Patent Application
20140073836
The present invention relates to systems and methods for promoting bone growth using electrical energy.
When utilized in Combined Magnetic Field (CMF) bone growth stimulators, the cyclotron resonance relationship detailed in U.S. Pat. No. 5,059,298 is effective when the entire region requiring bone growth is subjected to the CMF field containing the precise cyclotron resonance ratio for the selected ion(s). Dual coil CMF bone growth stimulators, like that described in U.S. Pat. No. 4,932,951, are adapted to produce this field, by placing the two coils opposite each other, similar to a Helmholtz configuration, such that the selected cyclotron resonance ratio is produced between the two coils across the entire region requiring treatment. However, single coil CMF bone growth stimulators, such as that described in U.S. Pat. No. 7,465,269, do not produce a CMF therapy in which the cyclotron ratio is constant across the region under treatment. This is because the magnitude of the magnetic field drops very quickly as the axial distance from the center of the coil increases. To illustrate this point,
The present invention addresses the drawback of single coil CMF bone growth stimulators, by automatically calculating and adjusting the stimulation therapy parameters (such as, for example, static B-field magnitude, and AC frequency) based upon parameters that are preprogrammed into a control unit at a manufacturing facility or patient dimensional parameters that are measured and programmed into a control unit by a therapist such as a physician.
The present invention provide systems and methods of applying a therapeutic magnetic field to a bone region of a human being, such as a lumbar spinal region, in order to promote the healing and growth of lumbar vertebrae, or other relevant vertebrae, following spinal fusion surgery, such as lumbar spinal fusion surgery. More specifically, in an embodiment, the present invention provides a system that produces a CMF that is precisely located and controlled across the entire spinal region requiring bone growth stimulation by utilizing lumbar spine dimensional input parameters to automatically calculate and drive the appropriate output therapy signal through a single coil. This provides an improved method of applying a CMF bone growth therapy to the lumbar spinal region over other single coil devices, such as those described in U.S. Pat. Nos. 5,792,040 and 7,465,269, which are incorporated by reference herein. The CMF therapy described in these patents uses low frequency magnetic fields that are functionally dependent upon ion cyclotron resonance frequencies as described in U.S. Pat. No. 4,932,951, which is incorporated by reference herein.
The present invention provides systems and methods for promoting bone growth by automatically adjusting, and programming delivery of electrical energy, such as a combined magnetic field, to a patient in need of bone growth.
By “operative state,” is the state of the system when it is being used to treat a patient.
Referring to
Prior to programming device 10 for operation, a physician can first makes measurements using, for example, manual and/or radiographic techniques. Referring to
Distance AB—the linear distance from the magnetic sensor 22 (line A) to the patient's posterior skin (line B) at the midsagittal plane, along line E, which is substantially vertically central to the magnetic sensor 22 and to the lumbar spinal region requiring treatment. By “substantially” is meant that the measurements need not be exact such as exactly central. Device 10 is fitted on the patient's lumbar back at substantially the center of the region requiring treatment in order to make this measurement.
Distance BC—the linear distance from the patient's posterior skin (line B) to the spinous process (line C) at the midsagittal plane, along line E, which is substantially vertically central to the magnetic sensor 22 and to the lumbar spinal region requiring treatment. This dimension is the minimum depth which requires bone growth therapy, and is determined using radiographic techniques such as, for example, X-rays, CT scans, and MRI's.
Distance BD—the linear distance from the patient's posterior skin (line B) to the anterior vertebral body (line D) at the midsagittal plane, along line E, which is substantially vertically central to the magnetic sensor 22 and to the lumbar spinal region requiring treatment. This dimension is the maximum depth which requires bone growth therapy, and is determined using radiographic techniques such as, for example, X-rays, CT scans, and MRI's.
While the above default dimensions have been selected to include the minimum and maximum lumbar spinal column depths at the region requiring treatment, it is understood that the physician has the flexibility to select minimum and maximum values case-by-case, based on any number of considerations. It is also understood that the linear distances could be measured from any point other than the magnetic sensor 22, such as substantially the center of the transducer coil 21, a surface of the lumbar transducer assembly 20, or any other reference point.
