Lithium Batteries for Implantable Biomedical Devices Chemistry and Applications

1
Lithium Batteries for Implantable Biomedical
Devices Chemistry and Applications
Presented at the Indiana University Department of
Chemistry, April 14, 2009

• Curtis F. Holmes, Ph.D.
• Greatbatch, Incorporated

2
Greatbatch, Incorporated

The company was founded in 1970 by Mr. Wilson
Greatbatch, an electrical engineer and the
co-inventor of the cardiac pacemaker, Mr.
Greatbatch believed in 1970 that the remaining
problem to be solved for the pacemaker was the
battery. He licensed the lithium/iodine
technology, hired experienced battery
scientists, and marketed the lithium/iodine
battery to the pacemaker industry. By 1977,
virtually all pacemakers were powered by lithium
batteries. The company has grown through
acquisition and market growth. Sales in 2006
were gt 270 million. There are 2200 employees at
present.
3
Critical Component Supplier
Batteries
Feedthroughs
Engineered Components
Capacitors
EMI Filters
Value Add Assembly
Commercial Batteries
Coated Electrodes
Enclosures
4
Greatbatch Facilities Products
Capacitors
Batteries
Engineered Components
Orthopedic and Surgical Devices
Enclosures
Commercial Batteries
EMI Filters
Coated Electrodes
Subassemblies
Feedthroughs
5
Interaction of electrical stimulation and body
tissue

• It has been known since the 1700s that
  interesting phenomena occur when electrical
  signals are applied to body tissues. These
  phenomena have led to the development of devices
  that treat diseases by stimulation of muscle or
  nerve tissues.

• In 1780, Luigi Galvani, working at the
  University of Bologna, found that the electric
  current delivered by a Leyden jar or a rotating
  static electricity generator would cause the
  contraction of the muscles in the leg of a frog
  and many other animals, either by applying the
  charge to the muscle or to the nerve.

6
Implantable Devices

• Cardiac Rhythm Management
• Neurostimulation
• Drug Delivery
• Hearing Improvement
• Left Ventricular Assist Devices/Totally
  Artificial Heart

7
Cardiac Rhythm Management

• Bradycardia
• 1960s - today
• Tachycardia/Ventricular Fibrillation
• 1980s - today
• Congestive Heart Failure
• 2000s

8
What does a pacemaker cure?

• We all have a pacemaker! - The heart's "natural"
  pacemaker is called the sinoatrial (SA) node or
  sinus node. It's a small mass of specialized
  cells in the top of the heart's right atrium
  (upper chamber). It generates the electrical
  impulses that cause the heart to beat.
• The natural pacemaker may be defective
  (Stokes-Adams syndrome), causing the heartbeat to
  be too fast, too slow or irregular. The heart's
  electrical pathways also may be blocked. A
  patient with a heart beat of less than 60 BPM is
  said to have bradycardia. A heart rhythm that
  is too slow can cause fatigue, dizziness,
  lightheadedness, fainting or near-fainting
  spells.
• Patients suffering from bradycardia need an
  artificial pacemaker to supply the same
  electrical impulses that the sinoatrial node
  provides in healthy people.
• Over 900,000 pacemakers per year are implanted
  worldwide.
• The first successful cardiac pacemaker, invented
  by Mr. Wilson Greatbatch and Dr. William
  Chardack, was assembled in Clarence, NY and
  implanted into a patient at the Veterans
  Hospital in Buffalo in 1960.

9
External Pacemaker Montefiore Hospital in 1958
The gentleman in this photograph, taken at the
Montefiore Hospital in New York in 1958, is Mr.
Pincus Shapiro. He is pushing a Zoll external
pacemaker. The device was connected to his heart
via a catheter that was implanted from Mr.
Shapiros left arm into his right ventricle. The
second electrode was embedded under the skin in
his chest. The boundaries of Mr. Shapiros world
were determined by the length of the extension
cord connecting his pacemaker to the wall socket.
10
Implantable Pacemaker History

• In 1958, Wilson Greatbatch designed and
  built an implantable pacemaker in his modest
  laboratory in Clarence, NY. He spent two years
  experimenting with dogs. In 1960, the first
  successful pacemaker in the United States was
  made by him and implanted in a patient at the
  Veterans Hospital in Buffalo. The surgeon was
  Dr. William Chardack, who had worked with
  Greatbatch to develop the device. Greatbatch
  licensed his invention to a company called
  Medtronic, now the worlds largest producer of
  implantable devices, and that was the start of
  the implantable device industry. Today many
  hundreds of thousands of pacemakers are implanted
  each year.

