DS7A CONSTANT CURRENT HIGH VOLTAGE STIMULATOR, MODEL DS7A; DS7AH CONSTANT CURRENT HIGH VOLTAGE STIMULATOR, MODEL DS7AH

K051357 · Digitimer , Ltd. · GWF · Sep 20, 2005 · Neurology

Device Facts

• Record ID: K051357
• Device Name: DS7A CONSTANT CURRENT HIGH VOLTAGE STIMULATOR, MODEL DS7A; DS7AH CONSTANT CURRENT HIGH VOLTAGE STIMULATOR, MODEL DS7AH
• Applicant: Digitimer , Ltd.
• Product Code: GWF · Neurology
• Decision Date: Sep 20, 2005
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 882.1870
• Device Class: Class 2

Intended Use

The DS7A and DS7AH are stimulators intended for use during neurological monitoring and assessment in a clinical environment. They are intended for use by trained personnel either competent to apply appropriate stimuli or under the supervision and instruction of one who is.

Device Story

DS7A/DS7AH are constant current high voltage stimulators for percutaneous nerve/muscle stimulation. Input: user-selected current (0-100mA for DS7A; up to 1A for DS7AH) and pulse width (50μs-2ms). Operation: isolated output stage generates square current pulses; variable compliance voltage up to 400V. Used in clinical settings by trained personnel for neurological assessment. Output: electrical pulses delivered via electrodes to stimulate tissue. Safety: integrated trip-out circuit monitors energy, pulse width, and current to prevent over-stimulation; provides visual warnings. Clinical benefit: enables precise nerve/muscle stimulation for diagnostic monitoring; DS7AH variant supports deep peripheral nerve stimulation using large electrode pads.

Clinical Evidence

No clinical data provided. Substantial equivalence is based on technological characteristics and bench testing/compliance with safety standards (EN 60601-1, EN 60601-1-2, EN 60601-2-40).

Technological Characteristics

Constant current stimulator; non-conductive plastic case with aluminum panels and polycarbonate labels. Output: 0-100mA (DS7A) or 0-1A (DS7AH); compliance voltage up to 400V. Pulse width: 50μs-2ms (DS7A) or 50-200μs (DS7AH). Connectivity: external trigger input (TTL compatible). Safety: energy-based trip-out circuit. Standards: EN 60601-1, EN 60601-1-2, EN 60601-2-40.

Indications for Use

Indicated for neurological monitoring and assessment in clinical environments. Intended for use by trained personnel or under their supervision. No specific age or gender restrictions provided.

Regulatory Classification

Identification

An evoked response electrical stimulator is a device used to apply an electrical stimulus to a patient by means of skin electrodes for the purpose of measuring the evoked response.

Predicate Devices

• Digitimer D185 Multipulse Cortical Stimulator (K020400)

Submission Summary (Full Text)

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# DIGITIMER Ltd - DS7A/DS7AH, 510(k) application

### E - 510(k) Summary

| Submitted by | |
|----------------------------|-----------------------------------------------------------------------|
| Name: | John Smale |
| | Managing Director |
| Company: | Digitimer Ltd |
| Address: | 37 Hydeway |
| | Welwyn Garden City |
| | Herts |
| | AL7 3BE |
| | UK |
| Telephone: | (44) 1707 328347 |
| FAX: | (44) 1707 373153 |
| Authorised<br>corespondent | |
| Name: | Harry J Benedict |
| | Managing Partner |
| Company: | MEPS-LLC |
| Address: | One East Broward Blvd |
| | Suite 700 |
| | Fort Lauderdale |
| | FL 33301 |
| Telephone: | [phone] |
| FAX: | [phone] |
| Contact person: | Harry J Benedict |
| Preparation date: | December 07, 2004 |
| Device names: | Digitimer DS7A and DS7AH Constant Current High Voltage<br>Stimulators |
| Common name: | Evoked Potential Stimulator |
| Classification name: | Evoked response electrical stimulator, per 21 CFR §<br>882.1870 |
| Device class: | 2 |
| Product code: | GWF |
| Predicate device | |
| 510(k) Number: | K020400 |
| Device Name: | Digitimer D185 Multipulse Cortical Stimulator |
| Common name: | Evoked Potential Stimulator |
| Classification Name: | Evoked response electrical stimulator, per 21 CFR § 882.1870 |
| Device class: | 2 |
| Product Code: | GWF |
| Date Received: | 02/06/2002 |
| Decision Date: | 08/23/2002 |

