MRS-2D

K961645 · Lexicor Medical Technology, Inc. · HCC · Oct 31, 1996 · Neurology

Device Facts

• Record ID: K961645
• Device Name: MRS-2D
• Applicant: Lexicor Medical Technology, Inc.
• Product Code: HCC · Neurology
• Decision Date: Oct 31, 1996
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 882.5050
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

BioLex is indicated for relaxation training using alpha EEG biofeedback. In the protocol for relaxation training, BioLex provides a visual and/or auditory signal that corresponds to the patient's increase in alpha activity as an indicator of achieving a state of relaxation.

Device Story

NRS-2D is a 2-channel electrophysiological signal acquisition and biofeedback device used with an IBM PC/AT compatible computer. It acquires EEG signals via electrodes, performs spectral analysis, and provides visual/auditory feedback to the patient. The system includes an isolated acquisition module with preamplifiers, filters (lowpass, highpass, notch), and a 12-bit A/D converter. A microprocessor manages electrode continuity checks and data transmission to the PC via a parallel port. BioLex software processes the digitized EEG to derive spectral parameters, which drive the feedback signals. Used in clinical settings to assist patients in achieving relaxation by increasing alpha activity. Healthcare providers monitor progress; therapy is discontinued if the patient fails to learn or experiences adverse effects like dizziness or anxiety.

Clinical Evidence

No clinical data provided. The submission relies on bench testing and technical specifications to demonstrate substantial equivalence.

Technological Characteristics

Two-channel EEG acquisition system; 12-bit A/D resolution; 128Hz sampling rate; 8,000 gain; >1 GΩ input impedance; >90 dB CMRR at 60 Hz. Includes 0.5-32 Hz bandpass and 60/50 Hz notch filters. Connectivity via parallel printer port. Power: 12 VDC switching supply (UL-544, CSA-223, TUV-601 compliant) or optional 9.6 VDC battery. Software: BioLex for spectral analysis and feedback. Materials: Electrically isolated module.

Indications for Use

Indicated for relaxation training using alpha EEG biofeedback. Contraindicated in patients unable to understand feedback principles, those with excessive behavioral problems or low IQ, those experiencing anxiety/unpleasantness with training, and patients with epilepsy where specific frequency training may trigger seizures.

Regulatory Classification

Identification

A biofeedback device is an instrument that provides a visual or auditory signal corresponding to the status of one or more of a patient's physiological parameters (e.g., brain alpha wave activity, muscle activity, skin temperature, etc.) so that the patient can control voluntarily these physiological parameters.

Special Controls

*Classification.* Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter when it is a prescription battery powered device that is indicated for relaxation training and muscle reeducation and prescription use, subject to § 882.9.

Predicate Devices

• Lexicor NRS-4 (K920038)

Submission Summary (Full Text)

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NRS-2D 510(k) Notification
Section 6

# 510(k) Summary
Lexicor NRS-2D
Date Prepared: 4/16/96

$K_{961645}$

OCT 31 1996

## TABLE OF CONTENTS

TABLE OF CONTENTS ... 6-2
SUBMITTER ... 6-2
CONTACT PERSON ... 6-2
DEVICE NAME ... 6-2
DEVICE DESCRIPTION ... 6-3
INTENDED USE ... 6-3
PREDICATE DEVICE ... 6-4
SUMMARY OF TECHNOLOGICAL CHARACTERISTICS ... 6-4

## SUBMITTER

Lexicor Medical Technology, Inc.
5589 Arapahoe Ave. #206
Boulder, CO 80303
Telephone: [phone]
FAX: [phone]

## CONTACT PERSON

Michael M. Shupe
Quality and Regulatory Affairs Manager

## DEVICE NAME

- Proprietary Name: NRS-2D
- Common Name: Electroencephalograph with an electroencephalogram signal spectrum analyzer and biofeedback options.
- Classification Names: Electroencephalograph
Analyzer, Spectrum, Electroencephalogram Signal
Device, Biofeedback

Lexicor Medical Technology, Inc.

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ATTACHMENT 9
NRS-2D 510(k) Notification
Section 6

# 510(k) Summary Lexicor NRS-2D

Date Prepared: 4/16/96
Revised: 7/29/96

## DEVICE DESCRIPTION

The NRS-2D is a two channel electrophysiological signal acquisition and biofeedback device. The product is designed for use with a standard IBM PC/AT compatible computer and associated peripheral equipment. When assembled with the computer, the NRS-2D system will acquire EEG and biofeedback data, perform signal spectral analysis and quantification and provide auditory and/or visual feedback. At the user's discretion the NRS-2D can be factory configured as a single channel device.

## INTENDED USE

The NRS-2D uses Lexicor's BioLex software to perform its intended use.

### BioLex Software

#### Description

BioLex provides visual and/or auditory feedback based on parameters derived from spectral analysis of the electroencephalogram (EEG) signal.

#### Indications

BioLex is indicated for relaxation training using alpha EEG biofeedback. In the protocol for relaxation training, BioLex provides a visual and/or auditory signal that corresponds to the patient's increase in alpha activity as an indicator of achieving a state of relaxation.

