MEDI-DX 7000

K964622 · Neuro-Diagnostic Assoc. · LLN · Dec 1, 1997 · Neurology

Device Facts

• Record ID: K964622
• Device Name: MEDI-DX 7000
• Applicant: Neuro-Diagnostic Assoc.
• Product Code: LLN · Neurology
• Decision Date: Dec 1, 1997
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 882.1200
• Device Class: Class 1

Intended Use

The Medi-Dx 7000 is a diagnostic device for the quantitative detection of sensory neurological impairments. The population of subjects for whom this device may be used for diagnostic purposes would include any individual capable of communicating their perception of cutaneous sensation. The Medi-Dx 7000 diagnostic examination may be conducted as part of a routine neurological examination or as a screening procedure for the detection of peripheral neuropathy which may be caused by various pathological conditions or exposures to toxic substances.

Device Story

Medi-Dx 7000 is a Current Perception Threshold (CPT) device for examining peripheral neuropathies. It generates sinusoidal electrical currents at 5 Hz, 250 Hz, and 2000 Hz (0 mA to 9.99 mA). Operated manually by clinicians in a clinic setting, the device delivers current via user-supplied electrodes to the patient's skin. The patient communicates their perception of the sensation to the clinician, who uses the device's LCD readout to determine the threshold. This quantitative assessment aids in diagnosing sensory neurological impairments. The device features a heavy-duty plastic case, battery power, and safety interlocks. It is designed to avoid RFI and includes output dampening for safety. Clinical benefit includes objective screening for neuropathy.

Clinical Evidence

No clinical data provided. Substantial equivalence is based on bench testing, comparison of electrical output parameters, and expert opinion regarding the physiological impact of the predicate's auto-test mode versus the subject device's manual mode.

Technological Characteristics

Current Perception Threshold (CPT) device; generates sinusoidal electrical currents at 5 Hz, 250 Hz, 2000 Hz; 0-9.99 mA output range. Powered by (8) 6V alkaline batteries. Features: LCD intensity readout, transformer-isolated output, safety interlock, digital waveform filter for analog output. Housed in non-conducting plastic case. No built-in battery charger. Four independent clocks for frequency production.

Indications for Use

Indicated for individuals capable of communicating perception of cutaneous sensation to detect sensory neurological impairments and screen for peripheral neuropathy caused by pathological conditions or toxic exposures.

Regulatory Classification

Identification

A two-point discriminator is a device with points used for testing a patient's touch discrimination.

Predicate Devices

• Neurometer by Neurotron (K853608)

Submission Summary (Full Text)

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DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
Food and Drug Administration
10903 New Hampshire Avenue
Document Control Center - WO66-G609
Silver Spring, MD 20993-0002

MAY 11 2017

Mr. James L. Hedgecock, Ph.D.
Owner
Neuro-Diagnostic Associates
445 Dartmoor Street
Laguna Beach, California 92651

Re: K964622
Trade/Device Name: Medi-Dx 7000
Regulation Number: 21 CFR 882.1200
Regulation Name: Two-point discriminator
Regulatory Class: Class I
Product Code: LLN
Dated: September 21, 1997
Received: October 2, 1997

Dear Mr. Hedgecock:

This letter corrects our substantially equivalent letter of December 1, 1997.

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA’s issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act’s requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements

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Page 2 – Mr. James L. Hedgecock

as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH’s Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Michael J. Hoffmann -S

for Carlos L. Peña, PhD, MS
Director
Division of Neurological
and Physical Medicine Devices
Office of Device Evaluation
Center for Devices and Radiological Health

Enclosure

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510 (k) SUMMARY 807.92

DEC - 1 1997

K964622

Submitted: James L. Hedgecock, DC, PhD
445 Dartmoor Street
Laguna Beach, CA 92651
Voice: 714-497-1207 Fax: [phone]

Contact person: Dr. James L. Hedgecock
Date Submitted: 11/06/97
Name of Device: Medi-Dx 7000 Current Perception Threshold (CPT) device
Equivalent Device: Neurometer by Neurotron; 510(k) 853608

## GENERAL DESCRIPTION OF THE MEDI-DX 7000:

The Medi-Dx 7000 is a Current Perception Threshold (CPT) device for the examination of peripheral neuropathies. It generates a sinusoidal electrical currents in the 5 Hz, 250 Hz and 2000 Hz frequencies from 0 mA to 9.99 mA.

The Medi-Dx 7000 weighs approximately 15 lbs. and is housed within a 12" x 5" x 11" heavy duty plastic case with metal face and rear panels. The rear panel has an access door for installation and replacement of (8) standard (6) Volt Alkaline Batteries. The Face panel has an 'ON/OFF' switch, a 'Battery Test' switch (also functioning as an automatic calibration switch), and three (3) switches, one for each of the frequencies; 5 Hz, 250 Hz and 2000 Hz respectively. The intensity control is immediately below an LCD which reads mA output. Two ports are available on the from panel for connection with electrodes (which are not provided with the unit and are ordered by the user from suppliers mentioned in the owners manual).

## INDICATIONS AND USAGE:

The Medi-Dx 7000 is a diagnostic device for the quantitative detection of sensory neurological impairments. The population of subjects for whom this device may be used for diagnostic purposes would include any individual capable of communicating their perception of cutaneous sensation.

