U.S. patent application number 17/262662 was filed with the patent office on 2021-06-17 for background stimulation for fitting cochlear implants.
The applicant listed for this patent is MED-EL Elektromedizinische Geraete GmbH. Invention is credited to Sascha Fuchs, Richard Penninger.
Application Number | 20210178160 17/262662 |
Document ID | / |
Family ID | 1000005445989 |
Filed Date | 2021-06-17 |
United States Patent
Application |
20210178160 |
Kind Code |
A1 |
Penninger; Richard ; et
al. |
June 17, 2021 |
Background Stimulation for Fitting Cochlear Implants
Abstract
A fitting arrangement is described for fitting electrode
contacts of cochlear implant electrode array implanted in a cochlea
of an implanted patient. This involves iteratively fitting multiple
fitting electrode contacts by for each of the fitting electrode
contacts: i. delivering fitting stimulation signals to the fitting
electrode contact and at least one neighboring electrode contact to
stimulate adjacent auditory neural tissue, wherein the fitting
stimulation signals are characterized by a charge level
distribution function having a non-zero noise level charge at the
at least one neighboring electrode contact and a response level
charge much greater than the noise level charge at the fitting
electrode contact, and ii. obtaining patient responses from the
implanted patient to the fitting stimulation signals. A
patient-specific fit map is then defined for the electrode contacts
of cochlear implant electrode array based on the patient
responses.
Inventors: |
Penninger; Richard;
(Innsbruck, AT) ; Fuchs; Sascha; (Innsbruck,
AT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MED-EL Elektromedizinische Geraete GmbH |
Innsbruck |
|
AT |
|
|
Family ID: |
1000005445989 |
Appl. No.: |
17/262662 |
Filed: |
June 25, 2019 |
PCT Filed: |
June 25, 2019 |
PCT NO: |
PCT/US19/38875 |
371 Date: |
January 22, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62702944 |
Jul 25, 2018 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 1/0541 20130101;
A61N 1/36039 20170801 |
International
Class: |
A61N 1/36 20060101
A61N001/36; A61N 1/05 20060101 A61N001/05 |
Claims
1. A non-transitory tangible computer-readable medium having
instructions thereon for fitting an implanted patient and a hearing
implant system having an implanted electrode array with a plurality
of electrode contacts, the instructions comprising: iteratively
fitting a plurality of fitting electrode contacts by for each of
the fitting electrode contacts: i. delivering fitting stimulation
signals to the fitting electrode contact and at least one
neighboring electrode contact to stimulate adjacent auditory neural
tissue, wherein the fitting stimulation signals are characterized
by a charge level distribution function having a non-zero noise
level charge at the at least one neighboring electrode contact and
a response level charge much greater than the noise level charge at
the fitting electrode contact, and ii. obtaining patient responses
from the implanted patient to the fitting stimulation signals; and
defining a patient-specific fit map for the electrode contacts of
cochlear implant electrode array based on the patient
responses.
2. The computer-readable medium according to claim 1, wherein the
charge level distribution function is a Gaussian distribution
function with a peak corresponding to the response level
charge.
3. The computer-readable medium according to claim 1, wherein the
charge level distribution function is a geometric distribution
function with a peak corresponding to the response level
charge.
4. The computer-readable medium according to claim 1, wherein the
fitting electrode contacts are fit sequentially starting from an
apical end of the electrode array back along the length of the
electrode array.
5. The computer-readable medium according to claim 1, wherein the
fitting electrode contacts are fit in a non-linear order along the
electrode array.
6. The computer-readable medium according to claim 1, wherein the
fitting electrode contacts are fit in an alternating sequence of
every other electrode contact along the length of the electrode
array.
7. The computer-readable medium according to claim 1, wherein the
patient responses include subjective response measurements.
8. The computer-readable medium according to claim 1, wherein the
patient responses include objective response measurements.
Description
[0001] This application claims priority from U.S. Provisional
Patent Application 62/702,944, filed Jul. 25, 2018, which is
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates to hearing implant systems,
and more specifically, to custom fitting of hearing implant systems
such as cochlear implants.
BACKGROUND ART
[0003] A normal ear transmits sounds as shown in FIG. 1 through the
outer ear 101 to the tympanic membrane (eardrum) 102, which
vibrates the ossicles of the middle ear 103 (malleus, incus, and
stapes). The stapes footplate is positioned in the oval window 106
that forms an interface to the fluid filled inner ear (the cochlea)
104. Movement of the stapes generates a pressure wave in the
cochlea 104 that stimulates the sensory cells of the auditory
system (hair cells). The cochlea 104 is a long narrow duct wound
spirally around its central axis (called the modiolus) for
approximately two and a half turns. The cochlea 104 includes an
upper channel known as the scala vestibuli, a middle channel known
as the scala media and a lower channel known as the scala tympani.