Dr. Chardack, Dr. Gage, and Mr. Greatbatch - 1960
Wilson Greatbatch today
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Implantable Pacemaker History

• Implantable pacemakers were also developed
  (independently) by Dr. Ake Senning and Dr. Rune
  Elmqvist in Sweden and Dr. Orestes Fiandra in
  Uruguay. Sennings invention led to the
  founding of a company called Siemens Elema, now
  part of St. Jude Medical, in Stockholm. Fiandra
  founded a company called Centro de Construccion
  de Cardioestimuladores del Uruguay (CCC) in
  Montevideo, Uruguay. Both companies are
  Greatbatch customers today.

• The first person to receive an internal pacemaker
  was Arne H. W. Larsson (1915 2001), an engineer
  in Sweden. Larsson lived until the age of 86,
  used a total of 26 pacemakers, and was a
  well-known personality in the world of cardiac
  pacing he often attended international
  pacemaker conferences as a guest of Siemens
  Elema. His device worked for only 3 days, and he
  remained unpaced until receiving a
  properly-operating device 3 years later.

Arne Larsson
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Early 1960s - Ten Batteries, two transistors!
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Modern Pacemaker One battery, thousands of
transistors
14
The Implantable Cardioverter/Defibrillator
What does it cure?

• Ventricular tachycardia - a potentially lethal
  disruption of normal heartbeat that may cause the
  heart to become unable to pump adequate blood
  through the body. The heart rate may be 160 to
  240 (normal is 60 to 100 beats per minute).
  Uncontrolled, it can lead to ventricular
  fibrillation.
• Ventricular fibrillation - a condition in which
  the heart's electrical activity becomes totally
  disordered. When this happens, the heart's lower
  (pumping) chambers contract in a rapid,
  unsynchronized way. (The ventricles "flutter"
  rather than beat.) The heart pumps little or no
  blood. The outcome of this condition, absent
  appropriate therapy, is both obvious and grim.

15
History of the ICD

• The ICD was invented by Dr. Michel Mirowski (1924
  - 1990) at the Johns Hopkins University in 1979.
• A dear friend and colleague of Dr. Mirowski had
  died of VF, and Mirowski believed that the
  disease could be treated by implanting a
  battery-powered device that detected VF and
  shocked the heart back into normal sinus rhythm.
  With Dr. Martin Mower and Dr. Stephen Heilman,
  Mirowski developed the first ICD, and it was
  produced by a company called Intec Systems (which
  was later acquired by Guidant).

- His idea was met with skepticism, criticism
(an English physician claimed it was unethical)
and, at the 1979 International Pacemaker
Conference in Montreal, with ridicule (When he
showed a movie of a dog that had been implanted
with a defibrillator and was revived from an
induced VF, someone asked him how long it had
taken him to train the dog to do that trick).
- But of course he was right Hundreds of
thousands are implanted today.
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ICD - 1989
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ICD 1998 Transvenous lead
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ICD 2007
The Ovatio ICD is produced by Sorin Group (ELA
Medical). With a volume of 29 cm3, it is the
smallest ICD currently on the market. It has
been approved for sale in the U. S. and in
Europe. The small size and rounded,
pacemaker-like shape of the device can be
attributed to the Greatbatch capacitor and
battery technology. Greatbatch also supplies
filtered feedthroughs and cases for the device.
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Congestive Heart Failure (CHF)

• CHF is a condition in which the heart's function
  as a pump is inadequate to meet the body's needs.
  It can be treated by a technique called
  biventricular pacing.
• It involves pacing in both ventricles - known as
  resynchronization.
• Historical note the first clinical trials of
  biventricular pacing were done using two
  pacemakers, since no one had developed a
  pacemaker capable of pacing both ventricles!
• Most devices also have ICD capability.
• Studies have demonstrated that this is a
  promising new approach to the treatment of CHF

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Neurostimulation What does it treat?