The Medi-Dx 7000 diagnostic examination may be conducted as part of a routine neurological examination or as a screening procedure for the detection of peripheral neuropathy which may be caused by various pathological conditions or exposures to toxic substances.

## GENERAL COMPARISON:

The Medi-Dx 7000 and the equivalent (Neurometer) device are essentially the same, they weigh and have approximately the same size. Both have the same minimum / maximum output (0.0 mA to 9.99 mA). The same current characteristic (sinusoidal waveform) and the same frequencies (5 Hz, 250 Hz and 2000 Hz). The Medi-Dx 7000 does not come with electrodes. However, it is recommended in the owner's manual that to the Medi-Dx 7000 owner purchase the equivalent (Neurometer) electrode system, manual and/or software analytic database from the Manufacturer/Distributor of the equivalent device (Neurometer).

## TECHNICAL DIFFERENCES:

1) The Medi-Dx 7000 does not have a built in battery charger, as does the equivalent device (Neurometer), which is powered by NiCd rechargeable batteries with a built in recharger.
2) The Medi-Dx 7000 is fully manually controlled and the Neurometer has a manual and an auto-test mode.
3) The Medi-Dx 7000 uses the voltage as-is without stepping up, so the maximum available voltage is +5 v to -5 v to operate the internal circuitry. The equivalent device has a step up of 10 times with an internal switching power supply, so the maximum voltage is +85 v to -85 v to operate the internal circuitry.

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Page 2
510 (k) SUMMARY
807.92
Medi-Dx 7000
Continued:

4) The Medi-Dx 7000 has an isolated output via the transformer. No transformer isolation of output is used in the equivalent device, which depends on non-failure of the charger and selector switch to prevent 110v AC leakage.
5) The Medi-Dx 7000 case is largely non-conducting plastic, whereas the equivalent device has an all metal case.
6) No-load conditions will not build up an electrical field at the electrodes, because the output is dampened. It is not known if the equivalent device has such output dampening.
7) Four independent clocks for frequency production are used in the Medi-Dx 7000 device. The equivalent device uses one master clock which is Crystal controlled. The result is that the equivalent device produces RFI and the Medi-Dx 7000 does not.
8) The Medi-Dx 7000 has a safety interlock which disconnects the power supply if the case is opened.
9) The Medi-Dx 7000 has a digital LCD output meter and the equivalent device does not.

## SIMILARITIES:

The following technical similarities are noted:

1) The Medi-Dx 7000 "WARNING" light flashes if the power drops below that needed to supply the maximum output of 9.99 mA. The equivalent device has a "WARNING" light that is "steady on" to warn of low batteries. This same light is used to warn of clipping of the waveform. In the case of clipping, the Warning light will flash when the intensity is increased, whereas the warning light will flash at 0 (zero) when the battery is low.
2) Neither device possesses any environmental risk from chemical, thermal, radiation or mechanical factors.
3) Both devices deliver current to the subject that is biologically compatible and possess no threat of injury to the patient or operator.
4) Both use an LCD readout of current.
5) Both use a master power switch.
6) The Medi-Dx 7000 uses separate switched to isolate each frequency and two switches cannot be turned on at the same time. The equivalent device uses a selector knob to isolate the frequencies.
7) Both use a digital waveform filter to produce and analog output.
8) Both manufacturers "burn in the devices for 168 hours and testing insures accuracy/calibration.

## Tests and trials:

Since the current output, waveform are the same, it is reasonable to assume that the two devices are the same in function and reliability.

It will be noted that almost all the differences relate to improved safety of the Medi-Dx 7000 as compared to the equivalent device. The only difference in operation is that the Medi-Dx 7000 does not use an auto-test mode, which is employed in the equivalent device. This auto-test mode is employed in such a way that the subject is purposely stimulated above the threshold and then below in such as fashion as to "home in" on the threshold. However, it is the contention of the Medi-Dx 7000 manufacturer and the opinion of neurologists and other medical experts the manufacturer has consulted with, that this practice can in practice actually alter the threshold by "over stimulating" the receptors and any supposed advantage in accuracy by testing in this auto-test mode is outweighed by the fact that this auto-test mode may be slightly increasing the current required to produce a threshold stimulation. In other words the over stimulation of the receptors causes receptor fatigue and more receptors, i.e. more current, is required to reach a threshold stimulation with each stimulation above the threshold. Several of these physicians have compared the devices clinically and have agreed to share their opinions if contacted. Their names and phone numbers will be supplied upon request.

Sincerely.


James L. Hedgecock

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510(k) 964622

Medi-Dx 7000

# INDICATIONS AND USE:

The Medi-Dx 7000 is a diagnostic device for the quantitative detection of sensory neurological impairments. The population of subjects for whom this device may be used for diagnostic purposes would include any individual capable of communicating their perception of cutaneous sensation.

The Medi-Dx 7000 diagnostic examination may be conducted as part of a routine neurological examination or as a screening procedure for the detection of peripheral neuropathy which may be caused by various pathological conditions or exposures to toxic substances.

Prescription Use ☑
(Per 21 CFR 801.109)