I. Determining When to Replace the Tubing
1. The tubing surface shows visible cracks or localized hardening and brittleness, failing to spring back to its original shape after being bent.
2. The tubing turns yellow or becomes severely discolored, is internally obstructed, or produces noticeable noise during auscultation.
3. Air leakage occurs in the tubing section during a seal test, resulting in a significant drop in auscultation volume.
II. Determining When to Replace the Chestpiece Diaphragm
1. The diaphragm surface is damaged or scratched, or the retaining ring is loose or shifted, preventing a complete seal.
2. High-frequency sounds are indistinct during auscultation, and tapping the diaphragm produces a muffled sound or noticeable noise.
3. The diaphragm is deformed and cannot sit flush against the chestpiece, showing localized indentations when pressed.
III. Determining When to Replace the Eartips
1. The silicone or rubber material of the eartips has hardened and lost elasticity, preventing a snug fit in the ear canal.
2. The eartip surface shows cracking or flaking, causing noticeable pressure or pain in the ear canal during use.
3. The eartips show severe aging or discoloration, and sound leakage persists even after adjusting the fit.
IV. General Replacement Guidelines
1. If a part exhibits any of the issues mentioned above and normal sound transmission cannot be restored through simple cleaning or adjustment, timely replacement is recommended.
2. For stethoscopes used frequently, it is recommended to inspect and replace the full set of wearable parts every 1–2 years to ensure auscultation accuracy.
