发现消费级摄像头无法恢复个体脉搏波形特征，提出用跨被试相关性检测模型坍塌。
Template Collapse and Information-Theoretic Limits in Camera rPPG Pulse Morphology Restoration
- 用跨被试皮尔逊相关性区分个体特征恢复与模板坍塌，新诊断方法
- 16种架构均未恢复个体波形，最高跨被试相关性达0.9999但真实上限仅0.601
- 变分自编码器能重建群体谐波结构，适合零样本泛化，但存在方向性幻觉
目标：消费级人脸摄像头远程光电容积脉搏波（rPPG）实现被动心血管监测，但单周期波形是否可编码动脉僵硬度生物标志物尚未明确。方法：在三个数据集共153名受试者上评估16种架构，涵盖六类模型，引入跨被试皮尔逊相关性以区分个体特异性恢复与模板坍塌。结果：所有架构均未能恢复个体波形特征（跨被试相关性范围0.773–0.9999；真实上限0.601）。监督对比学习（SupCon）收敛至log N = 4.844，为当前最强实证证据，表明所测试编码器家族无法从单周期rPPG中提取判别性形态结构。变分自编码器（VAE）解码器重建了输入中缺失的群体级谐波成分（H2/H1：输出0.310，输入0.275），并在零样本下泛化至UBFC数据集（r = +0.708）；方向性幻觉差距（p = 0.150）提示部分信号读取存在。意义：消费级摄像头无法编码个体动脉形态特征；跨被试相关性是波形重建基准中不可或缺的坍塌诊断指标。
原文摘要 · Abstract (English)
Objective: Consumer face camera remote photoplethysmography (rPPG) enables passive cardiovascular monitoring, but whether single-cycle waveform morphology encoding arterial stiffness biomarkers is recoverable from this measurement has not been characterised. Methods: We evaluated 16 architectures spanning six families on 153 subjects across three datasets, introducing cross-subject Pearson r to distinguish subject-specific recovery from template collapse. Results: No architecture recovered subject-specific morphology (cross-subject r range 0.773--0.9999; ground-truth ceiling 0.601). Supervised Contrastive (SupCon) converged to log N = 4.844, constituting the strongest available empirical evidence that no discriminative morphological structure is extractable from single-cycle rPPG by the encoder families tested. The VAE decoder restores population-level harmonic content absent from the rPPG input (H2/H1: 0.310 output vs. 0.275 input), generalising zero-shot to UBFC (r = +0.708); a directional hallucination gap (p = 0.150) suggests partial signal reading. Anti-collapse objectives fail when input carries no discriminative structure. Significance: Consumer cameras cannot encode individual arterial morphology; cross-subject r is a necessary collapse diagnostic for waveform reconstruction benchmarks.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品；中文卡片由大模型生成，请以原文为准。