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Cranial 4Pi is intended for patient immobilization in radiotherapy and radiosurgery procedures.

Cranial 4Pi is indicated for any medical condition in which the use of radiotherapy or radiosurgery may be appropriate for cranial and head & neck treatments.

Cranial 4Pi is an assembly of the following medical device/ accessory groups:

• CRANIAL 4PI OVERLAYS (CRANIAL 4PI CT OVERLAY, CRANIAL 4PI TREATMENT OVERLAY)
• CRANIAL 4PI HEADRESTS (CRANIAL 4PI HEADREST STANDARD, CRANIAL 4PI HEADREST LOW-NECK, CRANIAL 4PI HEADREST PLATFORM)
• CRANIAL 4PI HEADREST INLAYS (CRANIAL 4PI HEADREST INLAY STANDARD, CRANIAL 4PI HEADREST INLAY OPEN FACE, CRANIAL 4PI HEADREST INLAY H&N, CRANIAL 4PI HEAD SUPPORT STANDARD, CRANIAL 4PI HEAD SUPPORT WIDE)
• CRANIAL 4PI MASKS (CRANIAL 4PI BASIC MASK, CRANIAL 4PI OPEN FACE MASK, CRANIAL 4PI EXTENDED MASK, CRANIAL 4PI STEREOTACTIC MASK, CRANIAL 4PI STEREOTACTIC MASK 3.2MM)
• CRANIAL 4PI WEDGES AND SPACERS (CRANIAL 4PI WEDGE 5 DEG., CRANIAL 4PI WEDGE 10 DEG., CRANIAL 4PI SPACER 20MM, CRANIAL 4PI INDEXING PLATE)

The Cranial 4Pi Overlays are medical devices used for fixation of the patient in a CT- resp. linear accelerator - environment.

The Cranial 4Pi Headrests and the Cranial 4Pi Headrest Inlays are accessories to the Cranial 4Pi Overlays to allow an indication specific positioning of the patient's head and neck. The Cranial 4Pi Wedges and Spacers are accessories to the Cranial 4Pi Headrest Platform to adapt the inclination of the head support to the patients necks.

The Cranial 4Pi Masks are accessories to the Cranial 4Pi Overlays used for producing individual custom-made masks for patient immobilization to the Cranial 4Pi Overlay.

The provided text is a 510(k) Clearance Letter and 510(k) Summary for a medical device called "Cranial 4Pi Immobilization." This document focuses on demonstrating substantial equivalence to a predicate device, as required for FDA 510(k) clearance.

However, the provided text does not contain the detailed information typically found in a clinical study report or a pre-market approval (PMA) submission regarding acceptance criteria, study methodologies, or specific performance metrics with numerical results (like sensitivity, specificity, or AUC) that would be used to "prove the device meets acceptance criteria" for an AI/ML-driven device. The document primarily describes the device's components, indications for use, and a comparison to a predicate device to establish substantial equivalence.

The "Performance Data" section primarily addresses biocompatibility, mechanical verification, dosimetry, compatibility with another system, and mask stability. It does not describe a study to prove AI model performance against clinical acceptance criteria. The "Usability Evaluation" section describes a formative usability study, which is different from a performance study demonstrating clinical effectiveness or accuracy.

Therefore, many of the requested elements (especially those related to AI/ML model performance, ground truth establishment, expert adjudication, MRMC studies, or standalone algorithm performance) cannot be extracted from the provided text. The Cranial 4Pi Immobilization device appears to be a physical immobilization system, not an AI/ML diagnostic or prognostic tool.

Given the nature of the document (510(k) for an immobilization device), the concept of "acceptance criteria for an AI model" and "study that proves the device meets the acceptance criteria" in the traditional sense of an AI/ML clinical study does not apply here.

I will answer the questions based on the closest relevant information available in the provided text, and explicitly state where the information is not available or not applicable to the type of device described.

Preamble: Nature of the Device and Submission

The Cranial 4Pi Immobilization device is a physical medical device designed for patient immobilization during radiotherapy and radiosurgery. The 510(k) premarket notification for this device seeks to demonstrate substantial equivalence to an existing predicate device (K202050 - Cranial 4Pi Immobilization). This type of submission typically focuses on comparable intended use, technological characteristics, and safety/performance aspects relevant to the physical device's function (e.g., biocompatibility, mechanical stability, dosimetry interaction).

The provided documentation does not describe an AI/ML-driven component that would require acceptance criteria related to AI model performance (e.g., accuracy, sensitivity, specificity, AUC) or a study to prove such performance. Therefore, many of the questions asking about AI-specific validation (like ground truth, expert adjudication, MRMC studies, training/test sets for AI) are not applicable to this type of device and submission.

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

Based on the provided document, specific numerical "acceptance criteria" and "reported device performance" in the context of an AI/ML model are not available and not applicable. The document focuses on demonstrating substantial equivalence of a physical immobilization device.

However, the "Performance Data" section lists several tests and their outcomes, which serve as evidence that the device performs as intended for its physical function. These are not acceptance criteria for an AI model.

