ACCISS is to be used both for quidance and localization in open craniotomies and for surgeries which are traditionally performed with a stereotactic apparatus, such as biopsies, thalamotomies and electrode implants. The system may also be used to review medical images in a neurosurgical context.

Device Description

The Mayfield-ACCISSTM Workstation is a computer-based system designed for use in the OR. It has a compact design, sterilizable keyboard cover and electrical isolation for patient safety. Completely self-contained on a cart, the system transfers easily between OR and offices for use not only as a clinical tool but as a desk-top based clinical research tool and image-review workstation as well. A simple yet direct user interface screen with easy-to understand graphics displays the images.

The Mayfield-ACCISSTM Workstation is intended to correlate a patient's preoperative Computed Tomography (CT) and/or Magnetic Resonance (MRI) data with a patient's anatomy to assist in planning and performing surgery. The system is composed of a medical imaging workstation and position-sensing articulated arm with a probe that acts as a localizing device. The workstation computer is loaded with the patient's CT or MRI data. The image data set is correlated to the patient on the OR table by physically matching points such as scanned fiducial markers, anatomical features or surface points with corresponding points on the imaged data set. After the correlation, the indication of the probe orientation appears on the screen and moves through the CT or MRI data in correct relation to the probe as manipulated by the surgeon.

The Mayfield-ACCISSTM Workstation consists of the following" :

A. Workstation
B. Software
C. Probe Assembly
D. Pelorus Stereotactic System

AI/ML Overview

The provided text does not contain detailed information on acceptance criteria for device performance or a specific study proving the device meets those criteria. The document is a 510(k) summary for the Mayfield-ACCISS Workstation, primarily focusing on demonstrating substantial equivalence to predicate devices.

However, based on the information provided, here's a breakdown of what can be extracted and what is missing:

Description of the Acceptance Criteria and Study to Prove Device Meets Acceptance Criteria

The provided document (a 510(k) summary for the Mayfield-ACCISS Workstation) does not explicitly state specific quantitative acceptance criteria or a dedicated study designed to prove the device meets such criteria.

The document primarily focuses on establishing "substantial equivalence" of the Mayfield-ACCISS Workstation to previously cleared predicate devices. This typically involves demonstrating that the new device has the same intended use, similar technological characteristics, and raises no new questions of safety and effectiveness as compared to the predicate devices. This process does not usually involve presenting a separate, dedicated performance study with specific quantitative acceptance criteria in the same way a clinical trial or a performance validation study for a novel device would.

Instead, the submission states:

"The indications for the Mayfield-ACCISSTM Workstation are the same as those for the predicate stereotactic devices."
"The design of the Mayfield-ACCISS™ Workstation is similar in concept to the predicate stereotactic devices."
"The materials used in the manufacture of the hardware components of the Mayfield-ACCISSTM Workstation are similar to those used in the predicate devices."
"The manufacturing processes used in the Mayfield-ACCISS TM Workstation are similar to those used in the manufacture of predicate stereotactic devices."
"The specifications of the Mayfield-ACCISSTM Workstation are similar to those of the predicate stereotactic device."
"NOMOS thus considers the Mayfield-ACCISSTM Workstation substantially equivalent to the predicate devices."

The "performance" of the device, in the context of this document, is implicitly demonstrated by its similarity to predicate devices that have already been deemed safe and effective. There are no specific quantitative metrics or thresholds mentioned for accuracy, precision, or other performance characteristics of the surgical planning or guidance system itself in this summary.

Based on the provided text, the following information is either not available or cannot be fully answered:

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

Acceptance Criteria: Not explicitly stated in quantitative terms. The primary "acceptance criterion" for this 510(k) submission is demonstrating substantial equivalence to predicate devices.
Reported Device Performance: Not detailed in quantitative metrics. The document asserts that "The specifications of the Mayfield-ACCISSTM Workstation are similar to those of the predicate stereotactic device." but does not provide those specifications or performance results.

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

Not provided. No specific test set or study involving patient data is described as part of this 510(k) summary.

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 establishment process for a test set is described.

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

Not applicable. No test set adjudication is described.

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 performed or reported in this document. The device is a "computer-based stereotactic surgical planning system," not an AI-based diagnostic tool requiring MRMC studies for human reader performance improvement.

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

Not performed or reported in this document in the context of performance metrics. The device is described as a system that assists surgeons in planning and performing surgery, implying a human-in-the-loop operation.

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

Not applicable. No ground truth for a performance study is described.

8. The sample size for the training set

Not applicable. The document describes a "computer-based stereotactic surgical planning system" but does not mention any machine learning or AI components that would require a "training set" in the modern sense.