• Pain
• Incontinence
• Parkinsons Disease
• Epilepsy
• Spasticity
• Obesity
• Depression (in clinical trials)

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ANS Neurostimulator Devices
Primary Power Source Secondary Power
Source
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Cyberonics Vagus Nerve Stimulator
This device treats epilepsy through vagus nerve
stimulation and is much more effective than drug
therapy.
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Implantable Drug Delivery What does it provide?

• Chemotherapy
• Pain Relief
• Treatment of Diabetes
• Treatment of Cerebral Palsy
• Treatment of Multiple Sclerosis

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Implantable Drug Delivery Device
25
Implantable Hearing Devices

• This technology treats Serious Hearing Loss with
  a totally-implantable device

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The Envoy system fits in the skull, and leads
connect to transducer in middle ear.Greatbatch
supplies batteries, feedthroughs, and cases for
this device.
The Envoy Implantable hearing device

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Otologics Hearing Device
The Otologics Implantable Hearing Device
Tiny Greatbatch feedthroughs are used in the
Otologics device
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Left Ventricular Assist Device
The left ventricle is the large, muscular chamber
of the heart that pumps blood out to the body. A
left ventricular assist device (LVAD) is a
battery-operated, mechanical pump-type device
that is surgically implanted. It helps maintain
the pumping ability of a heart that can't
effectively work on its own. A typical LVAD has a
tube that pulls blood from the left ventricle
into a pump. The pump then sends blood into the
aorta (the large blood vessel leaving the left
ventricle). This effectively helps the weakened
ventricle.
29
Medical Device Usage

• Over five million people have been implanted with
  battery-powered devices.
• Devices treat heart problems, pain, epilepsy,
  chronic illnesses, hearing loss.
• Significant improvements in battery performance,
  electronic circuitry, and electrodes have
  permitted newer, smaller devices that perform a
  wide variety of functions.

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What is a battery (electrochemical cell)?

• Battery means a device consisting of one
  or more electrically connected electrochemical
  cells which is designed to receive, store, and
  deliver electric energy. An electrochemical cell
  is a self-contained system consisting of an
  anode, cathode, and an electrolyte, plus such
  connections (electrical and mechanical) as may be
  needed to allow the cell to deliver or receive
  electrical energy.
• -
  Federal Government Definition

31
Basic Cell
32
The Baghdad Battery
A 2,200-year-old clay jar found near Baghdad,
Iraq in 1936, has been described as the oldest
known electric battery in existence. The clay jar
and others like it have been attributed to the
Parthian Empire an ancient Asian culture that
ruled most of the Middle East from 247 B.C. to
A.D. 228. It is thought that the battery was
used to electroplate jewelry objects with gold
The nondescript earthen jar is only 5½ inches
high by 3 inches across. The opening was sealed
with an asphalt plug, which held in place a
copper sheet, rolled into a tube. This tube was
capped at the bottom with a copper disc held in
place by more asphalt. A narrow iron rod was
stuck through the upper asphalt plug and hung
down into the center of the copper tube not
touching any part of it.
33
The Voltaic pile

• In 1799, Alessandro Volta (1745 1827) arranged
  a vertical pile of metal discs (zinc with copper
  or silver) and separated them from each other
  with paperboard discs that had been soaked in
  saline solution. This stack became known as the
  voltaic pile and was the progenitor for modern
  batteries. The French word for battery is la
  pile.

