On top of these standard probes, there is a range of more specialised probes. They include internal probes, design for specific bodily orifices. Therefore, they have very small footprints. Transoesophageal or TEE probes produce images of the heart through the oesophagus. There are also pencil probes, also called CW Doppler probes, for measuring blood movement and sound. Additionally, there is a number of probes that are designed for surgical use, like laparoscopic probes.