skull cap requirements presentation group 5 engineering 4017 - engineering design
TRANSCRIPT
Skull Cap Requirements Skull Cap Requirements PresentationPresentation
Group 5
Engineering 4017 - Engineering Design
Project OverviewProject Overview
General DescriptionGeneral Description
What is EEG? Why is the
information being collected?
Refer to the following webpage http://www.epub.org.br/cm/n03/tecnologia/eeg.htm
FOR MORE INFO...
Mission StatementMission Statement
The reliable measurement over extended periods of scalp EEG
on consecutive occasions during mental function in everyday environments.
Existing SystemExisting System
Skull cap containing electrodes with wired connection.
Requires extensive preparation of scalp for usage.
System must be operated in a shielded environment.
Issues with Existing Issues with Existing SystemSystemLack of repeatabilityLack of mobilityLong setup timeShort length of experiment
before the results are affected by external factors
Requirement StructureRequirement Structure
Priority System– Essential - Match existing functionality
and/or core customer requirements– Highly Desirable - Extend the
functionality of the system and are achievable in the available time frame
– Desirable - May not be achievable in the available time frame & further research is required
Electrode PositioningElectrode Positioning
EssentialPosition 23 electrodes on the
skull according to the 10/20 positioning convention– 19 scalp electrodes– Two eye electrodes– Reference electrode– Isolated common
Signal ProcessingSignal Processing
EssentialProcess electrode signals to
make them suitable for input into customer’s existing computer system.
Experimental Experimental RepeatabilityRepeatabilityEssentialAbility to position system on
subject on subsequent occasions so that electrodes are within 1mm2 of original position.
Acceptable Noise LevelAcceptable Noise Level
EssentialNoise from external
electromagnetic fields and undesired physiological rhythms must be less than 1% of the recorded EEG signal.– E.g. power line hum, heart beats
Sampling SpecificationsSampling Specifications
EssentialRate: 1kHzResolution: better than .15VRange: ±400mV
Skull ImpedanceSkull Impedance
EssentialSkull impedance must be
reduced below 5k for the purposes of electrode measurement.
Scalp IrritationScalp Irritation
EssentialBased on ISO 10993-10,
irritation should be reduced to a level such that less than 2% of subjects experience irritation (as defined in the standard).
Highly DesirableHighly Desirable
Less than 1% deviation of data due to electrode polarisation.
Easily cleanable to medical grade cleanliness in accordance with Australian Standard AS 4187/1998.
Signal compensation for up to 0.05Hz of signal drift.
Highly Desirable, cont.Highly Desirable, cont.
Suitable for use on persons of different head dimensions, within the range of 53 to 60 centimetres head diameter as measured above the ears.
Possible to position system on subject's head within 15 minutes.
DesirableDesirable
Exist as a portable system that can operate for up to three hours without interruption.
Ability to transfer signals from the patient to a monitoring terminal without the need for physical connection.
Ability to select a subset of the EEG monitoring electrodes.
Desirable, cont.Desirable, cont.
Ability to select different sampling rates for data collection.
Suitable for use on wider range of adult head dimensions and extending to smaller sizes for children.
ConclusionConclusion
Requirements may be changed after consultation with the client
From these requirements, conceptual designs will be generated and evaluated, with the successful design being further refined into a final product design.
Refer to the Group’s Website - http://www.angelfire.com/il/skullcap/
FOR MORE INFO...