Cochlear Baha BI300, Baha BIM400 Instructions Manual

Cochlear™ Baha® Attract System

Radiographer’s Instructions for MRI

The Cochlear™ Baha® Attract System is a magnetic bone conduction implant system. The system includes an
osseointegrated BI300 Implant and a BIM400 Implant magnet that are implanted beneath the skin. A Baha Sound
Processor and a Sound Processor (SP) Magnet are worn on the head (see Fig. 1).

These guidelines are intended for radiologists performing MRI scans on a patient with the Cochlear Baha Attract
System. Please read this information carefully. For more information, contact Cochlear.

MRI Safety Information

The sound processor and Sound Processor Magnet must
be removed before entering a room where an MRI scanner
is located.

Non-clinical testing has demonstrated that the
BIM400 Implant Magnet, in combination with
a BI300 Implant, is MR Conditional.

It can be scanned safely under the following conditions.
Scanning under other conditions may result in severe
patient injury or device malfunction.

• Static magnetic field of 1.5 Tesla only

• Maximum spatial gradient field of 26600 Gauss/cm

(266 T/m)

• Maximum switched gradient slew rate per axis
of 200 mT/m/ms

• Maximum switched gradient amplitude per axis
of 45 mT/m

• Maximum MR System reported whole body averaged
specific absorption rate (SAR) of 2.0 W/kg

(Normal Operating Mode)

BI300 Implant

BIM400 Implant Magnet

Sound Processor Magnet

Baha Sound Processor

Figure 1

Additional instructions essential to safe use
in the MR environment:

Under the scan conditions defined above, the
BIM400 Implant Magnet is expected to produce a
maximum temperature rise of 2.1 °C after 15 minutes
of continuous scanning.

In non-clinical testing, the BIM400 Implant
Magnet produced a temperature rise of less than

2.1 °C (extrapolated) at a maximum whole body

averaged specific absorption rate (SAR) of 2.0 W/kg
(extrapolated) assessed by calorimetry for 15 minutes
of MR scanning in a 1.5 Tesla Intera, Philips Medical
Systems (Software: 12.6.1.3, 2010-12-02) MR Scanner.

Figure 2

In non-clinical gradient-induced heating testing, the
BIM400 Implant Magnet produced a temperature rise
(extrapolated) of less than 4.5 °C at a time rate of
change of the theoretical maximum worst-case gradient
magnetic field dB/dt (extrapolated) of 200 T/s during 30
min. of continuous exposure in a test laboratory system
(Pulsed Magnetic Field Generator) equivalent with a
gradient system of a 1.5 Tesla MR system.

In non-clinical testing with the implant magnet in
place, the image artefact caused by the device extends
approximately 11.5 cm (4.5 in.) from the BIM400
Implant Magnet when imaged with a gradient echo
pulse sequence and a 1.5 Tesla MRI system (see Fig. 2)

NOTE: MR System manufacturers may claim that
scanning patients with implanted devices is generally
contraindicated. This is a general precautionary claim
due to the fact that MR System manufacturers are
unable to ensure safety for all types of implantable
devices. Cochlear has performed specific testing for
the above implants and established the necessary
SAR safety limits as outlined. Recently available MR
Systems are able to monitor SAR levels. The MR System
manufacturer should be able to provide advice on how
to maintain SAR levels with their system.

Not ever yone with hearing loss is a candidate fo r a Baha System. All surgical p rocedures
include a n element of risk, and it is impossible to guarantee success . For complete
information regarding the risks and benefits of a Baha p rocedure, please refer to the
Instructions for use for t he Baha implant available at ww w.Cochlear.com/US/Baha Indications

www.Cochlear.com/US

Cochlear Americas
13059 East Peakview Avenue
Centennial, CO 80111 USA
Telephone: [phone]
Support: 1 800 483 3123

©Cochl ear Limited 2015. All rights r eserved. Hear now. An d always and other t rademarks and regis tered
trade mark s are the proper ty of Cochlear Li mited or Cochlear B one Anchore d Solutions AB. T he names
of actua l companies and p roducts mentioned h erein may be the tr ademarks of th eir respecti ve owners.

BUN264 ISS2 APR15

Cochlear Canada Inc.
2500-120 Adelaide Street West
Toronto, ON M5H 1T1 Canada
Telephone: [phone]
Fax: [phone]