SMR measurements, when the first and second analog IF electrical signals are received at the first and second input ports of the transmitter unit 204 between periods t2-t1 and t6-t5, the switching device 232 is in a first state for the same duration as defined in the hardware control sequences in Figures 9A-9B. In some embodiments, when the first and second analog IF electrical signals are not received at the first and second input ports of the transmitter unit 204, for example, between periods t4-t3 and t8-t7, the switching device 232 is in a second state for the same duration as defined in the hardware control sequences in Figures 9A-9B. In some cases, the switch device 232 is switched to a first state at time t0, before DAC waveform playback is enabled at time t1, and then switched to a second state at time t3, after DAC waveform playback is disabled at time t2.

[0051] In some embodiments, the switching time of the switch device 232 is in the range of 5 to 20 ns, less than or equal to 200 ns, less than or equal to 1 μs, or within another range. In some embodiments, the switch device 232 can receive and handle input signals having a power of up to 1 W or within another range. In some cases, the switch device 232 may be configured to handle higher power, for example, greater than 1 watt (W), up to tens of watts, up to 10 kilowatts (kW), or within another range depending on the HPA device 230.

[0052] A pulse sequence can include a series of pulses and delays; for example, a pulse sequence may include a first pulse, a time delay after the first pulse, and a second pulse after the time delay. The data processing unit 102 is configured to identify a first pulse profile for the first pulse, generate a first digital IF signal value based on the first pulse profile, and generate a first analog IF electrical signal based on the first digital IF signal value. The transmitter unit 122 operates to mix the first analog IF electrical signal with a local oscillator electrical signal to create a first magnetic resonance control signal, which is then transmitted to the resonator unit 106 of the magnetic resonance system 100. The data processing unit 102 is further configured to identify a second pulse profile, generate a second digital IF signal value based on the second pulse profile, implement a time delay, and generate a second analog IF electrical signal based on the second digital IF signal value. The transmitter unit 122 operates, and the second analog IF electrical signal is mixed with the local oscillator electrical signal to create a second magnetic resonance control signal, which is then transmitted to the resonator unit 106 of the magnetic resonance system 100.

[0053] Figure 2B is a schematic diagram showing an embodiment of an exemplary magnetic resonance system 240. The exemplary components of the magnetic resonance system 240 shown in Figure 2B are configured to receive a magnetic resonance detection signal from a resonator unit. As shown in Figure 2B, the exemplary magnetic resonance system 240 includes a signal processing unit 242 and a receiver unit 244. In some embodiments, the signal processing unit 242 and at least a portion of the receiver unit 244 operate at a raised temperature, such as room temperature, outside the cryogenic environment in which the resonator unit resides. In some cases, certain devices or components of the receiver unit 244 may reside within the cryogenic environment containing the resonator unit, or in a separate cryogenic environment at a separate cryogenic temperature. In some cases, the signal processing unit 242 and the receiver unit 244 may be implemented as the controller unit 122 and receiver unit 124 of the exemplary magnetic resonance system 100 in Figure 1, or in other forms. In some examples, the exemplary magnetic resonance system 240 may include further or different components, which may be configured as shown or in other forms.

[0054] As shown in Figure 2B, the signal processing unit 242 includes a controller unit 212, an ADC unit 220, and a DIO device 218. In some cases, the signal processing unit 242 may be implemented as the signal processing unit 202 in Figure 2A. In some embodiments, the controller unit 212 is configured to receive the digitized magnetic resonance detection signal from the ADC unit 220 and to operate the DIO device 218 to transmit a digital control signal. The acquisition of the magnetic resonance detection signal from the resonator unit may be controlled by the controller unit 212. In some embodiments, the receiver unit 244 is adapted to downconvert the magnetic resonance detection signal to an intermediate frequency. In some embodiments, the acquired magnetic resonance detection signal may be digitized phase-coherently at the intermediate frequency by the operation of the ADC unit 220. In some embodiments, the acquisition of the digitized magnetic resonance detection signal is synchronized with a digital control signal (e.g., a digital control signal applied to a switch device 252) according to a hardware control sequence (e.g., an exemplary hardware control sequence shown in Figures 9A-9B). The processor unit (for example, the processor unit 112 of the data processing device 102 in Figure 1) can operate to demodulate the digitized magnetic resonance detection signal digitally at an intermediate frequency for phase-sensitive detection. In some embodiments, the digital control signal is phase-locked to the output signal of the ADC unit 220. In some cases, the processor unit can operate to apply precise and arbitrary phase correction to the demodulated digitized magnetic resonance detection signal. When a multi-resonance magnetic resonance measurement is performed, the processor unit can operate to demodulate the digitized magnetic resonance detection signal using multiple IF carrier signals with different intermediate frequencies, and process the demodulated digitized magnetic resonance detection signals in parallel.

[0055] As shown in Figure 2B, the receiver unit 244 includes a switching device 252, a low-noise amplifier (LNA) device 254, a first bandpass filter device 256, a mixer device 258, a microwave synthesizer device 260, a second bandpass filter device 262, an intermediate frequency amplifier (IFA) device 264, and a low-pass filter device 268. In some cases, the receiver unit 244 may include further microwave hardware components (e.g., switches, mixers, amplifiers, attenuators, etc.) for processing the magnetic resonance detection signal, and the components of the receiver unit 244 may be configured in different ways. In some cases, the receiver unit 244 includes various stages of filtering and amplification to reduce the noise bandwidth. In some embodiments, the magnetic resonance detection signal received at the input port of the receiver unit 244 includes a low-level spin signal input, a high-level pulse transient digitization input, or other types of signals.

[0056] As shown in Figure 2B, the switch device 252 has an input port connected to the resonator device and an output port connected to the LNA input port of the LNA device 254. In some embodiments, the input port of the switch device 252 can receive magnetic resonance detection signals from the resonator unit. The input port of the first bandpass filter device 256 is connected to the LNA output port of the LNA device 254. The first input port of the mixer device 258 is connected to the output port of the first bandpass filter device 256, and the second input port of the mixer device 258 is connected to the microwave synthesizer 260 to receive local oscillator electrical signals. The input port of the second bandpass filter device 262 is connected to the output port of the mixer device 258. The input port of the IFA device 264 is connected to the output port of the second bandpass filter device 262. The input port of the low-pass filter device 268 is connected to the output port of the IFA device 264. The output port of the low-pass filter device 268 is connected to the input port of the ADC unit 220 of the signal processing unit 242. In some embodiments, the input and output ports of the components of the receiver unit 244 are connected to each other via waveguides, coaxial cables, or other types of signal lines.

[0057] As shown in Figure 2B, the switch device 252 of the receiver unit 244 includes a control port for receiving digital control signals from the DIO unit 218 of the signal processing unit 242 and is digitally controlled to perform high-speed blanking of the receiver unit 244 during the use of high-power pulses. For example, as shown in Figures 9A-9B, during periods t2-t1 and t6-t5, the digital control signals transmitted to the switch device 252 are in the "off" state for receiver blanking, and during periods t9-t8, the digital control signals transmitted to the switch device 252 are in the "on" state for signal acquisition. The LNA device 254 is operated at low power (e.g., less than 1W or another value) and has high gain (e.g., 30-50dB or another range). The first bandpass filter device 256 is a narrowband filter having a center frequency around the resonator frequency (f0) for noise reduction and a bandwidth larger than the resonator bandwidth. The microwave synthesizer device 260 is a low-phase-noise microwave synthesizer device configured to generate the system master oscillator signal and the analog spectrometer local oscillator electrical signal. In some cases, the microwave synthesizer device 260 may be implemented in a similar manner to, or in a different manner than, the microwave synthesizer device 224 of the transmitter unit 204 in Figure 2A. In some cases, the mixer device 258 is an IQ mixer device that receives the magnetic resonance detection signal and sets the frequency of the magnetic resonance detection signal to an intermediate frequency (f IF The system is configured to downconvert the signal from the mixer 258 to a certain format and to transmit the downconverted magnetic resonance detection signal to the second band filter device 262. IF +f LO For signal rejection and receiver bandwidth (±f IF ) suppresses noise outside of the intermediate frequency (f IFThis is a narrowband filter device with a center frequency of around ). The intermediate frequency amplifier (IFA) device 264 is configured to amplify the down-converted magnetic resonance detection signal before sending it to the signal processing unit 242. In some cases, the IFA device 264 may consist of a single amplifier device or a chain of amplifier devices to increase the gain. The low-pass filter device 268 is configured to have a center frequency of <2f to the ADC unit 220. IF This is an anti-aliasing filter with a cutoff frequency.

[0058] In some embodiments, the digital control signal generated by the signal processing unit 242 and received by the switch device 252 of the receiver unit 244 may be a transistor-transistor logic (TTL) signal having two TTL logic levels. When the TTL signal is at a voltage in the range of 1.5 to 5 volts (V), the TTL logic level is digital "1" or at the logical high level, and similarly, when the TTL signal is at a voltage in the range of 0 to 0.7V, the TTL logic level is digital "0" or at the logical low level. In some cases, the TTL logic level may be in a different range, and the digital control signal may be a different type of digital signal.

[0059] In some embodiments, the switch device 252 is configured to switch between a first state and a second state in response to a change in the state of a digital control signal at a control port. When the digital control signal received by the switch device 252 is in a first state (e.g., a high logic level), the switch device 252 is in a first state for coupling its input port to its output port, thereby enabling the transmission of the magnetic resonance control signal from the input port to the output port of the switch device 252 with little to no attenuation. When the digital control signal received by the switch device 252 is in a second state (e.g., a low logic level), the switch device 252 is in a second state for uncoupling its input port from its output port, thereby blocking the magnetic resonance control signal with considerable attenuation.

[0060] In some embodiments, the switch device 252 is a single-pole single-throw switch device. In some cases, the switch device 252 may be a different type of switch device. For example, the switch device 252 may have any number of poles, any number of throws, any number of input ports, output ports, and control ports. In some cases, the switch device 252 may have three or more states. In some cases, the control ports of the switch device 252 may interface with a 1-bit control line, a 2-bit control line, or other multi-bit control lines for receiving each type of digital control signal.

[0061] In some embodiments, the switching time of the switch device 252 is in the range of 5 to 20 ns, less than or equal to 200 ns, less than or equal to 1 μs, or within another range. In some embodiments, the switch device 252 can receive and handle input signals having a power of up to 1 W or within another range. In some cases, the switch device 252 may be configured to handle higher power, for example, in the range of greater than 1 W, up to tens of watts, up to 10 kilowatts (kW), or within another range depending on the LNA device 254.

[0062] In some cases, the digital control signal from the DIO unit 218 to the switch device 252 is synchronized with the output of the ADC unit 220. For example, as shown in the exemplary hardware control sequence in Figures 9A-9B, at time step t8, the switch device 252 switches from a second state to a first state, and during the period t9-t8, the switch device 252 remains in the first state while transmitting the digitized magnetic resonance detection signal (for example, to the processor unit 112 in Figure 1), and at time step t9, the switch device 252 switches from the first state to a second state.

[0063] Figure 3A is a schematic diagram of an exemplary signal processing unit 300 of a magnetic resonance system. The signal processing unit 300 may include a controller unit 302, two DAC units 316A and 316B, two ADC units 320A and 320B, and a DIO unit 318. In some cases, the exemplary signal processing unit 300 may be implemented as controller units 104, 202, and 242 in Figures 1, 2A to 2B, or in other forms. In some cases, the DAC units 316A and 316B, the ADC units 320A and 320B, and the DIO unit 318 may be implemented as described with respect to Figures 2A to 2B, or in other forms. In some examples, the exemplary signal processing unit 300 may include further or different components, which may be configured as shown or in other forms.

[0064] The exemplary signal processing unit 300 includes first-in, first-out (FIFO) buffer devices 304A, 304B, and 304C. In some cases, the FIFO buffer devices 304A, 304B, and 304C are configured to buffer data before sending it to their respective devices, e.g., DAC units 316A, 316B, DIO device 318, and other devices, according to a hardware-controlled sequence. In the examples shown, FIFO buffer device 304A is configured to buffer digital IF signal values ​​for generating analog IF I - quadrature phase signals, FIFO buffer device 304B is configured to buffer digital IF signal values ​​for generating analog IF Q - quadrature phase signals, and FIFO buffer device 304C is configured to buffer hardware control signals, the hardware control signals including timestamp values ​​and hardware control values. In some cases, FIFO buffer device 304C may be a circular FIFO buffer device that recycles and reuses commands stored in the buffer device. The digital IF signal values ​​and hardware control sequences are determined by one or more processor units of the computer system (e.g., processor unit 112 of data processing unit 102) based on the target pulse sequence and are configured to construct magnetic resonance control signals for the resonator unit. In some cases, FIFO buffer devices 304A, 304B, and 304C may be configured to perform other functions. In some embodiments, the operation of FIFO buffer devices 304A, 304B, and 304C is based on a timer comparison value determined by comparing the current time value, based on a clock signal produced by the internal clock 308, with a timestamp value in the hardware control sequence. In some cases, the clock signal produced by the internal clock 308 can be effectively delayed at the firmware level for each hardware component to ensure sub-ns synchronization of all outputs of the DAC unit, ADC unit, and DIO unit.In some cases, the clock signal is delayed by setting the timestamp value to a later time. For example, by setting the timestamp value of timestamp segment 334D in frame 332 to a later time, each trigger enable unit 312A, 312B, and 312C can be enabled at a later time, and each trigger enable unit 312A, 312B, and 312C then enables communication of the DAC trigger value, ADC trigger value, and DIO trigger value to the DAC unit, ADC unit, and DIO unit, respectively, so that the operation of each device is synchronized at the later time. In some cases, each of the FIFO buffer devices 304A, 304B, and 304C may contain a register, block random access memory (BRAM), or other types of memory devices that may be defined by width and depth.