#### Warnings and Contraindications

BioLex is contraindicated in patients with the following conditions:

1. Individuals who are unwilling or unable to understand the general principles and goals of the feedback used. This includes individuals with excessive behavioral problems or low IQ.

2. Individuals who experience anxiety or an unpleasant experience associated with EEG biofeedback training.

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NRS-2D 510(k) Notification
Section 6

# 510(k) Summary Lexicor NRS-2D

Date Prepared: 4/16/96

3. In epilepsy, there may be a causal relationship between EEG training of certain EEG frequencies and incidence of seizure.

Certain patients may be unable to learn to control the EEG through biofeedback. Therapy should be discontinued if periodic monitoring of therapeutic progress indicates that the patient is not learning despite adequate review of instructions for feedback.

## Side Effects

There have been clinical reports of dizziness, drowsiness, fatigue and anxiety associated with feedback employing alpha enhancement.

## Frequency and Duration of Treatment

Duration of treatment ranges from 1 to 30 sessions and frequency from 1 to 7 times weekly depending on the needs of the patient.

## Operation and Usage

Please refer to the Biolex Software Manual for complete operating instructions prior to use.

## PREDICATE DEVICE

Lexicor NRS-4, 510(k) K920038

## SUMMARY OF TECHNOLOGICAL CHARACTERISTICS

System Block Diagram


A simple software command will allow the user to check all electrode contacts at any time, while the patient is connected to the NRS-2D without having to disconnect the electrodes from the NRS-2D and check the electrode/skin contact with a separate impedance meter.

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NRS-2D 510(k) Notification
Section 6

# 510(k) Summary Lexicor NRS-2D

Date Prepared: 4/16/96

## Patient Interface

When EEG electrodes are used and applied properly, contact impedances below 5k-10k Ohms can be obtained.

## Acquisition and Preprocessing Unit

The acquisition and preprocessing unit is a self-contained electrically isolated module which amplifies and filters the subject's EEG signals and converts them from an analog to digital form.

Each of the NRS-2D's channels consists of a continuity checking circuit, followed by a preamplifier and then lowpass, highpass and notch filters.

The notch filter (60 Hz USA) attenuates electrical mains interference noise entering the signal path.

Finally the channels are scanned by a 12 bit combination multiplexer and Analog to Digital converter with Sample and Hold.

A microprocessor in the NRS-2D controls the continuity checking and A/D conversion process, transmits data to, and receives commands from the PC through on-board optical isolators. Communication with the PC is accomplished via a 25 conductor cable which connects to the NRS-2D back panel's DB-25 connector and to any PC parallel printer port.

A binary executable code for the microprocessor handles the communication between the Acquisition and the host software application (BioLex and NeuroLex). The code instructs the card to reset the input multiplexer, read the data into an area of dual-ported memory in the processor and set interrupt vector 7 of the host PC interrupt system. The host software's interrupt routine then reads the data form the processor memory into computer RAM. This process is repeated for each set of input samples of the digitized EEG.

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NRS-2D 510(k) Notification
Section 6

# 510(k) Summary
## Lexicor NRS-2D

Date Prepared: 4/16/96


## NRS-2D Functional Block Diagram

The NRS-2D has a fixed sampling rate of 128Hz, a fixed gain of 8,000 and a built in electrode continuity checking capability.

A simple software command will allow the user to check all electrode contacts at any time, while the patient is connected to the NRS-2D without having to disconnect the electrodes from the NRS-2D and check the electrode/skin contact with a separate impedance meter.

## Power

The NRS-2D uses a medical grade single output switching power supply with the following features:

- Universal input from 90-264VAC
- Power on LED
- Built-in EMI filter-class B
- Overvoltage and short circuit protection
- UL-544, CSA-223 and TUV-601 Safety approvals
- Output-12 VDC, 2A

A 9.6 VDC rechargeable battery pack is available as an option.

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ATTACHMENT 9
NRS-2D 510(k) Notification
Section 6

# 510(k) Summary
## Lexicor NRS-2D

Date Prepared: 4/16/96
Revised: 7/29/96

The following is a table of the NRS-2D specifications.

| Physical Dimensions | 6" (l) x 3" (w) x 1.125" (h) | AC Power | |
| --- | --- | --- | --- |
| Signal Acquisition | | Voltage | 100/240 volts, 30 watts, 50/60 Hz |
| Channels | 1 or 2 | Current | < 1 amp |
| Sampling Rate | 128Hz | Leakage Current | < 20μA |
| Frequency Resolution | 0.5 Hz | Fuses | 0.8 amp, 250 volt |
| Noise | < 2μV pp @ 0.5-32 Hz | Battery Power | |
| Notch Filtering | 60 or 50 Hz | Voltage | 9.6 volts |
| Common Mode Rejection Ratio | > 90 db at 60 Hz | Current | 600 MAH |
| Gain | 8k | Type | Rechargeable |
| Artifact Rejection | manual/automatic | Control Software | |
| Low Pass Filters | 32 Hz | BioLex | |
| High Pass Filters | 0.5 Hz | | |
| Input Impedance | >1 GΩ | | |
| A/D Resolution | 12 bits | | |
| | | | |

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