Policies and Procedures: Difference between revisions
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<div style="margin-left:0.0626in;margin-right:0in;"><u>'''Policy</u>: The
'''The Voice Intercom System will be used to facilitate communicate with subjects inside the Magnetically Shielded Room (MSR). The Intercom Electronics Box is located at the acquisition workstation / operator’s console. When at the Acquisition Console, the MEG operator can communicate with the subject inside the MSR through this device. This system works like a Walkie-Talkie, that is, when the operator is talking (depressing the “talk” button he/she cannot hear the subject and when he/she releases the button he/she can hear the subject speaking.'''
<br>
'''The controls for the volume level at the console and volume level inside the MSR are located on the Electronics Box at the Acquisition Console. There are no intercom controls inside the MSR. The parabolic microphone and flat speaker are located inside the MSR.'''
<br>
'''Procedure:'''
::1. Press the Red power button to turn ON the Intercom Electronics Box .
::2. Press the PUSH TO TALK button located on the front of the Intercom Electronics Box to speak to a subject inside the MSR.
::3. Release the button to hear the subject speak.
::4. Adjust the volume inside the MSR (so that the subject inside the MSR can hear the operator) using the knob labelled “MSR” located on the Intercom Electronics Box.
::5. Adjust the volume at the Acquisition Workstation / Operator’s Console (so that the operator at the console can hear the subject) using the knob labelled “Console” on the Intercom Electronics Box.
Reference:
::1.MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc. (www.ctf.com).
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Revision as of 16:33, 16 May 2018
Policies and Procedures Manual
These documents comprise the official policies and procedures for the MEG lab.
- MEG Core Facility
Operations(1.00)
Hours of Operation
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
- 1) Normal hours of operations 9:00-5:00 pm Monday - Friday. The MEG Core Facility staff will be available to assist users during normal hours of operation.
- 2) Users may schedule scans for after hours provided they have received training and are capable of operating MEG equipment in accordance with MEG policies and procedures.
After hours use authorization must be obtained from MEG Core staff.
- 2) Users may schedule scans for after hours provided they have received training and are capable of operating MEG equipment in accordance with MEG policies and procedures.
Laboratory Access
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
- 1) MEG Users will be given the MEG Lab keyless entry code during the MEG Orientation Training class.
- 2) During Normal Hours of Operations- the MEG Lab may or may not be locked, however, if locked access may be gained / the door can be unlocked by using the access code.
- 3) After Normal Hours of Operations and on the weekends- the MEG Lab will be locked, however, access can be gained by using the keyless entry system.
- 4) All equipment, except for all computers (acquisition and workstation), must be powered off upon departure.
- 5) It will be the responsibility of the user to make sure the lab is locked upon departure.
Scheduling (2.00)
Scheduling
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- I. Requesting Time -
- 1. Click on Login location near the bottom of the MEG Schedule/Calendar.
- 2. Enter “Username” and “Password”.
- 3. Click on Login.
- 4. On the calendar - Click on the at the day and time desired.
- 5. Enter the “Add Entry” form information –
- a. Investigator’s Name - enter the last name of the PI / last name of the person who is going to run the scan (acquisition computer). For example - BERMAN / J. Mitchell. In this case Dr. Berman is the PI and Judy Mitchell is running the scan.
- b. Description of experiment – provide a simple description
- c. Comments - Use this field to enter any private comments, subject name / phone number or MIS number. Information in this box will not appear on the published calendar. Important: ::::This box is for confidential information.
- d. Sensor position – Sitting or Supine.
- e. EEG electrodes – indicate whether EEG, EOG, EMG electrodes will be used.
- f. Date
- g. Time - military time.
- h. Duration – indicate how much time needed to complete your study. Please allow enough time for any possible delays (set up / prep time, subject late, equipment malfunction, etc.).
- i. Hold approval – only use holds if your subject needs to get back with you to confirm the appointment. Appointments can only be held for 2-3 days.
- j. Participants – DO NOT ALTER THIS FIELD (should always be admin for MEG staff who are doing the scheduling).
- k. Repeat Type – if a recurring appointment enter here; however, check with Staff Scientist before scheduling any repeats!
- l. Repeat End Date – *for recurring appointments only.
- m. Repeat Day (weekly) - *for recurring appointments only.
- n. Frequency – for recurring appointments only.
- 6. Click on “Save”.
- II. To Edit or Cancel an Appointment –
- a. Click on the login.
- b. Enter User Name and Password.
- c. Click on the entry to be changed (at the point where it gives the little popup detail description).
- d. Click on option: Edit entry, Delete entry, Add to My Calendar, etc.
*Please note: you must be the owner to be able to edit or delete an entry in the schedule.
- III. To Refresh the Calendar –
- 1. Click on My Calendar.
Facility Access Requests
National Institute of Mental Health
Subject: |
Date: 3/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- 1. A Facility Access Request (FAF) must be submitted electronically to become a MEG Lab user. The form may be accessed via the MEG Lab website at: http://kurage.nimh.nih.gov/meglab under User Information Becoming a User.
- 2. All the requested information must be provided, such as the protocol #, PI’s last name and the name of the person who be in the MEG Lab running the study. In addition, we must have a cell phone number so that we can contact you in an "emergency".
- 3. The username will be the user’s last name as entered on the Facility Access Form (FAF).
- 4. When a Facility Access Request Form is received the accounts administrator will assign an account and issue a temporary password.
- 5. An email notification of the account name and temporary password will be sent to each applicant.
- 6. User accounts may not be shared.
User / Subject Guidelines (3.00)
User Guidelines
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- I. Becoming a User
- 1. Protocol Approval
- a. User groups are required to have an IRB approved protocol with a description of the intended MEG research before a user account ID or scanning time can be assigned.
- 1. Protocol Approval
- I. Becoming a User
- 2. User Accounts
- a. A Facility Access Request must be filled out electronically (http://kurage.nimh.nih.gov/meglab ) to establish a user account. Filling out this request will initiate the process of establishing a user account ID and password.
- 2. User Accounts
- b. The account ID and password will give users access to the scheduling calendar and provide access to the MEG Core Facility data storage system. All requests must be sent electronically.
- d. The account ID information will be emailed to the email address provided in the Facility Access Request Form, generally within 24 hours, if not call the Staff Engineer at 301/402-2362.
- 3. MEG Orientation
- a. Users must schedule / attend an informal MEG orientation to become familiar with the lab operations and equipment.
- 3. MEG Orientation
- b. Established users with new protocols will be required to complete a “new” Facility Access Request for each new protocol indicating the new protocol number.
- II. Initiating a MEG Study
- 1. Study Design Review
- a. Users must provide the director and/or staff scientist with a description of the research study design including information regarding setup requirements, software and equipment needs.
- 1. Study Design Review
- II. Initiating a MEG Study
- 2. System Testing / Task Setup
- a. Users must schedule a time to test their task / paradigm, equipment, software, etc. When scheduling indicate in the scheduling module that the appointment is for a “system test”.
- 2. System Testing / Task Setup
- b. Indicate whether programming or scripting support will be needed for the stimulus program.
- c. Also, indicate whether technical support is needed – i.e., training or assistance with EEG/EP electrode placement or setup. If you have a specific electrode setup or placement and require MEG Core staff assistance you must provide a detailed description of your setup.
- 3. Pilot Studies
- a. Most protocols will require a pilot study to test equipment, paradigms / programs and refine procedures with a test subject. Users must provide their own volunteer subject; if this is an external volunteer, he/she must be consented according to IRB guidelines.
- 3. Pilot Studies
- b. You must schedule time for the pilot study via the web calendar. Please indicate in the description that time is being requested for a “pilot study”.
- 4. User Training
- a. There is a three-step training program specifically designed so that users can acquire practical experience. The user is expected to become competent in performing all aspects of MEGs on their own subjects. MEG Core staff is available to provide training and technical assistance.
- 1. Instruction – (without a subject) MEG setup instructions and equipment operation.
- 2. Observation – (with a subject) instructions and observation of MEG setup and scan.
- 3. Practicum – hands on training session running a subject during a MEG scan.
- a. There is a three-step training program specifically designed so that users can acquire practical experience. The user is expected to become competent in performing all aspects of MEGs on their own subjects. MEG Core staff is available to provide training and technical assistance.
- 4. User Training
- b. User training must be scheduled via the web-based calendar. You must indicate in the description that this is MEG Training – Instruction, MEG Training-Observation, or MEG Training-Practicum. MEG staff will assist users during all phases of this training.
