US20070142696A1 - Implantable medical devices - Google Patents

Abstract

An active implantable medical device comprising a therapeutic device, a controller and at least one rechargeable battery, wherein a single hermetically sealed housing encapsulates a therapeutic device, controller and rechargeable battery. A hermetically sealed housing additionally encapsulates a wireless interface and a commutator.

Description

FIELD OF THE INVENTION
• The present invention relates to improvements to active implantable medical devices. An active implantable medical device may generally include a power source (e.g. a battery), control means (e.g. an electronic circuit) and a means providing the therapeutic action (e.g. an electrode or mechanical pump).
BACKGROUND OF THE INVENTION
• An active implantable medical device in which the means providing the therapeutic action is an electrode system (e.g.: a pacemaker or implantable defibrillator) can often be constructed in such a way that all the components with the exception of the means providing the therapeutic action are enclosed inside a single package, which is usually hermetically sealed. However, more complicated active implantable medical devices, or those in which the therapeutic action is mechanical in nature (such as the AbioCor™ fully implantable artificial heart by Abiomed, Danvers, Mass., USA), have in the past, been implanted in multiple components having separate hermetically sealed housings for each implanted component. Typically, the implanted components included a controller, at least one battery, and a therapeutic device. For purposes of this specification, a therapeutic device means a medical device that: actively treats a medical condition of a patient, and requires a power source to operate. Examples of therapeutic devices include, but are not limited to: pacemakers, left ventricle assist devices, cochlear implants, implanted hearing aids, and neural simulators.
• As each implanted component generally includes a separate hermetic sealed housing, the implanted medical devices are often bulky and cumbersome. The increased surface area of multiple hermetical sealed housings may lead to increased risk of infection for patients implanted with such a device. Additionally, multiple implanted components add to the manufacturing cost, and may compromise the system reliability.
• U.S. Pat. No. 6,269,266—Leysieffer and U.S. Pat. No. 6,736,770—Leysieffer et al describe similar implantable medical devices wherein a therapeutic device and at least one battery are packaged together in hermetically sealed housing and implanted within the body of a patient. However, the devices described within these disclosures are limited to including a therapeutic device with a battery and do not include a controller or device controller within the said hermetically sealed housing. Thereby the devices may require a separate implanted controller with additional housing or the controller may be required to be carried externally relative to the patient.
• The present invention aims to or at least address or ameliorate one or more of the disadvantages associated with the above mentioned prior art.
BRIEF DESCRIPTION OF THE INVENTION
• In accordance with a first aspect the present invention consists of an active implantable medical device comprising a therapeutic device, a controller and at least one rechargeable battery, wherein a single hermetically sealed housing encapsulates said therapeutic device, said controller and said rechargeable battery.
• Preferably, said hermetically sealed housing additionally encapsulates a wireless interface.
• Preferably, said hermetically sealed housing additionally encapsulates a commutator.
• Preferably, said therapeutic device is a rotary blood pump.
• Preferably, a percutaneous lead is connected thereto.
• Preferably, a TETS is connected thereto.
• In accordance with a second aspect the present invention consists of an active implantable medical device comprising a therapeutic device, a controller, an electrically conductive coil and at least one rechargeable battery, wherein a first hermetically sealed housing encapsulates said controller, said electrically conductive coil and said rechargeable battery.
• Preferably, a second hermetically sealed housing encapsulates said therapeutic device.
• In accordance with a third aspect the present invention consists of an active implantable medical device comprising a therapeutic device, a controller, an electrically conductive coil and at least one rechargeable battery, wherein a first hermetically sealed housing encapsulates said electrically conductive coil and said rechargeable battery.
• In accordance with a fourth aspect the present inventions consists of a controller for a therapeutic device disposed within an active implantable medical device, said controller and said therapeutic device adapted to be powered by at least one rechargeable battery, wherein said controller and said therapeutic device and said rechargeable battery are all housed within a single hermetically sealed housing.
BRIEF DESCRIPTION OF THE DRAWINGS
• Embodiments of the present invention will now be described with reference to the accompanying drawings wherein:
• FIG. 1 depicts a front cross-sectional view of a first embodiment of the preferred invention;
• FIG. 2 depicts a schematic view of a second embodiment of the preferred invention;
• FIG. 3 depicts a schematic view of a third embodiment of the preferred invention; and
• FIG. 4 depicts a schematic view of a fourth embodiment of the preferred invention.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
• In a first preferred embodiment of the present invention, as depicted inFIG. 1, an active implantablemedical device16 is shown. In this embodiment, the active implantablemedical device16 includesrotary blood pump5 comprising: a DC brushless motor comprisingstator coils7 mounted on opposed sides of animpeller11. Theimpeller11 includes permanent encapsulated magnets (not shown) which interact and cooperate with thestator coils7, when sequentially energised. Preferably, the stator coils are energised in a manner to facilitate the imparting of a magnetic torque force on theimpeller11 to encourage theimpeller11 to rotate within a cavity of ahousing1. Theimpeller11 preferably includes fourblades9 connected bystruts10. Theblades9 preferably include a hydrodynamic bearing surface on the upper and lower surfaces of theblades9, which provide a means for hydrodynamic suspension when theimpeller11 is rotating at a sufficient speed.
• Preferably, blood is urged from aninlet17 to anoutlet8 by the centrifugal motion imparted by the rotating motion of theimpeller11. Thepreferred blood path6 through theblood pump5 is shown diagrammatically inFIG. 1.
• A similar blood pump to theblood pump5 of the first preferred embodiment is described in U.S. Pat. No. 6,227,797—Watterson et al and the description of that disclosure is herein included within this current embodiment.
• In this first preferred embodiment, the active implantablemedical device16 has a hermetically sealedhousing1 that encapsulates: a therapeutic device, namely the mechanical components of the blood pump5 (i.e. theimpeller11,stators7,inlet17 and outlet8); arechargeable battery3, and acontroller12 or pump controller. All of these implanted components are integrated and encapsulated into the one hermetically sealedhousing1.
