64 



MATTER WAVES: SOUND AND ULTRASOUND 



Other conditions reported treated successfully by this method at this date 

 include a case of cerebral palsy and one of phantom limb pain. The prin- 

 ciple is simple enough: to produce lesions, without excessive damage, at the 

 tiny spots in the brain which control the function which appears disordered. 

 Conversely, using this tool to inhibit temporarily the various functions con- 

 trolled by the brain, one not only can obtain a micromap, in three dimen- 

 sions, of the control sites, but learn something of the mechanism of control 

 as well. 



The facts of microirradiation and selective absorption and damage, augur 

 well for the future of "neurosonic therapy" as a strong competitor to the 

 mechanical, electrical, and chemical techniques now in use in brain dis- 

 orders. 



Figure 3-7. Equipment for Clinical Ultrasonic Irradiation of a Patient with a Hyper- 

 kinetic Mental Disorder. Upper right and insert: The multibeam irradiator itself. (Cour- 

 tesy of W. J. Fry, University of Illinois Biophysics Research Laboratory.) 



The Dunn-Fry Law 



As the quotation from Lord Kelvin (Chapter 1) said, it is always com- 

 forting to be able to state quantitatively an important fact. On animals it 

 has been found that the time, t, of irradiation to a chosen physiological state 

 — in this case to paralysis of the hind legs of young mice — is related to the 

 intensity, / (power), of the irradiating ultrasound (982 kc/sec, hydrostatic 



