How to filter Bitlocker Device using Powershell

Question

I just want to get internal Devices, which are with Bitlocker encrypted. But when I connect USB or external Hard drive, will be also read. actually, it should work just for internal devices. how could I filter ?

Here, I used this Code to get the devices

Get-CimInstance -Namespace "root\CIMV2\Security\MicrosoftVolumeEncryption" -Classname Win32_EncryptableVolume