Abstract: The present invention refers to a medical apparatus that allows to generate, non-invasively and at a requested depth shear waves of controlled frequency and amplitude. The purpose is to impact via mechanotransduction on cellular behavior, i.e. cell proliferation and cell migration. The aim is to aide classical tumor therapy for instance by rendering cells more receptive to drugs, or by gaining time during chemotherapy by reducing cell migration and hence slowing down the metastatic process.