EvokeDx®
Frequently Asked Questions &
Specifications
Frequently Asked Questions
Fourier TransformTraditionally, visual electrophysiology data has been analyzed in the time domain, typically with a transient response, looking at one or two peaks to try to draw conclusions as to whether or not the response is affected. EvokeDx features a discrete Fourier transform from the time domain to the frequency domain, allowing data from the entire response to be included in the analysis.
Much as when OCT leaped from the time domain to the spectral domain, an entirely new set of statistical tools are available in the frequency domain to simplify the clinician’s assessment of VEP and ERG responses.
EvokeDx is designed for visual electrophysiology measurement. This includes VEP, ERG, and our proprietary icVEP test strategy that was the subject of an NIH funded, multi-center clinical trial. icVEP is a low-contrast, high temporal frequency pattern that sinusoidally varies in contrast at 10 Hz. With a well functioning pathway, and the Fourier Transform, we expect to measure a sinusoidal variance in signal at exactly 10 Hz at the visual cortex.
This novel test strategy is available in three variants: single contrast bright check, sweep of contrasting, bright checks, and sweep of contrasting dark checks.
EvokeDx libraryEvokeDx features multiple visual electrophysiology test configurations with commonly used parameters for icVEP, VEP, and ERG.
Visual electrophysiology has been performed for decades using a large assortment of EEG sensors, both generic and speciality, built to gather as large as possible amplitudes in the least invasive manner (something that is generally mutually exclusive). Konan strategically utilizes standard snap connectors to give our customers a choice, both now and in the future, of the types of electrodes selected. Use of a proprietary connector would have locked you into purchasing single-supplier, high-cost products.
The standard EEG skin electrodes used for ERG testing are easy to prep for, apply, and also provide good signal amplitudes.
Our gaze monitoring system provides an on-screen video feed of the patient for the technician to easily monitor test progress and patient attention. Inattention, excessive blinking, and closed eyes will distort the collected data. Prompt attention to attentiveness will mean fewer test repeats, happier patients and better office efficiency.
EvokeDx will record one or two channels of data. With a 5-wire lead cable, a patient can be easily prepped to do bilateral ERG recordings in a single go.
Most Konan Medical products come standard with a permission-based, encrypted, remote access tool for on-request customer support. This feature of KonanCare provides our customers with expert technical and clinical assistance without the need for an on-site visit. KonanCare remote access is invaluable for staff training, hardware and software troubleshooting, and assistance with clinical interpretation.
EvokeDx compare functionEvokeDx’s “Compare” tool allows you to overlay two different exams to simply visually assess a change or difference. The Compare tool is useful to assess right versus left eyes at the same visit, or same eye over time.
Note that EvokeDx data is protected by 256-bit encryption and is HIPAA compliant.
Many early-adopter practices purchased (and often fully paid for) first-generation clinical electrophysiology devices. Just as purchasers of time-domain OCT devices found the expanded applications and robust assessment features clinically important enough to justify moving to a spectral domain system, our customers are echoing this with EvokeDx.
Another important consideration may be the ongoing costs of disposable products. If you have a first-generation device and find yourself annoyed with the high monthly electrode and cable replacement costs, and really wish that there were better analytic tools for clinical assessment available, contact sales@KonanMedical to get a tailored estimate of the real costs of ownership.
EvokeDx uses the same network-based file naming and location convention successfully used with our CellChek systems in thousands of clinical settings. A DICOM client is in the development pipeline.
Absolutely. Some first-generation systems may not have adequate safeguards for data protection to HIPAA requirements, and the doctor may have unintended liability for this non-compliance.