- 5. Scheduling Scan Time
- a. Scan time must be requested electronically via the web-based calendar at http://kurage.nimh.nih.gov/cal/. Currently scan time is scheduled on a first-come-first-served basis.
- 5. Scheduling Scan Time
- b. To Request Time – Enter User Name and Password; click on Login; enter form information; save.
- c. Approvals - All requests must be approved before they will go “live” on the public calendar. You will receive an email message notifying you that your time has been approved. All unapproved requests will appear in red.
- d. To Edit or Cancel an Appointment –
- • Enter User Name and Password; click on Login;
- • Click on the entry to be changed (at the point where it gives the little popup detail description);
- • Select an option: Edit entry, Delete entry, Add to My Calendar, etc.
- • *Please note: you must be the owner to be able to edit or delete an entry in the schedule.
- d. To Edit or Cancel an Appointment –
- e. To Update Calendar - click on My Calendar.
- f. Certain times in the schedule will be reserved for maintenance / quality assurance.
- g. Allow about 2 hrs per subject for MEG (depending upon the study) and about 3 hrs for a MEG with EEG.
- III. User Log
- Users MUST document any scan that they perform in the User Log Book. If a subject was set up for the MEG but the scan was not able to be performed – that scan must still be logged in the User Log Book with a comment explaining why the study was not performed.
- Subject information and all other pertinent information must be filled out in the log book, i.e., date, PI name, operator’s initials, protocol #, subject’s initials, MIS -#, and the gantry position. Do not leave any blank entries.
- IV. Lab Safety
- 1. Equipment Operation - When performing a MEG study there must be at least two persons assisting with a study; one person must be capable of operating the equipment.
- IV. Lab Safety
- 2. Subject Safety – a subject must never be left in the MSR. The subject must be observed at all times and must never be left alone in the MSR for any reason. Two persons must be available for assistance if the subject were suddenly to take ill or if something unexpected were to happen.
- 3. Chair / Table Safety – Care should be taken when raising the chair / table when you have a subject sitting or supine in the gantry. In order to avoid injury, it is important to understand how to operate the chair and table. Operating instructions are in the MEG Policy & Procedures Manual and the CTF Users Manual. The chair has a 300 lbs. maximum weight limit and if using the bed the weight limit is around 250 lbs. maximum.
- 4. Gantry Safety – It is important to understand how to operate the gantry. Never adjust the gantry (tilt or angle) when a subject is seated in the chair or lying on the table. Instructions are available in the MEG Policy & Procedures Manual and the CTF User’s Manual.
- 5. If a medical emergency occurs call X111. For Fire or Police call 9111. For any other emergency contact the director or staff scientist for assistance at the phone numbers posted in the lab.
- V. Process Improvement / Variance Reporting
- 1. Process Improvement / User Feedback – Users may make suggestions or give feedback to the MEG staff via the Variance Process Improvement Report. Feedback may also be provided via the MEG Discussion List at MEG_DISCUSSION@LIST.NIH.GOV.
- 2. Variance Reporting – Users are responsible for reporting complications, incidents, or problems that occur involving the facility via the Variance Process Improvement Report.
- 3. Equipment Failure -Users are also responsible for reporting any equipment failure or any equipment that may not be working properly via the Variance Process Improvement Report.
- 4. Broken Equipment - Any equipment that is inoperable or broken should be tagged with an Out of Service / Do Not Use sticker indicating the date and time taken out of service. Fill out the sticker including the name of the person making the report, phone number and a brief description of the problem.
- 5. All non-urgent communications will be reported using the Variance / Process Improvement Report.
- V. Process Improvement / Variance Reporting
- VI. Magnetically Shielded Room (MSR) Guidelines
- There are no known risks associated with MEG/EEG recordings. Although wearing metal objects while in the MSR (Magnetically Shielded Room) is not harmful to the individual, bringing metal objects in the MSR can result in a poor quality / uninterruptible recording. In addition, bringing magnetized objects into the MSR can cause trapped flux in the SQUIDS which can lead to long and expensive service to fix causing obvious interruptions and scheduling delays. Thus, we have established these guidelines:
- 1. Subjects should not bring any metal objects inside the MSR. Any subject entering the MSR must first “de-metal” (remove any metal objects; empty pockets; remove jewelry, hairclips, pens, clipboards etc.). These include belts, keys, watches, rings/earrings, necklaces, coins, eyeglasses and pieces of clothing with metal parts such as bras with under wires or bras with metal adjustment rings.
- 2. No one (not subjects / nor MEG Users) should bring electrical equipment inside the MSR. Objects such as cell phones, pagers, cameras, flashlights, or any other electrical equipment are strictly forbidden.
- 3. Magnets and anything magnetized is never allowed inside the MSR by anyone.
- 4. No one should wear shoes inside the MSR. To prevent any metal or magnetic dust from getting into the MSR shoes must be removed before entering the MSR.
- 5. Any “unapproved” equipment should not be brought into the MSR. Any “special” equipment must be approved by the director or staff scientist prior to its use.
- 6. Do not use small metal objects (i.e., staples, paper clips) around the MSR.
- 7. NO equipment will be left in the MSR other than the equipment that belongs in the MSR.
Subject Guidelines
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- 1. Subject Registration
- a. All subjects participating in MEG studies are required to have a valid medical record number (Medical Information System /MIS #).
- 1. Subject Registration
- b. It will be the responsibility of the principal investigator (PI) to make sure that all outpatients and control subjects have gone through the appropriate registration process and have a valid MIS#.
- c. A doctor’s order is not required for an MEG scan but a progress note must be placed in the subject’s chart indicating the nature of the scan performed, the date, time, and protocol number. The patient’s condition and general performance should also be noted. The progress must also be signed by the appropriate personnel.
- 2. Consent Forms
- a. An IRB approved consent form must be signed by all subjects prior to participating in any MEG research study.
- 2. Consent Forms
- b. Investigators are required to satisfy all Clinical Center documentation requirements.
- c. It will be the responsibility of the PI to assure that subjects have signed the appropriate consent form.
- 3. Subject Pre-Screening
- a. Although MEG/EEG poses no known risk to subjects, certain physical conditions may make subjects ineligible to participate in scanning. Some subjects will be ruled out for participation in scanning due to factors involving metallic foreign bodies which may prevent obtaining artifact free data.
- 3. Subject Pre-Screening
- b. It will be the responsibility of the PI to pre-screen subjects for the below listed contraindications during the selection process.
- Conditions That Will Rule Out a Subject:
- • Cardiac pacemaker / Cardiac or neural defibrillators
- • Metal fragments in the eyes
- • Metal plates, pins or bolts in head
- • Any magnetic implantation / implantations made from iron (ferrous products)
- Conditions That Will Rule Out a Subject:
- An Additional Consideration Which Will Rule Out a Subject:
- • Head size greater than 60 cm: if a subject’s head is too large to fit in the helmet
- An Additional Consideration Which Will Rule Out a Subject:
- 4. Subject Screening
- a. Investigators may use the MEG Screening Questionnaire and/or Handedness Form as a subject evaluation / screening tool.
- 4. Subject Screening
- b. All MEG subjects should be screened for the following items which may cause recording artifact.
- Conditions That May Rule Out a Subject:
- • Surgical aneurysm clips
- • Shrapnel
- • Intra-orbital metallic structures
- • Neurostimulator
- • Implanted pumps (i.e., Insulin pumps)
- • Steel pins from root canals; a permanent retainer
- • Ear implants (certain cochlear implants)
- • Metal rods, plates or screws in the body or mouth
- • Previous surgery (if metal was left in the body)
- • Hearing aids (should be removed before scanning)
- • Braces (causes severe artifact)
- • Tattoos (may have metallic paint)
- • Piercings (may have metallic ink)
- Conditions That May Rule Out a Subject:
- Other Considerations Which May Rule Out a Subject:
- • Head size: if a subject’s head is too fit in the helmet
- • Movement disorders (i.e., ticks, restless legs, etc., any condition that may cause excessive movement)
- • Vision / Hearing problems
- • Problems using response devices
- Other Considerations Which May Rule Out a Subject:
- c. The confidentially of the MEG Subject Screening Questionnaires and Handedness Forms will be the primary responsibility of the study’s principal investigator.
- 5. Subject Instructions
- a. Users/PI’s are responsible for giving subjects instructions prior to any scheduled procedure.
