Likar - looking great! Let's focus on #121 as starting place. Want to try four minor tweaks to produce two versions:
1. Spread out the U a little to more resemble a real stethoscope (see link to my drawing below)
2. Make stethoscope all same - not the tiny pieces sticking off at ears - just make it same size/scale as u and throw ear buds on tips at same scale (see link to my drawing below)
3. Remove the shadow effect at the bottom of the icon
4. One version with straight tie like #117 and one version wavy like current state of #121
http://cl.ly/1TIj