The hair cells connect to the spiral ganglion cells of the cochlear
nerve 105 that reside in the modiolus. In response to received
sounds transmitted by the middle ear 103, the fluid-filled cochlea
104 functions as a transducer to generate electric pulses which are
transmitted to the cochlear nerve 105, and ultimately to the
brain.
[0004] Hearing is impaired when there are problems in the ability
to transduce external sounds into meaningful action potentials
along the neural substrate of the cochlea 104. To improve impaired
hearing, auditory prostheses have been developed. For example, when
the impairment is related to operation of the middle ear 103, a
conventional hearing aid or middle ear implant may be used to
provide acoustic-mechanical stimulation to the auditory system in
the form of amplified sound. Or when the impairment is associated
with the cochlea 104, a cochlear implant with an implanted
stimulation electrode can electrically stimulate auditory nerve
tissue with small currents delivered by multiple electrode contacts
distributed along the electrode.
[0005] FIG. 1 also shows some components of a typical cochlear
implant system, including an external microphone that provides an
audio signal input to an external signal processor 111 where
various signal processing schemes can be implemented. The processed
signal is then converted into a digital data format, such as a
sequence of data frames, for transmission via external transmitting
coil 107 into the implant receiver 108. Besides receiving the
processed audio information, the implant receiver 108 also performs
additional signal processing such as error correction, pulse
formation, etc., and produces a stimulation pattern (based on the
extracted audio information) that is sent through an electrode lead
109 to an implanted electrode array 110. The electrode array 110
includes multiple electrode contacts 112 (also referred to as
electrode channels) on its surface that provide selective
stimulation of the cochlea 104.
[0006] A relatively small number of electrode channels are each
associated with relatively broad frequency bands, with each
electrode contact addressing a group of neurons with an electric
stimulation pulse having a charge that is derived from the
instantaneous amplitude of the signal envelope within that
frequency band. Current cochlear implant coding strategies map the
different sound frequency channels onto different locations within
the cochlea. FIG. 2 shows one example of the processing of a signal
using the cochlear implant stimulation (CIS) stimulation strategy.
The top of FIG. 2 shows the sound pressure characteristics of a
spoken "A" (/ay/) at a sound level of 67.2 dB. The middle waveform
in FIG. 2 shows a normal healthy auditory system response. The
bottom waveform in FIG. 2 shows a neural response of the auditory
nerve fibers under CIS stimulation.
[0007] FIG. 3 shows various functional blocks in a signal
processing arrangement for producing electrode stimulation signals
to electrode contacts in an implanted cochlear implant array
according to a typical hearing implant system. A pseudo code
example of such an arrangement can be set forth as:
[0008] Input Signal Preprocessing: [0009] BandPassFilter
(input_sound, band_pass_signals)
[0010] Envelope Extraction: [0011] BandPassEnvelope
(band_pass_signals, band_pass_envelopes)
[0012] Stimulation Timing Generation: [0013] TimingGenerate
(band_pass_signals, stim_timing)
[0014] Pulse Generation: [0015] PulseGenerate (band_pass_envelopes,
stim_timing, out_pulses) The details of such an arrangement are set
forth in the following discussion.
[0016] In the signal processing arrangement shown in FIG. 3, the
initial input sound signal is produced by one or more sensing
microphones, which may be omnidirectional and/or directional.
Preprocessor Filter Bank 301 pre-processes this input sound signal
with a bank of multiple parallel band pass filters (e.g. Infinite
Impulse Response (IIR) or Finite Impulse Response (FIR)), each of
which is associated with a specific band of audio frequencies, for
example, using a filter bank with 12 digital Butterworth band pass
filters of 6th order, Infinite Impulse Response (IIR) type, so that
the acoustic audio signal is filtered into some K band pass
signals, U.sub.1 to U.sub.K where each signal corresponds to the
band of frequencies for one of the band pass filters. Each output
of sufficiently narrow CIS band pass filters for a voiced speech
input signal may roughly be regarded as a sinusoid at the center
frequency of the band pass filter which is modulated by the
envelope signal. This is also due to the quality factor
(Q.apprxeq.3) of the filters. In case of a voiced speech segment,
this envelope is approximately periodic, and the repetition rate is
equal to the pitch frequency. Alternatively and without limitation,
the Preprocessor Filter Bank 301 may be implemented based on use of
a fast Fourier transform (FFT) or a short-time Fourier transform
(STFT). Based on the tonotopic organization of the cochlea, each
electrode contact in the scala tympani typically is associated with
a specific band pass filter of the Preprocessor Filter Bank 301.
