Frequently Asked Questions about the F1000
|Computer Requirements (2/8/02) New||Training Screen & Games||Shielded Cables (5/7/97)|
|Printers (2/8/02) New||Real Time Feedback||Verifying Hookups|
|Are Batteries Required?||"Sustained Activity Training"||Isn't EEG Sufficient?|
|Technical Support||EEG Amplifiers||Importance of signal integrity|
|Clinical Support||F1000 Sound System|
|Scrolling Displays||Multiple Stations(9/26/97)||F1000 hardware|
Q. What are the computer requirements for the F1000?
A. The F1000 will run on any IBM compatible computer capable of running Windows 98 so long as it provides a full length ISA card slot.. Any of todays computers are plenty fast for the F1000.
Unlike many instruments on the market, the F1000 does not use special serial or parallel ports and will run on virtually any computer. We do not use interrupts or DMA which can create conflicts between installed hardware and require involved configuration. The F1000 Interface Board plugs directly into card slot in the computer. This gives us direct fast access to the computers resources through the very stable ISA bus. This requires a full length ISA card slot be available in the computer. Newer name brand computers have eliminated the ISA card slot as part of a trend toward new interface standards. We have found that the custom computer shops can still build a computer that will work. Call us if you have any questions.
Q. What printers are supported by the F1000?
A. Any printer that is compatible with the Epson 24 pin color standard or the HP PCL 3 language standard will print in full color on the F1000. The printer must connect to the computer via a parallel printer port. A USB connection will not work.
The rapidly changing printer market has made it impossible to provide a list of compatible printers. Visit the Hewlett Packard web site www.hp.com for information on current and older printers.
Q. Why does the F1000 use its own sound system rather than an external sound card?
A. Computer sound cards are designed to simulate the sounds of musical instruments. When an instrument is played it produces a sequence of harmonics that vary with the attack, sustain, release characteristic that makes it familiar. While this type of synthesis can produce pleasing music, it is not suited to the requirements of proportional feedback information.
The F1000 uses a Yamaha synthesizer chip found in many of the quality keyboards. By making the chip part of the F1000 interface board, we have complete control over its operation and can make a variety of sounds not available on sound boards.
Q. Some systems advertise the availability of a large number of training screens for ADHD. What is available on the F1000?
A. The F1000 supports useful range of approaches to working with attentional difficulties. However, the issue here is not the number of screens, but rather the appropriateness of the training experience. F1000 training screens are designed to make the training objective foreground, and to avoid clutter. The training experience is informative rather than entertaining.
Q. Does the F1000 provide Real Time feedback?
A. Focused Technology does not resort to the use of meaningless terms such as "Real Time" to describe feedback speed. Instead, we publish the actual measured delays of the various filter types we make available. The 2 digitally tunable analog filters available in the F1000 provide response times which are as fast as the measured waveform allows. We then apply appropriate smoothing to achieve effective feedback. As an example, a 15-21 Hz beta filter with a smoothing factor of 10, results in approximately 50 milliseconds to produce a perceptible change in feedback.
Focused Technology is a pioneer in advocating and providing fast loop feedback. It has been a part of the F1000 since its inception.
Q. Does the F1000 provide what is sometimes referred to as "Sustained Activity Training"?
A. Sustained Activity Training refers to limiting feedback to activity sustained over "meaningful" intervals. The F1000 inherently provides this type of feedback in several ways. First, the smoothing method used in the analog filter systems results in output that is a function both of amplitude and duration. Increasing either the length or amplitude of an EEG event will result in increased feedback. Secondly, the F1000 feedback is proportional rather than binary. Feedback graphic and sound indicate the amount of signal produced giving the subject an indicator of success. Finally, the reward counter requires that the subject make criteria for a set time to receive a count. If criteria is lost, the time must be made again.
This has been a part of the F1000 for a number of years.
Q. Some systems provide only EEG feedback. Isn't EEG sufficient?
A. The EEG is a complex signal which is a mixture of activity in the brain. Often the EEG simply does not provide the specific information that is available in the autonomic modalities. The ability to monitor and feed back temperature, skin conductance, EMG, heart rate, and respiration in addition to EEG offers a look at the whole person. The availability of the autonomic modalities add endless possibilities to training and assists in watching for other components such as PTSD. You are not encumbered by the need to adhere to a narrow protocol which only addresses the needs of a small subset of potential clients.
Q. How does the F1000 hardware differ from other systems on the market?
A. The F1000 uses an integrated hardware interface to provide quality data to the computer.
EMG/EEG data are processed through separate isolators to avoid cross talk and artifact generation. Preamplifiers, isolators, and isolated power supplies (no batteries are required) are located in an external case. Processed signals are sent to an interface board installed in the host computer.
