Medical device systems and methods for providing spinal cord stimulation (SCS) are disclosed. The SCS systems and methods provide therapy below the perception threshold of the patient. The methods and systems are configured to measure neurological responses to stimulation and use the neurological responses as biomarkers to maintain and adjust therapy. An example of neurological responses includes an evoked compound action potential (ECAP).

An implantable stimulator device is disclosed for executing a stimulation program comprising a plurality of sub-programs, wherein the sub-programs are configured to be automatically sequentially executed by stimulation circuitry in the device. Control circuitry periodically stores log data to indicate where each sub-program is in its execution. If the device experiences an interruption that prevents the stimulation circuitry from executing the stimulation program, and upon receiving an indication that the stimulation circuitry can continue execution of the stimulation program, the control circuitry is configured to query the log data to determine a sub-program during which the interruption occurred, and using the log data, cause the stimulation circuitry to continue execution of the stimulation circuitry either at the beginning of the sub-program, or at a point during the sub-program when the interruption occurred.

A device for neurostimulation has a number N of electrodes. N is equal to or larger than 3. The device is configured to deliver via each electrode therapeutic electric phases of amplitudes I.sub.1, I.sub.2, . . . I.sub.N, with a frequency f and after each therapeutic electric phase a number of N−1 charge balancing electric phases. The charge balancing electric phases of the respective electrode each have a polarity that is opposite the polarity of the preceding therapeutic electric phase of the respective electrode. The device is configured to return for each electrode the current of each therapeutic electric phase in the other N−1 electrodes.

The disclosure describes example of subsensory electrical stimulation for providing therapy for incontinence. An implantable medical device (IMD) includes a memory configured to store a set of therapy parameters for subsensory electrical stimulation of a patient. The delivery of the subsensory electrical stimulation results in a therapeutic effect for incontinence therapy at a stimulation intensity that is in range of approximately 50% to 80% of a stimulation intensity at a sensory threshold, and the patient does not perceive delivery of the subsensory electrical stimulation and perceives delivery of stimulation at the sensory threshold. The IMD also includes therapy delivery circuitry configured to deliver the subsensory electrical stimulation based on the stored set of therapy parameters, including cycling the delivery of the subsensory electrical stimulation between an on-cycle and an off-cycle.

An implantable medical device is configured to receive an input that specifies a time domain allocation between two or more stored stimulation programs and to provide control signals corresponding to each of the two or more stimulation programs to stimulation circuitry to interleave the two or more stimulation programs in time according to the input. The time domain allocation may set a proportion of time during which each of the stimulation programs is active during repeating epochs. The time domain allocation may be set by a user to transition between configured stimulation programs or to specify stimulation that is based on two or more different stimulation programs. The time domain allocation may also be adjusted automatically to optimize an indication of an effectiveness of stimulation that is provided by the patient.

Systems and methods for identifying and treating patients with high frequency electrical signals. A representative method for identifying a patient as a candidate for pain treatment includes identifying a first sensory threshold, delivering an electrical signal to a neural population of the patient at a frequency in a frequency range of 1.5 kHz to 100 kHz and, while and/or after delivering the electrical signal to the patient, identifying a second sensory threshold of the patient. If the second sensory threshold is less than the first, the method can include identifying the patient as a candidate for receiving an electrical signal at a frequency in the foregoing range for pain treatment.

A method of blocking a nerve or neuron by applying an electrical stimulation to the nerve or neuron, wherein the electrical stimulation is of an intensity below the excitation threshold of the nerve or neuron for a length of time sufficient to produce a block of nerve conduction or neuron excitation.

A medical device with closed-loop responsive stimulation may include techniques to mitigate the impact on the therapy output of noise coupled into the medical device. A medical device according to this disclosure may determine the presence of noise and alter the closed loop policy to provide the necessary therapy to the patient and avoid prolonged under stimulation caused by the noise. The medical device may continue therapy, while testing for noise. When the device determines the noise level no longer affects the output therapy, the device may return the closed loop policy to a no-noise mode of operation. The medical device may also include techniques to mitigate the impact of manual adjustment while the medical device is subject to noise or is responding to changes in the patient's physiological signals.

Selective high-frequency spinal cord modulation for inhibiting pain with reduced side effects and associated systems and methods are disclosed. In particular embodiments, high-frequency modulation in the range of from about 1.5 KHz to about 50 KHz may be applied to the patient's spinal cord region to address low back pain without creating unwanted sensory and/or motor side effects. In other embodiments, modulation in accordance with similar parameters can be applied to other spinal or peripheral locations to address other indications.

Selective high-frequency spinal chord modulation for inhibiting pain with reduced side affects and associated systems and methods are disclosed. In particular embodiments, high-frequency modulation in the range of from about 1.5 KHz to about 50 KHz may be applied to the patient's spinal chord region to address low back pain without creating unwanted sensory and/or motor side affects. In other embodiments, modulation in accordance with similar parameters can be applied to other spinal or peripheral locations to address other indications.