[0065] In some cases, data (e.g., digital IF signal values ​​and hardware control sequences) may be written to the respective FIFO buffer devices 304A, 304B, and 304C during a write cycle and read from the respective FIFO devices 304A, 304B, and 304C during a read cycle. In the example shown, the digital IF signal values ​​are received in the controller unit 302 of the signal processing unit 300. The digital IF signal values ​​corresponding to the analog IF I-quadrature phase signal and the analog IF Q-quadrature phase signal are obtained and stored separately in the respective FIFO buffer devices 304A and 304B. Similarly, the hardware control sequences are received in the controller unit 302 and stored in the FIFO buffer device 304C. Reading the digital IF signal values ​​stored in the FIFO devices 304A and 304B is performed according to the hardware control sequences stored in the FIFO device 304C. In some cases, the hardware control sequence may be implemented as the exemplary hardware control sequences 900, 910 shown in Figures 9A-9B, and having the exemplary data format shown in Figure 3B or another format.

[0066] As shown in Figure 3A, the FIFO buffer device 304C includes an input port for receiving hardware control sequences and an output port for transmitting hardware control values ​​to the respective devices. In particular, the FIFO buffer device 304C includes two DAC trigger terminals, two ADC trigger terminals, one DIO trigger terminal, and a time terminal. The two DAC trigger terminals are connected to the D terminal of the DAC trigger-enable unit 312A, the two ADC trigger terminals are connected to the D terminal of the ADC trigger-enable unit 312C, and the time terminal is connected to the comparator device 310. The output port of the comparator device 310 is connected to the EN terminal of the respective DAC, ADC, and DIO trigger-enable units 312A, 312B, and 312C. The first output port of the DAC trigger-enable unit 312A is connected to the trigger terminal of the first FIFO buffer device 304A, and the second output port of the DAC trigger-enable unit 312A is connected to the trigger terminal of the second FIFO buffer device 304B. The output port of the DIO trigger-enable unit 312B is connected to the input port of the DIO unit 318. The first output port of the ADC trigger-enable unit 312C is connected to the ADC buffer device 322A, and the second output port of the ADC trigger-enable unit 312C is connected to the ADC buffer device 322B. The ADC buffer device 322A includes an input port connected to the output port of the ADC unit 320A, and the ADC buffer device 322B includes an input port connected to the output port of the ADC unit 320B. The output port of the ADC buffer device 322A is connected to the first input port of the multiplexer device 306B, and the output port of the ADC buffer device 322B is connected to the second input port of the multiplexer device 306B. A signal from the output port of the ADC trigger-enable unit 312C triggers the emission of information (e.g., magnetic resonance detection signals) stored in the ADC buffer devices 322A and 322B to the computer system.

[0067] The signal processing unit 300 is configured to deterministically trigger and control the outputs of the DAC units 316A, 316B, DIO unit 318, and ADC units 320A, 320B through the operation of their respective trigger-enable units 312A, 312B, and 312C. In some embodiments, each trigger-enable unit 312A, 312B, and 312C is operated independently while maintaining time synchronization and phase matching of the outputs of the DAC units 316A, 316B, DIO unit 318, and ADC units 320A, 320B. In some embodiments, each trigger-enable unit 312A, 312B, and 312C is further configured to disable DAC regeneration, ADC reading, and DIO. In certain cases, the trigger-enable units 312A, 312B, and 312C can be enabled and disabled multiple times in a pulse sequence.

[0068] In some embodiments, the DAC trigger-enable unit 312A, the ADC trigger-enable unit 312B, and the DIO trigger-enable unit 312C ensure phase coherence of the DAC units 316A, 316B, the ADC units 320A, 320B, and the DIO unit 318. During operation, hardware trigger signals are received from the FIFO buffer device 304C by the respective trigger-enable devices 312A, 312B, and 312C, and can be transmitted to the respective FIFO buffer devices 304A, 304B, the DIO unit 318, and the ADC buffer devices 322A, 322B according to timestamp values ​​in the hardware control sequence. For example, when a timestamp value carried by a timeline trigger signal from the FIFO buffer unit 304C in the hardware control sequence matches a time value from the internal clock 308, the trigger-enable units 312A, 312B, and 312C are turned on, allowing the hardware trigger signal to be transmitted from terminal D to terminal Q. The hardware trigger signal is then used to enable the FIFO buffer units 304A, 304B and the ADC buffer units 322A, 322B. Once the FIFO buffer units 304A, 304B and the ADC buffer units 322A, 322B are enabled, the digital IF signal values ​​stored in the FIFO buffer units 304A and 304B are sent from the controller unit 104 to the respective DAC units 316A and 316B, and the magnetic resonance detection signals stored in the ADC buffer units 322A and 322B are sent from the controller unit 302 to, for example, the signal processing unit 102. In this case, the outputs from DAC units 316A and 316B, ADC units 320A and 320B, and DIO unit 318 are synchronized with each other.

[0069] Figure 3B is a schematic diagram 330 of an exemplary data format of the FIFO buffer device 304C of the exemplary signal processing unit 300 in Figure 3A. As shown in Figure 3B, the FIFO buffer device 304C includes a stream of events, for example, multiple frames that describe hardware control values ​​in each timestamp value. For example, when each frame has a length of 64 bits, each frame may include a 48-bit timestamp segment, a 2-bit DAC trigger segment corresponding to DAC units 316A, 316B, a 2-bit ADC trigger segment corresponding to ADC units 320A, 320B, and a 12-bit DIO toggle segment. In some cases, the frames of the FIFO buffer device 304C may have different lengths, and the segment lengths may vary depending on the number of ADC units and DAC units and digitally controlled devices in the transmitter and receiver circuits.

[0070] In a particular example, the internal clock is a 48-bit timeline clock, which starts when an experiment is triggered externally. When the timestamp value of the timestamp segment in frame 332 matches the current value of the internal clock, the events defined by the hardware control values ​​of the respective ADC segment 334C, DAC segment 334B, and DIO toggle segment 334A in frame 332 are transmitted through their respective terminals to the respective trigger-enable units 312A, 312B, and 312C.

[0071] In some embodiments, the comparator device 310 operates to compare the timestamp value of timestamp section 334D in frame 332 with the current time value from the internal timer 308. When the timestamp value is equal to the current time value, the respective trigger-enable units 312A, 312B, and 312C are enabled, and the DIO trigger value, DAC trigger value, and ADC trigger value stored in the respective sections 334A, 334B, and 334C of frame 332 are passed from the D terminal to the Q terminal of the trigger-enable units 312A, 312B, and 312C. In particular, when the DAC trigger-enable unit 312A is enabled, the DAC trigger value is transmitted to the trigger terminal of the respective FIFO buffer devices 304A and 304B, and the digital IF signal values ​​in the current frame of the FIFO buffer devices 304A and 304B are transferred to the respective DAC units 316A and 316B. When the DIO trigger-enable unit 312B is enabled, the DIO trigger value is transmitted to the DIO unit 318, and further transmitted to the respective digital control devices of the transmitter and receiver units (for example, the switch devices 232 and 252 of the transmitter unit 204 and receiver unit 244 in Figures 2A and 2B). When the ADC trigger-enable unit 312C is enabled, the ADC trigger value in frame 332 is transferred to the ADC delay device 314, which uses the ADC delay device 314 to control the respective ADC buffer devices 322A and 322B associated with the respective ADC units 320A and 320B.

[0072] In some embodiments, when the timestamp value in frame 332 is not equal to the current time value of the internal clock 308, the trigger-enable units 312A, 312B, and 312C are disabled. In this case, the DAC trigger value, ADC trigger value, and DIO trigger value of frame 332 are not transferred to their respective devices.

[0073] In some embodiments, DAC units 316A and 316B are configured to receive digital IF signal values ​​from FIFO buffer devices 304A and 304B according to a hardware control sequence stored in FIFO buffer device 304C, convert the digital IF signal values ​​into analog IF I (quadrature phase control signal) and analog IF Q (quadrature phase control signal), and output the analog IF I (quadrature phase control signal) and analog IF Q (quadrature phase control signal) to a transmitter unit (e.g., transmitter unit 204 in Figure 2A). In some embodiments, DIO unit 318 receives digital trigger signals and converts them into a form suitable for driving hardware, such as emitter-coupled logic (ECL) signals, transistor-to-transistor logic (TTL) signals, etc.

[0074] Figure 4 is a flowchart illustrating an exemplary process 400. The exemplary process 400 can be performed, for example, by the operation of a magnetic resonance system. For example, the operation in exemplary process 400 may be performed by the operation of exemplary magnetic resonance systems 100, 200, 240 shown in Figures 1, 2A-2B, signal processing units 300, 340 in Figures 3A, 3C, or another type of system including further or different bypass circuits. Exemplary process 400 may include further or different operations, including operations performed by further or different components, and the operations may be performed in the order shown or in a different order. In some cases, the operations in exemplary process 400 may be combined, repeated or otherwise repeated or performed in a different manner.

[0075] In some cases, the operation of the exemplary process 400 shown in Figure 4 is performed as a process for generating and synchronizing magnetic resonance control signals and digital control signals for transmitter units 122, 204 in Figures 1 and 2A, as well as as a process for receiving magnetic resonance detection signals from receiver units 124, 244 in Figures 1 and 2B.

[0076] In 402, the pulse profile is identified. In some embodiments, the pulse profile includes a target pulse or a series of target pulses that will be used when performing a magnetic resonance measurement on a sample in a magnetic resonance system. For example, the pulse profile includes a time series of amplitudes and a time series of phases for a target pulse or a group of target pulses in a pulse sequence. In certain cases, multiple pulse profiles can also be identified. In some cases, when the pulse profile includes multiple pulses, the pulse profile may include one or more time delays that separate each pair of adjacent pulses. In some embodiments, the pulse profile is identified by the operation of the data processing device 102.

[0077] In some embodiments, the pulse in the pulse profile is characterized by pulse parameters. For example, a target pulse may have multiple pulse segments, each pulse segment characterized by amplitude, phase, frequency, and duration. In some embodiments, the pulse parameters of the pulse in the pulse profile define the amplitude envelope and phase envelope of the digital IF signal across the corresponding pulse segments.

[0078] Figure 5A includes a time series 500 of the amplitude of pulse intervals of a pulse with a duration of 500 ns and a time series 502 of the phase of pulse intervals of the pulse. As shown in Figure 5A, the pulse has 10 random pulse intervals, each defined by its respective amplitude, phase, and duration. As shown in Figure 5A, the exemplary pulse profile includes 10 pulse intervals. Each of the 10 pulse intervals may have at least one distinct pulse parameter. In some embodiments, the 10 pulse intervals in the exemplary pulse are consecutive. For example, the first pulse interval has an amplitude of 1, a phase of 15 degrees, and a duration of 60 ns, the second pulse interval following the first pulse interval has an amplitude of 0.48, a phase of -150 degrees, and a duration of 40 ns, and the third pulse interval following the second pulse has an amplitude of 0.65, a phase of -180 degrees, and a duration of 80 ns. In some cases, a pulse profile may include a different number of pulse segments, pulse segments in a different order, and pulse segments with different pulse parameters, or may be composed in a different manner.

[0079] In some cases, pulse profiles may be pre-configured and stored in a memory unit (e.g., the memory unit 116 of the data processing unit 102). In some cases, pulse profiles may be created on the data processing unit 102 or specified by the user. Pulse profiles may be received from a user device that is communicably connected to the data processing unit 102, for example, via a local network. In some cases, pulse profiles may be edited or modified by the user. Pulse profiles can be stored in the memory unit 116 of the data processing unit 102. In some cases, pulse profiles can be selected from the memory unit depending on the characteristics of the magnetic resonance measurement, the resonator device and the sample, and other factors. In some cases, pulse profiles can be generated, edited, and modified by the user. For example, a user can generate a pulse profile by specifying a target pulse (e.g., phase, amplitude, and duration) and a time delay for the type of magnetic resonance measurement. The generated pulse profile can be stored in the memory unit.

[0080] In some cases, the pulse profile may be modified at any stage of the magnetic resonance measurement so that the pulse parameters of the pulse can be changed, updated, or modified depending on the sample in the resonator unit and the requirements of the magnetic resonance measurement. For example, online adaptive updates may be used based on feedback from the magnetic resonance detection signal.

