Method for reducing the polarization of bioelectrical stimulation leads using surface enhancement, and product made thereby

A method for manufacturing a metallic electrode of an implantable lead for generating bioelectrical stimulation pulses and sensing bioelectrical signals, comprising the steps of:

• immersing the electrode in an electrolyte solution;
• enhancing the surface of the immersed electrode by repetitively applying oscillating anodic and cathodic currents to the electrode at a set frequency in the range of from 1 hertz to 10 kilohertz, said anodic and cathodic currents each having amplitudes in the range of from 1 milliampere to several amperes, so that a porous metallic hydrous oxide layer is formed on the surface of the immersed electrode;
• and
• reducing the hydroxide on the surface of the immersed electrode by applying lower amplitudes reducing current to the electrode, the reducing current having a set amplitude in the range of from approximately 1 microampere to approximately 100 milliamperes, said hydroxide reduction current being a DC current, said hydroxide reduction step further comprising the substeps of:
• repetitively measuring the voltage across the immersed electrode resulting from the applied hydroxide reduction current;
• and
• terminating said hydroxide reduction step when the measured voltage falls below a set threshold voltage.

A method for manufacturing a metallic electrode of an implantable lead for generating bioelectrical stimulation pulses and sensing bioelectrical signals, comprising the steps of:

• immersing the electrode in an electrolyte solution;
• enhancing the surface of the immersed electrode by repetitively applying oscillating anodic and cathodic currents to the electrode at a set frequency in the range of from 1 hertz to 10 kilohertz, said anodic and cathodic currents each having amplitudes in the range of from 1 milliampere to several amperes, so that a porous metallic hydrous oxide layer is formed on the surface of the immersed electrode;
• and
• reducing the hydroxide on the surface of the immersed electrode by applying lower amplitude reducing current to the electrode, the reducing current having a set amplitude in the range of from approximately 1 microampere to approximately 100 milliamperes, said hydroxide reduction current being a DC current, said hydroxide reduction step further comprising the substeps of:
• repetitively measuring the voltage across the immersed electrode resulting from the applied hydroxide reduction current;
• determining the rate of change of the measured voltage with respect to time;
• and
• terminating said hydroxide reduction step when the rate of change of the measured voltage with respect to time falls below a set threshold.

A method for manufacturing a metallic electrode of an implantable lead for generating bioelectrical stimulation pulses and sensing bioelectrical signals, comprising the steps of:

• immersing the electrode in an electrolyte solution;
• enhancing the surface of the immersed electrode by repetitively applying oscillating anodic and cathodic currents to the electrode at a set frequency in the range of from 1 hertz to 10 kilohertz, said oscillating currents being applied as a waveform, said waveform selected from the group consisting of square wave varying currents, sinusoidally varying currents, triangular wave varying currents and staircase varying currents, said anodic and cathodic currents each having individually set amplitudes, said oscillating currents being symmetric with respect to amplitude, said oscillating currents being symmetric with respect to duty cycle, said surface enhancing step further comprising the step of applying physical motion to the electrolyte solution, said physical motion applying step being performed by activating a sonicator, said surface enhancing step being performed for a set duration in the range of from 10 seconds to 72 hours, said anodic and cathodic currents each having amplitudes in the range of from 1 milliampere to several amperes, so that a porous metallic hydrous oxide layer is formed on the surface of the immersed electrode;
• and
• reducing the hydroxide on the surface of the immersed electrode by applying a lower amplitude reducing current to the electrode, the reducing current having a set amplitude in the range of from approximately 1 microampere to approximately 100 milliamperes, said hydroxide reduction current being a DC current, and said hydroxide reduction step further comprising the substeps of:
• repetitively measuring the voltage across the immersed electrode resulting from the applied hydroxide reduction current;
• and
• terminating said hydroxide reduction step when the measured voltage falls below a set threshold voltage.

A method for manufacturing a metallic electrode of an implantable lead for generating bioelectrical stimulation pulses and sensing bioelectrical signals, comprising the steps of:

• immersing the electrode in an electrolyte solution;
• enhancing the surface of the immersed electrode by repetitively applying oscillating anodic and cathodic currents to the electrode at a set frequency in the range of from 1 hertz to 10 kilohertz, said oscillating currents being applied as a waveform, said waveform selected from the group consisting of square wave varying currents, sinusoidally varying currents, triangular wave varying currents and staircase varying currents, said anodic and cathodic currents each having individually predetermined amplitudes, said oscillating currents being symmetric with respect to amplitude, said oscillating currents being symmetric with respect to duty cycle, said surface enhancing step further comprising the step of applying physical motion to the electrolyte solution, said physical motion applying step being performed by activating a sonicator, said surface enhancing step being performed for a set duration in the range from 10 seconds to 72 hours, said anodic and cathodic currents each having amplitudes in the range of from 1 milliampere to several amperes, so that a porous metallic hydrous oxide layer is formed on the surface of the immersed electrode;
• and
• reducing the hydroxide on the surface of the immersed electrode by applying a lower amplitude reducing current to the electrode, the reducing current having a set amplitude in the range of from approximately 1 microampere to approximately 100 milliamperes, said hydroxide reduction current being a DC current, and said hydroxide reduction step further comprising the substeps of:
• repetitively measuring the voltage across the immersed electrode resulting from the applied hydroxide reduction current;
• determining the rate of change of the measured voltage with respect to time;
• and
• terminating said hydroxide reduction step when the rate of change of the measured voltage with respect to time falls below a set threshold.

A method for manufacturing a metallic electrode of an implantable lead for generating bioelectrical stimulation pulses and sensing bioelectrical signals, comprising the steps of:

• immersing the electrode in a first electrolyte solution;
• cleaning the surface of said immersed electrode by alternately applying anodic and cathodic square wave currents to the electrode at a set frequency in the range of from 0.01 hertz to 1 hertz and for a duration ranging from 0.5 seconds to 1 hour, said anodic and cathodic currents each having amplitudes in the range of from 1 milliampere to 1 ampere;
• immersing the electrode in a second electrolyte solution;
• enhancing the surface of said electrode in said second solution by repetitively applying oscillating anodic and cathodic currents to the electrode at a set frequency in the range of from 1 hertz to 10 kilohertz, said anodic and cathodic currents each having amplitudes in the range of from 1 milliampere to several amperes, so that a porous metallic hydrous oxide layer is formed on the surface of the immersed electrode;
• and
• reducing the hydroxide on the surface of said electrode in said second solution by applying a lower amplitude reducing current to the electrode, the reducing current having a set amplitude in the range of from approximately 1 microampere to approximately 100 milliamperes.