Chemistry: electrical current producing apparatus – product – and – Current producing cell – elements – subcombinations and... – Cell enclosure structure – e.g. – housing – casing – container,...
Reexamination Certificate
1998-02-23
2001-07-24
Brouillette, Gabrielle (Department: 1745)
Chemistry: electrical current producing apparatus, product, and
Current producing cell, elements, subcombinations and...
Cell enclosure structure, e.g., housing, casing, container,...
C429S176000, C429S164000, C429S161000
Reexamination Certificate
active
06265100
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to hearing aids. More particularly, it may relate to a hearing aid system that may comprise a charger and a rechargeable hearing aid; wherein the hearing aid may be optically or inductively recharged.
The rechargeable hearing aid may utilize any conventional rechargeable battery. However, preferably, the rechargeable hearing aid may utilize a high energy rechargeable battery that may comprise at least one high energy rechargeable cell, such as: (a) a NiMH (nickel metal-hydride) rechargeable cell; or (b) a lithium based rechargeable cell.
As used herein, the generic term “lithium based rechargeable cell (or battery)” may be defined as an aqueous or non-aqueous cell or battery in which at least one of the Faradaic half cell reactions includes lithium ions as reactants and/or products. In this context, non-aqueous means that the electrolyte does not contain a significant amount of water. In addition, as used herein, the “lithium based rechargeable cell (or battery)” may be classified as either a lithium rechargeable cell (or battery) (i.e., one having a lithium metal or a lithium alloy anode); or as a lithium-ion rechargeable cell (or battery) (i.e., one having no significant amounts of metallic lithium in its anode). Further, the lithium based rechargeable cell (or battery) may have a solid electrolyte in the form of a polymer or gel; and the lithium-ion rechargeable cell (or battery) may have either a liquid electrolyte, or a solid electrolyte in the form of a polymer or gel. In this context, the polymer electrolyte may be either a true polymer, or the polymer may be plasticized or gelled with the addition of at least one low molecular weight organic liquid.
The materials and the chemical reactions in the high energy NiMH and lithium based rechargeable cells and batteries described herein are all conventional.
However, each improved, high energy, rechargeable battery that is described herein may have a novel cell stack design for maximizing the surface area of its cathode and anode, to reduce the battery's impedance, while simultaneously minimizing the battery's overall size or volume. The rechargeable hearing aid may be provided with a DC to DC voltage regulating circuit to help match the high energy rechargeable battery's output voltage the input voltage required by the hearing aid's audio amplifier and related circuitry, and to help provide high current during transients due to loud sounds.
SUMMARY OF THE INVENTION
In the United States alone, about five to eight million people use hearing aids. The vast majority of those hearing aids are powered by disposable batteries. Since disposable hearing aid batteries may have, on the average, a life of from about one to two weeks, the typical hearing aid user may use about 30 disposable batteries per year. As a result, about 150 million to 240 million disposable hearing aid batteries may be used each year in the United States alone.
However, the use of disposable hearing aid batteries may present many major problems. One problem may be that hearing aids using disposable batteries may have exposed battery contacts in their battery compartments, in order to make electrical contact with the disposable batteries. But if those exposed battery contacts become bent or dirty; or if they become corroded, such as due to leakage from the disposable batteries, the hearing aid may not function properly, or may not function at all, until costly repairs are made.
Another problem with using disposable hearing aid batteries may be that during replacement of the millions of disposable batteries used each year, a great number of the hearing aids involved may suffer damage to the hearing aid's battery compartment door, battery contacts, or other components; or the hearing aid may even be completely ruined, such as if it is accidentally dropped on a hard surface. Besides being costly, such damage may also cause the user great inconvenience or hardship, by depriving the user of the use of the hearing aid until it is repaired or replaced.
Disposable hearing aid batteries may also be a problem in that they may cause substantial difficulty and stress to the elderly, who constitute the vast majority of the users of hearing aids, and who may lack the manual dexterity, visual acuity, or skill needed to be able to easily replace the hearing aid batteries on their own.
A further problem with disposable hearing aid batteries is that they may cause adverse environmental consequences unless they are properly disposed of.
Disposable hearing aid batteries may also be a problem in that they are relatively costly. They are not only relatively costly to purchase, but they may also be relatively costly to properly dispose of when expended, in order to avoid adverse environmental consequences.
A further problem presented by disposable hearing aid batteries may be that the millions of disposable batteries that are discarded each year may present millions of chances each year for a small child to harm himself, or herself, by accidentally swallowing the battery, or by inserting it into his or her nose or ear.
Conventional rechargeable hearing aids using rechargeable NiCd (nickel cadmium) batteries have not been a commercial success, despite the relatively low cost of such batteries and their ability to deliver the high current pulses that may be required by hearing aids.
The lack of commercial success may be due to the fact that there may be many problems with conventional hearing aids using NiCd rechargeable batteries. One problem may be that such rechargeable hearing aids may have external electrical contacts for receiving electrical energy from an external power supply to recharge the NiCd battery. Such external electrical contacts may be prone to poor performance, or even failure, due to becoming dirty or corroded since the hearing aid may be exposed to harsh environmental factors, such as the user's perspiration.
A further problem with using rechargeable NiCd batteries in hearing aids may be that although rechargeable NiCd hearing aid batteries have been made small enough for BTE (behind the ear) and for some ITE (in the ear) hearing aids, it has not been possible to produce commercially successful, highly miniaturized rechargeable NiCd batteries suitable for use in the highly popular ITC (in the canal) and CIC (completely in the canal) hearing aids. This is because a conventional NiCd hearing aid battery that was small enough to fit in an ITC or CIC hearing aid would likely not store enough energy to provide the hearing aid with a sufficient number of hours of use between charges.
Using rechargeable NiCd hearing aid batteries may also be a problem in that they may have a relatively short cycle life (i.e., the number of times the battery can go through its discharge/recharge cycle). For example, although the cycle life of a NiCd hearing aid battery may vary widely depending on how it is used and recharged, it may have a useful life of only a few hundred cycles, or less, before its energy storage capacity becomes too small to be satisfactory. As a result, rechargeable NiCd hearing aid batteries may need to be replaced more frequently than may be desirable, since an ideal rechargeable hearing aid battery would have a cycle life sufficient for it to last the normal expected life of the hearing aid with which it is used.
In addition, rechargeable NiCd hearing aid batteries may have the further problem of suffering from a loss in their energy storage capacity after they have been in use for a while, due to what is known as their discharge “memory”. That is, if a rechargeable NiCd hearing aid battery is only partially discharged before being recharged, the result may be that it is only possible to discharge the battery to its earlier partial discharge point, rather than it being possible to discharge the battery to the full discharge capacity it had when it was new.
Another problem with rechargeable NiCd hearing aid batteries may be that they have a relatively low energy capacity per unit
Owens Boone B.
Passerini Stefano
Saaski Elric W.
Alejandro R.
Brouillette Gabrielle
Moravan Gregory W.
Research International, Inc.
LandOfFree
Rechargeable battery does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rechargeable battery, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rechargeable battery will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2505896