Tissue growth control apparatus and method

• US 4,313,438 A
• Filed: 07/14/1980
• Issued: 02/02/1982
• Est. Priority Date: 07/16/1979
• Status: Expired due to Term

• Current Assignee: Wilson Greatbatch
• Original Assignee: Wilson Greatbatch
• Inventors: Greatbatch, Wilson
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US06/167,752
• Time in Patent Office: 568 Days
• Field of Search: 128/82.1, 128/207.21, 128/389, 128/391, 128/784, 128/783, 128/419 F, 128/419 B, 128/419 C, 128/419 P, 128/419 R, 128/420 R
• US Class Current: 607/51
• CPC Class Codes: A61B 17/58 for osteosynthesis, e.g. bone plates, screws , setting implements or the like A61B17/14, A61B17/16 take precedence
• CPC Class Codes: A61F 2002/2821 Bone stimulation by electromagnetic fields or electric current for enhancing ossification
• CPC Class Codes: A61N 1/205 for promoting a biological process
• CPC Class Codes: A61N 1/326 for promoting growth of cells, e.g. bone cells
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators

Abstract

A method and apparatus for providing germicidal and healing treatment of tissue such as bone wherein an electrode of silver or like material is applied to a living tissue site to be healed, initially a direct voltage is applied to the electrode of a polarity driving the electrode as an anode to release silver ions to create a germicidal environment at the site, and thereafter a direct voltage of opposite polarity is applied to the electrode driving it as a cathode to stimulate healing of the tissue at the site. The apparatus is implanted in the body of a patient, and in one embodiment a battery is connected through a switch to the electrode and a reference electrode, the switch initially connecting the electrode as an anode and thereafter changeable by an external operator such as a magnet to connect the electrode as a cathode. In another embodiment, another electrode and an element cooperate with the treating electrode to form a galvanic couple with the treating electrode to create a germicidal environment and a predetermined time thereafter the arrangement changes to a biogalvanic couple with body fluid to cause healing of the tissue. In either embodiment a wave shaping circuit can be operatively associated with the treating electrode to facilitate external monitoring of the apparatus when implanted.

Claims

1. Apparatus for providing germicidal and healing treatment of tissue such as bone comprising:

(a) an electrode of silver adapted to be operatively connected to a living tissue site to be healed;

(b) an electrode of platinum adapted to be connected to a location spaced from the site to be healed;

(c) means for establishing an electrical current flow path between said electrodes; and

(d) means operatively associated with said platinum electrode for forming a galvanic couple with said silver electrode to cause electrical current flow in one direction through said silver electrode in a manner releasing silver ions to create a germicidal environment at said tissue site, said galvanic couple forming means after a predetermined time causing said platinum electrode and said silver electrode to form a biogalvanic couple with fluid in the body containing said tissue site to cause electrical current flow in the opposite direction through said silver electrode in a manner promoting healing of tissue at the site.

2. Apparatus according to claim 1, wherein each of said silver and platinum electrodes is in the form of a wire.

4. Apparatus according to claim 1, wherein said galvanic couple forming means comprises a body of magnesium carried by said platinum electrode, the size of said body being selected to determine the time duration of said galvanic couple, said magnesium body being consumed during the operation of said galvanic couple, said biogalvanic couple beginning operation upon complete consumption of said magnesium body.

5. Apparatus according to claim 1, further including means for enclosing said apparatus including any portion of said silver electrode not in operative contact with said tissue site to be healed, said enclosing means being of human body reaction-free material whereby said apparatus is implantable in the body of a patient.

6. Apparatus according to claim 1, further including wave shaping means operatively associated with said silver electrode for causing the electrical current flow relative to said silver electrode to have a waveform which is readily discernible by external patient monitoring apparatus.

3. Apparatus according to cliam 1, wherein said means for establishing said current flow path comprises electrical resistance means connected in series between said silver and platinum electrodes.

7. Apparatus for providing germicidal and healing treatment of tissue such as bone comprising:

(a) a treating electrode adapted to be placed in operative contact with a living tissue site to be healed, said treating electrode being of a material which releases ions to create a germicidal environment at the site in response to electrical current flow in one direction relative to said treating electrode and which promotes healing of tissue at the site in response to electrical current flow in the opposite direction;

(b) another electrode adapted to be connected at a location spaced from the site to be healed;

(c) means for establishing an electrical current flow path between said electrodes; and

(d) means for applying direct voltage of one polarity to said treating electrode to cause electrical current flow in said one direction to create a germicidal environment at the site and after a predetermined time applying direct voltage of the opposite polarity to said treating electrode to cause electrical current flow in the opposite direction to promote healing of tissue at the site, said direct voltage applying means comprising means operatively associated with said other electrode for forming a galvanic couple with said treating electrode to create said germicidal environment at the tissue site, said galvanic couple forming means after said predetermined time causing said other electrode and said treating electrode to form a biogalvanic couple with fluid in the body containing said tissue to promote healing at said tissue site.

8. A method of providing germicidal and healing treatment of tissue such as bone comprising the steps of:

(a) applying to a living tissue site to be healed an electrode of a material which releases ions to create a germicidal environment at the site in response to electrical current flow in one direction relative to said electrode and which stimulates healing of tissue at the site in response to electrical current flow in the opposite direction relative to said electrode;

(b) applying to said electrode for a predetermined time a d.c. voltage of a polarity causing said current flow in said one direction to drive said electrode as an anode and release ions to create said germicidal environment at the site;

(c) applying to said electrode after said predetermined time a d.c. voltage of opposite polarity causing said current flow in said opposite direction to drive said electrode as a cathode to stimulate healing of tissue at the site; and

(d) said steps of applying said voltages to said electrode comprising applying another electrode to a location spaced from the site to be healed, providing a galvanic couple with said first-named electrode for said predetermined time to create said germicidal environment, and providing a biogalvanic couple including both of said electrodes after said predetermined time for healing tissue at the site.