Abstract: The alignment and positioning of an external device relative to an internal device is indicated on a display and/or by an acoustical signal. In the disclosed application, the external device transcutaneously transmits electromagnetic energy to an internal receiver to provide electrical power for an implanted medical device. To ensure optimal coupling between the external transmitter and the internal receiver, two permanent magnets are disposed at spaced-apart positions on the internal receiver. The magnetic field strength of the permanent magnets is sensed by a pair of correspondingly spaced-apart Hall effect sensor on the external transmitter. As the external transmitter is moved about over the internal receiver, the signals produced by the Hall effect sensors drive a display of light emitting diodes (LEDs) that indicates when the maximum magnetic field strength is achieved, i.e.

Abstract: A solid model is constructed from surface point data that represent layers of an object. The model is represented as the level set of an implicit function that is fitted to the surface point data. In the two-dimensional application of the technique, a Delaunay triangulation is performed for each layer. In this step, surface points are connected to form Delaunay triangles; the data points are the vertices of the Delaunay triangles. A circumcircle is then created around each Delaunay triangle, passing through the three vertices of the triangle. To decimate the circumcircle data, overlapping circumspheres are merged according to a merging criterion. A pseudo-union of implicit functions for the reduced number of circumcircles provides an initial implicit function for the layer. Errors in the implicit function are substantially reduced by optimizing the position and/or radii of the circumcircles.

Abstract: A flexible patch provided with a plurality of light sources mounted in spaced-apart array on its undersurface and covered with an optically transparent polymer material. The light sources are energized with an electrical current supplied by a flexible polymer battery, which is preferably rechargeable. Electrical current is conveyed through a lead that extends from the flexible battery to the flexible patch and then through an electrical circuit that includes a plurality of conductive traces formed using a conductive ink applied to the surface of a flexible substrate that supports the light sources. The thickness of the flexible patch at its maximum is less than 1.0 millimeters. The light sources can be separately grouped, and the electrical current supplied to each group individually controlled to achieve a desired light intensity and/or duration exposure to the light therapy over different portions of the undersurface of the flexible patch and different portions of the treatment site.

Abstract: An external power head is energized by a motor causing movement of an element that produces a varying magnetic field, thereby inducing power in an implanted receiver coil within a patient's body. The external power head includes either one or more moving permanent magnets, or one or more moving elements that vary the magnetic flux coupled to the implanted receiver coil. As a result of the varying magnetic field experienced by the implanted receiver coil, an electric current flows from the implanted receiver coil to energize an implanted medical device.

Abstract: A method and apparatus for selectively engaging and disengaging an anchor to fix a medical device at a selected site within a patient's body. A shape memory alloy (SMA) such as Nitinol is used to fabricate one or more anchors for the medical device. The shape memory effect exhibited by the SMA is thermally activated. One embodiment of the anchor has a substantially circular shape when at its martensite temperature and reverts to an elliptical shape at its austenite temperature. Another embodiment is a substantially straight strip at its martensite temperature and has an end that curls to engage tissue when at its austenite temperature. Still another embodiment includes a pair of anchors that extend outwardly from each side of an elongate probe at their austenite temperature and retract inwardly against the sides of the probe at their martensite temperature. The change in the shape of the SMA elements tends to anchor the medical device or probe at the treatment site.

Abstract: Constructs including bars, capsules, beads, and sheets are configured with a radionuclide core that emits energetic particles activating a phosphorescent shell material surrounding the radionuclide core so that it emits light to administer light therapy or PDT. A biocompatible coating that is generally optically transparent encloses the radionuclide core and phosphorescent material to prevent a patient's body in which the constructs are disposed from being affected by any toxicity of the phosphorescent shell material. In a typical application of the constructs, a photoreactive agent is infused into the treatment site and selectively absorbed by abnormal tissue, for example, in a cancerous tumor. Light emitted by the phosphorescent material when activated by the energetic particles emitted from the radionuclide core administers photodynamic therapy, which destroys the abnormal tissue.

Abstract: Flexible probes are arranged to achieve a desired light distribution pattern for administering light therapy at a treatment site in a patient's body. The flexible probes (20, 20', 92) each include a flexible substrate on which are mounted light emitting devices (30) in spaced-apart array. An optically transparent, biocompatible envelope (36) encloses the flexible substrate and components mounted thereon. In one embodiment, a link (44) couples a pair of the flexible probes together in parallel alignment for insertion at the treatment site. Thereafter, the probes are moved relative to each other within the link to achieve the desired light distribution pattern. In another embodiment, the flexible probes include flexible leaders (70, 72) attached to their distal ends, which terminate in suture tabs (74) that can be affixed to tissue adjacent the treatment site.