The Preprocessor Filter Bank 301 also may perform other initial
signal processing functions such as and without limitation
automatic gain control (AGC) and/or noise reduction and/or wind
noise reduction and/or beamforming and other well-known signal
enhancement functions. An example of pseudocode for an infinite
impulse response (IIR) filter bank based on a direct form II
transposed structure is given by Fontaine et al., Brian Hears:
Online Auditory Processing Using Vectorization Over Channels,
Frontiers in Neuroinformatics, 3011; incorporated herein by
reference in its entirety.
[0017] The band pass signals U.sub.1 to U.sub.K (which can also be
thought of as electrode channels) are output to a Stimulation Timer
306 that includes an Envelope Detector 302 and Fine Structure
Detector 303. The Envelope Detector 302 extracts characteristic
envelope signals outputs Y.sub.1, . . . , Y.sub.K that represent
the channel-specific band pass envelopes. The envelope extraction
can be represented by Y.sub.k=LP(|U.sub.k|), where |.| denotes the
absolute value and LP(.) is a low-pass filter; for example, using
12 rectifiers and 12 digital Butterworth low pass filters of 2nd
order, IIR-type. Alternatively, the Envelope Detector 302 may
extract the Hilbert envelope, if the band pass signals U.sub.1, . .
. , U.sub.K are generated by orthogonal filters.
[0018] The Fine Structure Detector 303 functions to obtain smooth
and robust estimates of the instantaneous frequencies in the signal
channels, processing selected temporal fine structure features of
the band pass signals U.sub.1, . . . , U.sub.K to generate
stimulation timing signals X.sub.1, . . . , X.sub.K. The band pass
signals U.sub.1, . . . , U.sub.k can be assumed to be real valued
signals, so in the specific case of an analytic orthogonal filter
bank, the Fine Structure Detector 303 considers only the real
valued part of U.sub.k. The Fine Structure Detector 303 is formed
of K independent, equally-structured parallel sub-modules.
[0019] The extracted band-pass signal envelopes Y.sub.1, . . . ,
Y.sub.K from the Envelope Detector 302, and the stimulation timing
signals X.sub.1, . . . , X.sub.K from the Fine Structure Detector
303 are output from the Stimulation Timer 306 to a Pulse Generator
304 that produces the electrode stimulation signals Z for the
electrode contacts in the implanted electrode array 305. The Pulse
Generator 304 applies a patient-specific mapping function--for
example, using instantaneous nonlinear compression of the envelope
signal (map law)--That is adapted to the needs of the individual
cochlear implant user during fitting of the implant in order to
achieve natural loudness growth. The Pulse Generator 304 may apply
logarithmic function with a form-factor C as a loudness mapping
function, which typically is identical across all the band pass
analysis channels. In different systems, different specific
loudness mapping functions other than a logarithmic function may be
used, with just one identical function is applied to all channels
or one individual function for each channel to produce the
electrode stimulation signals. The electrode stimulation signals
typically are a set of symmetrical biphasic current pulses.
[0020] For an audio prosthesis such as a cochlear implant to work
correctly, some patient-specific operating parameters need to be
determined in a fit adjustment procedure where the type and number
of operating parameters are device dependent and stimulation
strategy dependent. Possible patient-specific operating parameters
for a cochlear implant include: [0021] THR.sub.1 (lower detection
threshold of stimulation amplitude) for Electrode 1 [0022]
MCL.sub.1 (most comfortable loudness) for Electrode 1 [0023] Phase
Duration for Electrode 1 [0024] THR.sub.2 for Electrode 2 [0025]
MCL.sub.2 for Electrode 2 [0026] Phase Duration for Electrode 2
[0027] . . . . [0028] Pulse Rate [0029] Number of fine structure
channels [0030] Compression [0031] Parameters of
frequency->electrode mapping [0032] Parameters describing the
electrical field distribution These patient-specific operating
parameters are saved in a file referred to as a fit map. A given
system may have multiple patient-specific fit maps for different
listening environments; for example, there may be one fit map for a
quiet environment and a different fit map for a noisy environment.
