A system, comprising: - an implantable medical device, wherein the implantable medical device comprises an ultrasound transducer configured to receive an ultrasound wave, - a packaging, wherein the packaging encloses an internal space, wherein the implantable medical device is arranged in the internal space, - a device mount arranged in the internal space, wherein the implantable medical device is fastened to the device mount in a releasable fashion, and wherein the device mount contacts an inner side of a portion of the packaging and forms an acoustic coupler configured to pass the ultrasound wave applied to an outer side of the portion of the packaging to the ultrasound transducer of the implantable medical device - an external device, wherein the external device is configured to generate the ultrasound wave, and wherein the external device is configured to be held against the outer side of the portion of the packaging so that said portion of the packaging butts against the device mount as well as against the external device and the ultrasound wave generated by the external device is transferable from the external device to the ultrasound transducer of the implantable medical device via said portion of the packaging and the device mount, and - a programming device that comprises a user interface and is configured to generate and send a command signal to the external device in case the programming device receives a corresponding input by a user via the user interface of the programming device, wherein the external device is configured to convert the command signal into the ultrasound wave and to send the ultrasound wave via the device mount to the implantable medical device to trigger the implantable medical device to perform a task, wherein the packaging comprises an outer recess formed in an outer side of the packaging, wherein the outer recess is configured to receive a portion of the external device so as to align the external device with respect to the device mount. - an implantable medical device, wherein the implantable medical device comprises an ultrasound transducer configured to receive an ultrasound wave, - a packaging, wherein the packaging encloses an internal space, wherein the implantable medical device is arranged in the internal space, - a device mount arranged in the internal space, wherein the implantable medical device is fastened to the device mount in a releasable fashion, and wherein the device mount contacts an inner side of a portion of the packaging and forms an acoustic coupler configured to pass the ultrasound wave applied to an outer side of the portion of the packaging to the ultrasound transducer of the implantable medical device - an external device, wherein the external device is configured to generate the ultrasound wave, and wherein the external device is configured to be held against the outer side of the portion of the packaging so that said portion of the packaging butts against the device mount as well as against the external device and the ultrasound wave generated by the external device is transferable from the external device to the ultrasound transducer of the implantable medical device via said portion of the packaging and the device mount, and - a programming device that comprises a user interface and is configured to generate and send a command signal to the external device in case the programming device receives a corresponding input by a user via the user interface of the programming device, wherein the external device is configured to convert the command signal into the ultrasound wave and to send the ultrasound wave via the device mount to the implantable medical device to trigger the implantable medical device to perform a task,