[0081] In 404, a digital IF signal value is generated. In some embodiments, the digital IF signal value is generated based on a specified pulse profile. In some embodiments, the pulse sequence in the specified pulse profile may be analyzed to identify the individual pulses in the pulse profile, the time delay, and the acquisition period in the pulse sequence. In some embodiments, the digital IF signal value is generated by modulating the respective amplitude envelope of the individual pulses in the specified pulse profile using a digitally generated intermediate frequency carrier signal (e.g., a digital IF carrier signal). In some embodiments, the phase of the digital IF carrier signal is shifted according to the phase envelope of the individual pulses in each pulse interval. In some embodiments, the digital IF carrier signal has a frequency of 200 MHz (e.g., an intermediate frequency), or another value which may be determined by the desired bandwidth and limits of the DAC and ADC units. In some embodiments, the digital IF carrier signal and the digital IF signal value are generated by the operation of the processor unit 112 of the data processing device 102.

[0082] In some embodiments, the digital IF signal value is obtained by sampling the modulated pulse at a sampling time. In some cases, the sampling time for obtaining the digital IF signal value can be set according to the intermediate frequency, the resolution of the signal processing device (e.g., DAC unit), or other factors. In some embodiments, the digital IF signal value is obtained at a sampling time of 1 ns, 2 ns, or another value. In some embodiments, the digital IF signal value is in the range of -1 to 1. In some embodiments, the digital IF signal value includes information on the time-dependent amplitude and phase of the target pulse in the pulse profile.

[0083] Figure 5B is a graph 510 showing the digital IF signal value as a function of time. In some embodiments, the digital IF signal value is generated based on time series 500, 502 of the amplitude and phase of exemplary pulses in the exemplary pulse profile shown in Figure 5A. In some embodiments, the digital IF signal value represents a pulse modulated using a digital IF carrier signal. The modulated pulse has an oscillating waveform that includes time-dependent amplitude and phase. In other words, the modulated pulse has an amplitude envelope defined by the amplitude envelope 500 in Figure 5A and a phase of the waveform in each pulse section defined by the phase of each pulse section shown in the phase envelope 502 in Figure 5A, with t=0 as the reference. Figure 5B further includes an enlarged view 512 of the time series of the digital IF pulse in a time window of 40–80 ns. The discontinuity 514 of the digital IF pulse is caused by the difference between the phases of two pulse sections (e.g., 15 degrees and -150 degrees) shown in the phase envelope 502 in Figure 5A.

[0084] Figure 5C includes time series 520 of the amplitude and 522 of the phase of exemplary and restored pulses, similar to those shown in Figure 5A. The amplitude and phase of the restored pulse are determined by demodulating the modulated pulse shown in Figure 5B using the same digital IF carrier signal. As shown in Figure 5C, the amplitude and phase of the original and restored pulses are consistent with each other. Overshoot in the amplitude and phase of the restored pulse is observed, in particular, at the boundary between two adjacent pulse segments.

[0085] In some embodiments, a magnetic resonance control signal is generated by processing two digital IF signals, for example, a digital I-quadrature signal and a digital Q-quadrature signal. In some cases, the digital Q-quadrature signal has a phase that is shifted relative to the phase of the digital I-quadrature signal. In this case, the digital IF signal values ​​include a time series of digital I-quadrature signal values ​​obtained by sampling the digital I-quadrature signal and a time series of digital Q-quadrature signal values ​​obtained by sampling the digital Q-quadrature signal. The time series of digital Q-quadrature signal values ​​is phase-shifted relative to the time series of I-quadrature signal values. The methods and systems presented herein enable image rejection, sideband suppression, and LO suppression by controlling the relative phase and amplitude of the digitally generated digital Q-quadrature signal values ​​and digital I-quadrature signal values. In some cases, the phase shift may be determined when the spectrometer is initially set up or in another manner.

[0086] Figure 6A includes the amplitude envelope 600 of the target pulse in an exemplary pulse profile, the phase envelope of the target pulse in an exemplary pulse profile, a first digital IF signal value 604, and a second digital IF signal value 606. As shown in Figure 6A, the target pulse consists of 10 pulse segments, each pulse segment being 100 ns. The first and second digital IF signal values ​​604 and 606 are generated based on the time series of the amplitude and phase 600 and 602 of the target pulse. In particular, the first and second digital IF signal values ​​shown in Figure 6A are generated by modulating pulses having the amplitude and phase shown in graphs 600 and 602 using a digital IF carrier signal having an intermediate frequency of 200 MHz. The first digital IF signal value 604 is generated based on the time series 600 and 602 of the pulse in the pulse profile, and the second digital IF signal value 606 is obtained by phase shifting the first modulated pulse. In some cases, the phase shift between the first and second digital IF signal values ​​is 90 degrees or less, or greater than 90 degrees. In some embodiments, the first digital IF signal value 604 represents the digital I-quadrature signal, and the second digital IF signal value 606 represents the digital Q-quadrature signal. In some embodiments, the digital I-quadrature signal value and the digital Q-quadrature signal value are obtained by sampling the modulated pulse at a sampling time (e.g., 1 ns).

[0087] Figure 6B includes the Fourier component 620 of the first output signal of the IQ mixer model. The IQ mixer model is a theoretical model that generates an output signal by multiplying input signals. The first output signal is obtained by passing the digital IF signal values ​​representing the first and second modulated pulses 602, 604 shown in Figure 6A through the IQ mixer device. An 800 MHz local oscillator electrical signal is received in the IQ mixer device. The effects of defects from the IQ mixer device can be understood by examining the frequency components of the first output signal. Two sideband signals of 600 MHz and 1 GHz are obtained.

[0088] Figure 6C includes the Fourier component 632 of the third output signal of the IQ mixer device. The third output signal is obtained by phase-shifting the digital IF signal values ​​representing the first and second modulated pulses 602, 604 shown in Figure 6A, and passing the phase-shifted waveform through the IQ mixer device. An 800 MHz local oscillator electrical signal is received in the IQ mixer model. The phase-shifted waveform can be used for image suppression. As shown in graphs 632 and 634, no sidebands are observed at 600 MHz.

[0089] In some embodiments, when a pulse sequence includes a series of pulses and a time delay, the rotation angle and phase shift are explicitly defined for each pulse in the pulse sequence. The pulses in the pulse sequence are coupled to each other, separated by their respective time delays. For example, a spin echo sequence is (π / 2). x -τ-π) φ This can be represented by the following. Each pulse in the pulse sequence may be performed as an arbitrary waveform that performs a corresponding operation (e.g., excitation, refocusing, etc.). In some embodiments, the pulse intervals of individual pulses and all pulses in the pulse sequence are referenced to t=0 of the digital IF carrier signal. To maintain the relative phase between pulses at any time delay, phase tracking of the digital IF carrier signal can be performed to determine the corresponding relative phase shift.

[0090] In some embodiments, the relative phase shift is determined based on the duration of the time delay and the cycle time of the intermediate frequency. The relative phase shift is relative to t=0 of the pulse sequence.

[0091] Figure 7A includes time series of amplitude and phase of the first exemplary pulse in the pulse sequence 700, 702. In some cases, the first exemplary pulse is π / 2 of the spin echo sequence. xThe pulse can represent excitation. Figure 7B includes time series of amplitude and phase of a second exemplary pulse in the pulse sequence 710, 712. In some cases, the second exemplary pulse is π of the spin echo sequence. y A pulse for refocusing can be represented. As shown in Figures 7A and 7B, each of the first and second exemplary pulses contains 10 random pulse segments, and each pulse segment of the pulse is defined by parameters including phase, amplitude, and time interval. The values ​​of the parameters for the pulse segments of the pulse are different from each other.

[0092] Figure 7C is a graph 720 showing the digital IF signal values ​​determined based on the time series of amplitude and phase 700, 702, 710, 712 of the first and second exemplary pulses in Figures 7A-7B. As shown in Figure 7C, the digital IF signal values ​​include a first modulated pulse 722A and a second modulated pulse 722B, the second modulated pulse 722B being coupled to the first modulated pulse 722A after a time delay 724. In particular, the first modulated pulse 722A is generated by modulating the amplitude envelope 700 of the first exemplary pulse shown in Figure 7A using the digital IF carrier signal. The first modulated pulse 722A has a time-dependent phase determined according to the phase envelope 702 of the first exemplary pulse shown in Figure 7A. The second modulated pulse 722B is generated by modulating the amplitude envelope 710 of the second exemplary pulse shown in Figure 7B using the same digital IF carrier signal. The second modulated pulse 722B has a time-dependent phase determined according to the phase envelope 712 of the second exemplary pulse shown in Figure 7B. The digital IF signal values ​​are generated by sampling the first and second modulated pulses 722A and 722B separated by a time delay 724. The digital IF carrier signal for modulating the amplitude envelopes 700 and 710 of the first and second exemplary pulses has an intermediate frequency of 200 MHz, and the time delay 724 is equal to 1000 ns.

[0093] Figure 7D includes graphs 730 and 732 showing the time series of amplitude and phase of the pulse sequence and the reconstructed pulse sequence. The pulse sequence includes the first and second pulses shown in Figures 7A and 7B, separated by a time delay 724. The reconstructed pulse sequence is generated by demodulating the digital IF signal values ​​in Figure 7C using the digital IF carrier signal used to generate the digital IF signal values ​​in Figure 7B when modulating the pulse sequence. As shown in Figure 7D, the reconstructed pulse sequence matches the pulse sequence.

[0094] Figure 7E is a graph 740 showing the digital IF signal values ​​determined based on the amplitude envelopes and phase envelopes 700, 702, 710, and 712 of the first and second exemplary pulses in Figures 7A and 7B. As shown in Figure 7E, the digital IF signal values ​​include a first modulated pulse 742A and a second modulated pulse 742B, the second modulated pulse 742B being coupled to the first modulated pulse 742A after a time delay 744. In particular, the first modulated pulse 742A is generated by modulating the amplitude envelope 700 of the first exemplary pulse shown in Figure 7A using a digital IF carrier signal. The first modulated pulse 742A has a time-dependent phase determined according to the phase envelope 702 of the first exemplary pulse shown in Figure 7A. The second modulated pulse 742B is generated by modulating the amplitude envelope 710 of the second exemplary pulse shown in Figure 7B using the same digital IF carrier signal. The second modulated pulse 742B has a time-dependent phase determined according to the phase envelope 712 of the second exemplary pulse shown in Figure 7B. The digital IF signal values ​​are generated by sampling the first and second modulated pulses 722A, 722B separated by a time delay 744. The digital IF carrier signal for modulating the amplitude envelopes 700, 710 of the first and second exemplary pulses has an intermediate frequency of 200 MHz, and the time delay 724 is equal to 996 ns.

[0095] Figure 7F includes graphs 750 and 752 showing the amplitude and phase envelopes of the pulse sequence and the reconstructed pulse sequence. The pulse sequence includes the first and second pulses shown in Figures 7A and 7B, separated by a time delay 744. The reconstructed pulse sequence is generated by demodulating the digital IF signal values ​​in Figure 7E using the digital IF carrier signal used to generate the digital IF signal values ​​in Figure 7E when modulating the pulse sequence. As shown in Figure 7F, the reconstructed pulse sequence matches the pulse sequence. As shown in Figure 7F, the correct phase can still be obtained even if the time delay 744 is not an integer multiple of 5ns.

[0096] Figure 7G includes graph 760 showing an enlarged view of the digital IF signal value 720 in Figure 7C and graph 762 showing an enlarged view of the digital IF signal value 740 in Figure 7E during a time window of 1465–1485 ns. As shown in Figure 7G, the initial phases of the second modulated pulses 722B and 742B of the digital IF signal values ​​720 and 740 are different, which is caused by the difference between the two time delays 724 and 744. In some cases, the difference between the two time delays 724 and 744, and therefore the difference between the two initial phases of the second modulated pulses 722B and 742B, can contribute to an unwanted phase shift relative to the phase envelope of the restored pulse sequence.

[0097] Figure 7H is graph 770, which shows an enlarged view of the time series of phases of two restored pulse sequences shown in graphs 732 and 752 of Figures 7D and 7F during a time window of 1475–1600 ns. Curve 772 is the time series of phases of a restored pulse sequence with a time delay of 1000 ns, and curve 774 is the time series of phases of a restored pulse sequence with a time delay of 996 ns. Differences are observed around 1470 ns and 1550 ns. In some embodiments, by adding or subtracting a predetermined phase shift value, the phase shift can be applied to the phase envelope 702 of the first exemplary pulse shown in Figure 7A or the phase envelope 712 of the second exemplary pulse shown in Figure 7B to correct unwanted phase shifts in the digital IF signal value.

