Radio transparent sensor implant package

Biocompatibility is an essential aspect of the medical device industry. Biocompatibility testing ensures that devices do not contain materials or substances that could be harmful to patients during initial use or over the course of time. Biocompatibility tests can be used to detect many possible negative side effects of a product on patient. These may include effects on cells and physiological systems, tissue irritation and inflammation, immunological and allergic reactions and the possibility of cellular mutations leading to cancer. Email:marketing@medicilon.com.cn Web:www.medicilon.com

A system is provided for the packaging of wireless electronics in a mammalian body, the system comprising: a package configured in a shape suitable for implantation in that body; the package being configured from a biocompatible material; and that biocompatible material having a high degree of radio wave transparency.

The invention relates to sensor packages, and more particularly, to a sensor package having high radio transparency.

Novel packaging capabilities targeted at reducing the size and increasing reliability are required for the advancement of biomedical implants. Biocompatible metals, used for chronic implants, and epoxies, used for short-term applications, are the two most common materials used in the packaging of biological implants.

Current biocompatible packaging materials all have limitations for implantable use. Epoxies and metals are the most commonly used materials because of their availability and ease of use. The major drawback of epoxy is that it can only be used for acute research due to the quick degradation of its polymer backbone which exposes the implant to the surrounding tissue. Chronic implantation requires an alternative material with long term reliability. Biocompatible metals which are commonly used for encasing implants hinder wireless telemetry because the casing creates a faraday cage. Wireless capabilities are compulsory because of aesthetics, comfort, and most importantly, reduced risk of infection. A novel set of packaging materials that enables wireless transmission of data and can be chronically implanted could provide tremendous advantages to existing and future biomedical technology.

Current microelectronic techniques are advancing everyday communication devices. From cell phones to radios, microelectronics offers the ability to make these portable devices more powerful, reliable, and smaller. These technological advancements need to be transitioned into biomedical devices. In some non-biomedical applications Low Temperature Co-fired Ceramics (LTCC) is used to achieve compact size and improved performance. These LTCC materials allow for the building of components, resistors, capacitors, and inductors, that when assembled on successive layers, and then combining those layers together, create a single product. Therefore smaller packages are created, removing commonly used off the shelf components. LTCC is not the only material that enables these new, smaller implantable devices. Silicon and Liquid Crystal Polymer (LCP) each enable the formation of conductive traces created on its surface. Utilization of such materials in implantable devices, could make these devices smaller and more efficient, minimizing trauma during surgery and producing better post-operative performance. Methods for such utilization have not been employed.

Among the challenges associated with utilizing such technologies in implantable devices, is the requirement that packages comprising such new materials will be required to pass standard biocompatibility testing, such as long-term implant and cytotoxicity testing.

What is needed, therefore, are techniques for constructing an biocompatible, radio transparent package.

One embodiment of the present invention provides a system for the packaging of wireless electronics and sensors in a mammalian body, the system comprising: a package configured in a shape suitable for implantation in the body; the package being configured from a biocompatible material; and the biocompatible material having a high degree of radio wave transparency.

Another embodiment of the present invention provides such a system wherein the biocompatible material is selected from the group of biocompatible materials consisting of liquid crystal polymer, poly(methyl methacrylate), low temperature co-fired ceramic, anisotropic conductive adhesive, silicon and combinations of thereof.

A further embodiment of the present invention provides such a system 1 wherein the package is provided with a plurality of layers of the biocompatible material, the layers being applied in a pattern, the pattern defines a structure in the shape suitable for implementation in the body.

Still another embodiment of the present invention provides such a system wherein the high degree of radio wave transparency is a degree of transparency that allows signals transmitted from an antenna disposed within the package to be transmitted to a receiver disposed externally to the body at a distance of about approximately 2 meters.

A still further embodiment of the present invention provides such a system wherein the high degree of radio wave transparency comprises a loss of not greater than 50 dB from an antenna disposed within a mammalian body.

Yet another embodiment of the present invention provides such a system wherein the high degree of radio wave transparency comprises having not greater than 50 dB of loss from an antenna disposed within the package.

A yet further embodiment of the present invention provides such a system further comprising a biocompatible coating.

Even another embodiment of the present invention provides such a system wherein the biocompatible coating comprises parylene.

One embodiment of the present invention provides a method for the manufacture of an implantable electronics package, the method comprising: Placing a first biocompatible material sheet on a first mold plate; Patterning an antenna and metal contacts upon a top surface of the first biocompatible material sheet; Disposing an electronics package upon the metal contacts; Draping a second sheet of biocompatible material over the first biocompatible material sheet and the electronics package; and Compressing the second sheet of biocompatible material against the top surface with a second mold plate having a recess for receiving the electronics package.

Another embodiment of the present invention provides such a method wherein the biocompatible material is a biocompatible selected from the group of materials consisting of liquid crystal polymer, poly(methyl methacrylate), low temperature co-fired ceramic, anisotropic conductive adhesive, silicon and combinations of thereof.

A further embodiment of the present invention provides such a method further comprising: creating a fenestration cut into the first biocompatible material sheet, thereby allowing internal components to interact with an environment external to the package.

Still another embodiment of the present invention provides such a method wherein the creating the fenestration comprises deep reactive ion etching the first biocompatible material sheet forming the fenestration.

A still further embodiment of the present invention provides such a method further comprising hermetically sealing the first biocompatible material sheet proximate to the fenestration with Anisotropic conductive adhesive to least one component of the electronics package, the component being disposed proximate to the fenestration, such that at least a portion of the component is exposed to the environment external to the implantable package.