• Preferably, the therapeutic device portions are mechanically operable. An example of a mechanical operable therapeutic device is the pumping motion of the impeller within therotary blood pump5.
• The hermetically sealedhousing1 preferably encapsulates the therapeutic device portions, therechargeable battery3, and thecontroller12. This encapsulation allows all of the implanted components of theblood pump5 to be positioned and mounted within thesingle housing1. This significantly reduces the surface area required by the entire active implantablemedical device16 by concentrating the volume of the active implantablemedical device16 in one area. Additionally, the implantation of the active implantablemedical device16 with a patient may be significantly easier and quicker for the clinician as there are fewer objects being implanted. A further advantage may be that having only asingle housing1 reduces the risk of infection, as the risk of infection is generally proportional to the surface area of the active implantablemedical device16.
• In the first preferred embodiment of the present invention, the hermetically sealedhousing1 is moulded around the internal components of the active implantablemedical device16. However, thehousing1 may alternatively encapsulate the implanted components by encasing the internal components in an alloy shroud, preferably titanium alloy, which is hermetically sealed by welding.
• Preferably, thecontroller12 receives instructions, data and power via apercutaneous lead2 which exits the patient and electrically connects to an external power source (not shown inFIG. 1) or external controller (not shown inFIG. 1). Thecontroller12 also includes a commutator circuit and sequentially energises thestators7 to produce the rotational torque drive force on theimpeller11 in accordance with a speed signal derived by thecontroller12. Thecontroller12 also is electrically connected to therechargeable battery3. Thecontroller12 uses therechargeable battery3 as a means for storing an electrical charge so that if thepercutaneous lead2 is disconnected the pump may continue to operate. Preferably, therechargeable battery3 is charged when thepercutaneous lead2 is connected to an external power source.
• Preferably, thecontroller12 may operate in a manner similar to the control method described in U.S. Pat. No. 6,866,625—Ayre et al. and the description of this disclosure is herein included within the present specification.
• Preferably, therechargeable battery3 may include at least one rechargeable battery and this rechargeable battery may be of any type. Preferably, the type of battery included within the active implantablemedical device16 is a Lithium Ion rechargeable battery supplying a 12V power supply.
• A second preferred embodiment, similar to first preferred embodiment, is depicted inFIG. 2. In the second preferred embodiment, therotary blood pump5 is driven by acommutator4 which receives a drive signal from thepump controller12.
• Preferably in the second embodiment, thepump controller12 may be able to selectively switch between the two power sources depending on the circumstances and the power requirements of the active implantablemedical device16.
• Additionally in the second preferred embodiment, thecommutator circuit4 is shown as a separate component within the hermetically sealedhousing1. Thecommutator circuit4 in this embodiment is also maintained and controlled by thepump controller12.
• FIG. 2 also depicts diagrammatically the manner by which thepercutaneous lead2 exits theskin layer17 of the patient and connects to anexternal power supply13. Preferably, the active implantablemedical device16 is also electrically connected to the external controller and/or data manager14 (herein referred to as ECDM14). TheECDM14 may serve as a backup controller in situations where thepump controller12 fails. Additionally, theECDM14 may manage and store relevant patient or active implantablemedical device16 data. The data may be received from thepump controller12 through thepercutaneous lead2. Preferably, theECDM14 maybe a personal computer or laptop computer running software designed specifically for the purpose of an active implantable medical device control and/or an active implantable medical device data management.
• Thepump controller12 may also be electrically connected to awireless interface15 as depicted inFIG. 2. Thewireless interface15 is also preferably encapsulated within the hermetically sealedhousing1.
• Preferably, thewireless interface15 is able to transmit and receive data and instructions without the use of thepercutaneous lead2. Thereby thepump controller12 may be able to wirelessly transmit and receive data and instructions to and from theECDM14. Preferably, any wireless interface protocol may be used including, but not limited to: Bluetooth™; Zigbee™; Wi-Fi™; 802.11a, b, & g.
• Theexternal power supply13 maybe a mains power connection which is rectified to provide the required power for the active implantablemedical device16 and/or it may also be rechargeable or long life batteries.
• Alternatively, thepercutaneous lead2 may be replaced with the transcutaneous energy transfer system (herein referred to as ‘TETS’). TETS generally comprises a two electrical conductive coils positioned either side of theskin layer17 of a patient. When a first coil energises an electrical current is induced the second coil and whereby allowing the transmission of energy and data via the TETS. The main advantage of TETS is that the patient is not required to have a permanent exit wound from which thepercutaneous lead2 extends. Additionally, one of the said coils may be included within thehousing1 and would further minimise the amount of components to be implanted within a patient.
• In a third embodiment of the present invention is depicted inFIG. 3, wherein a therapeutic device is hermetically sealed in ahousing1 with acontroller12,commutator4 andwireless interface15. The preferred therapeutic device for use with this second embodiment is arotary blood pump5. A battery is housed within a second hermetically sealedhousing20 along with a first electricalconductive coil21 of a TETS. Thefirst coil21 implanted beneath theskin layer17 interacts with a secondelectrically coil23 above theskin layer17. The first andsecond coils21 &23 interact by one coil inducing an electrical current in the opposed coil and thereby allowing the transmission and receipt of electrical energy and also coded data transmission across thetransmission link22 which formed between the first andsecond coils21 and23.
• In a fourth embodiment of the present invention is depicted inFIG. 4, wherein acontroller12 and abattery3 and afirst coil21 of the TETS are hermetically sealed within asecond housing20. A therapeutic device is hermetically sealed within afirst housing1.
• The above descriptions detail only some of the embodiments of the present invention. Modifications may be obvious to those skilled in the art and may be made without departing from the scope and spirit of the present invention.