[0098] Figure 7I shows graph 780, which illustrates the amplitude envelope of a second exemplary pulse similar to that shown in Figure 7B, and graph 782, which illustrates the phase envelope of the second exemplary pulse before and after applying a phase shift to compensate for the effects of the time delay 744. Curve 784 represents the original phase envelope 712 of the second exemplary pulse in Figure 7B, and curve 786 represents the compensated phase envelope of the second exemplary pulse shifted by approximately 90 degrees due to the time delay 744. In some cases, the phase shift applied to the pulse may be determined by the intermediate frequency, time delay, and other parameters.

[0099] In some embodiments, the operation of the processor unit 112 of the data processing device 102 generates a hardware control sequence based on information about the pulse sequence to be executed in the magnetic resonance system. The pulse sequence information of the pulse sequence, such as the time delay between two pulses and the length of the time segment for performing control operations (e.g., reading the magnetic resonance detection signal, digitizing the magnetic resonance detection signal to correct the pulse sequence, and other control operations) is used to construct the hardware control sequence. The hardware control sequence includes timestamps and hardware control values ​​for each time segment in the pulse sequence for controlling each device (e.g., trigger-enable units 312A, 312B, 312C and FIFO buffer devices 304A, 304B in the signal processing unit 300). For example, the hardware control sequence (e.g., hardware control sequences 900, 910 in Figures 9A-9B) includes timestamps for starting and stopping DAC waveform playback, timestamps for starting and stopping the data acquisition process, and timeline data for the switching states of the digitally controlled devices. In some cases, hardware control sequences include timeline data for performing other actions.

[0100] Hardware control values ​​for each time segment are configured to control the respective devices of the DAC, ADC, and DIO channels of the signal processing unit (e.g., DAC channel 324A, ADC channel 324B, and DIO channel 324C of signal processing unit 300). In some embodiments, the devices within the signal processing unit of the magnetic resonance system that receive the operation of each hardware control sequence are controlled by the hardware control values ​​of the hardware control sequence, which depend on the design of the signal processing unit. For example, using the signal processing unit 300 shown in Figure 3A, the hardware control values ​​are received by devices 312A, 312B, and 312C associated with DAC units 316A, 316B, and ADC units 320A, 320B, and DIO device 318 are controlled according to the timestamp so that the outputs of DAC units 316A, 316B, ADC units 320A, 320B, and DIO device 318 are controlled. In particular, the hardware control value output from the DAC TRIG terminal of the third FIFO buffer device 304C is configured to determine the outputs of the first and second FIFO buffer devices, and therefore the outputs of the DAC units 316A and 316B; the hardware control value output from the ADC TRIG terminal of the third FIFO buffer device 304C is configured to determine the output of the ADC delay device 314, and therefore the outputs of the ADC units 320A and 320B; and the hardware control value output from the DIO TRIG terminal of the third FIFO buffer device 304C is configured to determine the state of the digital control signal output from the DIO device 318. In some embodiments, the hardware control sequence is determined according to the signal processing unit, for example, according to the width of the FIFO buffer device, the number of DAC units, the number of DIO outputs, the number of ADC units, etc.

[0101] In some cases, a set of digital IF signal values ​​may be executed an arbitrary number of times in a pulse sequence. Hardware control values ​​can specify the same set of digital IF signal values ​​multiple times, thereby enabling arbitrary pulse repetitions in the magnetic resonance control signal. As soon as DAC waveform regeneration is enabled and a start point is defined, DAC waveform regeneration proceeds sequentially through the waveform until it is disabled. In some cases, values ​​are added to the processing registers as soon as ADC digitization is enabled. In some cases, additional information may be added to the FIFO buffer in real time during a given pulse sequence or experiment. In this way, adaptive control is enabled, and the repeated application of a given DAC waveform only needs to be stored once in the memory unit 114 of the data processing unit 102 and then sequentially added to the DAC FIFO buffer devices 304A and 304B.

[0102] In some cases, the timestamp resolution in the hardware-controlled sequence may be predetermined by the data processing device 102, set by the user, or modified. In some cases, the timestamp resolution may be determined according to the operating frequency or according to other device parameters of the signal processing unit. For example, when an FPGA device with an operating frequency of 1 GHz is used in the signal processing unit, the timestamp resolution in the hardware-controlled sequence is 1 ns.

[0103] In some embodiments, a hardware control sequence may be compiled by the operation of the processor unit 112 according to the design and hardware configuration of the controller unit 122 and converted into a set of hardware-specific commands. In some embodiments, when the hardware control sequence is executed, the set of hardware-specific commands (stored, for example, in the FIFO buffer device 304C of the signal processing unit 300 in Figure 3) may be read into the signal processing unit and executed by the signal processing unit. Each command includes a timestamp and a hardware control value corresponding to each time segment of the pulse sequence. In some embodiments, when the hardware control sequence is executed, the set of hardware-specific commands is executed by the signal processing unit. In some cases, multiple copies of the set of commands are stored in the FIFO buffer device 304C. Each of the multiple copies of the set of commands may be executed multiple times. One of the commands in the set of commands includes a delay period between iterations of the pulse sequence.

[0104] Once multiple pulse profiles are identified, multiple sets of digital IF signal values ​​may be generated for each pulse profile. Each set of digital IF signal values ​​may have the same or distinct intermediate frequencies. Multiple sets of digital IF signal values ​​are combined to create multiple resonant pulses. In some embodiments, each set of digital IF signal values ​​is analyzed to become multiple subsets. Each subset represents a modulated pulse corresponding to a pulse in a pulse profile. In some cases, each subset represents a modulated pulse that includes, for example, phase compensation to account for effects from time delay or other influences. In some embodiments, subsets of multiple sets of digital IF signal values ​​are stored separately in memory unit 116. In some embodiments, each subset is labeled with a pulse identifier, which indicates the memory address where the subset of digital IF signal values ​​for the corresponding pulse is stored.

[0105] When multiple resonance measurements are performed, the set of digital IF signal values ​​can represent multiple resonance pulses. In particular, the set of digital IF signal values ​​can include multiple subsets of digital IF signal values, each corresponding to a pulse modulated at a distinct intermediate frequency. For example, when a first pulse profile and a second pulse profile are identified by the operation of the data processing device 102, the pulses in the first pulse profile may be modulated by a first digital IF carrier signal having a first intermediate frequency, and the pulses in the second pulse profile may be modulated by a second IF carrier signal having a second distinct intermediate frequency. The first set of digital IF signal values ​​is generated based on the first pulse profile, and the second set of digital IF signal values ​​is generated based on the second pulse profile. The first and second sets of digital IF signal values ​​are superimposed to form a new set of digital IF signal values, which can be used when performing multiple resonance measurements. In some cases, the first and second sets of digital IF signal values ​​may be processed in a different manner to form a new set of digital IF signal values ​​for multiple resonance measurements. In this case, the new set of digital IF signal values ​​may be analyzed to form subsets, and each subset may be stored separately in the memory unit 116.

[0106] In 406, digital IF signal values ​​are stored. In some cases, after a subset of digital IF signal values ​​corresponding to pulses in a pulse profile is determined, the subset of digital IF signal values ​​can be stored separately as individual waveforms in the memory unit 116. Multiple subsets of digital IF signal values ​​can later be accessed by the controller unit 122 and used as inputs to the DAC units 214 and 216. In some embodiments, the subset of digital IF signal values ​​corresponding to pulses in a pulse profile to be performed by the magnetic resonance system includes both digital I-quadrature phase signal values ​​and digital Q-quadrature phase signal values, and the digital I-quadrature phase signal values ​​and digital Q-quadrature phase signal values ​​for pulses may be stored separately in the memory unit 116.

[0107] Figure 8 includes graphs 800, 802, 804, and 806 of subsets of digital IF signal values ​​for corresponding pulses in a pulse sequence. These subsets of digital IF signal values ​​are shown in Figure 7C and are stored separately in the memory unit for DAC waveform reproduction. Specifically, graph 800 shows the digital I-quadrature phase signal value for the first modulated pulse 722A, graph 802 shows the digital Q-quadrature phase signal value for the first modulated pulse 722A, graph 804 shows the digital I-quadrature phase signal value for the second modulated pulse 722B, and graph 806 shows the digital Q-quadrature phase signal value for the second modulated pulse 722B. The digital Q-quadrature phase signal values ​​and digital I-quadrature phase signal values ​​for the same modulated pulses are phase-shifted by 90 degrees relative to each other.

[0108] In some embodiments, hardware control sequences corresponding to pulse sequences are also stored in the memory unit 116. In some cases, when configured for magnetic resonance measurement, a subset of digital IF signal values ​​corresponding to pulses in the pulse sequence, and hardware control sequences or hardware-specific commands are obtained from the memory unit 116, and the subset of digital IF signal values ​​may be written to FIFO buffer devices 304A, 304B in a certain order. The subset of digital IF signal values ​​is read to the DAC unit in the same order as it is stored in the FIFO buffer devices according to the hardware control sequence. The subset of digital IF signal values ​​is converted in that order to analog IF I-codedrant control signals and analog IF Q-codedrant control signals, which are further converted to magnetic resonance control signals.

[0109] When the pulse sequence is executed in the magnetic resonance system, the output of the DIO unit is determined according to the hardware-controlled sequence. The output of the DIO unit is configured to synchronize the transmission electronics of the transmitter unit with the receiver electronics of the receiver unit.

[0110] Figures 9A-9B include a graph 900 and a corresponding table 910 of an exemplary hardware control sequence. The hardware control sequence may be determined based on pulse sequence information of a pulse sequence. The hardware control sequence is configured to control the devices or units of controller units 122, 202, 242 of magnetic resonance systems 100, 200, 240 as shown in Figures 1, 2A-2B. In some cases, the hardware control sequence may be used to control other devices or units of the magnetic resonance system. As shown in Figures 9A-9B, the exemplary hardware control sequence includes a series of timestamp values ​​and a series of control actions or a series of corresponding hardware control values ​​for controlling the output of each channel of a signal processing unit, e.g., a DAC channel, an ADC channel, and a DIO channel.

[0111] In some embodiments, the exemplary hardware control sequences in Figures 9A-9B represent a complete echo spin sequence. For example, at t=t0=0, the hardware control values ​​include DIO1 ON, DIO2 OFF, DAC OFF, and ADC OFF; at t=t1=25ns, the hardware control values ​​include DIO1 ON, DIO2 OFF, DAC ON, and ADC OFF; at t=t2=125ns, the hardware control values ​​include DIO1 ON, DIO2 OFF, DAC OFF, and ADC OFF; at t=t3=150ns, the hardware control values ​​include DIO1 OFF, DIO2 OFF, DAC OFF, and ADC OFF; at t=t4=1100ns, the hardware control values ​​include DIO1 ON, DIO2 OFF, DAC OFF, and ADC OFF; and at t=t5=112 At 5ns, the hardware control signal values ​​include DIO1 ON, DIO2 OFF, DAC ON, and ADC OFF; at t=t6=1225ns, the hardware control signal values ​​include DIO1 ON, DIO2 OFF, DAC OFF, and ADC OFF; at t=t7=1250ns, the hardware control signal values ​​include DIO1 OFF, DIO2 OFF, DAC OFF, and ADC OFF; at t=t8=1325ns, the hardware control signal values ​​include DIO1 OFF, DIO2 OFF, DAC OFF, and ADC ON; and at t=t9=11325ns, the hardware control signal values ​​include DIO1 OFF, DIO2 OFF, DAC OFF, and ADC OFF. During the period between t8 and t0, the magnetic resonance system transmits the magnetic resonance control signal to the resonator device, and during the period between t9 and t8, the magnetic resonance system receives the magnetic resonance detection signal from the resonator device.

[0112] In some cases, hardware control sequences can be converted or compiled into hardware-specific control commands according to the design of the signal processing unit. Hardware-specific commands may have a unique form that specifies hardware control values ​​at each timestamp. Figure 3B shows an exemplary format of hardware-specific commands from a hardware control sequence stored in the FIFO buffer device of a digital processing unit.

[0113] In some embodiments, when multiple resonance measurements are performed, a subset of digital IF signal values ​​may include frequency-multiplexed pulses. For example, pulses modulated at different intermediate frequencies may be superimposed on each other. A subset of digital IF signal values ​​representing multiple resonance pulses can be converted into a magnetic resonance control signal and transmitted to a resonator unit for multiple resonance measurements. To demonstrate the effectiveness of the method, the superimposed digital IF pulses can be independently demodulated using their respective IF carrier signals and their respective IF signals to obtain a first or second digital IF pulse. In some cases, a subset of digital IF signal values ​​may include three or more frequency-multiplexed pulses. In some embodiments, the IF frequencies of the digital IF carrier signals used to modulate the pulses are non-overlapping, meaning they are distinct from each other. The methods and systems presented herein enable simultaneous pulse transmission at multiple frequencies, the execution of high-fidelity multi-frequency experiments, and improved bandwidth by increasing intermediate frequencies. In some embodiments, digital IF signal values ​​representing frequency-multiplexed pulses may be used in applications such as multi-qubit control, dual electron-electron resonance (DEER) experiments, and other types of magnetic resonance applications. Frequency-multiplexed pulses can be simultaneously transmitted to the DAC unit and the resonator device. The signal received from the ADC unit may be multiplexed and separated at each intermediate frequency for detection.

