The present invention relates to a transcutaneous port for facilitating electronic communication between an amputation site and a prosthetic motor device. More specifically, the transcutaneous port has micro-textured external surfaces to enhance integration of the soft tissue and bone tissue with the transcutaneous port, which reduces microbial infiltration of the soft tissue site.
Transcutaneous devices have application in many areas of medicine, these including such areas as bone stents or pins where it is necessary to stabilize fragments of a bone during a period of healing, medication-dispensing soft tissue implants such as those that require external access by the needle of a syringe, and neural interface devices that require both physical stability at an amputation and/or nerve injury site and an external electrical port to which a prosthesis may be attached. These unique and diverse requirements, of transcutaneous devices have presented long-standing challenges within the medical disciplines, in which they exist.
Most transcutaneous devices must satisfactorily address requirements at three levels, namely, bone interface stability, soft tissue stability, and suitable properties of an external portion thereof. Accordingly, in a successful transcutaneous device, it is necessary to obtain a stable, reliable and bacteria free interface to both the hard and soft tissue surfaces thereof.
In the field of peripheral nerve interface development to develop a stable, practically useful mechanism for obtaining motor information from lesioned peripheral nerves, conduct this information out of the body and effectively activate prosthetic motor devices requires a stable nerve and skeletal attachment interface and a transcutaneous access port.
Common problems in the existing transcutaneous ports include instability of the transcutaneous ports which results in detachment of the device from the nerves, or the site and microbial infiltration at the interface between the transcutaneous port and surrounding soft tissue, which also results in the detachment.
U.S. Pat. No. 5,607,607 (to Naiman et al.) teaches a transcutaneous implant which has a first and a second microtexturized surfaces provided on the outer circumferential surface of the implant, and separated by a barrier zone. The transcutaneous implant is to be implanted within soft issue in situ, and both microtexturized surfaces are used for enhancing integration of the implant with the soft tissue. This type of transcutaneous implant is not anchored into bone and has no involvement with bone tissue, and its stability in an amputation site is limited.
Therefore, there is a strong need in the field of peripheral nerve interface development for improved transcutaneous ports which enables integration of the device with surrounding soft tissue and bone tissue, hence, provides feasibility for long term use of the transcutaneous port in situ for providing electronic communication to prosthetic motor devices.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
In one aspect, the present invention provides a transcutaneous port which can be surgically implanted into a site in a patient's body and serve as a basis of electrical communication between a prosthetic motor device and an amputation or trauma site.
Referring to
Bone fixation section 60 integrally extends from lower portion 24 of subcutaneous port section 20. Bone fixation section 60 includes transosseous collar portion 62 and a threaded shaft portion 66 integrally extending from transosseous collar portion 62. Threaded shaft portion 66 has bone fixation thread 68 for anchoring transcutaneous port 10 inside bone, which can be made same as those on the transosseous implant known in the art. Preferably, the inner diameter of threaded shaft portion 66 is equivalent to the diameter of transosseous collar portion 62.
In a further embodiment shown in
The transcutaneous port can be made of titanium or titanium alloy, such as those materials used for surgical implants, known in the art. In an exemplary embodiment, subcutaneous port section 20 has a height approximately 2.5 mm, wherein upper portion 22 has a height approximately 2.0 mm, top flange 28 has a thickness approximately 0.25 mm, and lower portion 24 has a height approximately 0.25 mm. Axial channel 40 has diameter approximately 1.0 mm and transverse channel 50 has a diameter approximately 0.2 mm. The external diameters of upper portion 22, top flange 28 and middle flange 29 are approximately 4.0, 5.0 and 7.0 mm, respectively. Bone fixation section 60 has a height approximately 2.0 mm, and transosseous collar portion 62 has a diameter approximately 2.5 mm.
As shown, upper portion 22 of subcutaneous port section 20 has a first micro-textured external surface 30, and transosseous collar portion 62 of bone fixation section 60 has a second micro-textured external surface 64. In the embodiment shown in
As shown, each microgroove 4 has a groove base 2 and a groove wall 3. The dimensions of the microgrooves 4 and ridges 6 are indicated by the letters “a”, “b”, “c” and “d”. These configurations include those having square ridges 6 and square microgrooves 4 (
In the microgroove configurations illustrated in
The microgrooves shown in
In the embodiment shown in
In the embodiment shown in
Furthermore,
From the embodiments illustrated in
The above-described micro-textured surfaces can be produced by laser based technologies known in the art, for example the instrument and methodology illustrated in details in U.S. Pat. Nos. 5,645,740 and 5,607,607, which are herein incorporated by reference in their entirety.
