CheckLimits

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CheckLimits#

class pulserver.ir.CheckLimits[source]#

Bases: object

The nerve, resonance and acoustic limits of a chain, and the VOPs of its SAR ratios, besides pypulseqpp.Opts.

Attributes:

  • pns (Any) – Nerve model of pypulseqpp.safety.check_pns: a ChronaxieModel or a SAFE description. None leaves out the PNS check.

  • pns_limit (float) – Largest PNS response allowed, as a fraction of the model’s threshold.

  • bands (tuple[pypulseqpp.safety._resonance.ForbiddenBand, …]) – Forbidden gradient bands of check_mech_resonance, on the physical axes. Without any, the resonance check is left out.

  • vops (pypulseqpp.safety._sar.VopModel | pathlib.Path | str | None) – VOPs and the global SAR matrices of their body models, or the .mat or .npz file holding them, which sar_ratios() reads; nothing is refused on SAR.

  • drive_per_hz (float | tuple[float, …]) – Channel drive per Hz of RF amplitude, in the VOPs’ drive unit: one value, or one per channel. A scale common to every channel cancels in the ratios.

  • default_shim (tuple[complex, …] | None) – Complex channel weights of a pulse played without an RF shim, and of the reference pulse; equal weights when None.

  • vop_coil (str | None) – The transmit configuration the scanner reports. When given, the VOP file’s metadata["transmit"] must name the same one.

  • vop_head_limit, vop_local_limit – The scanner’s head and local SAR limits, W/kg, in its current operating mode; sar_ratios() needs both.

  • acoustic (pypulseqpp.safety._acoustic.AcousticResponse | pathlib.Path | str | None) – The gradient coil’s acoustic transfer function on the physical axes, or the HDF5 file pypulseqpp.safety.read_acoustic_response reads it from. None leaves out the sound pressure check.

  • acoustic_interval (float) – Sampling interval in s the bins of an acoustic file refer to.

  • spl_peak_limit (float) – Largest peak sound pressure level allowed, in dB re 20 µPa; that of IEC 60601-2-33 by default.

  • spl_average_limit (float) – Largest A-weighted average sound pressure level allowed, in dB(A); that of IEC 60601-2-33 by default.

Raises:

ValueError – If the PNS limit or a SAR limit is not positive, or an acoustic file comes without its interval.

Methods

acoustic_response

Return the acoustic transfer function, read from its file where given as one.

Attributes

acoustic

acoustic_interval

bands

default_shim

drive_per_hz

pns

pns_limit

spl_average_limit

spl_peak_limit

vop_coil

vop_head_limit

vop_local_limit

vops

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