Funding for this research was provided by:
Endomagnetics Ltd, Cambridge
Text and Data Mining valid from 2018-02-16
Received: 6 December 2017
Accepted: 3 February 2018
First Online: 16 February 2018
Compliance with ethical standards
: All the authors declare they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.