K051357

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### DIGITIMER Ltd - DS7A/DS7AH, 510(k) application

#### Device Description

The Digitimer DS7A Stimulator provides constant current high voltage pulses of brief duration for percutancous stimulation during investigation of the electrical activity of nerve and muscle tissue. The output current is continuously variable over the range 0 to 100 milliamps, from a source voltage continuously variable from less than 100 volts to 400 volts, to meet the requirements of human pathological cases. Short pulse durations have been made available to minimise any discomfort to the subject. The pulse width range can be varied from 50 microsconds to 2 milliscconds in six steps. A specially designed isolated output stage maintains a square (current) pulse shape while minimising stimulus artefacts.

The Digitimer DS7AH Stimulator is a variant of the DS7A providing a higher maximum current at reduced pulse width. This option is offered to overcome the difficulty of stimulating deep peripheral nerves with large area electrode pads. The DS7AH option will provide a maximum stimulus current of 1 amp at up to 400 volts compliance at pulse widths up to 200 us.

#### Indications for use

The DS7A and DS7AH are stimulators intended for use during neurological monitoring and assessment in a clinical environment.

They are intended for use by trained personnel either competent to apply appropriate stimuli or under the supervision and instruction of one who is.

| Parameter | Predicate Device D185 | DS7A | DS7AH |
|-----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Intended application | Transcranial stimulation | Percutaneous stimulation | Percutaneous stimulation |
| Mode of operation | Constant voltage | Constant current | Constant current |
| Stimulus Output | Selected by continuously variable, multi-turn control, 0 to 1000 V (into 1k load) | Selected by continuously variable, multi-turn control and x1/x10 switch. Dial reading 0.00 to 9.99 giving 0 to 9.99 mA for x1 setting, and 0 to 99.9 mA for x10 setting | Selected by continuously variable, multi-turn control and x1/x10 switch. Dial reading 00.0 to 99.9 giving 0 to 99.9 mA for x1 setting, and 0 to 999 mA for x10 setting |
| Output Pulse | 50 microseconds (μs) wide pulses, user selectable from 1 to 9 pulses, repetition rate user variable between 1 and 9.9 ms | 50, 100, 200, 500, 1000, 2000 microseconds (μs) wide, single pulse | 50, 100, 200 microseconds (μs) wide, single pulse |
| Compliance | Max current 1.5A peak | Continuously variable from <100V to 400V | Continuously variable from <100V to 400V |
| Parameter | Predicate Device D185 | DS7A | DS7AH |
| Over<br>stimulation<br>protection | Safety trip out circuit<br>operated by the energy<br>of the output; limits the<br>number of pulses<br>available in one train<br>and inhibits<br>re-triggering outside<br>safe limits<br>Visual warning given<br>to operator if an<br>attempted stimulus is<br>outside operational<br>limits | Safety trip out circuit<br>operated by the energy<br>of the output; monitors<br>pulse width and<br>current and inhibits<br>re-triggering outside<br>safe limits<br>Visual warning given<br>to operator if an<br>attempted stimulus is<br>outside operational<br>limits | Safety trip out circuit<br>operated by the energy<br>of the output; monitors<br>pulse width and<br>current and inhibits<br>re-triggering outside<br>safe limits<br>Visual warning given<br>to operator if an<br>attempted stimulus is<br>outside operational<br>limits |
| Output<br>Connections | 4 mm shrouded sockets<br>(red and black) on 3/4"<br>centres Red socket goes<br>positive with reference<br>to black socket | Same | Same |
| Stimulus<br>initiation | Front panel push<br>button, foot switch or<br>external electrical<br>trigger signal | Same | Same |
| External<br>trigger input | +3 to 15 V +ve edge<br>TTL compatible | Same | Same |
| Construction | Non-conductive plastic<br>case, aluminium front<br>and rear panels fully<br>laminated with single<br>piece polycarbonate<br>labels | Same | Same |
| Application<br>of standards | Compliant with<br>EN 60601-1,<br>EN 60601-1-2, and the<br>relevant parts of<br>EN 60601-2-40 | Same | Same |

