Transcutaneous electrical and magnetic nerve stimulation devices are disclosed, along with methods of treating lower urinary tract disorders using energy that is delivered noninvasively by the devices. The disorders comprise overactive bladder, urge incontinence, stress, incontinence, urge frequency, non-obstructive urinary retention and interstitial cystitis/painful bladder syndrome. In embodiments of the disclosed methods, a posterior tibial nerve of a patient is stimulated non-invasively. Methods are disclosed for selecting protocol parameters for a nerve stimulation session for treating each individual patient, wherein modules of the bladder of the patient are represented as coupled non-linear oscillators.