[0114] Figure 11A includes graphs 1100 and 1102 showing the amplitude envelope and phase envelope of the first pulse of the pulse sequence, and graphs 1104 and 1106 showing the amplitude envelope and phase envelope of the second pulse of the pulse sequence. The first and second pulses are 1000 ns pulses, each containing 10 pulse segments within 10 equal time intervals.

[0115] Figure 11B includes graph 1110 showing a first subset of digital IF signal values ​​generated based on the amplitude envelope and phase envelope of the first pulse shown in Figure 11A. The first subset of digital IF signal values ​​is generated by modulating the amplitude envelope of the first pulse using a first digital IF carrier signal having a first intermediate frequency of 150 MHz. Figure 11B further includes graph 1112 showing a second subset of digital IF signal values ​​generated based on the amplitude envelope and phase envelope of the second pulse shown in Figure 11A. The second subset of digital IF signal values ​​is generated by modulating the amplitude envelope of the second pulse using a second digital IF carrier signal having a second intermediate frequency of 250 MHz. Figure 11B further includes graph 1114 showing a third subset of digital IF signal values ​​generated by superimposing the first and second subsets of digital IF signal values, and graph 1116 showing the Fourier transform of the third subset of digital IF signal values.

[0116] Figure 11C includes graphs 1120 and 1122 showing the amplitude and phase envelopes of the first pulse and the first reconstructed pulse obtained by demodulating a third subset of the digital IF signal values ​​at the first intermediate frequency. Figure 11C also includes graphs 1124 and 1126 showing the amplitude and phase envelopes of the second pulse and the second reconstructed pulse obtained by decomposing a third subset of the digital IF signal values ​​at the second intermediate frequency. As shown in Figure 11C, the reconstructed pulses coincide with the original first and second pulses. Overshoot may be observed at the pulse interval boundaries.

[0117] Figure 12A includes graphs 1200 and 1202 showing the amplitude and phase envelopes of the first pulse in the pulse sequence, graphs 1204 and 1206 showing the amplitude and phase envelopes of the second and third pulses in the pulse sequence, and graphs 1208 and 1210 showing the amplitude and phase envelopes of the fourth pulse in the pulse sequence. When the pulse sequence is a 4-pulse double resonance sequence, the first, second, and fourth pulses are observer pulses in the double resonance sequence, and the third target pulse is the pump pulse in the 4-pulse double resonance sequence. In some cases, the pulse sequence can be used in bio-EPR distance measurement or other types of measurement. Each of the first, second, third, and fourth pulses is a 1000 ns pulse containing 10 pulse intervals with equal time intervals (e.g., 100 ns). In some embodiments, the first, second, third, and fourth pulses may be coupled with a time delay to form a pulse sequence.

[0118] Figure 12B includes graph 1212 showing an embodiment of a first set of digital IF signal values, which includes three subsets of digital IF signal values ​​1220A, 1220B, and 1220C. The first set of digital IF signal values ​​is generated by modulating the first, second, and fourth pulses of the pulse sequence shown in Figure 12A using a first digital IF carrier signal having an intermediate frequency of 150 MHz, and correcting the phase shift according to the time delay between the two subsets of digital IF signal values. The first set of digital IF signal values ​​is configured to deliver observer pulses to the resonator. Figure 12B further includes graph 1232 showing an embodiment of a second set of digital IF signal values, which includes a third subset of digital IF signal value 1222. The second set of digital IF signal values ​​is generated by modulating the third pulse of the pulse sequence shown in Figure 12A using a second digital IF carrier signal having a second intermediate frequency of 250 MHz, and correcting the phase shift according to the time delay between the second and third pulses. Figure 12B includes graph 1234 showing the third set of digital IF signal values ​​generated by superimposing the first and second digital IF signals, and graph 1236 showing the corresponding Fourier transform of the third set of digital IF signal values, which exhibits two frequency peaks of 150 MHz and 250 MHz depending on the intermediate frequencies used to modulate the observer pulse and pump pulse in the pulse sequence.

[0119] Figure 12C includes graphs 1240 and 1242 showing the amplitude and phase envelopes of the original pulse sequence and the first restored pulse sequence obtained by demodulating a third set of digital IF signal values ​​shown in Figure 12B at a first intermediate frequency of 150 MHz. Both the amplitude and phase envelopes of the restored pulse sequence match the first, second, and fourth pulses of the pulse sequence shown in Figure 12A. Figure 12C further includes graphs 1246 and 1248 showing the amplitude and phase envelopes of the original pulse sequence and the second restored pulse sequence obtained by demodulating a third set of digital IF signal values ​​shown in Figure 12B at a second intermediate frequency of 250 MHz. Both the amplitude and phase envelopes of the restored pulse sequence match the third pulse of the original pulse sequence shown in Figure 12A. The original pulse sequence includes the first, second, third, and fourth pulses in Figure 12A, separated by the respective time delays defined in Figure 12B.

[0120] In 408, the digital IF signal value is converted to an analog IF electrical signal by the operation of controller units 122, 202, and 300 in Figures 1, 2A, and 3. In some embodiments, the digital IF signal value is received and converted to the respective analog IF electrical signal by the operation of the respective DAC units 214, 216, 316A, and 316B. In some embodiments, the conversion of the analog IF electrical signal and the output to the transmitter unit are controlled and synchronized according to a hardware control sequence. In some embodiments, the hardware control sequence is generated based on pulse sequence information corresponding to a pulse sequence to be performed by the magnetic resonance system. In some embodiments, the hardware control sequence, which specifies an action occurring at a particular timestamp relative to a shared and distributed clock, is configured to harmonize and synchronize the control of the input with the DAC units, ADC units, and DIO devices. In some embodiments, the hardware control value may include further information, such as the address of the DIO output terminal. In some cases, the format of each frame 332 in the third FIFO buffer device 304C may differ. For example, frame 332 may have more divisions, each containing hardware control values ​​for a specific device, and each division of frame 332 may have a different width.

[0121] In some embodiments, averaging is achieved by combining copies of a given timeline to create a larger periodic timeline. In some cases, arbitrary averaging can be enabled by using a cyclic FIFO buffer. In some cases, an additional time delay considering T1 recovery may be included in the timeline for averaging. To avoid unnecessary complexity in maintaining phase coherence, the time delay is an integer multiple of the duration of the digital IF carrier signal. In some embodiments, by using a timeline for signal averaging, even across various scans, it is ensured that all data in the experiment are phase-coherent.

[0122] For example, the digital I-quadrature phase IF signal value and the digital Q-quadrature phase IF signal value are received and stored in the respective FIFO buffer devices 304A and 304B of the signal processing unit 300. The outputs of the FIFO buffer devices 304A and 304B are controlled by the control signals received at their respective trigger terminals (TRIG). The control signals are generated according to the hardware control sequence (e.g., timeline data 900 and 910 shown in Figures 9A and 9B) received in the third FIFO buffer device 304C. Simultaneously with the FIFO buffer devices 304A and 304B being enabled (e.g., the control signal at the TRIG terminal is in its first state), the digital IF signal values ​​are received in the DAC units 316A and 316B until the FIFO buffer devices 304A and 304B are disabled, and the analog Q control signal and analog I control signal are generated by the operation of the respective DAC units 316A and 316B. The analog Q control signal and analog I control signal are then transmitted to the transmitter unit for further processing.

[0123] In some embodiments, multiple analog IF electrical signals are generated and separated by a time delay defined in a hardware control sequence. In particular, the time delay after the generation of the first analog IF electrical signal is carried out according to the hardware control sequence. After the time delay, the second digital IF signal value is received by the DAC unit and converted into a second analog IF electrical signal separated from the first analog IF electrical signal by the time delay.

[0124] In 410, a magnetic resonance control signal is generated. In some embodiments, the magnetic resonance control signal is generated by the operation of transmitter units 122, 204 in Figures 1, 2A. In some embodiments, the analog IF electrical signal is mixed with the local oscillator (LO) electrical signal to produce the magnetic resonance control signal. The magnetic resonance control signal is a single-sideband control signal obtained by controlling the relative phase of the digital Q-quadrature phase signal value and the digital i-quadrature phase signal value. In some embodiments, the magnetic resonance control signal may be further filtered, amplified, or processed before being delivered to the resonator device. When the magnetic resonance control signal is delivered to the resonator device of the magnetic resonance system, it can generate a control field. Once multiple pulse profiles are identified and multiple sets of digital IF signal values ​​are generated, multiple magnetic resonance control signals are generated based on multiple sets of digital IF signal values.

[0125] In some embodiments, a magnetic resonance detection signal (e.g., a spin signal) is received from the resonator unit and can be processed (e.g., amplified, filtered, down-converted, etc.) by receiver units 124, 244. In some embodiments, the down-converted magnetic resonance detection signal at an intermediate frequency is obtained using a mixer unit 258 and digitized in the signal processing unit 244 by the operation of an ADC unit 220. In some cases, the digital magnetic resonance detection signal value is generated by the ADC unit 220 and transmitted from the signal processing unit 242 to a processor unit, where the digital magnetic resonance detection signal value can be demodulated at an intermediate frequency. In some cases, the demodulated magnetic resonance detection signal can be phase-corrected. In some embodiments, the methods and systems presented in this application enable the application of precise and arbitrary phase correction to the magnetic resonance detection signal.

[0126] Figure 10 includes Graph 1002, which shows exemplary ADC data as a function of time. The ADC data is obtained by digitizing the raw data received in the ADC unit at an intermediate frequency of 200 MHz. This ADC data is located at the output port of the ADC unit. In some cases, the exemplary ADC data is obtained by experimentally implementing a similar spin echo sequence on an irradiated quartz spin sample. After a DIO2 toggle around 11000 ns, residual resonator ringdown can be observed, and the spin echo signal is seen around 14000 ns.

[0127] Figure 10 includes graph 1004 showing the demodulated ADC data (mV) as a function of time (ns). The ADC data is demodulated, filtered, and significantly reduced using an IF carrier signal generated digitally with an intermediate frequency to obtain a phase-sensitive signal, by the operation of the data processing device 102 in Figure 1. As shown in Figure 10, the demodulated ADC data includes the Q-quadrature phase signal 1012 and the I-quadrature phase signal 1014. The digital IF carrier signal is the same as the one used to modulate the pulses of the pulse sequence. Figure 10 further includes graph 1006 showing the demodulated ADC data (mV) as a function of time (ns). The ADC data is phase-shifted by 46 degrees to maximize the I-quadrature phase signal.

[0128] Some of the subjects and operations described herein may be implemented in digital electronic circuits, including structures disclosed herein and their equivalents, or in computer software, firmware, or hardware, or in one or more combinations thereof. Some of the subjects described herein may be implemented as one or more encoded computer programs on a computer storage medium for execution by a data processing device or for controlling the operation of a data processing device, i.e., as one or more modules of computer program instructions. The computer storage medium may be, or may include, a computer-readable storage device, a computer-readable storage board, a random or serial access memory array or device, or one or more combinations thereof. Furthermore, the computer storage medium may be a source or destination of encoded computer program instructions in artificially generated propagated signals, although these are not propagated signals. The computer storage medium may further be, or may include, one or more separate physical components or media.

[0129] Some of the operations described herein may be performed as operations performed by a data processing device on data stored on one or more computer-readable storage devices or received from other sources.

[0130] In a general manner relating to the above, the magnetic resonance system is operated.

[0131] In the first example, the magnetic resonance system includes a data processing unit and a superheterodyne spectrometer system. The data processing unit generates digital intermediate frequency (IF) signal information based on the pulse profile. The digital IF signal information is configured to suppress image sidebands in the magnetic resonance control signal. The superheterodyne spectrometer generates the magnetic resonance control signal based on the digital IF signal information.

[0132] Embodiments of the first example may include one or more of the following features: The digital IF signal information specifies one or more phase shifts based on a time series of phases specified by the pulse profile. The digital IF signal information includes a time series of I-quadrature phase signal values ​​and a time series of Q-quadrature phase signal values. The time series of Q-quadrature phase signal values ​​is phase-shifted relative to the time series of I-quadrature phase signal values. The time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values ​​each include a DC offset configured to reduce LO leakage. The digital IF signal information includes multiple sets of digital IF signal values ​​based on multiple pulses of the pulse sequence, and the superheterodyne spectrometer system is configured to generate multiple magnetic resonance control signals based on the multiple sets of digital IF signal values.

[0133] In the second example, a method for operating a magnetic resonance system includes, by operation of a computer system, identifying a pulse profile for pulses to be generated by the magnetic resonance system, generating a digital intermediate frequency (IF) signal value based on the pulse profile, storing the digital IF signal value in a memory unit, and generating an analog IF electrical signal based on the digital IF signal value. The method further includes mixing the analog IF electrical signal with a local oscillator (LO) electrical signal to produce a magnetic resonance control signal, and delivering the magnetic resonance control signal to a resonator unit in the magnetic resonance system.

