Stimulation devices and methods
Described here are stimulation systems and methods for stimulating one or more anatomical targets in a patient for treatment conditions such as dry eye. The stimulation system may include a controller and a microstimulator. The components of the controller and microstimulator may be implemented in a single unit or in separate devices. When implemented separately, the controller and microstimulator may communicate wirelessly or via a wired connection. The microstimulator may generate pulses from a signal received from the controller and apply the signal via one or more electrodes to an anatomical target. In some variations, the microstimulator may include a passive generation circuit configured to generate a pulse based on a signal received from the controller.
1. An implantable microstimulation unit comprising:
a housing comprising a stimulation circuit and a feedthrough at a first end of the housing, wherein the stimulation circuit does not include any internal logic or intelligence and does not have an internal battery; and
a flexible extension comprising at least one electrode and an energy-receiving inductive coil positioned within the flexible extension, wherein the electrode is connectable to the stimulation circuit via the feedthrough, and
wherein the flexible extension has a thickness that is less than a thickness of the housing and tapers to the thickness of the housing or has a thickness that is the same as the thickness of the housing, such that the first end of the housing and a first end of the flexible extension have corresponding and complementary shapes that connect to form the implantable microstimulation unit, wherein the implantable microstimulation unit has a length of about 0.6 cm to about 2 cm, a thickness of about 1 mm to about 2 mm, and a width of about 3 mm to about 8 mm.
2. The implantable microstimulation unit of claim 1 wherein the at least one electrode comprises a first electrode and a second electrode.
3. The implantable microstimulation unit of claim 2 wherein the first and second electrodes are positioned on a first side of the flexible extension.
4. The implantable microstimulation unit of claim 2 wherein the first electrode is positioned on a first side of the flexible extension, and the second electrode is positioned on a second side of the flexible extension.
5. The implantable microstimulation unit of claim 1 , wherein at least one of the at least one electrodes is textured or patterned.
6. The implantable microstimulation unit of claim 1 , wherein at least one of the at least one electrodes is recessed.
7. The implantable microstimulation unit of claim 1 wherein the stimulation circuit comprises a ramping control unit.
8. The implantable microstimulation unit of claim 1 wherein the microstimulation unit comprises one or more coatings.
9. The implantable microstimulation unit of claim 8 wherein at least one of the one or more coatings is configured to enhance charge injection capacity.
10. The implantable microstimulation unit of claim 8 wherein at least one of the one or more coatings is an insulating coating.
11. The implantable microstimulation unit of claim 1 wherein the microstimulation unit comprises one or more fixation elements.
12. The implantable microstimulation unit of claim 1 wherein the implantable microstimulation unit is configured to be positioned within an orbit of a patient's eye.