Sprague-Rappaport Adult Cardiology Bell

thingiverse

This bell is a 3D printed copy of a bell designed by Lane Craddock, MD. Dr. Craddock had an interest in Cardiac Auscultation and was examining a patient he suspected had mitral stenosis, a very low pitched murmur. Dr. Craddock could not hear it and his frustration was evident to the patient who happened to be a machinist. The patient inquired and Dr. Craddock sketched out what he felt was needed. The patient machined it from aluminum and gave it to Dr. Craddock who tested it and verified that it did help detect low pitched sounds.. Other Cardiologists asked about the bell and it was eventually sold in the Medical School book store.I replicated my well worn bell in FreeCAD but the threads were a challenge, They are none standard SAE/metric. I did not test available pipe threads. If someone knows the exact threads please post.I used the subtractive helix function in FreeCAD and after several tries, the uploaded version will easily thread on when made in Sunlu Tough Resin on an Hewlett-Packard Sprague-Rappaport stethoscope. H-P no longer manufacturers this Stethoscope and I did not test currently manufactured copies.