[0134] Embodiments of the second example may include one or more of the following features: The pulse profile defines a time series of amplitude and a time series of phase for a pulse. Generating a digital IF signal value includes identifying a phase shift of the pulse based on the phase time series and implementing the phase shift as a discontinuous time shift in the phase of the digital IF signal value. The digital IF signal value includes a time series of I-quadrature phase signal values ​​and a time series of Q-quadrature phase signal values. The time series of Q-quadrature phase signal values ​​is phase-shifted relative to the time series of I-quadrature phase signal values. The time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values ​​each include their respective DC offsets configured to reduce LO leakage.

[0135] Embodiments of the second example may include one or more of the following features: The method further includes generating multiple sets of digital IF signal values ​​based on multiple pulses of a pulse sequence, and generating multiple magnetic resonance control signals based on multiple sets of digital IF signal values. The method includes analyzing the pulse sequence to identify multiple pulses, multiple time delays, and one or more acquisition periods in the pulse sequence.

[0136] Embodiments of the second example may include one or more of the following features: The pulse profile includes a first pulse profile for a first pulse in a pulse sequence. The digital IF signal value is a first digital IF signal value. The analog IF electrical signal is a first analog IF electrical signal. The magnetic resonance control signal is a first magnetic resonance control signal. The pulse sequence includes a first pulse, a time delay after the first pulse, and a second pulse after the time delay. The method includes, by operation of a computer system, identifying a second pulse profile for the second pulse, determining a phase shift based on the duration of the time delay and the cycle time of the intermediate frequency, and generating a second digital IF signal value corresponding to the second pulse profile. The phase shift is applied to the second digital IF signal value. The method further includes storing a second digital IF signal value in a memory unit; generating a first analog IF electrical signal based on the first digital IF signal value and then performing a time delay; generating a second analog IF electrical signal based on the second digital IF signal value after the time delay; mixing the second analog IF electrical signal with a local oscillator (LO) electrical signal to produce a second magnetic resonance control signal; and delivering the second magnetic resonance control signal to a resonator unit in a magnetic resonance system.

[0137] Embodiments of the second example may include one or more of the following features: The method includes identifying multiple pulse profiles for a pulse, generating a set of digital IF signal values ​​for each pulse profile, and combining the sets of digital IF signal values ​​to create a set of digital IF signal values ​​representing multiple resonant pulses, each corresponding to a distinct resonant frequency, and each set of digital IF signal values ​​having a distinct intermediate frequency.

[0138] Embodiments of the second example may include one or more of the following features: the pulse includes multiple resonant pulses; the pulse profile includes a first pulse profile corresponding to a first resonant frequency of the pulse; the method includes, by operation of a computer system, identifying a second pulse profile corresponding to a second resonant frequency of the pulse; generating a first digital IF signal value having a first intermediate frequency based on the first pulse profile; generating a second digital IF signal value having a separate second intermediate frequency based on the second pulse profile; and generating a digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value.

[0139] Embodiments of the second example may include one or more of the following features: The method includes receiving a magnetic resonance control signal in a resonator unit and generating a control field in response to the magnetic resonance control signal by operation of the resonator unit. The method further includes receiving a magnetic resonance detection signal from the resonator unit, down-converting the frequency of the magnetic resonance detection signal to an intermediate frequency, generating a digital magnetic resonance detection signal value based on the down-converted magnetic resonance detection signal, and demodulating the digital magnetic resonance detection signal value at the intermediate frequency by operation of a computer system.

[0140] In the third example, the magnetic resonance system includes a computer system, a digital-to-analog converter (DAC) unit, a mixer unit, and circuitry. The computer system is configured to identify a pulse profile for a pulse, generate a digital intermediate frequency (IF) signal value based on the pulse profile, and store the digital IF signal value. The DAC unit is configured to convert the digital IF signal value into an analog IF electrical signal. The mixer unit is configured to mix the analog IF electrical signal with a local oscillator (LO) electrical signal to produce a magnetic resonance control signal. The circuitry is configured to deliver the magnetic resonance control signal to the resonator unit.

[0141] Embodiments of the third example may include one or more of the following features: The pulse profile defines a time series of amplitude and a time series of phase for a pulse. Generating a digital IF signal value includes identifying a phase shift of the pulse based on the phase time series and implementing the phase shift as a discontinuous time shift in the phase of the digital IF signal value. The digital IF signal value includes a time series of I-quadrature phase signal values ​​and a time series of Q-quadrature phase signal values. The time series of Q-quadrature phase signal values ​​is phase-shifted relative to the time series of I-quadrature phase signal values. The time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values ​​each include their respective DC offsets configured to reduce LO leakage.

[0142] Embodiments of the third example may include one or more of the following features: A computer system is configured to generate multiple sets of digital IF signal values ​​based on multiple pulses of a pulse sequence. A mixer device is configured to generate multiple magnetic resonance control signals based on multiple sets of digital IF signal values. The computer system is configured to analyze the pulse sequence to identify multiple pulses, multiple delays, and one or more acquisition periods in the pulse sequence.

[0143] Embodiments of the third example may include one or more of the following features: The pulse profile includes a first pulse profile for a first pulse in a pulse sequence. The digital IF signal value is a first digital IF signal value. The analog IF electrical signal is a first analog IF electrical signal. The magnetic resonance control signal is a first magnetic resonance control signal. The pulse sequence includes a first pulse, a time delay after the first pulse, and a second pulse after the time delay. The computer system is configured to identify a second pulse profile for the second pulse, determine a phase shift based on the duration of the time delay and the cycle time of the intermediate frequency, generate a second digital IF signal value corresponding to the second pulse profile, wherein the phase shift is applied to the second digital IF signal value, store the second digital IF signal value in a memory unit, and generate a first analog IF electrical signal based on the first digital IF signal value, and then perform a time delay. The DAC unit is configured to generate a second analog IF electrical signal based on the second digital IF signal value after the time delay. The mixer unit is configured to mix a second analog IF electrical signal with the local oscillator (LO) electrical signal to generate a second magnetic resonance control signal. The circuit is configured to deliver the second magnetic resonance control signal to the resonator unit in the magnetic resonance system.

[0144] Embodiments of the third example may include one or more of the following features: The computer system is configured to identify multiple pulse profiles for a pulse, generate a set of digital IF signal values ​​for each pulse profile, and combine the sets of digital IF signal values ​​to create a set of digital IF signal values ​​representing multiple resonant pulses: each pulse profile corresponding to a distinct resonant frequency, and each set of digital IF signal values ​​having a distinct intermediate frequency.

[0145] Embodiments of the third example may include one or more of the following features: The pulse includes multiple resonant pulses. The pulse profile includes a first pulse profile corresponding to a first resonant frequency of the pulse. The computer system is configured to identify a second pulse profile corresponding to a second resonant frequency of the pulse, generate a first digital IF signal value having a first intermediate frequency based on the first pulse profile, generate a second digital IF signal value having a separate second intermediate frequency based on the second pulse profile, and generate a digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value.

[0146] Embodiments of the third example may include one or more of the following features: The magnetic resonance system includes a superheterodyne spectrometer system including a mixer unit. The resonator unit is configured to receive a magnetic resonance control signal and to generate a control field in response to the magnetic resonance control signal.

[0147] The mixer unit is the first mixer unit. The circuit is the first circuit. The magnetic resonance system includes a second mixer unit, an analog-to-digital converter (ADC) unit, and a second circuit. The second mixer unit is configured to receive a magnetic resonance detection signal from the resonator unit and to downconvert the frequency of the magnetic resonance detection signal to an intermediate frequency. The ADC unit is configured to generate a digital magnetic resonance detection signal value based on the downconverted magnetic resonance detection signal. The second circuit is configured to deliver the magnetic resonance detection signal to the second mixer unit and to deliver the downconverted magnetic resonance detection signal to the ADC unit. The computer system is further configured to demodulate the digital magnetic resonance detection signal value at the intermediate frequency.

[0148] In the fourth example, a method for operating a magnetic resonance system includes: obtaining pulse sequence information corresponding to a pulse sequence to be executed by the magnetic resonance system through the operation of a computer system, wherein the magnetic resonance system includes a control unit, a digital-to-analog converter (DAC) unit, an analog-to-digital converter (ADC) unit, and a digital input / output (DIO) unit; generating a hardware control sequence based on the pulse sequence information, wherein the hardware control sequence includes a timestamp and hardware control values ​​for each time segment of the pulse sequence, and the hardware control values ​​for each time segment are configured to control the operation of the DAC unit, the ADC unit, and the DIO unit; storing the hardware control sequence in a memory unit; and executing the pulse sequence in the magnetic resonance system. Executing the pulse sequence includes controlling the operation of the DAC unit, the ADC unit, and the DIO unit according to the hardware control sequence through the operation of the control unit.

[0149] Embodiments of the fourth example may include one or more of the following features: Controlling the operation of the DAC unit, ADC unit, and DIO unit according to a hardware control sequence includes receiving a clock signal and delaying the clock signal for each hardware component to synchronize the operation of each hardware component. Controlling the operation of the DAC unit, ADC unit, and DIO unit includes causing the operation of the DAC unit to occur during a first subset of time segments and causing the operation of the ADC unit to occur during a second subset of time segments. The first subset of time segments corresponds to pulses in a pulse sequence, and the second subset of time segments corresponds to acquisitions in a pulse sequence. Controlling the operation of the DAC unit, ADC unit, and DIO unit includes synchronizing the transmission electronics to generate a magnetic resonance control signal during a first subset of time segments and synchronizing the receiver electronics to process a magnetic resonance detection signal during a second subset of time segments.

[0150] Embodiments of the fourth example may include one or more of the following features: The hardware control sequence includes pulse identifiers for a subset of time segments corresponding to pulses in the pulse sequence, each pulse identifier indicating a memory address where a digital IF signal value is stored. Executing the pulse sequence includes iteratively identifying one of the timestamps in the hardware control sequence, comparing a clock signal with the identified timestamp, and, upon detecting a match between the clock signal and the identified timestamp, transmitting a digital control signal according to the hardware control value associated with the identified timestamp.

[0151] Embodiments of the fourth example may include one or more of the following features: Storing a hardware control sequence in a memory unit includes storing a series of commands in a buffer memory unit, each command corresponding to a time segment in a pulse sequence. Each command includes a timestamp and a hardware control value for each time segment of the time segment, and executing the pulse sequence includes executing the commands stored in the buffer memory unit. Executing a command includes reading a command from the buffer memory unit and, for each command, generating a hardware control signal according to the hardware control value in the command at the time specified by the timestamp in the command. The method includes signal averaging the pulse sequence by repeatedly executing the series of commands and filling the buffer memory unit with multiple copies of the series of commands, each copy being executed multiple times. One of the commands in the series includes a delay period between iterations of the pulse sequence.

[0152] In the fifth example, the magnetic resonance system includes a digital-to-analog converter (DAC) unit, an analog-to-digital converter (ADC) unit, a digital input / output (DIO) unit, a memory unit configured to store hardware control sequences, a data processing unit configured to obtain pulse sequence information corresponding to a pulse sequence and to generate a hardware control sequence based on the pulse sequence information, and a control unit configured to control the operation of the DAC unit, ADC unit, and DIO unit according to the hardware control sequence when the pulse sequence is executed in the magnetic resonance system. The hardware control sequence includes a timestamp and hardware control values ​​for each time segment in the pulse sequence, and the hardware control values ​​for each time segment are configured to control the operation of the DAC unit, ADC unit, and DIO unit.

[0153] Embodiments of the fifth example may include one or more of the following features: The control unit is configured to receive a clock signal and to delay the clock signal for each hardware component in order to synchronize the operation of each hardware component. The control unit is configured to cause the operation of the DAC unit during a first subset of time segments and the operation of the ADC unit during a second subset of time segments. The first subset of time segments corresponds to pulses in a pulse sequence, and the second subset of time segments corresponds to acquisitions in a pulse sequence. The control unit is configured to synchronize the transmission electronics to generate a magnetic resonance control signal during the first subset of time segments and the receiver electronics to process a magnetic resonance detection signal during the second subset of time segments.

[0154] Embodiments of the fifth example may include one or more of the following features: The hardware control sequence includes pulse identifiers for a subset of time segments corresponding to pulses in the pulse sequence, each pulse identifier indicating a memory address where a digital IF signal value is stored. Executing the pulse sequence includes iteratively identifying one of the timestamps in the hardware control sequence, comparing a clock signal with the identified timestamp, and, upon detecting a match between the clock signal and the identified timestamp, transmitting a digital control signal according to the hardware control value associated with the identified timestamp.

[0155] Embodiments of the fifth example may include one or more of the following features: The data processing device includes a buffer memory unit configured to store a set of commands. The set of commands corresponds to each time segment in the pulse sequence. Each command includes a timestamp and a hardware control value for each time segment of the time segment. Executing the pulse sequence includes executing the set of commands stored in the buffer memory unit. Executing a command includes reading a command from the buffer memory unit and, for each command, generating a hardware control signal according to the hardware control value in the command at the time specified by the timestamp in the command. The data processing device is configured to signal average the pulse sequence by iterating through the set of commands. The data processing device is configured to fill the buffer memory unit with multiple copies of the set of commands, each copy being executed multiple times. One of the commands in the set of commands includes a delay period between iterations of the pulse sequence.