- 5. Subject Instructions
- b. Subjects should be informed not to wear these items:
- • Bras with underwires
- • Makeup (mascara, eye liner, eye shadow)
- • Clothing containing metallic (shiny) threads or glitter
- • Metal on clothing (i.e., metal buttons, snaps or trimming)
- b. Subjects should be informed not to wear these items:
- c. Subjects should be informed that metallic/magnetic items should not be taken into the Magnetically Shielded Room (MSR). These include such items as:
- • Belts
- • Keys
- • Watches
- • Coins
- • Eyeglasses
- •Cell phones
- • Pagers
- • Credit Cards
- • Small metal objects such as hair pins, paper clips, safety pins, etc.
- • Shoes (may have metallic dust particles on them)
- c. Subjects should be informed that metallic/magnetic items should not be taken into the Magnetically Shielded Room (MSR). These include such items as:
- d. It is the responsibility of the PI to inform subjects that if they arrive unprepared i.e., have metallic/magnetic parts on their clothing that cannot be easily removed, they may be asked to change into non-magnetic clothing which will be provided by staff.
- e. If there is any question about whether an object is magnetic, the object is not taken inside the MSR.
MEG / EEG (4.00)
MEG / EEG Setup Procedures
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- 1. Head Size / Fit Test
- a. Determine head size by measuring the subject’s head. The Gantry head limits are:
- 1. Head Size / Fit Test
Nasion-Inion Preauricular Point to
Preauricular PointCircumference < 40 cm < 40 cm < 59 cm
- b. Determine fit by placing the MEG helmet along with a protective cap over the subject’s head.
-
MEG Sizing Helmet-front
-
MEG Sizing Helmet-side
-
- 2. Fiducial Points/Head Coil Placements
*If subject has had previous digital pictures of the fiducial points retrieve images and match placement.
- 2. Fiducial Points/Head Coil Placements
- a. Place a small black dot near the nasion (indentation between the forehead and the nose); between the eyebrows midline.
- b. Place a small black dot at the left and right preauricular points centered (about 1.5Cm) in front of the tragus. This should be measured on a straight line from the tip of the tragus to the outer canthus for accuracy.
- c. Take a digital picture of these locations, download and print Place in subject’s MEG file for future reference.
- d. Attach a small (MEG) Adhesive Washers to each head localization coil.
- e. Attach head localization coils at the fiducial marks. *Make sure the marks line up with the center of the head coils. Place the:
- f. Place tape over the coil and the cable to secure.
- MEG HEAD COIL PLACEMENTS
RIGHT
PRE-AURICULAR POINTNASION LEFT
PRE-AURICULAR POINTRed Yellow Blue
References:
- 1. NIMH MEG Core Facility Data Tutorial Manual
- 2. MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc.
EEG Easy Cap Setup Procedures
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
- Procedure:
- A. Head Size / Fit Test
- 1. Determine head size by measuring the subject’s head.
- A. Head Size / Fit Test
- 2. Select cap size: Small (< 56 cm); Medium (< 58 cm); Large (< 60cm).
- 3. Determine MEG gantry fit by placing the MEG sizing helmet along with a protective cap over the subject’s head.
- B. Measuring & Marking Head
- 1. Measure and mark FP1, FP2, FPz and Cz.
- B. Measuring & Marking Head
- C. Mounting the Cap
- 1. Rotate the adaptors in cap so that the narrow opening is toward the back of the head.
- 2. Place anchoring adhesive washer on Fp1 & Fp2.
- 3. Press Fp1 & Fp2 onto adhesive washers. Have subject hold Fp1 & Fp2 in place while turning cap over the head. Gently pull cap over the head and ears into place.
- 4. Check and adjust cap so that the Cz electrode is at the Cz mark.
- 5. Check Fp1 & FP2 and O1 & O2 to assure that they are placed correctly, if not choose another cap size.
- 6. Anchor the cap either with the chest belt or the chin strap.
- 7. Snap electrodes into the adaptors in a systematic manner starting at the back of the head. Insert so that the lead wire points towards the narrow side of the adaptor.
- 8. Push electrode into the adaptor with the fingers or with the aid of an old ballpoint pen where the mine (point) has been removed. Pay attention not to bend or place excessive pressure on the lead wire where it attaches to the electrode.
Electrode Specifications
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
For large electrode arrays the use of an electrode cap system is recommended, however, alternative methods of electrode application may be used. Additionally, electrodes can be glued or pasted to the scalp using various types of electrodes. But because of the different properties of the various metals used for electrodes careful attention should be given to the choice of electrode material. These and other factors need to be considered when choosing electrodes for any MEG/EEG application. Below are the recommendations for electrode selection:
- 1. Silver/Silver-Chloride (Ag/AgCl) electrodes are recommended to take advantage of the DC response of the EEG amplifiers.
- 2. Sintered electrodes are preferred to avoid chloriding the electrodes after every few uses.
- 3. It is recommended that the lead length be at least 1.4 meters (48 inches) to allow the amplifier to be reasonably far away from the MEG sensors.
- 4. The material in the electrodes and associated connectors should be non-magnetic.
- 5. The thickness of the EEG electrode should be minimal to avoid fitting problems in the MEG helmet.
- 6. Electrodes should have the DIN style connector.
Reference:
- 1. CTF MEG System Operation and Technical Reference Manual (P/N 900-0028), VSM MedTech Ltd.
Polhemus Digitizatin System
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- 1. Mark the fiducial points (nasion, left & right preauricular points).
- 2. Take a digital picture of those points. Download to computer and print pictures.
- 3. Mount the Easy Cap on the subject. *Refer to the Easy Cap instructions.
- 4. Place the small Receiver Module at the top of the cap / head midline. Secure with tape.
- 5. Place the large transmitter on a non-metallic stand midline behind the subject. Tape the transmitter to the stand to secure.
- 6. Turn on the laptop computer:
- a. Double click on Electrode Digitizer Program. The software should detect two (2) stations if not check the connections then restart the program.
- 6. Turn on the laptop computer:
- b. In order to start - Define the Head Coordinate System.
- • Press the button on the Stylus Pen to begin.
- • To define the (head) coordinates (locate each head coil position) - Place the stylus pen tip at the center of the head coil location
(nasion, left preauricular, right preauricular) then - • Press the stylus button.
- b. In order to start - Define the Head Coordinate System.
- c. To begin Digitization – From the Laptop/Computer: Click on Digitizing Start/Stop.
- • Digitize all electrode positions by placing the stylus pen at the center of each electrode location then pressing the stylus button.
- —A single data point is collected each time the stylus button is depressed and a beep will alert the user to each acquired point.
- —The program will assign a number to the electrode position in the sequence that the electrodes are selected, I.e., 1, 2, 3, 4, etc.
- • Digitize all electrode positions by placing the stylus pen at the center of each electrode location then pressing the stylus button.
- c. To begin Digitization – From the Laptop/Computer: Click on Digitizing Start/Stop.
- • Click on Digitizing Start / Stop when done.
- • If a mistake is made:
- i) Press the stylus pen until all head coordinates have been entered then,
- ii) Press define Head Coordinates again. Do not save the previously acquired
locations simply, start over from the beginning.
- • If a mistake is made:
- d. Verify Digitization Accuracy. Review the diagram of the electrode placements which appears on the monitor. If the diagram is:
- • Correct then click on continue.
- • Not correct check to make sure that the receiver or transmitter did not move and repeat digitization.
- d. Verify Digitization Accuracy. Review the diagram of the electrode placements which appears on the monitor. If the diagram is:
- 7. Click on File / Save Menu.
- 8. Save the data to the Laptop hard drive and
- 9. Save the data to a floppy disk. The filename is the current date.
- 10. Exit the program. Eject disk. Turn off laptop.
- 11. Transfer Polhemus head coordinate file to computer at acquisition workstation / console.
- Note: The operator and anyone within 10 feet of the transmitter and receiver should de-metal. The general rule of thumb is three times the separation distance between the transmitter and receiver from any metal in the room. For example, if the separation distance is one foot, metal within three feet of the transmitter or receiver may cause distortion and inaccurate measurements.
Transferring the Polhemus Digitization File to the Acquisition Computer - 1. Insert the memory stick with the digitization file into input of the Acquisition Computer (Squid).
- 2. On the Acquisition Computer, open a new terminal window and cd to your user directory. This will be something like:
- cd users/<username>
- 3. Copy the file using mcopy:
- mcopy a:YYYYMMDD.pos
- 4. Refer to your montage file which should display the labels for the EEG electrodes
in the order in which they were digitized. This file looks something like this:- 1. fp1
- 2. fp2
- 3. f7
- 4. f3
- 5. fz
- 6. f4
- 7. f8
- and should be called: <something>.layout (e.g., “10-20.layout”).
