This project is the work of a large team, including Alex Pavlosky, Jennifer Glauche, Spencer Chambers, Mahmoud Al-Alawi, Kliment Yanev, Carrie Wakem and Tarek Loubani.
This project aims to create a research-validated stethoscope whose plans are
available freely and openly. The goal is for the bell to cost ~USD$1-2 to produce,
and the rest of the stethoscope to cost approximately the same. You can see the peer-reviewed publication relating to this stethoscope's validation here:
Currently, the stethoscope resulting from this project functions as well as the
market gold standard, the Littmann Cardiology III. This version is made and distributed in Canada under license from Health Canada.
Bill of Materials
1 stethoscope head (head.stl)
2 ear tubes (eartube.stl)
1 Y-piece (y_piece.stl)
1 Spring (spring.stl)
Some vendors are suggested. See Bill of materials ODS file for more information.
40cm - 50cm Silicone 12mm or 13mm OD, 8mm ID
8MM I.D X 12MM O.D NGP60 Clear Translucent Silicone Hose Pipe Tubing (USD$6.95/meter)
8MM I.D X 13MM O.D NGP60 Clear Translucent Silicone Hose Pipe Tubing (USD$7.34/meter)
20cm Silicone 6mm or 8mm OD, 4mm ID (cut into 10cm pieces)
4mm ID x 6mm OD
4mm ID x 8mm OD
Diaphragm: 40mm diameter cut from a report cover with approx 0.35mm plastic sheet
Staples 21639 report cover (UPC 718103160223) (USD$8.84)
You can cut the diaphragm by hand or with a stamp like this one
Earbuds: Any large-sized standard earbuds will do.
Silicone Earbuds 7 Pairs - Large size
Metal spring for holding ear tubes together
INFILL MUST BE 100%
All printed parts should be printed with ABS or PLA plastic at 0.2mm layer height,
though it is acceptable for the first layer to be 0.3mm.
We print the eartubes and Y-pieces with a brim of 2mm to ensure that none of the
parts lift off.
INFILL MUST BE 100%. Otherwise, the stethoscope will not print well.
Insert silicone into mold and allow to set as per manufacturer instructions.
Attach the diaphragm (40mm) to the stethoscope head.
Attach the stethoscope head to the silicone tube.
Attach the silicone tube to the T-Piece.
Attach spring to ear tubes.
Attach the T-piece to the ear tubes.
Attach the ear tubes to the molded earplugs.
Test the stethoscope as per the validation instructions.
Printing the inserts
The inserts are included in the manual directory. Using 8.5 x 11 (Legal) paper,
they can be printed at 8.25" page width with 95% scale for the top print and
90% scale for the bottom print using GIMP.
The top insert is cut at 14.5cm and again at 1cm creating two labels of 13.5cm height.
These inserts are printed on adhesive material.
The bottom insert is cut at a width of 20cm with a height cuts at 25cm, 15cm,
13.5cm and 3.5cm creating 10cm x 20cm inserts.
Changing and creating SCAD files
CrystalSCAD and OpenSCAD
were used to create all STL files. To recreate the stethoscope head, simply do:
gem install crystalscad
The SCAD files output from CrystalSCAD are found in source_files/stethoscope_head/output and are named as follows:
PrintableStethoscopeHead1Assembly_output.scad - The head
EarplugMold_output.scad - Earplug mold