The better the fit map, the more closely the hearing experience
from the electrical stimulation signals resembles the natural
acoustic hearing experience of unimpaired individuals.
[0033] One common method for fit adjustment is to behaviorally find
the threshold (THR) and most comfortable loudness (MCL) value for
each separate electrode contact. See for example, Ratz, Fitting
Guide for First Fitting with MAESTRO 2.0, MED-EL, Furstenweg 77a,
6020 Innsbruck, 1.0 Edition, 2007. AW 5420 Rev. 1.0 (English_EU);
incorporated herein by reference. Other alternatives/extensions are
sometimes used with a reduced set of operating parameters; e.g. as
suggested by Smoorenburg, Cochlear Implant Ear Marks, University
Medical Centre Utrecht, 2006; and U.S. Patent Application
20060235332; which are incorporated herein by reference. Typically
each stimulation channel is fitted separately without using the
information from already fitted channels. The stimulation current
on a given electrode typically is increased in steps from zero
until the MCL or THR is reached.
[0034] One approach for an objective measurement of MCLs and THRs
is based on the measurement of the ECAPs (Electrically Evoked
Compound Action Potentials), as described by Gantz et al.,
Intraoperative Measures of Electrically Evoked Auditory Nerve
Compound Action Potentials, American Journal of Otology 15
(2):137-144 (1994), which is incorporated herein by reference. In
this approach, a recording electrode in the scala tympani of the
inner ear is used. The overall response of the auditory nerve to an
electrical stimulus is measured very close to the position of the
nerve excitation. This neural response is caused by the
super-position of single neural responses at the outside of the
axon membranes. The amplitude of the ECAP at the measurement
position is typically in the ranges of .mu.V. When performing
objective measurements such as ECAP measurements in existing
cochlear implant systems, usually each electrode contact of the
implantable electrode array is scanned separately, increasing the
stimulation signal current on an electrode contact in steps from
zero or a very low level until an ECAP response is detected. Other
objective measurement approaches are also known, such as
electrically evoked stapedius reflex thresholds (eSRT).
[0035] Once the fit parameters such as MCL and THR are initially
established based on objective measurements, then an audiologist
can further fine tune the fit map based on their experience and any
available subjective feedback from the individual patient to modify
the existing fit map by scaling, tilting, smoothing, or changing
the shape of the fit map. However, the fitting audiologist needs to
have many years of clinical experience and the fitting process can
be quite time consuming. It is not trivial to test even some of the
many possible adjustment combinations. In addition, patient
feedback is not always available; for example, when the patient is
a small child.
[0036] Several attempts have been made to make fitting faster or
more automatic. The most recent development within this field is
Med-El's MAESTRO 7.0.1 Auditory Response Telemetry based fitting
entitled "ARTFit" which targets fitting based on objective
measures. During these objective measures the volume is increased
from low to high until an objective response is measured. Ideally,
this process is performed on every electrode until a response is
found or until the subject feels the need to indicate that the
stimulation has become too uncomfortable. In essence this means
that although an objective response is measured the subject still
needs to be able to indicate that the stimulation has become too
loud in order to obtain that objective response.
[0037] Despite the fact that the measurements can be performed with
a sedated patient or a patient under general anesthesia, it is
still uncommon to routinely perform objective measurements during
implantation surgery due to time constraints. Current fitting
strategies require adjustment of individual channels and then
adjustments of overall loudness. The process needs to be finished
completely in order to get a reliable map. Some efforts have been
made to replace parts of the process with objective measurements.
These require relatively lengthy measurements which by themselves
require loudness judgments to function. Once the objective
measurements are completed they lead to a MAP profile which then
again needs to be live adjusted.
SUMMARY
[0038] Embodiments of the present invention are directed to fitting
arrangements for fitting electrode contacts of cochlear implant
electrode array implanted in a cochlea of an implanted patient.
This involves iteratively fitting multiple fitting electrode
contacts by for each of the fitting electrode contacts: i.
delivering fitting stimulation signals to the fitting electrode
contact and at least one neighboring electrode contact to stimulate
adjacent auditory neural tissue, wherein the fitting stimulation
signals are characterized by a charge level distribution function
having a non-zero noise level charge at the at least one
neighboring electrode contact and a response level charge much
greater than the noise level charge at the fitting electrode
contact, and ii. obtaining patient responses from the implanted
patient to the fitting stimulation signals. A patient-specific fit
map is then defined for the electrode contacts of cochlear implant
electrode array based on the patient responses.