Once the dimensional parameters are determined, the physician can program these values into control unit 40 using user interface buttons 42. The dimensions are stored into the on-board memory 45 located in the control unit 40. Those skilled in the art understand that there exist various memory options which could be utilized to store this data, such as discrete memory integrated circuits, memory cards, or USB drives, among others. Also, the method by which the dimensions are entered by the physician could also be various, such as, for example, touchscreen displays, internal tactile switches, programming through an external computer, or other devices.
With the dimensional parameters stored in the memory 45 of control unit 40, processor 43 automatically calculates and drives the required range of CMF output parameters (static B-field magnitude, AC frequency, magnitude of AC field, etc.) such that the entire depth of lumbar vertebrae bone(s) requiring therapy is subjected to the selected cyclotron resonance ratio (in this case 383 Gauss per Hertz, assuming an AC frequency of 76.6 Hertz), in succession, from the minimum to the maximum programmed depths. Referring to
The cycling of CMF therapy described herein, differs from existing combined magnetic field bone growth stimulators in that the selected cyclotron resonance ratio moves across the region of treatment (such as 0 to 6 inches from the transducer housing). This allows the treatment to cover the entire lumbar spinal column depth of most patients at a pre-determined cycle velocity. The result is that each point along the treatment span will be subjected to the precise cyclotron resonance ratio for only a brief portion of the therapy session—roughly 200 milliseconds for each 20 mil section per cycle in the preferred embodiment. CMF bone growth technology previously known in the art, works by subjecting a specific region of treatment, such as the transverse processes or the area between two coils in the case of dual coil stimulator to the precise cyclotron resonance ratio continuously at a fixed depth for the entire therapy session. However, the present invention relates to bone growth achieved using a cycling combined magnetic field, even though each section of the region of treatment is not subjected to a continuous cyclotron resonance ratio.
It is understood that the dimensional parameters could be preprogrammed at the factory such that minimum and maximum treatment distances would accommodate patients of all shapes, sizes, and sexes. This embodiment would eliminate the need for the physician to make manual and radiographic measurements, and program this data into the device 10. A similarly effective magnetic field output could be produced by programming a single depth into the control unit 40, which would then automatically calculate and adjust the stimulation parameters such that the entire region requiring treatment is subjected to the selected cyclotron resonance ratio.
Although the present invention details a CMF lumbar device, the methods and techniques provided herein could be utilized for any bone growth stimulation technology (pulsed electromagnetic field, capacitive coupling, direct current, ultrasound, etc.), or any bone growth stimulation application (cervical, tibia, femur, scaphoid, humerus, ulna, fibula, etc.). Further, the techniques provided herein can be utilized for multi-coil bone growth stimulators.
Finally, the cyclotron resonance ratio of 383 Gauss per Hertz described herein is derived from the 3rd and 5th harmonics of the cations Mg2+ and Ca2+ respectively, as detailed in “The Charge-to-Mass ICR Signature in Weak ELF Bioelectromagnetic Effects” by Abraham R., which is also incorporated by reference herein. Also, any number of cyclotron resonance relationships related to bone growth can be utilized, as detailed in the above reference and in U.S. Pat. No. 4,932,951, which is incorporated herein
The foregoing description and examples have been set forth merely to illustrate the invention and are not intended as being limiting. Each of the disclosed aspects and embodiments of the present invention may be considered individually or in combination with other aspects, embodiments, and variations of the invention. Further, while certain features of embodiments of the present invention may be shown in only certain figures, such features can be incorporated into other embodiments shown in other figures while remaining within the scope of the present invention. In addition, unless otherwise specified, none of the steps of the methods of the present invention are confined to any particular order of performance. Modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art and such modifications are within the scope of the present invention. Furthermore, all references cited herein are incorporated by reference in their entirety.
This application claims priority to U.S. Provisional Patent Application Ser. No. 61/700,108, filed Sep. 12, 2012, the entirety of which is hereby incorporated by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 61700108 | Sep 2012 | US |
