In TRANS-FUSIMO, off-the-shelf hardware was used for the interfaces to the TTS and thus to perform a sonication in a moving abdominal organ. Thus, also the synchronization of all parts plays an important role. The whole TTS pipeline relies on the MRI acquisition and the transfer update rate. This data is then fed into the motion compensation and thermal monitoring algorithms. To compensate for latencies, it is necessary to align the clocks of all systems. Since such a synchronization of clocks is not always possible and may also not be sufficiently accurate for real-time applications we use a feature of currently available MRI hardware that starts a scan only if a TTL pulse is sent via an external trigger on a coaxial port. The TTS is connected to a NI USB-6008 (National Instruments, Austin, USA) digital/analog converter (DAQ) device which is accepting a command by TTS to send a trigger pulse to trigger the monitoring sequence at the MRI.
The images are then directly sent and imported into the TTS. This procedure is used not only for the monitoring image acquisition but also for the other imaging tasks including the acquisition of a planning image and of a spatial transducer calibration image. For these imaging tasks, however, there is no requirement on the real-time transfer of images.
The synchronization between the TTS and the FUS transducer is performed via the real-time API of the device which can be controlled by the TTS via the TRANS-FUSIMO server and the INSIGHTEC control PC (CPC).