Abstract: A plurality of light sources that emit light having a long wavelength are energized for an extended period of time to increase the likelihood of two photon absorption by cells that have preferentially absorbed a photoreactive agent such as psoralen. The cells are preferably microscopic metastatic cancer cells that are diffusely distributed throughout a treatment site, for example, within an organ. The plurality of light sources are arranged in a spaced-apart array, mounted on a support plate that includes a plurality of conductive traces. A plurality of such arrays are preferably mounted to a flexible sheet that can conform to an outer surface of an organ being treated. Because the light emitted by the light sources is in the infrared or near infrared waveband, it penetrates deeply into the tissue at the treatment site.

Abstract: An external power head is energized by a motor causing movement of an element that produces a varying magnetic field, thereby inducing power in an implanted receiver coil within a patient's body. The external power head includes either one or more moving permanent magnets, or one or more moving elements that vary the magnetic flux coupled to the implanted receiver coil. As a result of the varying magnetic field experienced by the implanted receiver coil, an electric current flows from the implanted receiver coil to energize an implanted medical device.

Abstract: A magnet used for concentrating a medical substance carried by a magnetic fluid at an internal treatment site. The magnet is inserted through an opening in a patient's body and advanced to the internal treatment site. Although an electromagnet is used in one alternative embodiment, the magnet is preferably a super neodymium or other rare earth permanent magnet having a high field strength. A probe that includes the magnet is coated with a biologically inert material, such as a TEFLON.TM. polymer. Alternatively, a plurality of such magnets can be employed. In the preferred embodiment, a magnetic fluid that includes particles coated with a photoreactive agent is injected into the patient's body, preferably, immediately adjacent to or inside the treatment site. The particles in the magnetic fluid are attracted to the magnet at the treatment site, and the concentration of the photoreactive agent absorbed into the tissue around the magnet at the internal treatment site is enhanced.

Abstract: A flexible probe constructed using a flexible circuit having a small cross-sectional profile. In the various disclosed embodiments of the flexible circuit, a flexible substrate includes a plurality of conductive traces that extend along opposite surfaces of the substrate. Light emitting devices (or other electronic devices) are mounted at spaced-apart intervals along the length of the conductive traces using a conductive adhesive/solder. A conductor couples a terminal on the outwardly facing side of each of the light emitting devices to the conductive trace that is disposed on the opposite side of the substrate. In one embodiment, this conductor comprises a short conductive bar that extends between the terminals of pairs of the light emitting devices that are mounted on opposite sides of the flexible substrate so that the pair of light emitting devices are connected in series.

Abstract: The efficacy of a plurality of PDT treatments following at least an initial PDT treatment is enhanced by increasing the neutrophil count of the patient substantially above a normal level. The increase in the neutrophil count leads to a more rapid removal of dead abnormal cells and stroma that have been destroyed, thereby enabling light administered in subsequent PDT treatments to more effectively reach and destroy still living abnormal cells on the surface of the tumor. The accelerated removal of dead tumor cells also enables a more accurate assessment of the treatment progress, since the actual tumor size should be more evident in image of the site. By enabling a tumor to be more rapidly destroyed by multiple PDT treatments, the risk of metastatic spread of abnormal cells away from the treatment site is also reduced.

Abstract: An implantable probe having a non-metallic insulating base, non-metallic conductive traces supported by the base, and a plurality of non-metallic light sources supported by the base and coupled to the conductive traces. The conductive traces and the light sources are fabricated from a conductive polymer, which does not cause any artifacts if the implantable probe is left at the treatment site while it is imaged. Further, the implantable probe includes an envelope that is transparent and hermetically encloses the base, the pair of conductive traces, and the light sources. At least a portion of the envelope is optically transparent, enabling light emitted by the light sources to illuminate an adjacent treatment site. The conductive traces and the base are substantially flexible, enabling the probe to be flexed without breaking when the implantable probe is advanced within the body to the treatment site.

Abstract: A method and apparatus for applying beat to a treatment site prior to effecting photodynamic therapy. The perfusion of a drug into abnormal tissue in a tumor (12) is enhanced by heating the treatment site at which the tumor is disposed using a heat source (26) mounted on a fixture (20, 34) separate from a light source (28) on a probe used to effect the photodynamic therapy. Alternatively, the heat source and light source may comprise different types of light emitting diodes (LEDs) arranged in an array on a probe (14) disposed at the treatment site. Also mounted on the fixture is a temperature sensor (30), which produces a signal indicative of the temperature at the treatment site. In response to this signal, a controller (24/36) controls the heat source to prevent vascular damage. In addition to enhancing the perfusion of a photoreactive agent into the treatment site, heating the tissue at the site prior to initiating the PDT greatly enhances the efficacy of this treatment.