34
Cell Chemistry and Thermodynamics

• Cell Voltage
• Cathode materials and anode materials have
  different electrochemical potentials, determined
  by thermodynamics
• The cell open circuit voltage (OCV) represents
  the difference of cathode and anode
  electrochemical potentials. The OCV of the
  battery is determined by the Gibbs Free Energy of
  the battery reaction, according the following
  equation
• ?G -nF Eº ?H - T ? S
• where ?G is the Gibbs Free Energy, n is the
  number of moles transferred in the cell reaction,
  F is the Faraday Constant (96,500 coul/mole),
  and Eº is the OCV.
• ?S (nF) ? Eº
• ? T

35
Cell Chemistry and Thermodynamics

• Important Battery Properties
• Capacity (Ampere hours) ?0t Idt
• Energy (Watt hours) ?0t E.Idt
• Power (Watts) E.I
• where I is current, E is voltage, and
  t is time.

36
Types of Lithium Implantable Medical Batteries

• Lithium/Iodine
• Lithium/CFx
• Lithium/Silver Vanadium Oxide (SVO)
• Lithium/Manganese Dioxide
• Q Technologies
• High Rate QHR
• Medium Rate QMR
• Lithium/Hybrid (CFx and SVO Mixture)
• Lithium Ion Rechargeable

37
Types of Lithium Implantable Medical Batteries

• Two Battery Systems will be discussed in detail
  in this presentation the Lithium/Iodine
  pacemaker battery and the Lithium/Silver Vanadium
  Oxide Defibrillator Battery.

38
Batteries for Pacemakers

• The lithium/iodine battery was developed and
  patented by scientists at Catalyst Research
  Corporation in the early 1970s. Their invention
  was based on work done at the Jet Propulsion
  Laboratory in the late 1960s and published in
  the Journal of the Electrochemical Society. Mr.
  Wilson Greatbatch licensed the fundamental
  patents from CRC and, with battery scientists
  Ralph Mead and Frank Rudolph, invented and
  patented many improvements (e. g., anode coating
  and the case-grounded design).
• The first lithium/iodine cell was implanted in
  Italy in April 1972. Before that time,
  pacemakers were powered by zinc/mercuric oxide
  batteries that were short-lived, unreliable,
  unpredictable, and discharged hydrogen gas.
• Since that time, millions of cells have been
  implanted.
• Most pacemakers currently being implanted use
  lithium/iodine cells, although some advanced
  pacemakers are using Li/CFx, lithium hybrid
  cathode batteries, and QMR cells.

39

Batteries for Pacemakers

• April 2009 marked the 37th anniversary of the
  first implant of a pacemaker powered by a
  Li/Iodine battery. The implant occurred in
  Italy.
• Since that time, millions of cells have been
  implanted.
• Although several lithium-based chemical systems
  have seen use in pacemakers (silver chromate,
  cupric sulfide, thionyl chloride, manganese
  dioxide, titanium disulfide), the lithium/iodine
  battery became the only remaining pacemaker
  battery technology until the introduction of
  liquid electrolyte batteries such as Li/CFx and
  the hybrid battery (mixed CFx and silver
  vanadium oxide) in the last few years. It
  remains the most widely-used pacemaker battery
  today.
• The battery has compiled a remarkable record of
  reliability and predictable performance.
• It is arguably the first successful
  commercialization of a lithium-anode battery.
• It will continue to be used for the foreseeable
  future.

40

The Lithium/Iodine battery

• One could argue that, based on standard battery
  performance criteria, its not a very good
  battery!
• It cant start a car, run a cell phone, or even
  power a flashlight.
• It has very high internal resistance
• It doesnt work well when its cold.
• It doesnt work well when its too hot (above
  55C).
• Temperatures above 60C will permanently damage
  the cell. It explodes like a bomb at 180.5ºC
  (the melting point of lithium).
• Its not inexpensive to manufacture.
• BUT Put it at 37C and ask it to provide 10
  50 microamperes of current, and it will do it
  reliably for many years.

41

The Lithium/Iodine Battery

• It has been said that it is a very elegant
  battery system
• Elegant in its simplicity
• Simple cell reaction
• Straightforward cell design
• Elegant in its complexity
• Very complicated interactions among iodine, PVP,
  and lithium
• Performance shows a very strong dependence on
  cell discharge current
• Elegant in its performance record
• Remarkable record of reliability and usefulness
  for 37 years.

