TECHNICAL FIELD

The disclosure relates to medical devices and, more particularly, to medical devices that deliver electrical stimulation therapy.

BACKGROUND

Medical devices may be used to treat a variety of medical conditions. Medical electrical stimulation devices, for example, may deliver electrical stimulation therapy to a patient via electrodes. Electrical stimulation therapy may include stimulation of nerve, muscle, or brain tissue, or other tissue within a patient. An electrical stimulation device may be fully implanted within the patient. For example, an electrical stimulation device may include an implantable electrical stimulation generator and one or more implantable leads carrying electrodes. The electrical stimulation device may comprise a leadless stimulator. In some cases, implantable electrodes may be coupled to an external electrical stimulation generator via one or more percutaneous leads or fully implanted leads.

Medical electrical stimulators may be used to deliver electrical stimulation therapy to patients to relieve a variety of symptoms or conditions such as chronic pain, tremor, Parkinson's disease, depression, epilepsy, urinary or fecal incontinence, pelvic pain, sexual dysfunction, obesity, or gastroparesis. An electrical stimulator may be configured to deliver electrical stimulation therapy via leads that include electrodes proximate to the spinal cord, pelvic nerves, gastrointestinal organs, peripheral nerves, or within the brain of a patient. Stimulation proximate the spinal cord and within the brain are often referred to as spinal cord stimulation (SCS) and deep brain stimulation (DBS), respectively.

SUMMARY

In general, this disclosure describes programming techniques for medical devices that deliver electrical stimulation. In particular, this disclosure describes a user interface that is able to receive, as user input, a desired amplitude for individual stimulation pulses that are to be delivered to a particular electrode in an electrical stimulation system. In addition, this disclosure describes programming techniques for utilizing such user input defining a desired amplitude to determine parameters of an electrical stimulator that achieve the desired amplitude. In accordance with various techniques of this disclosure, the electrical stimulator achieves the desired amplitude while maintaining the amplitude of other stimulation pulses delivered to one or more other electrodes.

To illustrate, an example electrical stimulator includes a master power source having an adjustable master amplitude and a stimulation generator coupled to multiple electrodes. The stimulation generator delivers electrical stimulation pulses to electrodes at various amplitudes specified by the user. In some examples, the master power source may include a master voltage amplitude and/or a master current amplitude used to achieve individual amplitudes for individual electrodes. In examples involving a master electrical current amplitude, the stimulation generator includes, for each electrode, a finite number of individually controllable current regulator branches. In this way, by selectively activating some or all of the current regulator branches, the stimulation generator may deliver electrical stimulation pulses at an electrical current amplitude that is a fraction of the master electrical current amplitude. In such examples, a fraction is defined as the particular number of regulator branches activated at that time for a particular electrode compared to a total number of regulator branches available.

In an illustrative example, the stimulation generator may deliver, to a first electrode, stimulation pulses having a first electrical current amplitude that is a first fraction of the master amplitude. Similarly, the stimulation generator may deliver, to a second electrode, stimulation pulses having a second electrical current amplitude that is a second fraction of the master amplitude, which in some instances, may be equivalent to the first fraction. In this example, the stimulation generator may increase or decrease the electrical current amplitude delivered to an adjustment-targeted electrode by either activating more or less current regulator branches that correspond to the adjustment-targeted electrode, by increasing the master amplitude, or some combination of the two.

In some instances, where a desired electrical current amplitude for a particular electrode exceeds the master electrical current amplitude, the stimulation generator may adjust the master electrical current amplitude, up to a maximum electrical current amplitude available from the master current source. In some examples, however, the user may only want to affect the electrical current amplitude for one electrode and not affect the electrical current amplitude for other electrodes, which may happen when the master electrical current amplitude is increased without any changes to electrode fractions. Thus, in order to maintain the stimulation pulses delivered to other electrodes at previously defined current amplitudes, the stimulation generator may adjust fractions of non-adjustment targeted electrodes. In addition, the electrical stimulator may adjust the master amplitude up to a maximum amplitude available from the particular power source in order to provide a sufficient master amplitude to support the desired electrical current amplitudes for individual stimulation pulses. In any event, a user may request from the electrical stimulation system adjustments, or initial settings, for electrical current amplitudes that may be controlled from a user interface. As such, the user interface receives, as user input, a desired electrical current amplitude for an electrode targeted for adjustment.