Abstract: A plurality of embodiments for a flexible probe used to provide photodynamic therapy (PDT) and to effect other medical procedures at an internal treatment site inside a patient's body. Each of the embodiments of the flexible probe (100, 108, 130, 158, 182, 190, 220, 280, 370, 390, 440, 460, 520) includes a flexible substrate (102, 184, 196, 222, 250, 282, 412, 462, 482, 502, 522) on which are disposed conductive traces (414, 466, 468, 488, 490, 504, 506, 524, 526) electrically connected to leads through which electrical current and signals are conveyed. A plurality of light sources (104, 192, 256, 286, 418, 436, 470, 492, 508, 542) or other micro-electronic circuits are connected to the conductive traces and mounted on the flexible substrate. Each of the embodiments of the flexible probes is enclosed within a transparent, biocompatible polymer envelope (106, 110, 464, 522).

Abstract: An implantable probe having an elongated sheath with provision for remotely positioning a device disposed within the elongated sheath. In one embodiment, the device is a circuit board, and a shape memory alloy (SMA) such as Nitinol is used to fabricate one or more actuators that are coupled to the circuit board. The shape memory effect exhibited by the SMA actuator is thermally activated. Electrical current is selectively applied to the actuator to resistively heat the SMA to a temperature sufficient to change its shape. When the shape of the SMA changes, the actuator moves the circuit board or other device longitudinally within the elongated sheath so that the light emitted is directed to a different portion of a treatment site. In another embodiment, the circuit board is rotated about its longitudinal axis within the sheath.

Abstract: A plurality of embodiments for a flexible probe used to provide photodynamic therapy (PDT) and to effect other medical procedures at an internal treatment site inside a patient's body. Each of the embodiments of the flexible probe (100, 108, 130, 158, 182, 190, 220, 280, 370, 390, 440, 460, 520) includes a flexible substrate (102, 184, 196, 222, 250, 282, 412, 462, 482, 502, 522) on which are disposed conductive traces (414, 466, 468, 488, 490, 504, 506, 524, 526) electrically connected to leads through which electrical current and signals are conveyed. A plurality of light sources (104, 192, 256, 286, 418, 436, 470, 492, 508, 542) or other micro-electronic circuits are connected to the conductive traces and mounted on the flexible substrate. Each of the embodiments of the flexible probes is enclosed within a transparent, biocompatible polymer envelope (106, 110, 464, 522).

Abstract: Several embodiments of relatively compact transmitter coils and receiver coils having an improved transcutaneous power transfer efficiency. The transmitter coils are preferably applied to the outer surface of a cutaneous layer on a patient's body and held in place using adhesive tape or other appropriate supporting material. Implanted within the patient's body is a receiver coil. To improve the power transfer efficiency of one embodiment, a transmitter coil and receiver coil include cores having pole faces with a substantially larger area than the cross section of the core at other locations. In addition, the core of the receiver coil is substantially shorter than that of the transmitter coil so that the lines of flux produced by the transmitter coil tend to pass through the pole faces of the receiver coil in greater density than they would if the pole faces of the transmitter and receiver cores were spaced identically.

Abstract: A method and apparatus for enhancing transcutaneous energy transfer to provide power to a medical device that is disposed within the body of a patient. A magnetic field is created by an external transmitting coil (200), which induces an electrical current in a receiving coil (300) that has been placed under the patient's skin (100). The flux path magnetic permeability between the receiving and transmitting coils is enhanced by the implantation of particles (120) into dermis (104) within the skin at that site. The particles, which comprise soft iron or other material having a characteristic high magnetic permeability, are preferably implanted using either a hypodermic needle (150) or a medical air injection device (160). A biocompatible material such as Teflon.TM. is applied as a coating (123) to the particles. To implant the particles, they are preferably first suspended in a liquid, forming a mixture that is readily delivered to the desired location.

Abstract: A method and apparatus for administering intracorporeal photopheresis to blood flowing in a patient's body to destroy an undesirable component in the blood, where the undesirable component has absorbed a photoreactive agent having a characteristic light absorption waveband. The apparatus includes an implantable housing that is adapted to be placed transcutaneously within a patient's body. An inlet and outlet for a fluid path through the housing are provided and are coupled to a patient's circulatory system so that they convey blood into and out of the housing. Light sources disposed within the housing(or externally disposed and coupled to the housing by optical fibers) emit light having a waveband substantially equal to the absorption waveband of the photoreactive agent. A portion of the fluid path within the housing is optically transparent so that blood is irradiated with light from the light source.