[0156] In the sixth example, a method for operating a magnetic resonance system includes accessing digital intermediate frequency (IF) signal values ​​for multiple resonance pulses. The digital IF signal values ​​include multiple intermediate frequencies associated with multiple resonance frequencies of the multiple resonance pulses. The method further includes generating an analog IF electrical signal based on the digital IF signal values, generating a multiple resonance magnetic resonance control signal based on the analog IF electrical signal, and delivering the multiple resonance magnetic resonance control signal to a resonator unit in the magnetic resonance system.

[0157] Embodiments of the sixth example may include one or more of the following features: The method further includes, by operation of a computer system, identifying a first pulse profile corresponding to a first resonance frequency of a multiple resonance pulse; identifying a second pulse profile corresponding to a second resonance frequency of the multiple resonance pulse; generating a first digital IF signal value having a first intermediate frequency based on the first pulse profile; generating a second digital IF signal value having a separate second intermediate frequency based on the second pulse profile; and generating a digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value. The multiple resonance pulse includes a double resonance pulse in a double electron-electron resonance (DEER) measurement. The first resonance frequency corresponds to a first electron resonance frequency, and the second resonance frequency corresponds to a second electron resonance frequency.

[0158] Embodiments of the sixth example may include one or more of the following features: The method includes receiving a magnetic resonance control signal in a resonator unit and generating a control field in response to the magnetic resonance control signal by operation of the resonator unit. The method further includes receiving a magnetic resonance detection signal from the resonator unit, down-converting the magnetic resonance detection signal, generating a digital magnetic resonance detection signal value based on the down-converted magnetic resonance detection signal, demodulating the digital magnetic resonance detection signal value at a first intermediate frequency by operation of a computer system, and demodulating the digital magnetic resonance detection signal value at a second intermediate frequency.

[0159] In the seventh example, the magnetic resonance system includes a computer system, a digital-to-analog converter (DAC) device, a mixer device, and circuitry. The computer system is configured to access digital intermediate frequency (IF) signal values ​​for multiple resonant pulses. These digital IF signal values ​​include multiple intermediate frequencies associated with multiple resonant frequencies of the multiple resonant pulses. The DAC unit is configured to convert the digital IF signal values ​​into analog IF electrical signals. The mixer device is configured to mix the analog IF electrical signals with local oscillator (LO) electrical signals to produce magnetic resonance control signals. The circuitry is configured to deliver the multiple resonant magnetic resonance control signals to the resonator unit.

[0160] Embodiments of the seventh example may include one or more of the following features: The computer system is configured to identify a first pulse profile corresponding to a first resonance frequency of a multiple resonance pulse; identify a second pulse profile corresponding to a second resonance frequency of the multiple resonance pulse; generate a first digital IF signal value having a first intermediate frequency based on the first pulse profile; generate a second digital IF signal value having a separate second intermediate frequency based on the second pulse profile; and generate a digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value. The multiple resonance pulse includes a double resonance pulse in a double electron-electron resonance (DEER) measurement. The first resonance frequency corresponds to a first electron resonance frequency, and the second resonance frequency corresponds to a second electron resonance frequency.

[0161] Embodiments of the seventh example may include one or more of the following features: A resonator unit is configured to receive a magnetic resonance control signal in the resonator unit and to generate a control field in response to the magnetic resonance control signal. A mixer unit is a first mixer unit. A circuit is a first circuit. The magnetic resonance system includes a second mixer unit, an analog-to-digital converter (ADC) unit, and a second circuit. The second mixer unit is configured to receive a magnetic resonance detection signal from the resonator unit and to downconvert the magnetic resonance detection signal. The ADC unit is configured to generate a digital magnetic resonance detection signal value based on the downconverted magnetic resonance detection signal. The second circuit is configured to deliver the magnetic resonance detection signal to the second mixer unit and to deliver the downconverted magnetic resonance detection signal to the ADC unit. A computer system is further configured to demodulate the digital magnetic resonance detection signal value at a first intermediate frequency and to demodulate the digital magnetic resonance detection signal value at a second intermediate frequency.

[0162] This specification contains many details, but these should not be understood as limitations on the scope of what can be claimed, but rather as descriptions of features specific to particular examples. Certain features described herein or shown in the relevant drawings of separate embodiments may be further combined. Conversely, various features described or shown in the context of a single embodiment may further be implemented separately or in any preferred subcombination in multiple embodiments.

[0163] Similarly, although the operations are depicted in a specific order in the drawings, this should not be understood as meaning that such operations must be performed in a specific order or sequence shown, or that all illustrated operations must be performed, in order to achieve the desired result. In certain circumstances, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the embodiments described above should not be understood as meaning that such separation is necessary in all embodiments, and the described program components and systems can generally be integrated into a single product or packaged into multiple products.

[0164] Many examples have been described. Nevertheless, it will be understood that various modifications may be made. Therefore, other examples are within the scope of the attached claims.

Claims

1. A magnetic resonance system, A data processing device that generates digital intermediate frequency (IF) signal information based on a pulse profile, wherein the digital IF signal information is configured to suppress image sidebands in a magnetic resonance control signal; A superheterodyne spectrometer system that generates the magnetic resonance control signal based on the digital IF signal information, A magnetic resonance system equipped with this feature.

2. The magnetic resonance system according to claim 1, wherein the digital IF signal information specifies one or more phase shifts based on a time series of phases specified by the pulse profile.

3. The aforementioned digital IF signal information, I - Time series of quadrature phase signal values, The magnetic resonance system according to claim 1, comprising Q - a time series of orthogonal phase signal values, wherein the time series of Q - orthogonal phase signal values ​​is phase-shifted with respect to the time series of I - orthogonal phase signal values.

4. The magnetic resonance system according to claim 3, wherein generating the magnetic resonance control signal involves mixing an analog IF electrical signal with a local oscillator (LO) signal, and the time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values ​​each include a DC offset configured to reduce leakage of the LO signal.

5. The magnetic resonance system according to claim 1, wherein the digital IF signal information includes a plurality of sets of digital IF signal values ​​based on a plurality of pulses of a pulse sequence, and the superheterodyne spectrometer system is configured to generate a plurality of magnetic resonance control signals based on the plurality of sets of digital IF signal values.

6. A method for operating a magnetic resonance system, Due to the operation of the computer system, To identify the pulse profile for the pulses that will be generated by the magnetic resonance system, The process involves generating a digital intermediate frequency (IF) signal value based on the aforementioned pulse profile, The memory unit stores the digital IF signal value, To generate an analog IF electrical signal based on the aforementioned digital IF signal value, In order to generate a magnetic resonance control signal, the analog IF electrical signal is mixed with the local oscillator (LO) electrical signal, The magnetic resonance control signal is transmitted to the resonator unit in the magnetic resonance system. A method that includes this.

7. The method according to claim 6, wherein the pulse profile defines a time series of amplitude and a time series of phase for the pulse.

8. The generation of the aforementioned digital IF signal value is Identifying the phase shift of the pulse based on the aforementioned time series of phases, The method according to claim 7, further comprising performing the phase shift as a discontinuous time shift in the phase of the digital IF signal value.

9. The aforementioned digital IF signal value is, I - Time series of quadrature phase signal values, The method according to claim 6, comprising Q - a time series of orthogonal phase signal values, wherein the time series of Q - orthogonal phase signal values ​​is phase-shifted with respect to the time series of I - orthogonal phase signal values.

10. The method according to claim 9, wherein the time series of I-quadrature signal values ​​and the time series of Q-quadrature signal values ​​each include a DC offset configured to reduce leakage of the LO signal.

11. Generating multiple sets of digital IF signal values ​​based on multiple pulses of a pulse sequence, The method according to claim 6, further comprising generating a plurality of magnetic resonance control signals based on the plurality of sets of digital IF signal values.

12. The method according to claim 11, comprising analyzing the pulse sequence to identify the plurality of pulses, the plurality of time delays, and one or more acquisition periods in the pulse sequence.

13. The pulse profile includes a first pulse profile for a first pulse of a pulse sequence, the digital IF signal value is a first digital IF signal value, the analog IF electrical signal is a first analog IF electrical signal, and the magnetic resonance control signal is a first magnetic resonance control signal. The pulse sequence includes the first pulse, a time delay after the first pulse, and a second pulse after the time delay. The method described above is As a result of the operation of the aforementioned computer system, Identifying a second pulse profile for the second pulse, The phase shift is determined based on the duration of the time delay and the cycle time of the intermediate frequency, To generate a second digital IF signal value corresponding to the second pulse profile, wherein the phase shift is applied to the second digital IF signal value. The memory unit stores the second digital IF signal value, After generating the first analog IF electrical signal based on the first digital IF signal value, the time delay is performed. After the aforementioned time delay, a second analog IF electrical signal is generated based on the second digital IF signal value. To generate a second magnetic resonance control signal, the second analog IF electrical signal is mixed with the local oscillator (LO) electrical signal, The method according to claim 6, further comprising delivering the second magnetic resonance control signal to the resonator unit in the magnetic resonance system.

14. Identifying multiple pulse profiles for the aforementioned pulse, wherein each of the pulse profiles corresponds to a different resonance frequency. To generate a set of digital IF signal values ​​for each of the aforementioned pulse profiles, wherein each set of digital IF signal values ​​has a distinct intermediate frequency. The method according to claim 6, comprising combining the set of digital IF signal values ​​to produce a combined set of digital IF signal values ​​representing multiple resonant pulses.

15. The pulse includes multiple resonant pulses, The pulse profile includes a first pulse profile corresponding to a first resonance frequency of the pulse, The above method, through the operation of the computer system, Identifying a second pulse profile corresponding to the second resonance frequency of the pulse, Based on the first pulse profile, a first digital IF signal value having a first intermediate frequency is generated, Based on the second pulse profile, a second digital IF signal value having a separate second intermediate frequency is generated, The method according to claim 6, comprising generating the digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value.

16. The method according to claim 6, wherein the magnetic resonance system comprises a superheterodyne spectrometer that mixes the analog IF electrical signal with the LO electrical signal.

17. The resonator unit receives the magnetic resonance control signal, The method according to claim 6, further comprising generating a control field based on the magnetic resonance control signal by the operation of the resonator unit.

18. Receiving a magnetic resonance detection signal from the aforementioned resonator unit, The frequency of the magnetic resonance detection signal is down-converted to an intermediate frequency, The process involves generating a digital magnetic resonance detection signal value based on the down-converted magnetic resonance detection signal, As a result of the operation of the aforementioned computer system, The method according to claim 17, further comprising demodulating the digital magnetic resonance detection signal value at the intermediate frequency.

19. A magnetic resonance system, Identifying the pulse profile for a pulse, The process involves generating a digital intermediate frequency (IF) signal value based on the aforementioned pulse profile, The digital IF signal value is stored. A computer system configured to perform the following: A digital-to-analog converter (DAC) device configured to convert the aforementioned digital IF signal value into an analog IF electrical signal, A mixer device configured to mix the analog IF electrical signal with a local oscillator (LO) electrical signal in order to generate a magnetic resonance control signal, A circuit configured to transmit the magnetic resonance control signal to the resonator unit, A magnetic resonance system equipped with this feature.

20. The magnetic resonance system according to claim 19, wherein the pulse profile defines a time series of amplitude and a time series of phase for the pulse.

21. The generation of the aforementioned digital IF signal value is Identifying the phase shift of the pulse based on the aforementioned time series of phases, The magnetic resonance system according to claim 20, further comprising performing the phase shift as a discontinuous time shift in the phase of the digital IF signal value.

22. The aforementioned digital IF signal value is, I - Time series of quadrature phase signal values, The magnetic resonance system according to claim 19, comprising Q - a time series of orthogonal phase signal values, wherein the time series of Q - orthogonal phase signal values ​​is phase-shifted with respect to the time series of I - orthogonal phase signal values.

23. The magnetic resonance system according to claim 22, wherein the time series of I-quadrature phase signal values ​​and the time series of Q-quadrature phase signal values ​​each include a DC offset configured to reduce leakage of the LO signal.

24. The magnetic resonance system according to claim 19, wherein the computer system is configured to generate a plurality of sets of digital IF signal values ​​based on a plurality of pulses of a pulse sequence.

25. The magnetic resonance system according to claim 19, wherein the computer system is configured to analyze the pulse sequence to identify the plurality of pulses, the plurality of delays, and one or more acquisition periods in the pulse sequence.

