Symmetric magnet arrangement for medical implants

• US 9,615,181 B2
• Filed: 07/09/2013
• Issued: 04/04/2017
• Est. Priority Date: 07/09/2012
• Status: Active Grant

• Current Assignee: MED-EL Elektromedizinische Gerate GmbH (MED-EL Corporation)
• Original Assignee: MED-EL Elektromedizinische Gerate GmbH (MED-EL Corporation)
• Inventors: Nagl, Markus, Lechleitner, Thomas, Lampacher, Peter, Amrhein, Wolfgang, Weidenholzer, Gunther
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): Reddy, Sunita
• Application Number:
  US13/937,442
• Publication Number:
  US 20140012071A1
• Time in Patent Office: 1,365 Days
• Field of Search: 600 25, 607136, 607137, 623 10, 381 60
• CPC Class Codes: A61N 1/36036 of the outer, middle or inner ear
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: H04R 11/02 Loudspeakers
• CPC Class Codes: H04R 25/606 acting directly on the eardrum, the ossicles or the skull, e.g. mastoid, tooth, maxillary or mandibular bone, or mechanically stimulating the cochlea, e.g. at the oval window

Abstract

An arrangement is described for a hearing implant system. An implantable housing has an outer surface configured to lie under and parallel to the skin of the implanted patient. An implant magnet arrangement is located within the implantable housing and has multiple local magnetic sections with different independent local magnetic fields that are combined together to form a net magnetic field with at least two-fold symmetry and zero net magnetic dipole moment, wherein the magnetic fields are oriented parallel to the outer surface of the implant housing.

Claims

1. An implantable bone conduction transducer arrangement for a medical implant system for a patient user, the arrangement comprising:

an implantable housing configured to be fixedly attached to skull bone of the patient user with an outer surface immediately under and parallel to overlying skin of the patient user; and

a disk shaped transducer magnet located within the implantable housing and configured to magnetically interact with an external magnetic drive component fixedly attached on the overlying skin of the patient user to develop a mechanical bone conduction stimulation signal to the skull bone via the implantable housing, wherein the transducer magnet is characterized by a radial center surrounded by an outer circumference, and wherein the transducer magnet is characterized by;

i. an inner local magnetic field located within the radial center and having a first magnetic pole, and

ii. an outer local magnetic field distributed about the outer circumference and having a second magnetic pole opposite to the first magnetic pole, and wherein the inner local magnetic field and the outer local magnetic field combine together to form a net magnetic field, the net magnetic field having radial symmetry and zero net magnetic dipole moment, wherein within the arrangement itself the local magnetic fields and the net magnetic field are oriented parallel to the outer surface of the implantable housing and parallel to the overlying skin of the patient user.