[0039] In further specific embodiments, the charge level
distribution function may be a Gaussian or geometric distribution
function with a peak corresponding to the response level charge.
The fitting electrode contacts may be fit sequentially starting
from an apical end of the electrode array back along the length of
the electrode array. Or the fitting electrode contacts may be fit
in a non-linear order along the electrode array and/or in an
alternating sequence of every other electrode contact along the
length of the electrode array. The patient responses may include
subjective and/or objective response measurements.
[0040] Embodiments of the present invention also include a cochlear
implant system fit to an implanted patient using any of the above
methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 shows anatomical structures of a typical human ear
with a cochlear implant system.
[0042] FIG. 2 shows an example of signal processing using the
cochlear implant stimulation (CIS) stimulation strategy
[0043] FIG. 3 shows various functional blocks in a signal
processing arrangement for a typical cochlear implant system
[0044] FIG. 4 shows a block diagram of a cochlear implant fitting
system according to an embodiment of the present invention.
[0045] FIG. 5 shows various logical steps in a fitting process
according to an embodiment of the present invention.
[0046] FIGS. 6A-6C show charge distributions for a fitting process
according to one specific embodiment.
[0047] FIGS. 7A-7C show charge distributions for a fitting process
according to another specific embodiment.
DETAILED DESCRIPTION
[0048] Embodiments of the present invention are directed to
cochlear implant fitting arrangements that produce a
patient-specific fit map more quickly than with existing approaches
without undesirably elevating the risk of overstimulation (without
exceeding MCL). The described method applies stimulation to the
cochlear implant user in a most comfortable way by masking
neighboring electrodes. This method also applies the charge levels
on more than one electrode contact to provide a more time efficient
fitting procedure.
[0049] FIG. 4 shows a block diagram of a cochlear implant fitting
system according to an embodiment of the present invention. Control
Unit 401 for Recording and Stimulation, for example, a Med-El
Maestro Cochlear Implant (CI) system, generates stimulation signals
and analyzes response measurements. Connected to the Control Unit
401 is an Interface Box 402, for example, a Diagnostic Interface
System such as the DIB II conventionally used with the Maestro CI
system that formats and distributes the input and output signals
between the Control Unit 401 and the system components implanted in
the Patient 406. For example, as shown in FIG. 4, there may be an
Interface Lead 403 connected at one end to the Interface Box 402
and at the other end having Electrode Plug 407 that then divides
into a Cochlear Implant Electrode Array 405 and an Extra-Cochlear
Ground Electrode 404. The Control Unit 401 is configured for
fitting electrode contacts of the Cochlear Implant Electrode Array
405. The Control Unit 401 includes a fitting processor with at
least one hardware implanted processor device and is controlled by
software instructions to perform the fitting process including
delivering to at least one of the electrode contacts a test
stimulation sequence which is at a variable charge level and a
variable stimulation rate over time. After delivering a stimulation
pulse, an electrode contact on the Cochlear Implant Electrode Array
405 may be used as a sensing element to determine current and
voltage characteristics of the adjacent tissue.
[0050] More specifically, the fitting system depicted in FIG. 4 is
operated to iteratively fit multiple fitting electrode contacts on
the implanted electrode array following the basic logical steps as
shown in FIG. 5. First, step 501, a set of fitting contacts is
selected. For example, this may be all of the electrode contacts
sequentially starting from an apical end of the electrode array
back along the length of the electrode array. Or the set of
selected fitting electrode contacts may be all of the electrode
contacts fit in a non-linear order along the electrode array. Or
the set of the elected fitting contacts may be an alternating
sequence of every other electrode contact along the length of the
electrode array. The latter case reduces the required time by 50%.
Fitting parameters for the unselected electrode contacts may be
calculated by interpolating (or extrapolating) from the parameters
derived for the selected electrode contacts.
[0051] Then, for each of the fitting electrode contacts, step 502,
fitting stimulation signals are delivered to the fitting electrode
contact and at least one neighboring electrode contact to stimulate
adjacent auditory neural tissue, step 503. The fitting stimulation
signals are characterized by a charge level distribution function
that has a non-zero noise level charge at the at least one
neighboring electrode contact and a response level charge much
greater than the noise level charge at the fitting electrode
contact. For a distribution function with a peak k and parameter p,
and a noise function with random values from 0 to q: [0052]
chargeLvl(x,n)=chargeLvl(x,n-1)+dist(k,p)+noise(x,q) [0053]
chargeLvl(x,0)=constant noise(k,q)=0.
