Neuromodulation device

Abstract

The invention provides devices and methods that can prevent or ameliorate bronchoconstriction. In particular, the invention provides devices and methods in which a signal is delivered to the vagus nerve or the pulmonary branches of the vagus nerves. The signal is able to treat bronchoconstriction and prevent and/or ameliorate bronchoconstriction.

What is claimed: 
     
         1 . An apparatus for inhibiting the neural activity of a vagal nerve of a patient, the apparatus comprising:
 one or more transducers each configured to apply a signal to a vagal nerve of the patient; and   a controller coupled to the one or more transducers, the controller controlling the signal to be applied by each of the one or more transducers, such that the signal inhibits the neural activity of the vagal nerve to reduce parasympathetic tone response in the patient.   
     
     
         2 . An apparatus according to  claim 1 , wherein the signal applied by each of the one or more transducers is a non-destructive signal. 
     
     
         3 . An apparatus according to  claim 1 , wherein the signal at least partially inhibits neural activity in the vagal nerve. 
     
     
         4 . An apparatus according to  claim 3 , wherein the signal at least partially blocks neural activity in the nerve. 
     
     
         5 . An apparatus according to  claim 1 , wherein the signal applied by each of the one or more transducers is independently selected from an electrical signal, an optical signal, an ultrasonic signal, a mechanical signal and a thermal signal. 
     
     
         6 . An apparatus according to  claim 5 , wherein the signal or signals is an electrical signal, and the one or more transducers configured to apply the signal is an electrode. 
     
     
         7 . An apparatus according to  claim 6 , wherein the signal comprises an alternating current (AC) waveform of kilohertz frequency. 
     
     
         8 . An apparatus according to  claim 6 , wherein the signal comprises a charge-balanced direct current (DC) waveform. 
     
     
         9 . An apparatus according to  claim 6 , wherein the signal comprises, substantially sequentially, the steps of:
 (i) applying a DC ramp followed by a plateau and charge-balancing;   (ii) applying a first AC waveform, wherein the amplitude of the waveform increases during the period the waveform is applied;   (iii) a second AC waveform having a lower frequency and/or lower amplitude than the first waveform.   
     
     
         10 . An apparatus according to  claim 6 , wherein when the signal comprises one or more AC waveforms, said one or more AC waveforms each have a frequency of 5-25 kHz. 
     
     
         11 . An apparatus according to  claim 6 , wherein the signal has a voltage of 1-15V. 
     
     
         12 . An apparatus according to  claim 1 , wherein the reduction in parasympathetic tone produces a physiological response selected from one or more of: a decrease in airway smooth muscle tone, an increase in blood oxygen saturation, a decrease in blood carbon dioxide concentration, a decrease in respiratory rate, an increase in total lung capacity, and an increase in forced expiration volume. 
     
     
         13 . An apparatus according to  claim 1 , wherein the action potential or pattern of action potentials in the vagal nerve more closely resembling that exhibited by a healthy individual than before the application of the signal 
     
     
         14 . An apparatus according to  claim 1 , wherein the apparatus further comprises a detector element to detect one or more physiological parameters in the patient. 
     
     
         15 . An apparatus according to  claim 14 , wherein the controller is coupled to said detector element, and causes said one or more transducers each to apply said signal when the physiological parameter is detected to be meeting or exceeding a predefined threshold value. 
     
     
         16 . An apparatus according to  claim 14 , wherein one or more of the detected physiological parameters is selected from parasympathetic tone, airway smooth muscle (ASM) tone, blood oxygen saturation, blood carbon dioxide concentration, respiratory rate, total lung capacity, and forced expiration volume. 
     
     
         17 . An apparatus according to  claim 1 , wherein the vagal nerve in which the neural activity is modulated is at least one pulmonary branch of a vagal nerve. 
     
     
         18 . An apparatus according to  claim 1 , wherein the modulation in neural activity as a result of the one or more transducers applying the signal is substantially persistent. 
     
     
         19 . An apparatus according to  claim 1 , wherein the modulation in neural activity is temporary. 
     
     
         20 . A method of relieving bronchoconstriction in a patient comprising:
 implanting in the patient an apparatus according to  claim 1 ;   positioning at least one transducer of the apparatus in signaling contact with a vagal nerve of the patient; and   activating the apparatus.