- 5. Run the mkeeglayout.py program to create a .eeg file:
- mkeeglayout.py -l <something>.layout YYYYMMDD.pos
- 5. Run the mkeeglayout.py program to create a .eeg file:
- 6. This will create YYYYMMDD.eeg.
- 7. In Acq, click on the “Window / EEG Channel Parameters” menu.
- 8. Click on the “File / Open EEG File”, and enter the .eegfilename.
- 9. Highlight all the EEG channels by clicking and dragging.
- 10. Select “Accept New Attribute Values”.
- 11. Impedances may also be checked from this screen or Exit.
- Rev 4/12/18
Reference:
- 1. Polhemus Fastrak System (http://www.polhemus.com/fastrak.htm).
Fudicial Points Digital Images
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Three or four views will be taken: 1) Right tragus fiducial point position; Left tragus fiducial point position; Nasion position (on the forehead between the eyebrows); and 4) subject full view (this picture is optional).
Procedure:
- 1. TURN ON THE POWER
- a. Press the power button.
- 2. FOCUSING AN IMAGE:
- a. To FOCUS / FRAME images (especially when taking close-up-shots) use the SHUTTER BUTTON.
- 2. FOCUSING AN IMAGE:
- b. Frame the picture in the IMAGE DISPLAY (for a close up; with the camera about 12 inches away from the object).
- c. Press the ZOOM IN BUTTON then
- d. Press and hold the SHUTTER BUTTON (large round silver button) halfway down to allow the camera to adjust the focus and exposure, then
- 3. TAKING A PICTURE:
- a. Press the SHUTTER BUTTON all the way down to take the picture.
- 3. TAKING A PICTURE:
- 4. VIEWING IMAGES:
- a. Press the MENU / PLAY button to turn on the image display. The last picture you took or viewed appears on the image display.
- 4. VIEWING IMAGES:
- b. Use the CONTROLLER (OK) to scroll through the images.
- c. After reviewing the images, press the PREVIEW BUTTON to turn off the image display.
- 5. UPLOADING / PRINTING images:
- a. Turn camera OFF.
- 5. UPLOADING / PRINTING images:
- b. Connect the camera via the USB cable to a computer running Windows with the HP camera software (Ebi).
- c. Turn the camera on.
- d. Open the HP Photo Imaging Software by double clicking on the icon on the desktop.
- e. Right click then select "MOUNT VOLUME".
- f. Open the DCIM folder.
- g. Open the FOLDER labelled "152_(number for the current month); Jan=1, Feb=2...
- h. Copy pictures and drag to the appropriate "USER" folder. If you don't have a user folder first create one.
- i. Rename the pictures by date taken (Example, 20151201a, 20151201b, 20151201c, etc.
- j. Deletes all pictures from the Camera - if you delete the pictures from the DCIM Folder this will delete your pictures from the camera.
- k. Right click to UNMOUNT the volume.
- l. Unplug the camera.
- m. Turn off camera.
- n. Log out of the computer.
- 6. PRINTING IMAGES:
- a. Select pictures to be printed.
- b. Right Click then sleect OPEN with --> PhotoPrint. Or Left Click on FILE then --> Select Open with PhotoPrint.
- c. Click on FILE then --> /Select PRINT SETUP.
- d. Select "COLOR" as the printer (the HP Laserjet Printer near the Stimulus Computer).
EEG Impedance Check on the MEG System
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
After the electrodes are attached to the subject’s scalp / electrode cap placed, the electrode impedance(s) will be checked to ensure good contact. The impedances measured should only be used to judge scalp contact and should not be considered a precise measure of actual impedance. Ideal impedances for scalp electrodes typically range from 1-5kohms. Impedances for other non-cerebral electrodes ideally should be < 50kohms.
Procedure:
- 1. Attach electrodes to the scalp / place cap.
- 2. Touch the static discharge button before connecting electrodes or cap connector jig to the amplifier unit. Connect the electrodes or electrode cap to the amplifier unit.
- 3. Launch ACQ - Run the appropriate EEG program.
- 4. Select the EEG Setup Window menu.
- 5. Highlight desired channels.
- 6. Click on CHECK IMPEDANCE.
- a. The results are displayed in the appropriate columns.
- b. To check the impedance of all active EEG channels, press the CTRL key on the keyboard at the same time as clicking on the impedance check button.
- c. Please note: The impedance check requires 3 electrodes: The electrode being measured and at least 2 other electrodes.
- 7. Click OK / EXIT.
Reference:
- 1. Data Acquisition Manual, p/n 900-0006, CTF Systems Inc. (www.ctf.com).
EEG Impedance Check using the Grass Impedance Meter
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
An external impedance check should be performed on all electrodes used for EEG, EOG or EMG using the Grass S88 Impedance Meter. The Grass Impedance Meter measures AC impedance (resistance and capacitance). When two or more electrodes are plugged into the electrode switch positions, all electrodes except the one selected electrode being measured are connected and provide the reference for the one being measured.
To perform an Impedance Check, at least two electrodes are required to be plugged in to the impedance meter.
Procedure:
- 1. The Electrode Selector Switch should be at position 1 - 10.
- 2. Plug the ground electrode (Grd) into electrode jack 1 position.
- 3. Plug the other electrode(s) into the jack positions 2 - 10 in a systematic manner.
- 4. Press the Red ON Button to activate the impedance check. *The power will automatically shutoff after approximately 2 minutes. (There is no OFF button.)
- 5. If the impedance is too high:
- a. Take a cotton tip swab dipped in Nuprep (Abralyt or other skin prep) and twirl against the skin.
- b. Re-insert electrolyte.
- c. Re-measure impedance.
- d. Repeat this process until all impedances are within acceptable levels.
- 5. If the impedance is too high:
- Impedance Recommendations
EEG Electrodes 5-10K ohms EMG Electrodes (EOG, ECG, etc.) < 50K ohms
- 6. If the impedance exceeds 199.9K ohm, a “1” will appear in the left display window with all other digits blanked out indicating that the impedance is too high to be read:
- a. Take a cotton tip swab dipped in Nuprep (Abralyt or other skin prep) and twirl against the skin.
- b. Re-insert electrolyte.
- c. Re-measure impedance.
- d. Repeat this process until all impedances are within acceptable levels.
- 6. If the impedance exceeds 199.9K ohm, a “1” will appear in the left display window with all other digits blanked out indicating that the impedance is too high to be read:
Reference:
1. Grass EZM Electrode Impedance Meter Instructions Manual, Grass Instrument Division, Astro-Med, Inc.
Magnetically Shielded Room (MSR) & Subject Support (5.00)
Magnetically Shielded Room (MSR)
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
I. MSR Room Lighting
- Turning on the lights in the MSR:
- Depress the square green button on the VAC Power Supply Unit which is located on the bottom shelf of the equipment stand outside the MSR.
- Dimming the lights in the MSR:
- Use the Brightness (black) knob to dim the light.
- Turning on the lights in the MSR:
II. MSR Door Operation
- Closing the Door:
- 1. Push the door up to the door frame as far as possible.
- 2. Press the OPEN/CLOSE BUTTON (Black Button) until the air locks activate and the door begins to close then quickly release the button to seal the door.
- Closing the Door:
- Opening the Door:
- 1. Press the OPEN/CLOSE BUTTON (Black Button) until the air locks release and the door begins to open then quickly release the button.
- 2. Pull the door open.
- Opening the Door:
- Door Emergency Operation:
- 1. Emergency Door Open Button - If the door fails to open, press the EMERGENCY OFF BUTTON (red button) located on the wall outside of the MSR. There is also an EMERGENCY OFF BUTTON located on the inside of the MSR door.
- 2. Emergency Door Open Key - If the door fails to open when using the Emergency Off Button, then insert the EMERGENCY DOOR KEY in the upper and lower Emergency Unlock (yellow) keyholes and turn. This will manually release the door locks. Keys and keyholes are located on both sides of the MSR door.
- Door Emergency Operation:
III. MSR Monitors
- A. Oxygen Monitor
- The Safetnet Oxygen Monitor which is mounted in the MEG Lab on the wall just outside the MSR measures the percentage of oxygen in the MEG lab which may be an indication of the air exchange in the MSR and/or the general integrity of the Dewar and related equipment. Refer to Policy No. 10.15 Daily System Monitors / Quality Assurance.
- B. He Gas Flow Meter
- The Gilmont Gas Flow Meter is located inside the MSR mounted on the back left wall. It monitors the MEG Dewar helium level or rate of Helium boil off which gives an indication of the general integrity of the MEG Dewar and related equipment. Refer to Policy No. 10.15 Daily System Monitors / Quality Assurance.