42
Lithium/Iodine Battery
43
Lithium Anode

• Atomic Number 3 Atomic Mass 6.941 amu
• Melting Point 180.54 C Boiling Point
  1347.0 CNumber of Protons/Electrons 3 Number
  of Neutrons 4 Classification Alkali Metal
  Crystal Structure Cubic Density _at_ 293 K 0.53
  g/cm3 Color silvery
• Ionization Potential 5.39 eV
• Electrochemical Equivalent 3.86 Ah/Gram
• Trivia Note Lithium metal is one of only two
  materials that react with elemental nitrogen at
  room temperature (if humidity is present)!

44
Anode Coating

• In the early 1970s it was discovered by
  Greatbatch scientists that coating the anode with
  PVP dissolved in a volatile solvent greatly
  affected the performance of the cell. The
  coating was done with a camels-hair paint brush.
  The PVP was dissolved in tetrahydrofuran and
  painted onto the anode. The THF was dried, and
  the PVP remained on the anode. This improvement
  was patented in 1976 (patent Number 3,957,533)
• The coating has a profound positive effect on the
  discharge characteristics of the cell.
• Studies at Medtronic in the 1980s showed that
  the coating led to the formation of a yellow
  liquid exhibiting ionic conductivity during
  discharge, contributing to the observed
  improvement in cell performance.
• In 1987 a substrate coating method was developed.
  It is a much more efficient way of coating the
  anode and results in much more uniform coating
  weights and cell performance.

45
Substrate Coating

• Substrate coating was originally introduced as a
  manufacturing efficiency improvement An inert
  substrate material is impregnated with PVP
  dissolved in a volatile solvent, and substrate
  coating blanks are punched out in the shape of
  the anode and pressed onto the anode in the anode
  pressing process.
• Further studies and data indicated that, in
  addition to the production benefits, substrate
  coating has a very positive effect on cell
  performance.
• Uniformity of the coating layer is increased.
• Self-discharge is reduced.
• Better higher-current performance is seen.

46
Comparison of LiI formed from uncoated and coated
anode cells
LiI Crystal Structure Uncoated Anode Cell LiI
is a bonded mass of small granules in a matrix of
amorphous LiI
LiI Crystal Structure Coated Anode Cell LiI has
individual crystallites that are equiaxed and
well-formed
47
Comparison of discharge curves of uncoated and
coated anode cells
48
Lithium Iodide Electrolyte/Separator

• Ionic Salt
• Density 3.494 gr/cm3
• Lithium Ion Conductivity 10-7 S/cm
• Negligible Electronic Conductivity
• Negligible Iodide ion conductivity
• Self-forming, Self-healing
• Structure greatly modified by coating the anode
  with PVP

49
The Iodine/Polyvinylpyridine (PVP) cathode
material
The Iodine/PVP material is formed by a thermal
reaction between iodine and PVP. The reaction
occurs above the melting point of iodine
(113C). This thermal reaction is exothermic
and produces a tar-like material that melts
slightly below the melting point of iodine. At
the 30/1 weight ratio used at Greatbatch, the
material is mostly elemental iodine at unit
thermodynamic activity, with a small amount of
the reaction product of iodine with PVP
50
DSC of Formation of the Cathode Material
51
Phase Diagram of the Iodine/PVP Material
dotted line is 37 C
As the cell is discharged, the cathode material
transitions from region 6 through region 5, and
finally to region 4. Region 6 is a 2-phase system
containing the eutectic melt and pure iodine.
Region 5 is a single phase liquid material.
Region 4 is a two-phase system wherein the
one-to-one iodine/monomer unit adduct phase
coexists with the melt.
52
Conductivity of the Iodine/PVP cathode material
The conductivity of the iodine/PVP material has
been shown to be electronic in nature. Electron
Paramagnetic Resonance spectroscopy of the
cathode material shows a single narrow signal
with a g value of 2.002. This indicates that
there exist free (unpaired) electrons in the
material. The conductivity is a function of the
ratio of iodine to PVP in the material, as shown
in the next slide.
53
Conductivity of the Iodine/PVP cathode material
54
Thermodynamic Characteristics of the
Lithium/Iodine Reaction (300º K)

