Implantable devices using rechargeable zero-volt technology lithium-ion batteries

• US 7,248,929 B2
• Filed: 04/18/2003
• Issued: 07/24/2007
• Est. Priority Date: 07/30/1999
• Status: Expired due to Term

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation), Quallion, LLC (EnerSys)
• Original Assignee: Quallion, LLC (EnerSys), Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Woods, Carla Mann, Tsukamoto, Hisashi, Chen, Joey, Meadows, Paul M
• Primary Examiner(s): Getzow; Scott M.
• Application Number:
  US10/419,000
• Publication Number:
  US 20030195581A1
• Time in Patent Office: 1,558 Days
• Field of Search: 607/33, 607/61, 607/34, 607/32, 607/60
• US Class Current: 607/61
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

An implantable medical device, such as an implantable pulse generator (IPG) used with a spinal cord stimulation (SCS) system, includes a rechargeable lithium-ion battery having an anode electrode with a substrate made substantially from titanium. Such battery construction allows the rechargeable battery to be discharged down to zero volts without damage to the battery. The implantable medical device includes battery charging and protection circuitry that controls the charging of the battery so as to assure its reliable and safe operation. A multi-rate charge algorithm is employed that minimizes charging time while ensuring the battery cell is safely charged. Fast charging occurs at safer lower battery voltages (e.g., battery voltage above about 2.5 V), and slower charging occurs when the battery nears full charge higher battery voltages (e.g., above about 4.0 V). When potentially less-than-safe very low voltages are encountered (e.g., less than 2.5 V), then very slow (trickle) charging occurs to bring the battery voltage back up to the safer voltage levels where more rapid charging can safely occur. The battery charging and protection circuitry also continuously monitors the battery voltage and current. If the battery operates outside of a predetermined range of voltage or current, the battery protection circuitry disconnects the battery from the particular fault, i.e. charging circuitry or load circuits.

Claims

1. An implantable device comprising:

electronic circuitry that performs a specified function;

an implantable rechargeable battery that provides operating power for the electronic circuitry; and

battery charging and protection circuitry that receives power from an external charger and controls the charging of the rechargeable battery to protect the rechargeable battery from overcharge and undercharge conditions;

wherein the implantable rechargeable battery comprises a lithium-ion or lithium-ion polymer battery having an anode electrode with a substrate made substantially from titanium whereby the rechargeable battery may discharge to zero volts without damage; and

wherein the battery charging and protection circuitry applies a charging current to said rechargeable battery as a function of a rechargeable battery voltage.

2. The implantable device of claim 1 wherein the battery charging and protection circuitry applies a trickle charge current I1 to the rechargeable battery when the battery voltage ranges from zero volts to a first voltage V1, applies a second charging current I2 to the rechargeable battery when the battery voltage ranges from the first voltage V1 to a second voltage V2, and applies a third charging current I3 to the rechargeable battery when the battery voltage ranges from the second voltage V2 to a fully-charged voltage V3.

3. The implantable device of claim 2 wherein the first voltage V1 comprises about 2.5 V, the second voltage V2 comprises about 4.0 V, and the fully-charged voltage V3 comprises about 4.1 V, and wherein the trickle charge current I1 is less than or equal to the third charging current I3, and wherein the third charging current I3 is less than the second charging current I2.

4. The implantable device of claim 1 wherein the substrate is made substantially from a titanium alloy.