US-12623073-B2 - Implantable bone growth stimulator

US12623073B2US 12623073 B2US12623073 B2US 12623073B2US-12623073-B2

Abstract

A bone growth stimulator includes an antenna configured to receive electromagnetic signals in a radio frequency band, and a controller having a power source including a supercapacitor electrically connected to the antenna. The supercapacitor stores a charge in accordance with the electromagnetic signals received by the antenna. The bone growth stimulator further includes a cathode extending from the controller to a desired location of bone growth and an anode electrically connected to the power source and extending from the controller. Electrical energy travelling from the anode to the cathode stimulates bone growth in a patient.

Inventors

John Gorski
Jason Gorski
Daniel J. Mastella

Assignees

Ortho Dynamics LLC

Dates

Publication Date: 20260512
Application Date: 20220127

Claims (9)

1 . A bone growth stimulator comprising: a body configured to have a first surface directly in contact with a bone when implanted; a printed circuit board attached to the body on a second surface opposite the first surface; an antenna configured to harvest far field electromagnetic signals from a transmitter in a radio frequency band, wherein an electric field vector E and a magnetic field vector B of the far field electromagnetic signals are perpendicular to each other; a controller attached to the printed circuit board and having a power source including a supercapacitor, the controller being electrically connected to the antenna, wherein the controller causes the supercapacitor to store a charge in accordance with energy captured from the far field electromagnetic signals harvested by the antenna; a cathode extending from the controller through the body and configured to be directly contacting the bone; and an anode electrically connected to the power source and extending from the controller, wherein: electrical energy travelling from the anode to the cathode stimulates bone growth in a patient; both the cathode and the anode are electrically isolated from the body, and a frequency of the far field electromagnetic signals received by the antenna is greater than 800 megahertz and less than 300 gigahertz, and a distance between the transmitter and the bone growth stimulator is greater than one meter and less than 80 feet.
2 . The bone growth stimulator of claim 1 , wherein the controller is programmed to cause the supercapacitor to store the energy of the far field electromagnetic signals harvested by the antenna.
3 . The bone growth stimulator of claim 1 wherein the body is a bone plate, the printed circuit board is attached directly to the bone plate on the second surface and the bone plate is formed from at least one of stainless steel, titanium, and carbon fiber.
4 . The bone growth stimulator of claim 1 , wherein the body is in a form of a hollow surgical screw formed from at least one of stainless steel, titanium, and carbon fiber.
5 . The bone growth stimulator of claim 1 , wherein the body includes a spinal cage formed from at least one of stainless steel, titanium, and carbon fiber.
6 . The bone growth stimulator of claim 3 , wherein the antenna is a metal conductor or a flexible printed circuit board disposed on the bone plate.
7 . The bone growth stimulator of claim 3 , wherein the antenna is embedded in the bone plate.
8 . The bone growth stimulator of claim 4 wherein the antenna is electrically isolated from the body and extends from the controller to an area outside of the body.
9 . The bone growth stimulator of claim 5 , wherein the antenna is electrically isolated from the body and extends from the controller to an area outside the body.

Description

BACKGROUND Bone fractures can be the result of trauma, overuse, or certain diseases that weaken bone structure. Traditional methods of healing bone fractures involve aligning the bone segments and limiting motion at the fracture site until the bone heals. Often times, individuals with a bone fracture must wear a cast or splint until healing is complete. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an example bone growth stimulator. FIG. 2 illustrates a side view of the example bone growth stimulator of FIG. 1. FIG. 3 illustrates a partial cross-sectional view of another example bone growth stimulator. FIG. 4 illustrates a perspective view of another example bone growth stimulator. FIG. 5 illustrates an example transmitter used to energize the bone growth stimulator. FIGS. 6A-6B illustrate other example bodies that may be used with the bone growth stimulator. FIG. 7 illustrates another example controller that may be used with the bone growth stimulator. FIG. 8 illustrates the electric field vector (E-field) perpendicular to the magnetic field vector (B-field) in a far-field region. DETAILED DESCRIPTION Traditional methods of bone healing using a cast or using a splint to limit motion takes a long time. On average, healing a bone can take weeks or months or may ultimately not heal at all. Stimulating the area with electromagnetic energy, however, can expedite bone healing. Applying electromagnetic energy directly to a fractured bone requires surgically implanting a bone stimulating device. Traditional bone stimulating devices are physically connected to a power supply implanted in the patient's body via a wire. The power supply limits the effectiveness of the direct bone stimulator. One solution is a bone growth stimulator that can be powered wirelessly. For example, a bone growth stimulator may include an antenna configured to receive electromagnetic signals in a radio frequency band, and a controller having a power source including a supercapacitor electrically connected to the antenna. The supercapacitor stores a charge in accordance with the electromagnetic signals received by the antenna. The bone growth stimulator further includes a cathode extending from the controller to a desired location of bone growth and an anode electrically connected to the power source and extending from the controller. Electrical energy travelling from the anode to the cathode stimulates bone growth in a patient. The elements shown may take many different forms and include multiple and/or alternate components and facilities. The example components illustrated are not intended to be limiting. Indeed, additional or alternative components and/or implementations may be used. Further, the elements shown are not necessarily drawn to scale unless explicitly stated as such. As illustrated in FIG. 1, an example bone growth stimulator 100 includes a body 105, a cathode 110, an anode 115, an antenna 120, a power source 125, and a controller 130. The components can be assembled to form the bone growth stimulator 100, which can be surgically implanted in a patient to stimulate bone growth. The body 105 shown in FIG. 1 takes the form of a metal plate. The body 105 may be formed from a material approved for implantation in a human or animal body 105. Example materials for the body 105 may include stainless steel, titanium, or carbon fiber. As shown in FIG. 1, the body 105 has a generally rectangular shape with a length of approximately 1-18 inches and a width of approximately 0.25-4 inches depending on the bone on which the bone growth stimulator 100 will be implanted and whether the bone growth stimulator 100 is to be used to heal a human bone or an animal bone. For instance, a larger body 105 may be used on larger human bones or bones of large animals such as horses or cows. The body 105 may define holes 135 for receiving bone screws or other fasteners that can be used to attach the body 105 to a person or animal. The cathode 110 is a negatively charged terminal extending from the controller 130. When the bone growth stimulator 100 is implanted in a patient, the cathode 110 may be placed on the part of the bone where growth is desired. In some instances, the cathode 110 is a conductive wire extending from the controller 130. In other instances, the cathode 110 is an exposed conductive pad, such as a copper pad, on the controller 130. The type of cathode 110 used may depend upon the design of the body 105, where the bone fracture occurred, and so on. For instance, the cathode 110 may be a wire in instances where it is impossible or impractical for a conductive pad on the controller 130 to be in physical contact with the site of the bone fracture. Alternatively, having the cathode 110 take the form of the conductive pad may be more suitable for instances where the conductive pad can be placed in physical contact with the site of the bone fracture. To increase the likelihood of uniform bone stimulation, multiple anodes 115 may be inco