- C. Liquid Helium Level
- The AMI Model 135 Liquid Helium Level Monitor which is located on the stand just outside the MSR measures the amount of helium inside the MEG Dewar. Refer to Policy No. 10.15 Daily System Monitors / Quality Assurance.
References:
- 1. VacuumSchmelze.
- 2. MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc. (www.ctf.com).
Gantry Operation
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
There are two Gantry controls which are located on the side of the Gantry base: 1) the Brake Lever and, 2) the Tilt Control Lever. The Gantry controls have been designed so that the operator is required to use two hands to operate.
- Please note:
- • The Brake Lever and the Tilt Control Lever must be engaged more-or-less at the same time.
- Please note:
- • Pulling up on the Brake Lever turns on the power and releases the brake.
- • Releasing the Brake Lever engages the lock and turns off the power.
- • The Tilt Control Lever is OFF when in the center position.
Procedure:
To re-position / move the Gantry - lift the Brake Lever and hold it in the up position then:
- 1. If raising the gantry,
- a. While still holding the Brake Lever in the release (up) position, lift the Tilt Control Lever handle until the brake is released. You might hear a click or feel the pressure release. Maintain this position until the desired angle of tilt is reached.
- b. As the Tilt Control Lever handle is lifted further the gantry will begin to rise faster.
- c. When the angle of tilt is reached first release the Tilt Control Lever and then release the Brake Lever.
- 2. If lowering the gantry,
- a. While still holding the Brake Lever in the release (up) position, lift the Tilt Control Lever handle to raise the gantry up a few degrees until you hear the click or the Dewar begins to move in the upward direction. This action will release the brake then allow the gantry to lower.
- b. Then push the Lever in the downward direction. Pushing the Tilt Control Lever handle down will cause the gantry to lower.
- 4. Returning the Tilt Control Lever to the center “OFF” position will cause the gantry motion to slow to a stop.
- 5. Release the brake lever allowing it to go back to the horizontal position to turn off the power and engage / lock the brake.
- Gantry Recording Positions
Sitting Position 15 degrees Supine Position 90 degrees Reclined Position at various degrees of tilt
References:
- 1. MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc. (www.ctf.com).
Chair Operation
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
- Please Note: Chair Weight Limit - The MEG chair can accommodate subjects who weight up to approximately 300 lbs.
The MEG Chair Height can be raised and lowered for optimal positioning of the subject in the gantry. The chair is a pneumatic-hydraulic unit and there may be a 2-3 second delay when turning controls from the unlocked to the locked position or when making chair adjustments.
- Turn the hand wheel and valves slowly when making any adjustments to allow the air pressure to equalize.
- The Chair Back Rest Tilt can be adjusted for various angles of reclined recording. And, the gantry angle can be adjusted for various angles of reclined recording, however, when the chair is in the upright position the gantry should be at 15 degrees.
- The operator should be completely familiar with the operation of the controls before operating the chair with a subject or patient’s head inside the gantry.
- There are two kinds of controls:
- -The Hand Wheel which controls the directions and rate of movement and
- -The Valve Lock controls which adjustment is selected or activated; it locks and unlocks the Back Rest and the Height controls.
Procedure:
- 1. CHAIR BACKREST ADJUSTMENT
- The TILT Valve Lock - is located on the front panel of the armrest near the top, locks and unlocks the tilt function of the chair backrest.
- 1. CHAIR BACKREST ADJUSTMENT
- a. Slowly turn the TILT Lock Valve to the unlocked position.
- b. Start in the upright position then adjust of necessary or requested by the subject. Position the backrest to provide the optimal level of neck and back alignment and comfort.
- c. With the TILT Lock Valve in the UNLOCKED position the hand wheel controls the movement of the backrest / the backrest angle. Turn the hand wheel:
- • Clockwise to move the backrest forward.
- • Counter-clockwise for backward motions.
- d. The Lock Valve should always be left in the LOCKED position unless adjustments are being made.
- 2. CHAIR HEIGHT ADJUSTMENT
- The ELEVATION Lock Valve – located on the front panel of the armrest near the bottom, locks and unlocks the height function of the chair.
- 2. CHAIR HEIGHT ADJUSTMENT
- a. Slowly turn the Elevation Lock Valve to the unlocked position. * If this valve is released too fast the chair will “jump” in the direction last activated.
- b. Position the subject so that his/her head is at or near the top of the dewar. Care should always be exercised when adjusting the chair height while a subject is seated under the gentry. *When trying to determine how close to the top of the Dewar the subject is positioned periodically ask the subject to raise himself/herself up in the dewar to determine how much room is remaining. Do not raise the chair while the subject is rising up in the chair. Ask the subject to relax back to whatever is comfortable for them, then adjust the chair to the subject.
- c. Turn the Hand Wheel:
- • Clockwise to make the chair move upward.
- • Counter-clockwise for downward motions.
- c. Turn the Hand Wheel:
- d. Turn the Elevation Lock Valve to locked position unless adjustments are being made.
- e. When lowering the chair leave at least 3 inches in the bellows.
- 3. CHAIR MOVEMENT
- The BRAKE Lock Valve - is located on the side panel. It locks and unlock the brakes for the chair’s back and forward movement on the (plexiglass) track. The brake provides only a light braking effect.
- 3. CHAIR MOVEMENT
- a. Turn the valve to the UNLOCKED position. While it is possible to move the chair with the brake in the LOCKED position this should be avoided as it will cause premature wear to the brake pad.
- b. Physically push the chair back so that the subject’s head is positioned directly under the gantry; the back of the head should at the back of the dewar. Two people are required to move the chair so that the chair glides evenly on the track and is not torqued to one side or the other which might damage or break the track. Move the chair into position with one person pushing from each side of the chair.
- c. After adjusting the chair set the Brake Valve to the LOCKED position to prevent movement of the chair.
- d. When done recording, unlock the Brake Valve to move the chair forward to allow the subject to exit the chair without bumping their head on the Dewar or the Dewar arm.
- Always check to make sure that cables are not on the track before moving the chair.
References:
1. MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc. (www.ctf.com).
Bed Operation
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Please Note: Bed Weight Limit - The MEG bed can accommodate subjects who weight up to approximately 250 lbs. Before placing the bed, the chair must be at the lowest possible height. The arm rest must be removed and the chair back rest must be tilted to approximately 45-degrees. The gantry must be tilted to 90 degrees. Two people must manually lift the bed and place it onto the chair pedestal.
Procedure:
- 1. Lower the Gantry to 90o tilt (horizontal position). Gantry Controls are located on the right side of the base. The controls require the operator to use both hands to operate. If either handle is released the gantry motion will stop.
- a. Raise the Brake Control Lever (lower / long handle).
- b. Then raise the Direction Control Lever (upper / shorter handle). This will release the brake.
- c. Then move the Direction Control Lever in the downward direction.
- d. Using the Angle Indicator readout located on the gantry near the front pivot point position, lower the gantry to 90 degrees.
- e. Release the Direction Control Lever to stop the motion. Release the Brake Control Lever.
- 2. Lower the chair and slide the chair forward.
- 3. Recline the chair backrest to approximately a 45 degree tilt.
- 4. Remove the arm rest from the chair.
- 5. The back cushion may be removed or left in place.
- 6. If the top portion of the bed will have its angle adjusted, place the Roller Wheel Assembly and follow the steps below; if not skip to section 7.
- • If the chair back cushion has been left in place, first slide the backrest cushion to its lowest position.
- • Mount the Roller Wheel Assembly to the exposed seat back support plate. *These steps are optional if the bed it is to be used in the flat/horizontal position.
- • If the head end cushion will have its angle adjusted, the cushion lock bolts should be removed from their locked position and stored in the holes I the blocks to which they are tied.
- • The head end cushion of the bed can be adjusted in angles from horizontal to approx. 30 degrees using a link to the adjustable chair backrest.
- 7. Using two people, lift the bed by the ends using the hand grips which are mounted to the under side of the bed. *Lift the bed above the optical cables and any other sensitive equipment.
- 8. Set the bed onto the unpadded armrests of the chair. Align the holes on the bed frame with the holes on the pedestal.
- 9. Insert the four mounting bolts, which are tied to the base of the bed, through the holes in the bed base / pedestal.
- a. All four bolts should be screwed in a couple of turns and
- b. Fully tightened when all four are engaged.
- 10. Raise the bed so that it is level with the Dewar.
- 11. Slide the bed back so that it rests against the Dewar.
- Never operate the gantry while a subject’s head is in the helmet.
