{"artifact_id":"L1-069","layer":"L1","title":"Magnetic Particle Imaging (MPI)","domain":"Medical Imaging","sub_domain":"Superparamagnetic iron-oxide tracer imaging","physics_fingerprint":{"L_DAG":4.0,"title":"Magnetic Particle Imaging (MPI)","domain":"Medical Imaging","carrier":"radio_wave","primitives":["L.drive_field","L.selection_field_ffp","D.receive_coil","int.temporal"],"sub_domain":"Superparamagnetic iron-oxide tracer imaging","noise_model":"gaussian","problem_class":"nonlinear_inverse","solution_space":"3D_tracer_concentration","difficulty_delta":5,"integration_axis":"temporal","sensing_mechanism":"mpi_ffp_scan"},"observable_profile":{"metric":"PSNR_dB","regime":"Existence of the recovered 3D tracer concentration is guaranteed within the declared Omega bounds. Uniqueness is local rather than global (non-convex landscape); convergence depends on initialisation and priors. Stability is moderately conditioned (kappa_eff ~= 20); spatial_relaxation dominates the stability cliff; tracer_distribution and the remaining mismatch parameters contribute higher-order bias terms. Additive gaussian thermal/electronic noise sets the irreducible data-fidelity floor, while TV / wavelet-sparsity / deep priors stabilise recovery at the ill-conditioned end of Omega.","secondary":"SSIM"},"size_tiers":{"center_spec":{"omega":{"H":128,"W":128,"Z":64,"SNR_dB":20,"N_harmonics":20,"f_drive_kHz":25,"spatial_relaxation":0.0,"tracer_distribution":0.0,"drive_field_harmonics":0.0,"coil_sensitivity_error":0.0},"input_format":"measurement_only","problem_class":"mpi","forward_operator":"mpi_forward","epsilon_fn_center":"20.0"},"omega_bounds":{"H":32,"W":32,"Z":[8,256],"SNR_dB":[0.0,35.0],"N_harmonics":[5,100],"f_drive_kHz":[5,50],"spatial_relaxation":[0.0,0.3],"tracer_distribution":[0.0,0.3],"drive_field_harmonics":[0.0,0.3],"coil_sensitivity_error":[0.0,0.3]},"epsilon_bounds":{"psnr_db":[5.0,45.0]},"allowed_problem_classes":["mpi"],"allowed_omega_dimensions":["H","W","Z","N_harmonics","f_drive_kHz","SNR_dB","spatial_relaxation","tracer_distribution","drive_field_harmonics","coil_sensitivity_error","spatial_relaxation","tracer_distribution","drive_field_harmonics","coil_sensitivity_error"],"allowed_forward_operators":["mpi_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":400,"metric":"PSNR_dB"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xd667e923b42a7e570729f61b099f1850c7402ccdf2a5ef4672bf583fe102c1d6","chain_tx_hash":"0x35fda28a37fe8bdbe112439e5d1a5b3c668b1ede4349679e82f908eea582971c","chain_block":41552304}