Apparatus and method for aiding formation of bone forming material

Claim 3

The apparatus according to claim 1 wherein said current inducing means comprises a field coil coupled to an a.c. signal generator.

Claim 4

The apparatus according to claim 1 wherein said current inducing means comprises the stray fields of the mains.

Claim 5

The apparatus according to claim 2 wherein said a.c.signal generator comprises means for superimposing on said a.c.signal a modulating signal having a frequency of at least three times the fRequency of said a.c. signal.

Claim 6

The apparatus according to claim 1 for treating a, bone structure having an opening which is a gap caused by a fracture, wherein said second electrode is a metal splint adapted to be attached to the bone structure for fixing it.

Claim 7

The apparatus according to claim 5 wherein said metal splint comprises a plate-like member having a circumferential groove housing said pick-up coil.

Claim 8

The apparatus according to claim 5 wherein said pick-up coil is wound around a core of a material of low reluctance, said core forming an open-ended magnetic circuit.

Claim 9

The apparatus according to claim 1, further including a capacitor connected in parallel to said pick-up coil to form a resonant circuit tuned substantially to the frequency of the induced current.

Claim 10

The apparatus according to claim 1, wherein the frequency is below 150 c/s and preferably between 1 and 65 c/s.

Claim 11

The apparatus according to claim 1, wherein said frequency is between about 10 and 30 c/s.

Claim 12

The apparatus according to claim 1, wherein said harmonics content is below 20 percent and preferably below 10 percent.

Claim 13

The apparatus according to claim 1, wherein said current density at said electrodes is below 10 microamperes per square millimeter, and preferably between 3 and 7 microamperes per square millimeter.

Claim 14

The apparatus according to claim 1, wherein the coil and the coil leads are insulated up to the point where the electrodes are adapted to enter into the bone structure.

Claim 15

The apparatus according to claim 1 wherein said pick-up coil is mechanically connected to a medical splint adapted to reinforce and fix the bone structure.

Claim 16

The apparatus according to claim 1 wherein said frequency is between 10 c/s and 1,000 c/s.

Claim 17

In an apparatus for aiding formation of bone forming material in the region of a bone structure of a living being including a splint for positioning the bone, and means for securing the splint to the bone, the improvement comprising at least one first electrode of elongated slender shape adapted to be inserted into the bone structure; a second electrode adapted to be positioned at least partially on the side of the bone structure which is opposite to said first electrode for being d.c.-coupled to a portion of the living being; and, at least one pick-up coil having a first terminal and a second terminal, said first terminal being connected to said first electrode and said second terminal being adapted to be conductively connected to the bone structure, said coil being adapted to be arranged in inductive relationship with a signal generating means for inducing within said coil an a.c. current having gradual, gentle slopes, a frequency below 1,000 c/s, and a magnitude which produces a current density of no more than 10 microamperes per square millimeter at said electrodes.

Claim 18

In an apparatus for aiding formation of bone forming material in the region of a bone structure of a living being including a splint for positioning the bone, and means for securing the splint to the bone, the improvement comprising at least one first electrode of elongated slender shape adapted to be inserted into the bone structure; a second electrode adapted to be positioned at least partially on the side of the bone structure which is opposite to said first electrode for being d.c.-coupled to a portion of the living being; and, at least one pick-up coil having a first terminal and a second terminal, said first terminal being connected to said first electrode and said second terminal being adapted to be conductively connected to the bone structure, said coil being adapted to be arranged in inductive relationship with a signal generating means for inducing within said coil an a.c. current having gradual, gentle slopes, a frequency below 1,000 c/s, and a magnitude which produces a current density of no more than 10 microamperes per square millimeter at said electrodes.

Claim 19

The apparatus as defined in claim 16, further comprising: a screw having at least its outer surface made of insulating material and connecting the splint to the bone structure and wherein said first electrode is located within said screw so that said first electrode is insulated from the splint.

Claim 20

The apparatus as defined in claim 16, wherein the splint is a plate-like member made of a non-magnetic material and said second terminal is connected to the splint.

Claim 21

The apparatus as defined in claim 18, wherein said plate is a sheet-metal member having a thickness not greater than 3 millimeter.

Claim 22

The apparatus as defined in claim 16 further comprising a rod-shaped magnetic core and wherein said pick-up coil is wound on said magnetic core.