Claims (10)

1. An active implantable medical device comprising a therapeutic device, a controller and at least one rechargeable battery, wherein a single hermetically sealed housing encapsulates said therapeutic device, said controller and said rechargeable battery.

2. The active implantable medical device as claimed inclaim 1, wherein said hermetically sealed housing additionally encapsulates a wireless interface.

3. The active implantable medical device as claimed inclaim 1, wherein said hermetically sealed housing additionally encapsulates a commutator.

4. The active implantable medical device as claimed inclaim 1, wherein said therapeutic device is a rotary blood pump.

5. The active implantable medical device as claimed inclaim 1, wherein a percutaneous lead is connected thereto.

6. The active implantable medical device as claimed inclaim 1, wherein a TETS is connected thereto.

7. An active implantable medical device comprising a therapeutic device, a controller, an electrically conductive coil and at least one rechargeable battery, wherein a first hermetically sealed housing encapsulates said controller, said electrically conductive coil and said rechargeable battery.

8. An active implantable medical device as claimed inclaim 7, wherein a second hermetically sealed housing encapsulates said therapeutic device.

9. An active implantable medical device comprising a therapeutic device, a controller, an electrically conductive coil and at least one rechargeable battery, wherein a first hermetically sealed housing encapsulates said electrically conductive coil and said rechargeable battery.

10. A controller for a therapeutic device disposed within an active implantable medical device, said controller and said therapeutic device adapted to be powered by at least one rechargeable battery, wherein said controller and said therapeutic device and said rechargeable battery are all housed within a single hermetically sealed housing.

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