EEG/EMG signals are processed through tunable hardware filters and level detectors before analog to digital conversion. The filters continuously process signals without the use of computer resources. The filter output is typically read by the computer at 1/64 second intervals. Filter channel response time is very short and is primarily dependent on the nature of the physiological signal. Raw signals can also be monitored and processed, but with the same inherent limitations mentioned above. Raw signals can be sampled at rates up to 4096 samples/sec depending upon the computer speed and other tasks in progress. Data is converted by a 12 bit high speed analog to digital converter.
Temperature and EDR use a separate 13 bit high precision ratiometric analog to digital conversion. This conversion provides stable, high resolution information necessary in particular for effective temperature feedback. The software currently provides .002 deg. F resolution. The hardware is capable of .001 deg. F.
The analog to digital converters are totally independent and perform simultaneous conversions to enhance system speed. They are available for additional channels such as heart rate and respiration. The F1000 provides much more than a simple battery operated analog to digital interface.
Q. How is the F1000 powered? Does it require batteries?
A. The F1000 receives its power from the host computer. This also means that the F1000 will operate on any power system world wide so long as the computer is compatible. No batteries are used. Battery powered instruments involve a constant maintenance demand. Repeatedly changing batteries cause wear and tear on the instrument. There is also the problem of battery failure during a session.
Q. Compare the F1000 EEG amplifiers with other systems on the market.
A. Manufacturers are constantly changing their instruments so it is difficult to comment on specific specifications. The following chart may help.
|Specification||Low End Systems||F1000||Comments|
|Common Mode||90 DB||>120DB||A measure of ability to reject extraneous signals. An increase of 20DB results in 10 times greater rejection|
|Differential Impedance||200K ohms||20G ohms||A low value makes electrode impedance more critical requiring increased skin prep.|
|Common Mode Impedance||Not Spec||20G ohms||A low value reduces the effectiveness of common mode rejection|
|Signal Bandwidth||2-32 Hz||2-1000Hz||The upper frequency is programmable in the F1000.|
Q. Why are shielded EEG cables important?
A. Shielded electrode cables prevent external electrical fields from causing artifacts in the EEG. These fields can originate in electrical wiring, as cable movement, or even movement of persons such as the therapist. The latter is particularly serious in dry climates where static charges accumulate.
The F1000 uses shielded cables integrated with custom amplifiers to provide remarkably artifact free signals. It is possible to engage the subject in kinesthetic activities with a minimum of artifact.
Q. Can the F1000 shielded cables be adapted for use on other manufacturers equipment?
A. Effective use of shielded cables requires amplifiers designed for them. A simple grounded shield can actually cause poorer signals under some circumstances.
Q. How are hookups verified on the F1000?
A. The F1000 provides for observing the raw EEG as a scrolling waveform display. The waveforms can be raw or filtered. In addition the signal can be observed in a spectral format as histogram bars or color map. The spectral display shows data in the range of 2-63 Hz allowing the clinician to observe 60 Hz interference. In instruments which cut off at 32 Hz, 60 Hz interference can, if large enough, distort the EEG without the clinician knowing it.
Q. Why all the emphasis on signal integrity?
A. While this may seem extreme, it is necessary for effective neurofeedback training. The EEG feedback experience is much more subjective than other types of biofeedback. A poor signal results in a frustrating experience where the subject feels he or she cannot connect with the experience. Worse yet, some will simply make up an internal image or experience and associate it with movement, muscle tension, or in many cases random feedback signals unrelated to their own EEG.
Q. Can't I just inhibit artifacts to assure that feedback is based upon reliable signals?
A. This is a misconception prevalent in the neurofeedback field. Often a real EEG indication is associated with movement or muscle activity. If an artifact associated with this activity results in feedback being inhibited, the subject is confused. Another way of putting it is that the inhibit changes a false positive into a false negative. As the F1000 demonstrates, there is no need for frequent artifacts.
Q. Some "gurus" say scrolling display of the EEG waveform is necessary to verify reliable data during feedback training. How does the F1000 approach this assertion?
A. Effective use of a scrolling display to verify data requires constant monitoring by the clinician. Typical scroll times run from 2-8 seconds. Once an artifact has scrolled off the screen it is no longer available for examination. Few clinicians make it a practice to constantly monitor the screen. The F1000 provides continuous recording of the raw EEG signal for post session review. In our own practice we routinely review post session data as part of our quality control. Careful examination is needed to distinguish artifact from the signal and cannot be done in 2-8 seconds.
Q. Who provides technical support for the F1000?
A. At Focused Technology you have access to the engineer who designed both the hardware and software for the F1000. Unlike large corporations support is provided by the person who knows the system. There is no need to wait for the person answering the phone to contact an engineer or programmer (possibly overseas) for an answer.