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 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.

AI/ML Overview

The provided 510(k) summary for the DIGITIMER Ltd DS7A/DS7AH Constant Current High Voltage Stimulators does not contain the kind of performance data, study details, or acceptance criteria typically associated with AI/ML-driven medical devices that would require such granular information.

This device is a physical stimulator and its approval is based on substantial equivalence to a predicate device (Digitimer D185 Multipulse Cortical Stimulator, K020400), rather than a clinical study demonstrating AI model performance against acceptance criteria. The application focuses on technical specifications and safety standards directly comparable between the new device and its predicate.

Therefore, most of the requested information cannot be extracted from this document, as it describes a different type of regulatory submission and device.

Here's a breakdown of why and what little can be inferred:

1. A table of acceptance criteria and the reported device performance

Acceptance Criteria: Not explicitly stated as performance metrics with thresholds in the context of an AI/ML model. For this type of device, acceptance criteria are generally related to electrical performance specifications, safety standards (e.g., EN 60601-1, EN 60601-1-2), and demonstrating that these meet or exceed the predicate device's capabilities without introducing new safety or effectiveness concerns. These are essentially the technical specifications and safety compliance.
Reported Device Performance: The document provides a "Substantial Equivalence Comparison" table that lists parameters for the Predicate Device D185, DS7A, and DS7AH. The "performance" here is described by these specifications, such as stimulus output range, pulse width, compliance voltage, and safety features.

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
Over-stimulation protection	Safety trip out circuit operated by the energy of the output; limits the number of pulses available in one train and inhibits re-triggering outside safe limits Visual warning given to operator if an attempted stimulus is outside operational limits	Safety trip out circuit operated by the energy of the output; monitors pulse width and current and inhibits re-triggering outside safe limits Visual warning given to operator if an attempted stimulus is outside operational limits	Safety trip out circuit operated by the energy of the output; monitors pulse width and current and inhibits re-triggering outside safe limits Visual warning given to operator if an attempted stimulus is outside operational limits
Output Connections	4 mm shrouded sockets (red and black) on 3/4" centres Red socket goes positive with reference to black socket	Same	Same
Stimulus initiation	Front panel push button, foot switch or external electrical trigger signal	Same	Same
External trigger input	+3 to 15 V +ve edge TTL compatible	Same	Same
Construction	Non-conductive plastic case, aluminium front and rear panels fully laminated with single piece polycarbonate labels	Same	Same
Application of standards	Compliant with EN 60601-1, EN 60601-1-2, and the relevant parts of EN 60601-2-40	Same	Same

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Not applicable. This device is a hardware stimulator. Its performance is characterized by engineering and electrical testing, not by evaluating an algorithm on a dataset.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not applicable. No ground truth in the context of expert review of data is established for this type of device. Performance is verified through technical compliance and physical testing.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable.

5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not applicable. This is not an AI/ML device, and no MRMC study was conducted.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not applicable. This is a standalone hardware device, not an algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The "ground truth" for this device's approval is its adherence to specified electrical
parameters, safety standards (e.g., EN 60601-1 series), and a demonstration of substantial equivalence to a legally marketed predicate device (K020400). This involves engineering measurements and compliance testing, not clinical "ground truth" data for an algorithm.

8. The sample size for the training set

Not applicable. There is no training set for a hardware stimulator.

9. How the ground truth for the training set was established

Not applicable.

Summary

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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
Authorisedcorespondent
Name:	Harry J Benedict
	Managing Partner
Company:	MEPS-LLC
Address:	One East Broward Blvd
	Suite 700
	Fort Lauderdale
	FL 33301
Telephone:	(954) 713-8017
FAX:	(954) 523-1911
Contact person:	Harry J Benedict
Preparation date:	December 07, 2004
Device names:	Digitimer DS7A and DS7AH Constant Current High VoltageStimulators
Common name:	Evoked Potential Stimulator
Classification name:	Evoked response electrical stimulator, per 21 CFR §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 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
Overstimulationprotection	Safety trip out circuitoperated by the energyof the output; limits thenumber of pulsesavailable in one trainand inhibitsre-triggering outsidesafe limitsVisual warning givento operator if anattempted stimulus isoutside operationallimits	Safety trip out circuitoperated by the energyof the output; monitorspulse width andcurrent and inhibitsre-triggering outsidesafe limitsVisual warning givento operator if anattempted stimulus isoutside operationallimits	Safety trip out circuitoperated by the energyof the output; monitorspulse width andcurrent and inhibitsre-triggering outsidesafe limitsVisual warning givento operator if anattempted stimulus isoutside operationallimits
OutputConnections	4 mm shrouded sockets(red and black) on 3/4"centres Red socket goespositive with referenceto black socket	Same	Same
Stimulusinitiation	Front panel pushbutton, foot switch orexternal electricaltrigger signal	Same	Same
Externaltrigger input	+3 to 15 V +ve edgeTTL compatible	Same	Same
Construction	Non-conductive plasticcase, aluminium frontand rear panels fullylaminated with singlepiece polycarbonatelabels	Same	Same
Applicationof standards	Compliant withEN 60601-1,EN 60601-1-2, and therelevant parts ofEN 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 (800) 638-2041 or (301) 443-6597 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

Page 1 of 1

Regulation Number and Section

§ 882.1870 Evoked response electrical stimulator.

(a)
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.(b)
Classification. Class II (performance standards).