It has been found that micro-textured surface having alternating microgrooves and ridges having width and depth in a range from about 1.5 μm to about 50 μm encourages ingrowth of soft tissue and bone tissue cells into the microgrooves, and achieves a strong integration of an implant having such micro-textured external surface with surrounding soft tissue or bone tissue. The ingrowth is directional along the pathway of microgrooves. Such surface property in controlling cellular growth has been illustrated in detail in U.S. Pat. Nos. 5,645,740 and 5,607,607, which are herein incorporated by reference in their entirety.
Furthermore, it has also been found that the preferential dimension of the microgroove, defined by width and depth of the groove, is different for different tissues. For example, the dental implants manufactured by Bio-Lok International, Inc., Deerfield Beach, Fla., which have a groove width about 8 micron in the region for soft tissue, and a groove width about 12 micron in the region for bone tissue, were clinically proved to enhance implant integrations with soft tissue and bone tissue, respectively, and were recently approved by the Federal Drug Administration for dental use.
In a preferred embodiment of the present invention, the co-parallel linear microgrooves and ridges, as shown in
In a further aspect, the present invention is directed to a method of providing a stable neural interface to a prosthesis using the transcutaneous port of the present invention. As shown in
The term “neural signal source” used herein includes, but is not limited to, muscles, nerves, and lesioned peripheral nerves due to amputation. It should be understood that various muscles in the soft tissues are rich in nerve density, and hence these muscles can be used as neural signal source.
It can be appreciated that the transcutaneous port of the present invention can also be used as a communication platform for transmitting electrical signals from outside into a location inside the body for stimulation.
In a further embodiment, the present invention provides a transcutaneous port 200 as shown in
Subcutaneous section 220 has a first micro-textured external surface 230 which comprises a multiplicity of alternating microgrooves 4 and ridges 6. Bone fixation section 260 has a transosseous collar portion 262 and a threaded shaft portion 266. Transosseous collar portion 262 has a second micro-textured external surface 264, which comprises a multiplicity of alternating microgrooves 4 and ridges 6. The first and second micro-textured external surfaces 230 and 264 are the same as the first and second micro-textured external surfaces 30 and 64, respectively, which are described above in transcutaneous port 10.
As shown in
The transcutaneous port of the present invention has substantial advantages over the existing transcutaneous port known in the art. Several structural features are implanted together on the transcutaneous port to provide stability for long term use of the transcutaneous port. More specifically, threaded shaft portion of bone fixation section anchors the transcutaneous port into bone. Middle flange substantially increases the contact areas between tissue and the transcutaneous port. More importantly, the first and second micro-textured external surfaces in subcutaneous port section and bone fixation section, respectively, enhance integrations of the soft tissue and bone tissue with the transcutaneous port, thereby providing two zones of strong integration. Such integration reduces microbial infiltration of the soft tissue site and establishes an interface between the transcutaneous port and the tissue, which can survive the amputation prosthetic environment.
While the present invention has been described in detail and pictorially shown in the accompanying drawings, these should not be construed as limitations on the scope of the present invention, but rather as an exemplification of preferred embodiments thereof. It will be apparent, however, that various modifications and changes can be made within the spirit and the scope of this invention as described in the above specification and defined in the appended claims and their legal equivalents.
This application is a continuation-in-part of application Ser. No. 10/237,355, filed Sep. 6, 2002, now abandoned, which claims the benefit under 35 USC 119 (e) of the provisional patent application Ser. No. 60/317,568 filed, Sep. 6, 2001. All parent applications are hereby incorporated by reference by their entirety.
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6210376 | Grayson | Apr 2001 | B1 |
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7766881 | Reinmann | Aug 2010 | B2 |
Number | Date | Country | |
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20050267591 A1 | Dec 2005 | US |
Number | Date | Country | |
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60317568 | Sep 2001 | US |
Number | Date | Country | |
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Parent | 10237355 | Sep 2002 | US |
Child | 11127949 | US |