An example of a system comprises a patch of electrodes for placement on tissue containing neural tissue, and a tissue tester configured to measure an electrical characteristic of tissue. The tissue tester may include a test controller and switches. The test controller and the switches may be configured to connect different combinations of the electrodes to create subsets of two or more electrodes to measure the electrical characteristic of tissue using the subsets. The test controller may be configured to measure an electrical characteristic of tissue using the subsets within the set of electrodes placed on the tissue, and compare measurements of the electrical characteristic and identify a neural target for a therapy based on the comparison of the measurements of the electrical characteristic for tissue at the neural target relative to adjacent non-neural tissue.