- For subject safety one side rail must be in place before allowing a subject to get onto the bed; place the second rail after the subject has mounted the bed.
References: 1. MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc. (www.ctf.com.)
Stimulus / Response / Monitoring Equipment (6.00)
DLP Projector
National Institute of Mental Health
Subject: |
Date: 5/18 |
Recommended By: |
Distribution: MEG Core Facility |
- The ProPixx DLP Back Projector system consists of a projector and a screen mounted to the gantry. Images are projected through a hole in the shielded room wall into a set of mirrors which projects the image onto the screen.
- Features:
- -The image size is up to 40 degrees visual field for eye-screen distance of 37.2 to 52.5 cm.
- -a native resolution of 1920 x 1080 and can be driven with refresh rates up to 500Hz (RGB mode) or 1440 Hz (Greyscale mode) with deterministic timing.
- -Uses high brightness LEDs as a light source, giving a larger color gamut
- -The LEDs support high bit depth and high frequency full color stimulation.
- -TACHISTOSCOPC stimulation capability.
- Equipped with:
- -a complete digital I/O subsystem that synchronizes subject I/Os to video refresh with microsecond precision.
- -High-contrast white screen for precision color operation.
- I. Powering the Projector:
- *The Projector has a 30-40 ms delay before it displays an image.
- II. Positioning the Projector:
- The position of the projector does not need to be changed. For further information or help see MEG Staff.
- III. Lens Adjustments:
- Manual Adjustment
- To Focus - Turn the knurled ring (the silver and black lens collar) at the outer end of the lens to adjust the focus until the image is sharp.
- *The projector lens should be centered in the middle of the screen and should be perpendicular to the mirror; otherwise the image will be distorted, making viewing difficult.
- To Focus - Turn the knurled ring (the silver and black lens collar) at the outer end of the lens to adjust the focus until the image is sharp.
- Manual Adjustment
- To Zoom - Turn the smooth ring on the lens, closest to the case, to adjust the zoom so that the image fills the screen.
- IV. Program Adjustment:
- All functions, like resolution, can be changed from the desktop of the stimulus computer. However, if changes are made, please change back to the default settings when done.
- V. The Remote Controller:
- The Remote control has a 40 degree reception angle. The Remote must be pointed at the projector's LED (which is located in the back left corner of the projector) within that 40 degree angle to be received.
- Using The Remote To Power The Projector On - Press POWER ON on the Remote Control to switch the projector ON.
- Using The Remote To Power The Projector Off - Press POWER OFF on the Remote Control to switch the projector to OFF / SLEEP mode.
- VI. Projector Status Indicators:
- The Projector's LEDs supply info on the power status and the energy status of the projector.
•AWAKE MODE: Press the POWER button and release, the projector will power ON.
The LED will be a solid BLUE light.•SLEEP MODE: Press the POWER button for 3 secs,
the LEDs will be a solid RED.
The projector will be in the sleep mode.
•THERMAL SHUTDOWN: Flashing RED LEDs indicates the lamp is shutting down.
When flashing stops, the projector is in the SLEEP Mode (OFF)
as indicated by the solid RED LEDs.
- VII. Reversing The Projection Scheme For Supine Recording – To Be Determined
- a. Press MENU.
- b. Use OPTION2 menu
- c. Select REAR projection- choose this option if pictures are projected from the rear of a reflective screen.
- d. Select CEILING mount – choose this option if the projector is installed on the ceiling (or upside down).
- VII. Reversing The Projection Scheme For Supine Recording – To Be Determined
- VIII. Mirror Adjustments
- Wall Mirror Adjustments for Seated Recording:
- 1. Project an image onto the mirror.
- Wall Mirror Adjustments for Seated Recording:
- VIII. Mirror Adjustments
- 2. Adjust the wall mirrors:
- a. Position the top mirror in front of the lens so that the image is reflected down to the bottom mirror.
- 2. Adjust the wall mirrors:
- b. Adjust the bottom mirror so that the image is projected centered onto the screen.
- IX. Ceiling Mirror Adjustments for Supine Recording:
- 1. Place the ancillary wall mirror (smaller mirror) on the 2nd set of wall brackets.
- IX. Ceiling Mirror Adjustments for Supine Recording:
- 2. Position the top mirror so that it projects onto the smaller mirror. Position the smaller mirror so that it projects onto the ceiling mirror.
- 3. Slide the ceiling mirror into position so that the image from the ceiling mirror is projected onto the screen.
- X. Screen Adjustments – There are two screens:
- a) the original screen with the original color pallet and,
- b) a white screen for high-resolution color.
- X. Screen Adjustments – There are two screens:
- 1. Position the screen so that the image is projected centered onto the screen. If possible, the screen should be perpendicular to the floor.
- 2. The screen distance can be increased or decreased by loosening the black knob located on the telescoping screen arm and adjusting the arm length.
- 3. If necessary, the screen can also be removed and flipped so that it is closer to the subject. Loosen the knob located on the telescoping screen arm. Pull the arm out, flip the screen and re-insert. Position the screen and tighten the knob.
- 4. Use the black knob located on the gantry mounting bar to raise and lower the screen.
- *If you use the High-Resolution Screen please put the original screen back in place when done.
Reference: 1. Propixx DLP Projector User Manual.
Nerve / Muscle Stimulator
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
The Grass S88 Stimulator is a dual output general purpose stimulator intended for nerve and muscle stimulation procedures. The two output channels can be operated independently or synchronized to produce complex paradigms. The outputs are non-isolated constant voltage positive pulses. Features include computer compatibility and flexibility of synchronization circuits: the synchronous inputs and outputs are TTL, 5 volts, PC compatible. A rear DB25S connector permits external analog control of the timing circuits. The Stimulus Isolation Unit (SIU) allows for applications requiring isolation and/or constant current. Grass S88 Electrical Nerve/Muscle Stimulator - Stimulation is triggered via TTL outputs from the S88 to the MEG system electronics.
Procedure: 1. Power Switch a. The POWER toggle switch is flanked by the ON pilot lamp and the red overload lamp.
b. In the ON position, the pilot lamp will glow orange, indicating that line power is being supplied to the instrument.
c. The OVERLOAD lamp will glow red in the event of a short circuit at either output. The circuit overload shuts off the HIGH VOLTAGE power supply.
d. The red indicator lamp will remain ON until the POWER switch is turned OFF for a few seconds.
2. Stimulus ON-OFF-ON Lever Switch a. The STIMULUS ON-OFF-ON LEVER SWITCH is located at the right-hand corner of each channel.
b. The upper ON position is for continuous voltage at the output; the lever switch will remain depressed (in the on position) when released; power will remain ON until the lever is switched to the up or off position.
c. In the lower ON position the lever switch will remain ON only if it is depressed; it will return to the OFF position as soon as it is released.
-1-
MEG Core Facility Grass S88 Nerve/Muscle Stimulator Procedures Manual Policy No. 6.10 -2-
3. Stimulus Mode The S88 FUNCTION can be set to deliver: a. Single – the RED SINGLE pushbutton is for manual operation (single independent pulses); also, delivers single repetitive stimulus. b. Repeat – repetitive stimulus; continuous presentation of a selected stimulus pattern (recurring pulses). c. Trains – trains per seconds (TPS) covers a range of 0.01 to 100 TPS; delivers a select number of pulses in defined intervals/delays. d. Twin Pulses – pulse per seconds (PPS); delivers two pulses of identical voltage and duration; the time between the onset of the first and second twin pulse is determined by the DELAY Circuit; twin pulses can be obtained singly, repetitively on in trains of pulses (can be used to determine nerve and muscle refractory times. e. Trains of Twin Pulses – delivers two pulses together in a series in defined intervals/delays from its single output.
4. Controls
All controls are equal to the setting on the dial multiplied by the setting indicated on the decade (multiplier) switch.
a. Rate – determines the rate at which pulses are delivered in pulses per second (1/100 sec to 100 PPS).
b. Delay – length of time before the pulse starts; pre-pulse interval (10usec to 10 sec).
c. Duration – pulse length; determines the length of time (T) in milliseconds that a pulse of a given frequency and voltage is delivered [1 msec to 10,000 msec (10 sec)].
d. Volt Control - Controls the intensity / strength of the pulse; range at the output is from 0.01 to 150 volts. Always begin with the VOLTS dial set to minimum (1) and increase until the desired stimulus intensity is achieved.
e. Voltage Decade (multiplier) Switch- multiplier switch; the output impedance is also determined from the Volts Decade Switch.
