Hybrid Quantum-inspired Kolmogorov-Arnold Networks for Privacy-Aware Federated Biosignal Learning
Authors: Chun-Hua Lin, Samuel Yen-Chi Chen, Yu-Chao Hsu, Kuo-Chung Peng, Jiun-Cheng Jiang, Chi-Sheng Chen, Tai-Yue Li, Nan-Yow Chen, +2 more
Organizations: Department of Physics and Center for Theoretical Physics, National Taiwan University, Taipei, Taiwan · National Center for High-Performance Computing, National Institutes of Applied Research, Hsinchu, Taiwan · Brookhaven National Laboratory, Upton, NY, USA · School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea · Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan · Beth Israel Deaconess Medical Center, Harvard University, Boston, MA, USA · Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan · Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
Electrocardiogram (ECG) recordings are sensitive biomedical data, limiting the ability of hospitals and wearable devices to share raw signals for centralized model training. Federated learning addresses this practical privacy constraint by enabling collaborative model training while keeping raw biosignal data at their respective sources. However, federated ECG classification remains challenging due to limited client-side samples, imbalanced arrhythmia labels, and non-independent and identically distributed (non-IID) data across clients. These constraints require classifiers that are both communication-efficient and robust to cross-client distribution shifts. In this work, we evaluate a hybrid quantum-inspired Kolmogorov-Arnold network (HQKAN) against a multilayer perceptron (MLP) for five-class arrhythmia classification on the MIT-BIH dataset and three-class classification on the INCART dataset under federated averaging (FedAvg). Across multiple client configurations, HQKAN improves most aggregate and minority-class metrics while using 37.35% fewer trainable parameters and reducing communication cost by 24.89% on MIT-BIH; on INCART, it achieves corresponding reductions of 44.81% and 36.41%. These results indicate that HQKAN offers a compact, communication-efficient and robust alternative to the MLP baseline for privacy-aware federated learning on biosignal data.
Figures & tables
Fig. 1: ROC curves (a) and precision-recall curves (b) for the three minority classes (S, V, F) under IID and non-IID federated partitions on MIT-BIH, comparing the MLP baseline against HQKAN. Curves are averaged over five random seeds.
Fig. 2: ROC curves (a) and precision-recall curves (b) for the majority class N and minority classes S and V under IID and non-IID federated partitions on INCART, comparing the MLP baseline with HQKAN. Curves are averaged over five random seeds.
Setting
Clients
Model
macro-F1 ↑
κ↑
Brier ↓
IID
8
MLP
0.726 ± 0.008
0.764 ± 0.011
0.127 ± 0.007
HQKAN
0.739 ± 0.006
0.776 ± 0.008
0.119 ± 0.005
16
MLP
0.672 ± 0.007
0.686 ± 0.013
0.178 ± 0.009
HQKAN
0.716 ± 0.018
0.744 ± 0.025
0.137 ± 0.017
32
MLP
0.633 ± 0.008
0.626 ± 0.013
0.232 ± 0.011
HQKAN
0.687 ± 0.012
0.701 ± 0.017
0.164 ± 0.011
TABLE I: Performance of MIT-BIH dataset with 5 local epochs (mean ± std over 5 seeds). Non-IID uses α=0.3 .
Setting
Clients
Model
macro-F1 ↑
κ↑
Brier ↓
IID
8
MLP
0.815 ± 0.015
0.882 ± 0.013
0.047 ± 0.007
HQKAN
0.838 ± 0.023
0.898 ± 0.017
0.040 ± 0.009
16
MLP
0.764 ± 0.014
0.824 ± 0.017
0.071 ± 0.007
HQKAN
0.806 ± 0.036
0.864 ± 0.036
0.054 ± 0.011
32
MLP
0.743 ± 0.014
0.793 ± 0.026
0.090 ± 0.011
HQKAN
0.773 ± 0.032
0.827 ± 0.039
0.068 ± 0.014
TABLE II: Performance of INCART dataset with 5 local epochs (mean ± std over 5 seeds). Non-IID uses α=0.3 .
Setting
Class
Model
PPV
Sen
Spe
IID
S
MLP
0.282 ± 0.009
0.739 ± 0.018
0.951 ± 0.003
HQKAN
0.334 ± 0.030
0.747 ± 0.014
0.961 ± 0.006
V
MLP
0.669 ± 0.017
0.881 ± 0.003
0.969 ± 0.002
HQKAN
0.705 ± 0.019
0.908 ± 0.012
0.973 ± 0.003
F
MLP
0.147 ± 0.015
0.868 ± 0.007
0.962 ± 0.004
HQKAN
0.239 ± 0.022
0.837 ± 0.014
0.980 ± 0.003
TABLE III: Per-class performance at 32 clients and 5 local epochs of MIT-BIH dataset (mean ± std over 5 seeds). Non-IID uses α=0.3 .
Setting
Class
Model
PPV
Sen
Spe
IID
N
MLP
0.994 ± 0.000
0.945 ± 0.010
0.961 ± 0.003
HQKAN
0.995 ± 0.001
0.956 ± 0.013
0.966 ± 0.004
S
MLP
0.199 ± 0.025
0.838 ± 0.009
0.961 ± 0.008
HQKAN
0.278 ± 0.076
0.833 ± 0.013
0.974 ± 0.009
V
MLP
0.916 ± 0.014
0.966 ± 0.004
0.989 ± 0.002
HQKAN
0.895 ± 0.038
0.974 ± 0.005
0.985 ± 0.006
TABLE IV: Per-class performance at 32 clients and 5 local epochs of INCART dataset (mean ± std over 5 seeds). Non-IID uses α=0.3 .
Fig. 3: Robustness to client label heterogeneity at 32 clients and 5 local epochs of MIT-BIH dataset. The x-axis uses Hellinger distance to summarize label skew, with larger values indicating stronger non-IID partitions. The y-axis reports AUROC or AUPRC of different models. Each point corresponds to one Dirichlet concentration α .
Fig. 4: Robustness to client label heterogeneity at 32 clients and 5 local epochs of INCART dataset. The x-axis uses Hellinger distance to summarize label skew, with larger values indicating stronger non-IID partitions. The y-axis reports AUROC or AUPRC of different models. Each point corresponds to one Dirichlet concentration α .
School of Electrical and Electronic Engineering, Nanyang Technological University, Republic of Singapore · Lee Kong Chian School of Medicine, Nanyang Technological University, Republic of Singapore