In this way, processing circuitry of the electrical stimulator may cause an adjustment to a first electrical current amplitude, while maintaining the electrical current amplitudes of other electrodes as close to the original electrical current amplitude. That is, a single user input of one desired electrical current amplitude for a particular electrode targeted for adjustment, whether setting the amplitude anew or adjusting a previously set amplitude, may result in an implementation of the desired electrical current amplitude. The desired electrical current amplitude may be implemented regardless of whether the desired current amplitude is greater than, less than, or equal to a master electrical current amplitude, while simultaneously maintaining the electrical current amplitude delivered to other electrodes not targeted for adjustment by adjusting the number of current regulator branches corresponding to the non-adjustment targeted electrodes.

In one example, this disclosure is directed to a neuromodulation system comprising: a first electrode; a second electrode; a stimulation generator configured to deliver first stimulation pulses to the first electrode and second stimulation pulses to the second electrode, wherein a first electrical current amplitude of the first stimulation pulses is a first fraction of a master amplitude and a second electrical current amplitude of the second stimulation pulses is a second fraction of the master amplitude. The neuromodulation system further comprises a processor configured to generate an initial instruction for the stimulation generator to deliver: (i) the first simulation pulses based on the first fraction of the master amplitude, and (ii) the second stimulation pulses based on the second fraction of the master amplitude. The processor is further configured to receive user input comprising a desired electrical current amplitude; and determine that an adjustment to the first electrical current amplitude of the first stimulation pulses is required based on the desired electrical current amplitude. The processor is further configured to determine, based at least in part on a comparison of the desired electrical current amplitude to the master amplitude, a target adjustment. The processor is further configured to: (A) determine, as the target adjustment, an adjustment to at least the first fraction, or (B) determine, as the target adjustment: (i) an adjustment to the master amplitude, and (ii) an adjustment to at least the second fraction relative to the master amplitude adjustment. The processor is further configured to generate, based at least in part on the target adjustment, an adjustment instruction for the stimulation generator to deliver the first stimulation pulses at the desired electrical current amplitude and deliver the second stimulation pulses at approximately the same second electrical current amplitude.

In another example, the disclosure is directed to a method that comprises: generating an initial instruction for a stimulation generator to deliver: (i) first simulation pulses based on a first fraction of a master amplitude, and (ii) second stimulation pulses based on a second fraction of the master amplitude; and receiving user input comprising a desired electrical current amplitude. The method further comprises determining that an adjustment to the first electrical current amplitude of the first stimulation pulses is required based on the desired electrical current amplitude. The method further comprises determining, based at least in part on a comparison of the desired electrical current amplitude to the master amplitude, a target adjustment. The method further comprises (A) determining, as the target adjustment, an adjustment to at least the first fraction, or (B) determining, as the target adjustment: (i) an adjustment to the master amplitude, and (ii) an adjustment to at least the second fraction relative to the master amplitude adjustment. The method further comprises generating, based at least in part on the target adjustment, an adjustment instruction for the stimulation generator to deliver the first stimulation pulses at the desired electrical current amplitude and deliver the second stimulation pulses at approximately the same second electrical current amplitude.

In another example, the disclosure is directed to a computer-readable storage medium including instructions that, when executed, cause at least one processor to at least: generate an initial instruction for a stimulation generator to deliver: (i) first simulation pulses based on a first fraction of a master amplitude, and (ii) second stimulation pulses based on a second fraction of the master amplitude; and receive user input comprising a desired electrical current amplitude. The instructions, when executed, further cause the at least one processor to at least: determine that an adjustment to the first electrical current amplitude of the first stimulation pulses is required based on the desired electrical current amplitude. The instructions, when executed, further cause the at least one processor to at least: determine, based at least in part on a comparison of the desired electrical current amplitude to the master amplitude, a target adjustment, the target adjustment comprising: (i) adjustment to at least the first fraction, or (ii) an adjustment to the master amplitude and an adjustment to at least the second fraction relative to the adjustment to the master amplitude. The instructions, when executed, further cause the at least one processor to at least: generate, based at least in part on the target adjustment, an adjustment instruction for the stimulation generator to deliver the first stimulation pulses at the desired electrical current amplitude and deliver the second stimulation pulses at approximately the same second electrical current amplitude.

The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

