Length measuring devices
Length measuring devices are used to measure the length of the shunt. The defined measurement should be the same as the shaft length of the prosthesis being used. If in doubt, always used the next prosthesis in length!
Length measuring devices are made by several manufacturers. Some of them are shown in the following, although this selection is by no means exhaustive.
![Blom-Singer® Voice Prosthesis Sizing Device (measuring prosthesis). The sizing prostheses (1) are constructed like a Blom-Singer Duckbill prosthesis, but without the valve slit.](/fileadmin/_processed_/3/6/csm_messgeraet1_w01_251e09dc80.jpg)
![The scale in mm is on the bar (1). A soft replaceable silicone wing (2) is attached to the end of the bar.](/fileadmin/_processed_/d/d/csm_messgeraet3_w01_4c2f50aba9.jpg)
Measuring the shunt length
The display of the correct shunt length measurement is indicated on the shunt model with the Blom-Singer® measuring prosthesis as 16 Fr. diameter. Other measuring devices work in the same way
![On the tracheal side, the smallest but still clearly legible millimeter figure is indicated at a gentle pull. This is the correct shaft length for the voice prosthesis to be used](/fileadmin/_processed_/b/7/csm_messgeraet9_w01_712c72e6a1.jpg)