26. The pulse profile includes a first pulse profile for a first pulse of a pulse sequence, the digital IF signal value is a first digital IF signal value, the analog IF electrical signal is a first analog IF electrical signal, and the magnetic resonance control signal is a first magnetic resonance control signal. The pulse sequence includes the first pulse, a time delay after the first pulse, and a second pulse after the time delay. The aforementioned computer system Identifying a second pulse profile for the second pulse, The phase shift is determined based on the duration of the time delay and the cycle time of the intermediate frequency, To generate a second digital IF signal value corresponding to the second pulse profile, wherein the phase shift is applied to the second digital IF signal value. The second digital IF signal value is stored in the memory unit, The system is configured to generate the first analog IF electrical signal based on the first digital IF signal value, and then perform the time delay. The DAC unit is configured to generate a second analog IF electrical signal based on the second digital IF signal value after the time delay. The mixer device is configured to mix the second analog IF electrical signal with the local oscillator (LO) electrical signal in order to generate a second magnetic resonance control signal. The magnetic resonance system according to claim 19, wherein the circuit is configured to deliver the second magnetic resonance control signal to the resonator unit in the magnetic resonance system.

27. The aforementioned computer system Identifying multiple pulse profiles for the aforementioned pulse, wherein each of the pulse profiles corresponds to a different resonance frequency. To generate a set of digital IF signal values ​​for each of the aforementioned pulse profiles, wherein each set of digital IF signal values ​​has a distinct intermediate frequency. The magnetic resonance system according to claim 19, configured to combine a set of digital IF signal values ​​in order to produce a combined set of digital IF signal values ​​representing multiple resonant pulses.

28. The pulse includes multiple resonant pulses, The pulse profile includes a first pulse profile corresponding to a first resonance frequency of the pulse, The aforementioned computer system Identifying a second pulse profile corresponding to the second resonance frequency of the pulse, Based on the first pulse profile, a first digital IF signal value having a first intermediate frequency is generated, Based on the second pulse profile, a second digital IF signal value having a separate second intermediate frequency is generated, The magnetic resonance system according to claim 19, configured to generate the digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value.

29. The magnetic resonance system according to claim 19, comprising a superheterodyne spectrometer including the mixer device.

30. The resonator unit comprises the resonator unit, The resonator unit receives the magnetic resonance control signal, The magnetic resonance system according to claim 19, configured to generate a control field in response to the magnetic resonance control signal.

31. The mixer device is the first mixer device, the circuit is the first circuit, and the magnetic resonance system is Receiving a magnetic resonance detection signal from the aforementioned resonator unit, The frequency of the magnetic resonance detection signal is down-converted to an intermediate frequency. A second mixer device configured to perform the following: An analog-to-digital converter (ADC) configured to generate a digital magnetic resonance detection signal value based on the down-converted magnetic resonance detection signal, The magnetic resonance detection signal is transmitted to the second mixer device, The down-converted magnetic resonance detection signal is transmitted to the ADC unit. It comprises a second circuit configured to perform the following: The magnetic resonance system according to claim 19, wherein the computer system is further configured to demodulate the digital magnetic resonance detection signal value at the intermediate frequency.

32. A method for operating a magnetic resonance system, Due to the operation of the computer system, The objective is to obtain pulse sequence information corresponding to a pulse sequence to be executed by the magnetic resonance system, wherein the magnetic resonance system includes a control unit, a digital-to-analog converter (DAC) unit, an analog-to-digital converter (ADC) unit, and a digital input / output (DIO) unit. The process involves generating a hardware control sequence based on the pulse sequence information, wherein the hardware control sequence includes a timestamp and a hardware control value for each time segment of the pulse sequence, and the hardware control value for each time segment is configured to control the operation of the DAC unit, the ADC unit, and the DIO unit. The hardware control sequence is stored in a memory unit, A method comprising executing the pulse sequence in the magnetic resonance system, wherein the execution of the pulse sequence includes controlling the operation of the DAC unit, the ADC unit, and the DIO unit in accordance with the hardware control sequence by the operation of the control unit.

33. Controlling the operation of the DAC unit, the ADC unit, and the DIO unit according to the hardware control sequence, Receiving a clock signal, The method according to claim 32, further comprising delaying the clock signal for each hardware component in order to synchronize the operation of each hardware component.

34. Controlling the operation of the DAC unit, the ADC unit, and the DIO unit is The operation of the DAC unit occurs during a first subset of the time segment, wherein the first subset of the time segment corresponds to a pulse in the pulse sequence. The method according to claim 32, comprising causing the operation of the ADC unit to occur during a second subset of the time segment, wherein the second subset of the time segment corresponds to the acquisition in the pulse sequence.

35. Controlling the operation of the DAC unit, the ADC unit, and the DIO unit is Synchronizing transmission electronic equipment to generate a magnetic resonance control signal during the first subset of the time segment, The method according to claim 34, further comprising synchronizing receiver electronics to process a magnetic resonance detection signal during the second subset of the time segment.

36. The method according to claim 32, wherein the hardware control sequence includes pulse identifiers for a subset of the time segments corresponding to the pulses of the pulse sequence, and each pulse identifier indicates a memory address in which a digital IF signal value is stored.

37. Executing the aforementioned pulse sequence repeatedly Identifying one of the timestamps in the hardware control sequence, Comparing the clock signal with the identified timestamp, The method according to claim 32, further comprising detecting a match between the clock signal and the identified timestamp, and transmitting a digital control signal according to the hardware control value associated with the identified timestamp.

38. Storing the hardware control sequence in a memory unit includes storing a series of commands in a buffer memory unit, wherein the series of commands correspond to each of the time segments in the pulse sequence, and each command includes the timestamp and the hardware control value for each of the time segments. The method according to claim 32, wherein executing the pulse sequence includes executing the command stored in the buffer memory unit.

39. Executing the aforementioned command Reading the command from the buffer memory unit, The method according to claim 38, further comprising generating a hardware control signal for each command according to the hardware control value in the command at the time specified by the timestamp in the command.

40. The method according to claim 38, comprising signal averaging of the pulse sequence by repeatedly executing the series of commands.

41. The method according to claim 38, comprising filling the buffer memory unit with a plurality of copies of the series of commands, wherein each copy is executed multiple times.

42. The method according to claim 38, wherein one of the commands in the series of commands includes a delay period between repetitions of the pulse sequence.

43. A magnetic resonance system, Digital-to-analog converter (DAC) unit, Analog-to-digital converter (ADC) unit, Digital input / output (DIO) unit, A memory unit configured to store hardware control sequences, To obtain pulse sequence information corresponding to the pulse sequence, To generate the hardware control sequence based on the pulse sequence information. A data processing device configured to perform the following, wherein the hardware control sequence includes a timestamp and a hardware control value for each time segment in the pulse sequence, and the hardware control value for each time segment is configured to control the operation of the DAC unit, the ADC unit, and the DIO unit. When the pulse sequence is executed in the magnetic resonance system, a control unit is configured to control the operation of the DAC unit, the ADC unit, and the DIO unit according to the hardware control sequence. A magnetic resonance system equipped with this feature.

44. The control unit, Receiving a clock signal, The system according to claim 43, further configured to delay the clock signal for each hardware component in order to synchronize the operation of each hardware component.

45. The control unit, The operation of the DAC unit occurs during a first subset of the time segment, wherein the first subset of the time segment corresponds to a pulse in the pulse sequence. The system according to claim 43, wherein the operation of the ADC unit occurs during a second subset of the time segment, the second subset of the time segment being configured to occur in a pulse sequence corresponding to acquisition.

46. The control unit, Synchronizing transmission electronic equipment to generate a magnetic resonance control signal during the first subset of the time segment, The system according to claim 43, configured to synchronize receiver electronics for processing magnetic resonance detection signals during the second subset of the time segment.

47. The system according to claim 43, wherein the hardware control sequence includes pulse identifiers for a subset of the time segments corresponding to the pulses of the pulse sequence, and each pulse identifier indicates a memory address in which a digital IF signal value is stored.

48. Executing the aforementioned pulse sequence repeatedly Identifying one of the timestamps in the hardware control sequence, Comparing the clock signal with the identified timestamp, The system according to claim 43, further comprising detecting a match between the clock signal and the identified timestamp, and transmitting a digital control signal according to the hardware control value associated with the identified timestamp.

49. The system according to claim 43, wherein the data processing device includes a buffer memory unit configured to store a series of commands, the series of commands corresponding to the respective time segments in the pulse sequence, each command including the timestamp and hardware control value for each time segment of the time segment, and executing the pulse sequence includes executing the series of commands stored in the buffer memory unit.

50. Executing the aforementioned command Reading the command from the buffer memory unit, The system according to claim 49, further comprising generating a hardware control signal for each command according to the hardware control value in the command at the time specified by the timestamp in the command.

51. The system according to claim 49, wherein the data processing device is configured to signal average the pulse sequence by repeatedly executing the series of commands.

52. The system according to claim 49, wherein the data processing device is configured to fill the buffer memory unit with multiple copies of the series of commands, and each copy is executed multiple times.

53. The system according to claim 49, wherein one of the commands in the series of commands includes a delay period between repetitions of the pulse sequence.

54. A method for operating a magnetic resonance system, Accessing a digital intermediate frequency (IF) signal value for a multiple resonant pulse, wherein the digital IF signal value includes a plurality of intermediate frequencies associated with a plurality of resonant frequencies of the multiple resonant pulse. To generate an analog IF electrical signal based on the aforementioned digital IF signal value, The process involves generating a multi-resonance magnetic resonance control signal based on the aforementioned analog IF electrical signal, The multi-resonance magnetic resonance control signal is transmitted to the resonator unit in the magnetic resonance system. Methods that include...

55. Due to the operation of the computer system, Identifying a first pulse profile corresponding to the first resonance frequency of the multiple resonance pulses, Identifying a second pulse profile corresponding to the second resonance frequency of the multiple resonance pulses, Based on the first pulse profile, a first digital IF signal value having a first intermediate frequency is generated, Based on the second pulse profile, a second digital IF signal value having a separate second intermediate frequency is generated, The method according to claim 54, further comprising generating the digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value.

56. The method according to claim 55, wherein the multiple resonance pulse includes a double resonance pulse in a double electron-electron resonance (DEER) measurement.

57. The method according to claim 56, wherein the first resonance frequency corresponds to a first electron resonance frequency, and the second resonance frequency corresponds to a second electron resonance frequency.

58. The magnetic resonance control signal is received in the resonator unit, The method according to claim 54, further comprising generating a control field in response to the magnetic resonance control signal by the operation of the resonator unit.

59. Receiving a magnetic resonance detection signal from the aforementioned resonator unit, The magnetic resonance detection signal is down-converted, The process involves generating a digital magnetic resonance detection signal value based on the down-converted magnetic resonance detection signal, Due to the operation of the computer system, The digital magnetic resonance detection signal value is demodulated at a first intermediate frequency. The method according to claim 54, further comprising demodulating the digital magnetic resonance detection signal value at a second intermediate frequency.

60. A magnetic resonance system, A control unit configured to access digital intermediate frequency (IF) signal values ​​for multiple resonant pulses, wherein the digital IF signal values ​​include a plurality of intermediate frequencies associated with a plurality of resonant frequencies of the multiple resonant pulses, A digital-to-analog converter (DAC) device configured to convert the aforementioned digital IF signal value into an analog IF electrical signal, A mixer device configured to mix the analog IF electrical signal with a local oscillator (LO) electrical signal in order to generate a magnetic resonance control signal, A circuit configured to deliver the multi-resonance magnetic resonance control signal to the resonator unit A magnetic resonance system equipped with this feature.

61. Identifying a first pulse profile corresponding to the first resonance frequency of the multiple resonance pulses, Identifying a second pulse profile corresponding to the second resonance frequency of the multiple resonance pulses, Based on the first pulse profile, a first digital IF signal value having a first intermediate frequency is generated, Based on the second pulse profile, a second digital IF signal value having a separate second intermediate frequency is generated, The magnetic resonance system according to claim 60, comprising a computer system configured to generate the digital IF signal value by superimposing the first digital IF signal value and the second digital IF signal value.

62. The magnetic resonance system according to claim 61, wherein the multiple resonance pulses include a double resonance pulse in a double electron-electron resonance (DEER) measurement.

63. The magnetic resonance system according to claim 62, wherein the first resonance frequency corresponds to a first electron resonance frequency, and the second resonance frequency corresponds to a second electron resonance frequency.

64. The aforementioned resonator unit, The resonator unit receives the magnetic resonance control signal, The magnetic resonance system according to claim 60, configured to generate a control field in response to the magnetic resonance control signal.

65. The mixer device is the first mixer device, the circuit is the first circuit, and the magnetic resonance system is Receiving a magnetic resonance detection signal from the aforementioned resonator unit, The magnetic resonance detection signal is down-converted. A second mixer device configured to perform the following: An analog-to-digital converter (ADC) configured to generate a digital magnetic resonance detection signal value based on the down-converted magnetic resonance detection signal, The magnetic resonance detection signal is transmitted to the second mixer device, The down-converted magnetic resonance detection signal is transmitted to the ADC unit. It comprises a second circuit configured to perform the following: The computer system further The digital magnetic resonance detection signal value is demodulated at a first intermediate frequency. The magnetic resonance system according to claim 60, configured to demodulate the digital magnetic resonance detection signal value at a second intermediate frequency.

Images