#### Substantial Equivalence Comparison

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# DIGITIMER Ltd - DS7A/DS7AH, 510(k) application

#### Substantial equivalence

The Digitimer DS7A and the Digitimer DS7AH are substantially equivalent in terms of safety and effectiveness to the Digitimer D185 (510(k) #K020400).

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Image /page/3/Picture/1 description: The image shows the logo for the Department of Health and Human Services, USA. The logo is circular and contains the text "DEPARTMENT OF HEALTH AND HUMAN SERVICES, USA" around the perimeter. In the center of the circle is an abstract symbol that resembles an eagle or other bird-like figure.

SEP 2 0 2005

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Digitimer Ltd. c/o Mr. Harry J. Benedict Official Correspondent MEPs-LLC One East Broward Boulevard, Suite 700 Fort Lauderdale, Florida 33301

Re: K051357

Trade/Device Name: Digitimer DS7A and DS7AH Constant Current High Voltage Stimulators Regulation Number: 21 CFR 882.1870 Regulation Name: Evoked response electrical stimulator Regulatory Class: II Product Code: GWF Dated: August 8, 2005 Received: August 9, 2005

Dear Mr. Benedict:

We have reviewed your Section 510(k) premarket notification of intent to market the device we have teviewed your bocurer be device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate for use stated in the encrosure) to togally the enactment date of the Medical Device Amendments, or to conninered prices that have been reclassified in accordance with the provisions of the Federal Food, Drug, de rices mat have been resuire approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The r ou may, mereleve, mains of the Act include requirements for annual registration, listing of general controll provision practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it if your device is crassified (vonal controls. Existing major regulations affecting your device can thay be subject to sublications, 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 r rease be actived that I Drimination that your device complies with other requirements of the Act that I Dri has mater and regulations administered by other Federal agencies. You must or any I cacal statuted and regainents, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); good manufacturing practice requirements as set OF It Fact 877) facemes (21 (QS) regulation (21 CFR Part 820); and if applicable, the electronic forth in the quart of wyrovisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2- Mr. Harry J. Benedict

This letter will allow you to begin marketing your device as described in your Section 10(k) I his letter will anow you to begin mailering of substantial equivalence of your device to a legally premarket nothcation. The PDA mixing of backansal request and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please If you desire specific advice for your do roo care and surface note the regulation entitled, Comaci the Office of Comphance at (21 tristication" (21CFR Part 807.97). You may obtain "Misbranding by reference to premance noutheast to act from the Division of Small
other general information on your responsibilities under the Act from the 2000 600 000 other general Information on your responsible in to toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html

Sincerely vours.

Barbara Buchner
for

Mark N. Melkerson Acting Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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#### Indications for Use

510(k) Number: K051357

#### DIGITIMER DS7A and DS7AH CONSTANT CURRENT HIGH Device Name: VOLTAGE STIMULATORS

Indications for use:

The DS7A and DS7AH are stimulators intended for use during neurological monitoring and assessment in a clinical environment.

assessment in a chinear environment
They are intended for use by trained personnel either competent to apply appropriate stimuli or under the supervision and instruction of one who is.

Prescription Use __ V (Part 21 CFR 801 Subpart D)

-

AND/OR

Over-The-Counter Use _ (21 CFR 807 Subpart C)

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

barbare buehm

Restorative, Division of Gener and Neurological Devices

**510(k) Number** k05

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