Electric pulse generators

Abstract

This disclosure relates to an in vivo treatment of a skin lesion of a mammal comprising application of electrical energy to the skin lesion in a form of electrical pulses. At least one electrical pulse is applied. The pulse duration may be at least 1 nanosecond at the full-width-half-maximum. This treatment may prevent at least growth of the lesion.

We claim: 
     
         1 . A system for delivery of electrical pulses to tissue comprising:
 a pulse generator configured to generate at least one pulse with an amplitude of at least 1 kV that has a duration of no longer than 1,000 nanoseconds, the pulse generator comprising:
 a tank circuit comprising a first capacitor-inductor pair connected in series with a second capacitor-inductor pair; 
 a first switch from a terminal of the circuit to ground; and 
 a second switch between the pairs switchable to ground; and 
   a pulse delivery device operatively connected with the pulse generator, the pulse delivery device comprising a delivery electrode and a ground electrode spaced apart such that the at least one pulse from the pulse generator produces an electric field between 10 kV/cm and 100 kV/cm between the electrodes, wherein at least a portion of at least one of the ground electrode or the delivery electrode comprises an electrically insulating material configured to prevent electrical arcing between the delivery electrode and the ground electrode.   
     
     
         2 . The system of  claim 1 , wherein the at least a portion of an outer surface of the at least one of the ground electrode or the delivery electrode is coated with the electrically insulating material. 
     
     
         3 . The system of  claim 2 , wherein the entire outer surface of the delivery electrode, the ground electrode, or both, is coated with the electrically insulating material. 
     
     
         4 . The system of  claim 1 , wherein the electrically insulating material is thick enough to reduce or prevent electrical arcing between the delivery electrode and the at least one ground electrode when the delivery electrode is inserted into, pressed against, or brought in close proximity to the tissue. 
     
     
         5 . The system of  claim 1 , wherein a thickness of the electrically insulating material is at least 1 nanometer. 
     
     
         6 . The system of  claim 1 , wherein the system includes multiple ground electrodes, and at least a portion of each ground electrode comprises the electrically insulating material. 
     
     
         7 . The system of  claim 1 , wherein the electrically insulating material comprises fluoropolymer, parylene, polyimide, ceramic, glass or mixtures thereof. 
     
     
         8 . The system of  claim 1 , wherein the electrically insulating material comprises polytetrafluoroethylene. 
     
     
         9 . The system of  claim 1 , wherein the pulse delivery device is configured to deliver the at least one pulse to a skin lesion. 
     
     
         10 . The system of  claim 9 , wherein the skin lesion comprises malignancies, precancerous lesions, human papilloma virus (HPV) infected cells, immune-related conditions, seborrheic keratosis, acrocordon, aged skin, wrinkled skin, damaged skin, or combinations thereof. 
     
     
         11 . The system of  claim 9 , wherein the skin lesion comprises basal cell carcinoma, squamous cell carcinoma, actinic keratosis, warts, or combinations thereof. 
     
     
         12 . The system of  claim 1 , wherein the delivery electrode is configured to penetrate tissue. 
     
     
         13 . The system of  claim 1 , wherein the delivery electrode is configured not to substantially penetrate tissue. 
     
     
         14 . The system of  claim 1 , wherein the ground electrode is configured not to substantially penetrate tissue. 
     
     
         15 . The system of  claim 1 , wherein the pulse generator and pulse delivery device are configured to apply electrical energy of at least 65.0 mJ per mm 3 . 
     
     
         16 . The system of  claim 1 , wherein the pulse generator and pulse delivery device are configured to apply electrical energy of at least 260.0 mJ per mm 3 . 
     
     
         17 . The system of  claim 1 , wherein the pulse generator and pulse delivery device are configured to apply electrical energy of at least 520.0 mJ per mm 3 . 
     
     
         18 . The system of  claim 1 , wherein the pulse generator is configured to generate the at least one pulse with a duration between 1 nanosecond to 100 nanoseconds. 
     
     
         19 . The system of  claim 1 , wherein the pulse generator is configured to generate electrical energy sufficient to reduce a volume of a skin lesion by at least 30%. 
     
     
         20 . The system of  claim 1 , wherein the pulse generator is configured to generate electrical energy sufficient to clear a skin lesion.