inv_hpi_fit.h File Reference

HPI (Head Position Indicator) fitting — estimates the MEG dewar-to-head transform from coil-current signals. More...

#include "../inv_global.h"
#include <fiff/fiff_ch_info.h>
#include "inv_sensor_set.h"
#include "inv_signal_model.h"
#include <fiff/fiff_dig_point_set.h>
#include <fiff/fiff_dig_point.h>
#include <fiff/fiff_coord_trans.h>
#include <Eigen/Core>
#include <Eigen/Geometry>
#include <QSharedPointer>

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Classes
struct	INVLIB::CoilParam
	Estimated dipole parameters (position, moment, goodness-of-fit) for a single HPI coil. More...
struct	INVLIB::HpiFitResult
	Complete HPI fit output: per-coil dipole parameters, head-to-device transform, fit error, and head movement distance. More...
class	INVLIB::InvHpiFit
	Drives one HPI fit (per-coil dipole localisation, coil ordering, dewar-to-head transform). More...

Namespaces
namespace	FWDLIB
	Forward modelling — BEM solver, spherical models, sensor/coil definitions and the lead-field assembly that links current dipoles to MEG/EEG sensor readings.
namespace	FIFFLIB
	FIFF file I/O, in-memory data structures and high-level readers/writers.
namespace	INVLIB
	Inverse source estimation (MNE, dSPM, sLORETA, dipole fitting).

Macros
#define	metatype_HpiFitResult

Detailed Description

HPI (Head Position Indicator) fitting — estimates the MEG dewar-to-head transform from coil-current signals.

SPDX-License-Identifier: BSD-3-Clause Copyright (c) 2026 MNE-CPP Authors

Author

Christoph Dinh chris.nosp@m.toph.nosp@m..dinh.nosp@m.@mne.nosp@m.-cpp..nosp@m.org

Since

2.0.0

Date

March 2026

INVLIB::InvHpiFit fits a magnetic dipole to each HPI coil from the projected MEG data, matches the fitted coils to the digitised coil locations and returns the resulting dewar↔head coordinate transform. The class drives the same pipeline used by Elekta/MEGIN MaxFilter and mne-python's mne.chpi: per-coil dipole localisation, frequency ordering, large-movement detection and quaternion-formatted position storage. Inputs are the projected sensor data, the SSP projector and an InvHpiModelParameters spec; output is an HpiFitResult that downstream stages can feed to head-movement-corrected averaging or continuous co-registration.

Definition in file inv_hpi_fit.h.

Macro Definition Documentation

metatype_HpiFitResult

#define metatype_HpiFitResult

Definition at line 381 of file inv_hpi_fit.h.