The design of a portable device for field studies in developing countries

The design of a portable renography device is described together with some preliminary feasibility studies. A robust scintillation detector, in which the photomultiplier is replaced by a solid state photodiode with a high gain preamplifier, forms the basis of the design. As well as eliminating the fragile photomultiplier, the use of a photodiode considerably reduces the size of the assembly and a detector small enough to fasten to the patient's body has been developed. The bulky and heavy renography stand and the high voltage supply are no longer required. All the electronic circuits and power supplies have been built into a personal computer but a more robust system could be produced using a dedicated single board computer. In the preliminary experiments 113Inm DTPA was used as a tracer. This radionuclide has a very short half life (100 min) so the absorbed radiation dose is low even in patients with renal failure. It is obtained from a generator containing 113Sn with a very long half life (110 days) so delays in delivery of several weeks can be tolerated. (author). 5 refs, 5 figs, 1 tab