• In the first four positions, the output impedance is 250 ohms and is constant at these four positions: i. X.01, ii. X.1, iii. X1 and iv. X10(SIU).
• At X10(25Ω) the output impedance is 25 ohms.
• For special applications requiring low impedance, high current output - set the multiplier to X10(25Ω). This position is provided for use with low impedance electrodes to obtain a relatively high current out. When using this mode, caution should be taken since very high stimulus currents can be delivered.
• When a Stimulus Isolation Unit (SIU) is connected in series with the output the:
i. X10(SIU) position is recommended for 15 to 150 volts out; *The SIU7
Isolation /Constant Current Unit should be operated at all times with the stimulator VOLTS multiplier set to the X10(SIU).
ii. X1 position is recommended for outputs of less than 15 volts.
MEG Core Facility Grass S88 Nerve/Muscle Stimulator Procedures Manual Policy No. 6.10 -3-
f. Train Rate – in the S2 TRAIN position, trains of stimulus patterns are presented at the output of S2 at the rate set by this control.
g. Train Duration - in the S2 TRAIN position, trains of stimulus patterns are presented at the output of S2 at the duration set by this control.
h. Train Mode – To obtain trains, this switch must be in the SINGLE or REPEAT position.
Grass S88 Stimulator Specifications Train Rate (S1 and S2) 1/100 sec to 100 TPS (4 decades) Train Duration 1msec to 10 secs (4 decades) Rate (S1 and S2) 1/100 sec to 1000 PPS (5 decades) Pulse Delay (S1 and S2) 10usec to 10 secs (6 decades) Pulse Duration (S1 and S2) 10usec to 10 secs (6 decades) Synchronous Outputs (TTL) S1, S2 S1 Delay, S2 Delay, Train; Front Panel: 10 usec, 50Ω Rear Panel: 1 or 10 msec and Train End Synchronous Inputs (TTL) Train Duration, S1 Delay, S2 Delay, Trigger from rising or falling edge Rear Connector (DB25S) All SYNC INPUTS and OUTPUTS; External Analog Timing Control Volts Out (S1 and S2) 10mV to 150V (4 decades) Peak Output Current 150mA with 1000Ω on highest range Output Impedance 250Ω nominal on all voltage ranges 25Ω and 100kΩ on highest range AC Power 115/230V, 50/60Hz, 125 watts peak, 20 watts standby
The maximum power output is 22 watts. Current out is 150 milliamperes with a 1000-ohm load. Output Impedance is determined by the position of the VOLTS multiplier switch. All parameters are accurate to +5%.
• The output is a positive (with respect to chassis ground) non-isolated constant voltage square pulse. • The S88 cannot deliver a true symmetrical biphasic pulse which is equal in positive and negative amplitudes. • However, if a Model Stimulus Isolation Unit (SIU)5 is used at either the S1 or S2 output, a biphasic waveform can be produced which, although not symmetrical, does have a negative and positive component which is equal in effective energy in terms of coulombs, if averaged over a sufficiently long period of time. • It is possible to obtain a true symmetrical biphasic pulse by mixing the output pulses from both S1 and S2 outputs through two Stimulus Isolation Units. Polarity can be changed only by connecting the S88 in series with an SIU and reversing polarity at the output of the SIU.
Reference:
1. Grass S88 Muscle / Nerve Stimulator Manual
Auditory Stimulus System
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
determined by the user or staff.
The auditory stimulus is produced using Presentation or SoundBlaster software. The interface includes: a Stereo amplifier, a pair of low-distortion silicone tubes which have
about a 10 msec delay (due to the length of the tubing) and a bandwidth of 5kHertz, foam ear inserts (in various sizes) to fit in the subject’s ear canal, and a sound level meter
to calibrate sound delivered to the subject.
Procedure:
1. Attach the Foam Ear Tip Insert into the short Auditory Tubing Inserts. A connector (tube nibble) is required to keep the insert from coming out.
2. Attach the short Auditory Tubing Inserts onto the end of the Low Distortion Silicone Auditory Tubes which are hanging on each side of the Gantry mounting bar.
- Place Red on the right side and the Blue on the left.
3. Slowly roll (rather than squeeze) the Foam Ear Tip into so that they are as small as possible.
4. Quickly insert the compressed plug well into the ear canal.
5. Hold in the ear with finger tip until expansion is complete.
6. Repeat process for the remaining ear.
7. The tubing may be taped to the ear or on the subject’s cheek to assure that
- the insert does not become dislodged during testing.
8. Click on Presentation or SoundBlaster software from the desktop on the Stimulus Computer located at the operator’s console.
9. Test to make sure that the equipment is working properly and to assure that the sounds
- are being delivered to both left and right ears.
10. Adjust the sound intensity to the desired level (db).
How To Place Foam Ear Tip Inserts
For A Secure & Comfortable Fit1. Roll the tube really tight (usually better if you use both hands). 2. Figure out how the tube should go in the ear canal first by determining
the angle of the ear canal. Generally, the ear canal goes up at an angle.3. Pull the ear out and up to open up the canal. 4. Then gently push the tube in so that it is situated behind the tragus. 5. Hold the tube in place for several seconds to allow the tube to expand in the ear canal.
*If you do not hold the tube in place while it expands it is possible that it might be push out
of the ear canal while expanding.Note: if the tube does not go or fit in the ear canal do not force it in; take the tube back out and re-roll;
if it still does not fit, use a smaller size.
Reference:
- 1. Auditory Tubing User Instructions.
Eye Tracking System
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
The Infrared Eye Position Tracking System – The infra-red eye tracking system captures a zoomed in video of the subject’s eye after calibration, and can estimate
gaze position onto a screen providing gaze coordinates and pupil dilation. Gaze position can then be broadcast to the stimulus and/or ACQ computer for
real-time or post-hoc analysis.
The Infrared Eye Position Tracking System includes the:
- 1. Infrared Camera (located in the MSR).
- 2. Infrared Light
- 3. Eye Tracking Computer
- 4. Eye Tracking Software
Response Devices
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Procedure:
- I. Lumitouch Response Pad
- The Lumitouch is a fiber optic response keypad where there are five response buttons arranged in a row to correspond to the thumb and the fingers. The response keypads and cabling are fabricated from 100% plastic materials and therefore do not cause electromagnetic interference. The fiber-optic cables run from the pads through a wave guide to a controller box which is connected to the stimulus PC via a USB cable.
- 1. Place the response pad on the left or right arm rest.
- 2. Arrange fingers so that all or a subset of fingers can be used in natural
- order and positioning when responding to visual and/or auditory stimuli.
- 3. Place the cables so that they are not on the MEG chair’s track when the chair is being moved.
- 4. Instruct the subject in the use of the Lumitouch Response Keypad for the research study task.
- II. FORP Response Pad
- The FORP is a Fiber-Optic Response Pad (FORP) where the 4 keys arranged in a diamond pattern. There are 4 colored buttons which are arranged in a diamond pattern: Blue=1, Yellow=2, Green=3, Red=4. The response keypads and cabling are fabricated from 10% plastic materials and therefore do not cause electromagnetic interference. The fiber-optic cables run from the pads through a wave guide to a controller box which is connected to the stimulus PC via a USB cable.
- 1. Instruct the subject to hold or cup the response pad in the dominant or non-dominant hand while using the thumb to respond to the appropriate color, position, number or pattern. ::::Position the pad so that the cable is in the superior orientation.
- 2. Place the cables so that they are not on the MEG chair’s track when the chair is being moved.
- 3. Instruct the subject in the use of the FORP Response Pad for the research study task.
- III. Joy Stick Control
- The Joy Stick is a manual input device with a moveable control lever that can be tilted in various directions to control pointing devices or on-screen objects used for graphic applications.
- 1. Instruct the subject to grasp the joystick control lever.
- 2. Place the cable so that they are not on the MEG chair’s track when the chair is being moved.
- 3. Instruct the subject in the use of the joystick for the research study task.
- IV. Motion Detector
- The laser Motion Detector is a device that contains a physical mechanism or electronic sensor that quantifies movement which is integrated with or connected to other devices that alert the user of the presence of a moving object within the field of view.
- V. Optical Microphone
- An Optical Microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal.
- VI. Pneumatic Air Pressure Device
- The Pneumatic Air Pressure Device is attached to the pressure response ball which the subject squeezes to indicate a response. The unit can be calibrated for a gradated response or the thresholds can be set to give an on / off response.
Stimulation Devices
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
response input, subject reaction and / or response time.