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

Not applicable. (See #8)

Summary

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Section B - Summary & Certification

Summary of Safety and Effectiveness Mayfield-ACCISS Workstation

Pursuant to Section 513(i) of the Federal Food, Druq, and Cosmetic Act

l. General Information:

Classification Name: Stereotactic Instruments

Common/Usual Name: Computer-based stereotactic surgical planning system

Trade/Proprietary Name: Mayfield-ACCISS Workstation

Applicant's Name and Address:

Marvin L. Sussman, Ph. D., Vice President, Administration and Regulatory Affairs NOMOS Corporation 2591 Wexford Bavne Road Sewickley, PA 15143

II. Name of predicate device(s):

ISG Allegro Viewing Wand (K911783) Pelorus Arc Carrier (K851659A) CORITechs CORITaxic I Workstation (K915791) Cordis Micra Microosurgical Instruments (K862971) - for use of Titanium in contact with Brain Tissue

III. Classification:

Neurosurgical stereotactic instruments and accessories are Class II (21 CFR 882.4560 Neurological Devices Panel).

IV. Performance Standards:

No applicable performance standards have been established by FDA under section 514 of the Food, Drug and Cosmetic Act.

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V. Intended Use and Device Description:

Intended Use: ACCISS is to be used both for quidance and localization in open craniotomies and for surgeries which are traditionally performed with a stereotactic apparatus, such as biopsies, thalamotomies and electrode implants. The system may also be used to review medical images in a neurosurgical context.

Introduction: Stereotactic surgical systems superimpose on the patient a coordinate system which can be used to direct a probe or other surgical instrument, based upon diagnostic imaging information, to a predetermined point inside the cranium. When the point is established, surgical instruments are inserted in the instrument holder of stereotactic systems such as the BRW/CRW (K811452) or Leksell (Preamendments device) systems to biopsy and/or remove a lesion. Recently, systems have been developed which allow the determination of surgical paths without the use of a conventional stereotactic frame such as the ISG Viewing Wand (K911783).

The Mayfield-ACCISSTM Workstation consists of the following" :

A. Workstation
B. Software
C. Probe Assembly
D. Pelorus Stereotactic System

The hardware configuration will be as stated or functionally similar.

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Training Accessories E.

1 Plastic Skull 50 CT/MR Skin Markers

Supported Modalities

CT MRI

Options:

Color Printer 9-Track Tape Drive

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VI. Summary of Substantial Equivalence*:

Indications: The indications for the Mayfield-ACCISSTM Workstation are the same as those for the predicate stereotactic devices.

Design: The design of the Mayfield-ACCISS™ Workstation is similar in concept to the predicate stereotactic devices.

Materials: The materials used in the manufacture of the hardware components of the Mayfield-ACCISSTM Workstation are similar to those used in the predicate devices. Material in direct, transient contact with central nervous system (CNS) tissue/fluids is ATSMB398-94 Grade 2 titanium. Titanium has been used in a number of devices which are transiently used in direct contact with CNS tissues/fluids, such as Cordis Micra Microsurgical Instruments (K862971). Therefore, OMI and NOMOS consider the use of titanium for the manufacture of the probe to be the same as the intended use for Microsurgical Instruments used for the direct brain contact. No new biocompatability issues are raised. Differences in structural materials are addressed through labeling.

Manufacturing: The manufacturing processes used in the Mayfield-ACCISS TM Workstation are similar to those used in the manufacture of predicate stereotactic devices.

Specifications: The specifications of the Mayfield-ACCISSTM Workstation are similar to those of the predicate stereotactic device.

Conclusions: The indications, design, materials, manufacturing, and specifications of the Mayfield-ACCISS workstation do not raise any new unresolved issues relating to safety and effectiveness.

NOMOS thus considers the Mayfield-ACCISSTM Workstation substantially equivalent to the predicate devices.

*Any statement made in conjunction with this submission regarding substantial equivalence to any other product only relates to whether the product can be lawfully marketed without premarket approval or reclassification and is not to be interpreted as an admission or used as evidence in patent infringement litigation. As the Commissioner of the FDA has indicated, ". . . a determination of substantial equivalence under the Federal Food, Drug, and Cosmetic Act relates to the fact that the product can lawfully be marketed without premarket approval or reclassification. This determination is not intended to have any bearing whatever on the resolution of patent infringement suits." 42 Fed. Req. 42,520 et seg. (1977).

Regulation Number and Section

§ 882.4560 Stereotaxic instrument.

(a)
Identification. A stereotaxic instrument is a device consisting of a rigid frame with a calibrated guide mechanism for precisely positioning probes or other devices within a patient's brain, spinal cord, or other part of the nervous system.(b)
Classification. Class II (performance standards).