Device type is the second principal axis of market taxonomy. ECG‑based detectors, which employ multi‑lead electrodes to capture electrical cardiac activity, dominate the clinical segment, accounting for roughly 55 % of total units because of their diagnostic accuracy and established regulatory pathways. PPG‑based sensors, leveraging optical light absorption to infer pulse waveforms, comprise about 30 % of the market; they are favored in wearable and home‑care applications where ease of use and cost efficiency outweigh the need for full ECG fidelity. Acoustic‑sensor devices, which analyze heart sounds via digital stethoscopes, hold a niche 8 % share, primarily in tele‑cardiology platforms that integrate auscultation with arrhythmia alerts. Finally, AI‑enabled platforms that combine data from multiple modalities and apply machine‑learning classifiers represent an emerging 7 % segment, driven by investments in cloud infrastructure and the promise of predictive arrhythmia risk scoring. This type‑based segmentation clarifies the allocation of R&D resources, informs pricing differentials, and shapes the competitive landscape across the Heart Beat Irregularity Detection Device market.