Systems and methods for electrodes for insulative electronic weaponry
An electronic weapon with an installed deployment unit, from which at least one tethered electrode is launched, provides a stimulus current through a target to inhibit locomotion by the target. The wire tether, also called a filament, conducts the stimulus current. The one or more electrodes, according to various aspects of the present invention, perform one or more of the following functions in any combination: binding the filament to the electrode, deploying the filament from the deployment unit, coupling the electrode to the target, and distributing a current density with respect to a region of target tissue and/or a volume of target tissue. For an electrode that includes a body and a spear, the spear may be implemented with conductive rings or with materials that include integrated conductive and insulative substances (e.g., conductive fibers in insulative composite material). Relatively high electric field flux density at a tip of the spear may be reduced or avoided by practice of the invention.
1. A deployment unit for use with an electronic weapon, the deployment unit providing a current from a signal generator of the electronic weapon through tissue of a human or animal target, the current for inhibiting voluntary movement by the target, the deployment unit comprising:
a housing;
an interface that couples the housing to the signal generator, the interface for receiving the current;
a filament that conducts the current, the filament stored in the housing prior to deployment, the filament coupled to the interface for receiving the current;
an electrode stored in the housing prior to deployment; and
a propellant that in operation propels the electrode away from the housing to deploy the filament toward the target; wherein the electrode comprises
a binding and deploying structure mechanically coupled to the filament to deploy the filament from the housing; and
a coupling and diffusing structure comprising a shaft and a tip, the coupling and diffusing structure mechanically coupled to the binding and deploying structure, the coupling and diffusing structure capable of activating the tip for a first portion of the current at a first activation voltage and capable of activating at least a portion of the shaft for a second portion of the current at a second activation voltage less than the first activation voltage.
2. The deployment unit of claim 1 wherein the shaft comprises a plurality of conductors spaced apart from the tip that cooperate to form a series circuit for the current through the target.
3. The deployment unit of claim 2 wherein each conductor comprises a ring about an axis of the shaft.
4. The deployment unit of claim 2 wherein:
the shaft further comprises an insulative material; and
each conductor comprises a particle integrated within the insulative material.
5. The deployment unit of claim 1 wherein the coupling and diffusing structure couples to the target as a consequence of the tip penetrating clothing or tissue of the target.
6. The deployment unit of claim 1 wherein the coupling and diffusing structure comprises composite material.
7. The deployment unit of claim 1 wherein the binding and deploying structure is formed with the coupling and diffusing structure.
8. The deployment unit of claim 1 wherein:
the shaft comprises a first volume and a second volume;
the first volume and the second volume are of equal measure;
the first volume is located closer to the tip than the second volume; and
the first volume has a lower conductivity at an activation voltage than the second volume has at the activation voltage.
9. An electrode, for providing a current from an electronic weapon through tissue of a human or animal target, the current for inhibiting voluntary movement by the target, the electrode comprising:
a tip; and
a shaft that supports the tip and penetrates tissue of the target; wherein
the shaft inhibits conduction of the current through the tip; and
the shaft diffuses a portion of the current into target tissue, thereby reducing a remainder of the current conducted through the tip.
10. The electrode of claim 9 wherein the tip comprises a barb that mechanically couples the electrode to tissue of the target.
11. The electrode of claim 9 wherein diffusing by the shaft decreases flow of current into target tissue through the tip.
12. The electrode of claim 9 wherein the shaft comprises a resistive material.
13. The electrode of claim 9 wherein the shaft comprises a composite material.
14. A method for conducting a current into tissue of a human or animal target, the method comprising:
propelling a wire-tethered electrode from an electronic weapon to penetrate tissue of the target, the electrode comprising a tip and a shaft that inhibits conduction of the current through the tip; and
diffusing the current into target tissue along a length of the shaft wherein
a. the current interferes with the target's voluntary use of its skeletal muscles; and
b. the shaft penetrates the tissue along the length.
15. The method of claim 14 wherein interfering comprises causing involuntary contraction of skeletal muscles.
16. The method of claim 14 wherein interfering comprises causing pain to the target to motivate the target to voluntarily stop moving.
17. A deployment unit for use with an electronic weapon, the deployment unit providing a current from a signal generator of the electronic weapon through tissue of a human or animal target, the current for inhibiting voluntary movement by the target, the deployment unit comprising:
a housing;
an interface that couples the housing to the signal generator, the interface for receiving the current;
a filament that conducts the current, the filament stored in the housing prior to deployment, the filament coupled to the interface for receiving the current;
an electrode stored in the housing prior to deployment; and
a propellant that in operation propels the electrode away from the housing to deploy the filament toward the target; wherein
the electrode comprises a spear that, after the electrode is propelled away from the housing to deploy the filament toward the target, penetrates tissue of the target along a length of the spear;
the spear inhibits conduction of the current through a tip of the spear; and
the spear diffuses a portion of the current along the length of the spear to reduce an electric field density that would otherwise occur at the tip.