• Li ½ I2 ? LiI
• ?G ?H - T?S
• From JANAF Thermochemical Tables
• ?G -64.451 kcal/mole
• ?H -64.551 kcal/mole
• T?S -0.101 kcal/mole
• ?G ?H - T?S -nF Eº
• Eº 2.8 volts
• ?S (nF) ? Eº
• ? T
   

55
Lithium/ Iodine Cell Reaction

56
Discharge curves of a typical Li/Iodine battery
at various constant resistive loads
57
The Selim-Bro Curve
This curve provides a standard method of
predicting battery capacities for a given load.
The curve is formed by plotting the achieved
capacity of a primary battery as a function of
the logarithm of the current drain (ref R. Selim
and P. Bro, Performance Domain Analysis of
Primary Batteries, J. Electrochem. Soc. 118,
829, (1971)). A typical curve takes the general
form of an inverted "U." The capacity is lower
at heavy loads because of polarization, i.e. the
battery is not as efficient because the current
drain is such that the resistivity of the battery
causes the voltage to decline. At lighter loads,
the capacity becomes lower because of
self-discharge.
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59
The Implantable Cardioverter/Defibrillator

• Treats Ventricular Tachycardia
• Detects Ventricular Fibrillation and administers
  shock directly to the heart to restore normal
  sinus rhythm

60
Batteries for Implantable Cardiac Defibrillators
The lithium/silver vanadium oxide battery

• Scientists at Greatbatch, Inc. developed the
  lithium/silver vanadium oxide (Li/SVO) battery
  system in 1982. It was adapted for use in the
  implantable defibrillator a few years later.
• In 1987 the first ICD powered by Li/SVO was
  implanted in Sydney, Australia.
• Li/SVO has become the technology standard and
  most ICDs use the system.
• SVO has the ability to deliver high power
• It has high volumetric energy density

61
Lithium/Silver Vanadium Oxide Battery
62
Silver Vanadium Oxide (SVO)

• Silver Vanadium oxide (Ag2V4O11) belongs to a
  class of chemical compounds of somewhat
  indeterminate stoichiometry called Vanadium
  Oxide Bronzes.
• They were first synthesized and studied by
  Casalot, Pouchard, and coworkers at the Centre
  national de la recherche scientifique in France.
  They were interested in the compounds rather
  interesting magnetic properties.
• SVO can be synthesized via several different
  reactions. The reaction used at our company is
  the thermal decomposition of Vanadium Pentoxide
  and Silver Nitrate
• 2V2O5 2AgNO3 ? Ag2V4O11 2NO2 O2
• The compound exists in several phases depending
  on the conditions of synthesis.

63
Silver Vanadium Oxide Structure
64
SEM Image of Silver Vanadium Oxide

65
Li/SVO Battery Characteristics

• Cell Reaction Ag2V4O11 7 Li ?
  Li7Ag2V4O11
• High Voltage 3.2V
• High Capacity 1.37 Ah/cm3
• High Power 20-30 mA/cm2
• DOD Indication Staged Disch. Profile
• Long Shelf Life Self Disch.lt2/Year
• Safety and Reliability Extensively Tested
• Issues Studied Rdc Growth/V-Delay

66
Defibrillator Battery 3-year discharge curve
67
Discharge Curve/Cell Reaction first plateau

68
Q Technology a brief introduction

• A new cell system has been developed that
  provides high energy density, high power and high
  stability
• A suitable battery technology for next generation
  ICDs
• Proven technology with patent protection and with
  5 years real time cell test data
• Flexible and scaleable cell design to meet the
  market needs
• Mechanistically based performance model developed
  to predict battery performance under various
  applications

69
Q Technology Combining the Carbon Monofluoride
and SVO Chemistries
70
Summary

• Over five million people have been implanted with
  battery-powered devices.
• Devices treat heart problems, pain, epilepsy,
  chronic illnesses, hearing loss, and other human
  illnesses.
• These devices are powered by lithium batteries,
  which offer high energy density, reliability, and
  longevity.
• Significant improvements in battery performance,
  electronic circuitry, and electrodes have
  permitted newer, smaller devices that perform a
  wide variety of functions.