Magnitude programming for implantable electrical stimulator

#The present invention relates to implantable stimulators, e.g., an implantable neural stimulator, and more particularly to a system and method for programming the magnitude (e.g., amplitude) of the stimulation pulses that are generated by such neural stimulator. The invention may be used with a wide variety of neural stimulators, e.g., spinal cord stimulators, brain stimulators, urinary incontinence stimulators, cochlear stimulators, and the like.

#Neural stimulation systems of the type with which the present invention may be used are described in the art, e.g., in U.S. Pat. No. 5,603,726. Such stimulator systems typically include: (1) an implantable pulse generator; (2) an electrode array connected to the implantable pulse generator; and (3) some means, e.g., an external programmer, for controlling or programming the implantable pulse generator. In operation, the implantable pulse generator generates an electrical stimulation pulse, or pulse sequence, in accordance with a prescribed pattern or stimulation strategy. Each pulse may be programmed or set to a desired magnitude (amplitude and/or pulse width), and applied at a set or programmed rate (or frequency) to surrounding body tissue through a selected pair or grouping of electrode contacts of a multiple electrode array.

#U.S. Pat. No. 5,895,416 teaches one type of method and apparatus for controlling and steering an electric field. The '416 patent steers the size and location of the electric field in order to recruit only target nerve tissue and exclude unwanted nerve tissue. Such steering is done by changing the voltage amplitude at each anode in response to changes in electrode impedance of an electrode array in order to maintain a constant anodic current.

#The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:

#FIG. 1 shows a simplified block diagram of a neural stimulation system;

#FIG. 2 illustrates a typical current stimulation waveform, and defines stimulus parameter values that are typically used to characterize an electrical stimulus;

#Corresponding reference characters indicate corresponding components throughout the several views of the drawings.

#The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims.

#The present invention may be used with many different types of neural stimulators. By way of illustration, the invention will be described in terms of a spinal cord stimulator system (SCS). However, it is to be understood that the invention is not limited to use only with a SCS, but may also be used with other types of multi-electrode neural stimulators, e.g., a deep brain stimulator, a functional electrical stimulator (FES), a cochlear stimulator, or the like.