Procedure:
- I. Air Puff Stimulator
- The Air Puff Stimulator is a tactile sensory nerve stimulator. The Air-puff stimulator is applied to the fingertip. It produces a puff of air which provides tactile stimulation that
produces a measurable sensory response in the nerve.
- II. LED Flasher
- The LED Flasher is a light emitting diode which flashes a red strobe light for visual system stimulation.
- III. PIEZO BUZZER
- A buzzer device which has no moving parts which uses the electromechanical interaction between the mechanical and the electrical state in a crystalline material to measure
pressure, acceleration, strain or force and converts them to an electrical charge.
Video Camera Operation
National Institute of Mental Health
Subject: |
Date: 11/03 |
Recommended By: |
Distribution: MEG Core Facility |
using the Video Cassette Recorder. The video camera system will be utilized in accordance with the manufacturer’s guidelines and MEG Core Facility policies and procedures.
There are two cameras located inside the MSR: 1) an infrared and 2) a color camera. The infrared camera is displayed on Channel 1; the color camera is displayed on Channel 2.
Procedure:
- 1. Position / Re-position cameras manually for optimal viewing / display.
- 2. Press the channel button located on the Video Display Monitor to change from Camera 1 to Camera 2 or vice versa.
Voice Intercom System
National Institute of Mental Health
Subject: |
Date: 11/03 |
Recommended By: |
Distribution: MEG Core Facility |
The Voice Intercom System will be used to facilitate communicate with subjects inside the Magnetically Shielded Room (MSR). The Intercom Electronics Box is located at the acquisition workstation / operator’s console. When at the Acquisition Console, the MEG operator can communicate with the subject inside the MSR through this device. This system works like a Walkie-Talkie, that is, when the operator is talking (depressing the “talk” button he/she cannot hear the subject and when he/she releases the button he/she can hear the subject speaking.
The controls for the volume level at the console and volume level inside the MSR are located on the Electronics Box at the Acquisition Console. There are no intercom controls inside the MSR. The parabolic microphone and flat speaker are located inside the MSR.
Procedure:
- 1. Press the Red power button to turn ON the Intercom Electronics Box .
- 2. Press the PUSH TO TALK button located on the front of the Intercom Electronics Box to speak to a subject inside the MSR.
- 3. Release the button to hear the subject speak.
- 4. Adjust the volume inside the MSR (so that the subject inside the MSR can hear the operator) using the knob labelled “MSR” located on the Intercom Electronics Box.
- 5. Adjust the volume at the Acquisition Workstation / Operator’s Console (so that the operator at the console can hear the subject) using the knob labelled “Console” on the Intercom Electronics Box.
Reference:
- 1.MEG/EEG Operation and Technical Reference Manuals, CTF Systems Inc. (www.ctf.com).
Data Acquisition / Data Analysis (7.00)
Data Acquisition
National Institute of Mental Health
Subject: |
Date: 10/03 CURRENTLY UNDER REVISION
|
Recommended By: |
Distribution: MEG Core Facility |
The Acquisition Computer controls all aspects of electronics, tuning, aquisition and data storage. The Acquisition Computer is configured with CTF's Omega software.
Infection Prevention / Control (9.00)
Infection Control / Universal Precautions
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
Quality Assurance / Risk Management (10.00)
QA /QI Risk Management Plan
National Institute of Mental Health
Subject: |
Date: 1/03 |
Recommended By: |
Distribution: MEG Core Facility |
to pursue opportunities for improvement. The quality of services provided will be identified by predetermined, validated and/or approved criteria, indicators, standards, practice
guidelines, and/or parameters which are objective, measurable, based on current knowledge, research practice and/or experience and defined within institutional, departmental
and laboratory policies and procedures.
Procedure:
STEP I. ASSIGN RESPONSIBILITY
- Identify the principle person responsible for administering the program and others team members’ responsibilities.
STEP II. DEFINE THE TYPES OF SERVICES PROVIDED –
- Identify the types of services.
STEP III. DELINEATED SCOPE OF SERVICES -
- Identify groups / clientele serviced and staff responsibilities / duties in providing services.
STEP IV. DETERMINE IMPORTANT ASPECTS OF CARE -
- Identify broad categories of areas of interest, opportunities for improvement, problems or areas of concerns.
STEP V. IDENTIFY INDICATORS –
- Identify specific components of care (problems or concerns) to be studied based upon written criteria, standards, guidelines,
and parameters of care or services, relevant to the essential or critical aspects of care or services.
Indicators - are problems or concerns. Criteria - are predetermined measurable elements used as a basis for establishing standards. Standards - are professionally developed expressions of the measure of acceptable variation from a given norm or criteria.
- Indicators can be:
- - used to review staff performance, systems processes, practices, supplies, equipment, facility conditions, etc.
- - drawn from standards of professional practice, significant changes in occurrence, size, or scope in the results of care or services
- provided and facility standards; institute policies and procedures; standards developed by professional organizations; standards
- established by accreditation organizations.
- provided and facility standards; institute policies and procedures; standards developed by professional organizations; standards
- Indicators can be:
STEP VI. DETERMINE THRESHOLD LEVELS FOR INDICATORS -
- Threshold is the beginning or starting point of an evaluation of care and/or service triggered by exceeding pre-established indicators, criteria.
STEP VII. COLLECT AND IDENTIFY DATA -
- Tabulate, summarize and where appropriate statistical analysis will be performed on the select aspects of service for a specified period of time. Once tabulated, data will be considered as “fact” for the purposes of the study.
STEP VII. EVALUATE AND ANALYZE DATA / IDENTIFY DEFICIENCIES -
- A. Determine Appropriateness - The study should answer questions such as: Are studies being conducted appropriately? To answer questions relating to the study proper benchmarks must be constructed which correctly identify efficacious procedures, optimal outcomes or ideal organization.
- B. Evaluate and Revise Criteria - Criteria are used to measure the extent to which the actual delivery of service conforms to the optimal delivery of service. The criteria used in evaluation studies should attempt to establish the parameters of legitimate medical or clinical conduct in relation to a particular problem, population, modality or program.
- C. Evaluate Data - Appraise and assess data.
- D. Identify Deficiencies - Recognize opportunities for improvement and categorize deficiencies.
STEP VIII. INSTITUTE CORRECTIVE ACTION / INTERVENTIONS / PLAN OF ACTION -
- A. Personnel deficiency problem:
- 1. Lack of knowledge → education.
- 2. Lack of skill → training.
- 3. Attitudes in relation to task → education / training / discipline.
- 4. Lack of adequate staffing → hiring / re-allocation of manpower or duties.
- A. Personnel deficiency problem:
- B. Program deficiency problem:
- 1. Structure.
- 2. Policy.
- 3. Procedure.
- B. Program deficiency problem:
- C. Organizational deficiency problems:
- 1. Structure.
- 2. Policy.
- 3. Procedure.
- C. Organizational deficiency problems:
STEP IX. OUTCOME OF CORRECTIVE ACTION TAKEN / ASSESS OR MONITOR THE IMPACT -
- The impact of the corrective action will be observed via the Variance process. At a reasonable time after corrective action is completed, indicators/deficiencies will be:
- A. Reviewed - to determine that appropriate changes have occurred.
- B. Re-audited - whenever there is an overall average of less than 85% compliance.
Training & Education (11.00)
Compliance (12.00)
Quality Assurance Manual
This manual contains information on the MEG Core Facility Quality Assurance - Quality Improvement / Risk Management Program. These programs monitor and evaluate the quality of services provided in order to pursue opportunities for improvement. This manual is currently under development.
Tutorials
Here is some tutorial documentation that has been compiled as a complement to the information available on the website. Some of the topics are covered in more depth in these manuals, although the information on the website may be more current.
MEG Data Acquisition Tutorial (last updated 8/22/03), update coming soon)
MEG Data Acquisition Tutorial (last updated 8/22/03), update coming soon)
MEG Data Analysis Tutorial (last updated 8/13/03, update coming soon)
MEG Data Analysis Tutorial (last updated 8/13/03, update coming soon)
How To Instructions
These are instructions or handouts which cover various different topics pertinent to the performance of MEG scans and/or data analysis.
*MEG Fiducial Placement Instructions *
MEG Fiducial Placement Instructions
Octave Class
Tom gave a short tutorial on switching from Matlab to Octave. Here are the class notes: Octave class (MS PowerPoint Presentation) This reflects versions 2.9.10 of Octave. Also, here are two sample scripts:
*anything.m *
mkmesh.m
Miscellaneous Documentation
SensLayout-275 — a color picture showing the sensor names and relative locations (ps).
SensLayout-275 - a color picture showing the sensor names and relative locations (pdf).