Transcript Safety Issues with Medtronic Long Range Telemetry Implants

Safety Issues with Medtronic
Long Range Telemetry Implants
Chris Fuller
6/23/06
Medtronic
• An innovative, forward-thinking, wonderful
company which has saved many lives.
• Employs some of the most brilliant and capable
engineers and scientists I know.
• Managed by individuals unfamiliar with highreliability RF product development and
manufacturing.
– Risks patient safety unnecessarily by evaluating their
long-range telemetry implants much the same way as
older, low-frequency implants.
• My Goal: Help Medtronic quietly understand
and correct serious RF design evaluation and
test issues before someone dies.
Why is RF Different?
Capacitor model for low
frequency circuits
Minimum Capacitor model for
radio frequency circuits
• Capacitor values and their parasitics change as they age and with
varying voltages, temperatures, humidity, and vibration levels.
• Slight changes in capacitor values and parasitics can cause great
changes in circuit performance.
• Other types of component types are similarly affected (e.g. transistors,
inductors, resistors, etc.)
Design Verification Highlights
• Commercial cell phone basestation manufacturer:
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Extensive evaluation of each sub-circuit.
Accelerated Life Testing (ALT) for several weeks.
Use of parts “burned in” BEFORE production.
Detailed production testing of each radio.
• Military and NASA: In family with cell phones
• Medtronic:
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Did not evaluate each sub-circuit as extensively.
Abbreviated, lower stress and unproven ALT.
Less thorough burn in process.
Official production testing less than for cell phone
basestations.
RF Stability
• RF instability: loss of control of an RF circuit.
Can lead to non-functionality, high current mode
and/or circuit failure.
– Most extensively studied RF parameter for a cell
phone radio circuit.
– Some indications of instability for Concerto found
during DVT, but not reported.
– Medtronic stability verification for Concerto is
substandard and incomplete.
• Concerto has unacceptably high unknown risk
for instabilities
Medtronic Regulatory Issues
• Medtronic has a history of non-compliance with
regulatory rules.
– In violation of FCC rules for all CRM implants and programmers
in-service prior to FCC R&O FCC-03-149A1 on June 25, 2003.
– Medtronic V.P. for Regulatory affairs reported that Medtronic
would rather pay a fine than comply with their regulatory
requirements.
– Medtronic submitted a fraudulent SAR report to the FCC for
Concerto listing me as an author though I asked that my name
be removed from the report.
• Getting away with breaking the rules has led Medtronic
to break the rules in design and production for the new
long-range telemetry implants.
• Allowing Medtronic to bend or break the rules has led to
behavior that is not doing Medtronic or their patients any
favors.
My Role at Medtronic
• I was the focal point for developing the initial
implant and programmer production test plans.
– I acquiesced to management pressure to produce a
substandard plan which reduced testing over time.
• I primarily defined and performed much of the
engineering testing (EVT/DVT) on the D1C
which was used to minimize Concerto testing.
– I signed off on test plans that I knew to be inadequate.
– I performed some of the Concerto testing.
Disavowal
Until Medtronic provides evidence that they have
evaluated the safety of the Concerto implant to a
commercial high-reliability level, I disavow all work I have
performed for Medtronic including all production related
work, failure mode and effect analyses, worst case
analyses, engineering verification tests, design
verification tests (DVT), design reviews and all regulatory
work, including all regulatory submittals.
Sincerely,
Christopher Fuller
8901 River Ridge Circle
Bloomington, MN 55425
June 22, 2006