Features
| FEATURE | BENEFIT |
|---|---|
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OLED stimulus display
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Premium specification, with linearization and microsecond timing, successfully addresses luminance artifact contamination known to affect LCD displays
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NIH clinical data
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Multi-center clinical study: differentiation of glaucoma and normals with icVEP-LC
1
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All-in-one design
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Beautiful, compact, delivered in one box, and can be mobilized with optional case
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Patented icVEP test strategies
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Low Contrast Bright (single step), Bright Sweep, Dark Sweep
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Gaze monitor
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On-screen gaze monitoring allows operator to easily monitor both test recording and patient attention |
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Test library
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16 different icVEP, VEP, ERG
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EvokeDx Viewer
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Viewer application allows secure remote access by physician to test results on device
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Touch-screen UI
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Double-shielded, internal amplifier ... no need for the patient to hold parts of the test equipment
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Fourier transform analytics
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T2circ, Sine : Cosine, Amp-Phase, and MSC
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Single or dual channel recording
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Record single channel (3 lead) or bilateral ERG or simultaneous VEP & ERG (5 lead) ... in one go!
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Very short interval testing
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Test is divided into multiple short sequences typically 2 to 6 seconds each
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Luminance calibration
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Simple (auto and semi-auto) calibration, linearization, and calibration history
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Child-attention animations
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Selectable high-quality videos to capture and hold attention
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Synchronous data collection
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Data collection is synchronized using low-latency Polling technique (non-IRQ) with the stimulus frame rate to eliminate time gap shifting and enhance Fourier transformed calculations
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Auditory cues for patient
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No sound (or associated data contamination) from intra-test sound files
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Low-cost, disposable electrodes
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Other systems may require costly, proprietary electrodes ... EvokeDx uses low-cost solutions for patient disposables.
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| EMR | EHR | Local or network reports configuration |
| Simple software upgrades | Software is easily kept current with either on-request or on-screen notice of a new version |
| Integrated data backup |
Local or network locations |
Specifications
| EVOKEDX STIMULUS | |||
|---|---|---|---|
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Resolution
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1920 x 1080
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Patterns
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Patented isolated-check, checkerboard, gratings, windmill-dartboard, uniform field
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Frame rate
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60 Hz
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Temporal functions
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Sine wave, square wave, superimposed two sinusoid
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Grey level
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8 bit resolution
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Sweep display
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Up to 10 steps with variable contrast, spatial frequency, and
temporal frequency |
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Gamma correction
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Software
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DATA ACQUISITION
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Analog - digital
conversion |
16 bit resolution
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Data-timing control
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Low-latency Polling method (non-IRQ) to synchronize data collection to stimulus frame rate to decrease variability in response measures
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Sampling rate
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480 S/s
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Electrodes
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3 and 5 with disposable AgCl
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SIGNAL AMPLIFICATION - meets or exceeds ISCEV - International Society for Clinical Electrophysiology of Vision and FDA regulatory requirements
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Channels
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Differential, One or Two
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Filters
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Fourier bandwidth 0.5 to 100 Hz, Fourier notch filter
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Gain
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20,000
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Input range
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+/- 6 mV
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CMRR
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Common Mode Rejection
Ratio > 120 dB |
Input impedance
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2 X 1012
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| Ohm isolation voltage | 1.5 kV |
Power supply
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+8 to +15 VDC |
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DATA PROCESSING
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Steady-state response
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Spectrum analysis
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T
2
CIRC
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Digital Fourier Transform driven statistical analysis reducing complex waveform to amplitude and phase angle
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Transient response
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Artifact removal
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MSC
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Coherence (Magnitude Squared Coherence) of recorded response
compared to frequency response noise |
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Digital filters
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Low, high, even/odd, notch
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FSTAT
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Statistical definition of difference between two samples and confidence interval
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SYSTEM HARDWARE
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Integrated computer
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Operator: 22" touchscreen
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Power
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100-240 VAC; 50/60 Hz; 5.5 A; isolation transformer included
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Gaze / eye monitoring
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Infrared 770-950 nm camera (ISO grp)
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WiFi / bluetooth
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Printing, EMR network communications, secure support
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Dimensions
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20.7 x 9.5 x 16.4 inches W x D x H (52.6 x 41.6 x 16.2 cm)
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Weight
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50 lbs (22.7 kgs)
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REGULATORY
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USA
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FDA 510(k) K081591
5
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Japan
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Certificate # 229AGBZX00100000 (COSMOS CORP)
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Europe
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CE mark
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