[0054] Patient responses, which may include subjective and/or
objective response measurements, are then obtained from the
implanted patient to the fitting stimulation signals, step 504.
This is done for each fitting electrode contact while saving the
charge level of each individual electrode contact that provides the
stimulation signals. A patient-specific fit map is defined for the
electrode contacts of cochlear implant electrode array based on the
patient responses, step 505.
[0055] FIGS. 6A-6C show charge distributions for three iterations
of a fitting process where the charge level distribution function
is a Gaussian distribution function with a peak corresponding to
the response level charge. For example, one specific Gaussian
distribution function may have a standard derivative .sigma.=0.5
and .mu.=1. FIGS. 7A-7C show charge distributions for three
iterations of a fitting process where the charge level distribution
function is a geometric distribution function with a peak
corresponding to the response level charge with p=0.9, p (0.1) and
k=1, where the values of .mu. and k represent the electrode contact
currently being fitted.
[0056] These techniques are especially useful for an electrode
array with a low number of electrode contacts since the number of
iterations needed equals the number of electrode contacts. It will
be appreciated that the charge level on all electrode contacts
steadily rises with the number of iterations. This means that the
initial charge level for the response measurement is higher, but
still the desired maximum charge level can be calculated more
quickly, as charge levels should not get too high. Alternatively a
relative factor between the selected fitting electrode contact and
the at least one neighboring electrode contact can be chosen to
avoid the at least one neighboring electrode contact being too
loud. Alternatively this risk can be avoided by setting a maximum
charge level limit over all the electrode contacts which cannot be
surpassed by the charge levels on neighboring electrode
contacts.
[0057] The fitting process typically may start with a flat map at
MCL levels. A clinical randomization factor may be selectable
depending on the ability of the patient to judge loudness. The
patient then can be presented with different versions of the
randomized map with instructions to judge if a map is "too loud".
Each of the maps can be presented for 5 seconds unless the user
presses a "too loud"/"skip" button. The longer the fitting process
runs, the better the final map will be, and the final map is based
on the maximum charge level measured for each electrode
contact.
[0058] Background stimulation on the neighboring electrode contacts
makes the patient more loudness tolerant, particularly as to
electrode contacts near the electrode opening into the cochlea
where high frequency sounds are perceived. A higher starting value
is chosen for each consecutive electrode contact based on the
previous iteration of stimulation, which leads to a more time
efficient fitting procedure. There also is better mimicking of
channel interaction during the fitting of each individual electrode
contact so the channel interaction portion of the fitting process
can be omitted.
[0059] Embodiments of the invention may be implemented in part in
any conventional computer programming language. For example,
preferred embodiments may be implemented in a procedural
programming language (e.g., "C") or an object oriented programming
language (e.g., "C++", Python). Alternative embodiments of the
invention may be implemented as pre-programmed hardware elements,
other related components, or as a combination of hardware and
software components.
[0060] Embodiments can be implemented in part as a computer program
product for use with a computer system. Such implementation may
include a series of computer instructions fixed either on a
tangible medium, such as a computer readable medium (e.g., a
diskette, CD-ROM, ROM, or fixed disk) or transmittable to a
computer system, via a modem or other interface device, such as a
communications adapter connected to a network over a medium. The
medium may be either a tangible medium (e.g., optical or analog
communications lines) or a medium implemented with wireless
techniques (e.g., microwave, infrared or other transmission
techniques). The series of computer instructions embodies all or
part of the functionality previously described herein with respect
to the system. Those skilled in the art should appreciate that such
computer instructions can be written in a number of programming
languages for use with many computer architectures or operating
systems. Furthermore, such instructions may be stored in any memory
device, such as semiconductor, magnetic, optical or other memory
devices, and may be transmitted using any communications
technology, such as optical, infrared, microwave, or other
transmission technologies. It is expected that such a computer
program product may be distributed as a removable medium with
accompanying printed or electronic documentation (e.g., shrink
wrapped software), preloaded with a computer system (e.g., on
system ROM or fixed disk), or distributed from a server or
electronic bulletin board over the network (e.g., the Internet or
World Wide Web). Of course, some embodiments of the invention may
be implemented as a combination of both software (e.g., a computer
program product) and hardware. Still other embodiments of the
invention are implemented as entirely hardware, or entirely
software (e.g., a computer program product).
[0061] Although various exemplary embodiments of the invention have
been disclosed, it should be apparent to those skilled in the art
that various changes and modifications can be made which will
achieve some of the advantages of the invention without departing
from the true scope of the invention.
* * * * *