• Saline Extraction: No sensitization reactions observed.
• Cottonseed Oil Extraction: No sensitization reactions observed.
  Test article did not elicit sensitization reactions (guinea pigs). Positive controls validated sensitivity.
  Irritation Testing (ISO 10993-23):
• No irritation observed (rabbits) compared to control based on erythema and edema scores for saline and cottonseed oil extracts.
  Test article met requirements for Intracutaneous (Intradermal) Reactivity Test. Positive controls validated sensitivity. |
  | Mechanical Tests | Relevant for fulfillment of IEC 60601-1 requirements. | All mechanical tests relevant for fulfillment of IEC 60601-1 requirements were carried out successfully. |
  | Dosimetry Tests | Verify that dose attenuation is acceptable. | Tests to verify that dose attenuation is acceptable with the hardware components were carried out successfully. |
  | Compatibility Tests| Compatibility with ExacTrac Dynamic 2.0. | Compatibility with ExacTrac Dynamic 2.0 was tested successfully. |
  | Mask Stability | Cranial 4Pi SRS mask 3.2 mm (vs. 2mm predicate) to have higher stability against head movement. | Technical validation test to prove that the Cranial 4Pi SRS mask 3.2 mm... having a 3.2 mm top mask sheet instead of 2mm has a higher stability against head movement was carried out successfully. |
  | Usability Evaluation| Evaluate the usability of the subject devices. | Formative usability evaluation performed in three different clinics with seven participants to evaluate the usability of the subject devices. (Specific findings not detailed, but the study was performed). |

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

• Sample Size for Test Set: Not applicable/not stated in the context of an AI/ML test set. The usability evaluation involved "seven participants" in "three different clinics." For biocompatibility, animal studies were performed (guinea pigs for sensitization, rabbits for irritation; specific number of animals not stated but implied to be sufficient for ISO standards).
• Data Provenance: Not applicable for an AI/ML test set. The usability evaluation involved "three different clinics" but the country of origin is not specified.

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. This device is a physical immobilization system, not an AI/ML diagnostic or prognostic tool that requires expert-established ground truth on medical images.

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

• Not applicable. This information is relevant to validating AI/ML diagnostic performance against ground truth, which is not described for this device.

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 an AI/ML-specific study design. The device is a physical immobilization system, not an AI assistance tool for human readers.

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

• Not applicable. This is an AI/ML-specific validation. There is no AI algorithm component described for this physical device.

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

• Not applicable. No ground truth for diagnostic or prognostic purposes is established for this physical device. The "performance data" relies on standards compliance (e.g., ISO, IEC), physical measurements, and usability feedback.

8. The sample size for the training set

• Not applicable. There is no AI model described that would require a training set.

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

• Not applicable. There is no AI model described.

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The Cranial 4Pi Immobilization is a device used for immobilization of the patient's •cranial area •head and neck area in a CT- and linear accelerator environment.

The Cranial 4Pi Immobilization device is indicated for any medical condition in which the use of radiotherapy or radiosurgery may be appropriate for cranial and head & neck treatments.

The Cranial 4Pi Immobilization group of devices is used for fixation and repositioning of the patient's head and neck in a CT- and linear accelerator environment.

The SRS 4Pi CT Table Overlay (43430) is a medical device used for fixation and repositioning of the patient's head and neck in a CT- environment.

The mask sets Cranial 4Pi Stereotactic Mask (43450) / Cranial 4Pi Basic Mask (43451) / Cranial 4Pi Openface Mask (43452) are medical devices used for producing custom-made masks for patient fixation to the Overlay Board in a CT- and linear accelerator environment.

The device is portable. The system consists of two Overlays, three types of thermoplastic mask sets with the corresponding rear head support and a Target Pointer. The system fixates a patient mechanically to hold them still during CT scanning and again during Treatment. The Overlays (one for Linac room) are used to rigidly attach to multiple Table top/Couch Top types and to provide an interface to the Mask sets. The Target Pointer is used for performance of isocenter quality assurance procedures in a linear accelerator environment.

The provided text describes a medical device, Cranial 4Pi Immobilization, which is used for patient immobilization during radiotherapy and radiosurgery. The 510(k) submission primarily focuses on establishing substantial equivalence to a predicate device and details verification activities related to mechanical stability, usability, and biocompatibility.

However, the provided document does NOT contain information about any study that proves the device meets specific acceptance criteria related to its performance in terms of patient immobilization accuracy or any AI/imaging-related performance metrics. The text outlines the device's function (immobilization) and general safety/effectiveness verification, but it does not present a table of acceptance criteria with reported device performance outcomes for areas like:

• Accuracy of immobilization (e.g., maximum displacement allowed vs. measured displacement)
• Repeatability of patient positioning
• Performance compared to human readers (MRMC study)
• Standalone algorithm performance
• Details on test set or training set characteristics (sample size, provenance, ground truth establishment, expert adjudication).

The document is a regulatory submission for a physical immobilization device, not a software-driven AI diagnostic or therapeutic device. Therefore, questions 2 through 9 regarding study design, sample size, expert involvement, and AI performance are not applicable to the content provided.

Based on the provided text, I can only address the general nature of the "acceptance criteria" through the lens of safety and effectiveness for a physical device, and the "study" as the verification activities performed for regulatory clearance.

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria for this type of physical immobilization device are largely focused on mechanical stability, usability, and biocompatibility, rather than diagnostic accuracy or AI performance metrics. The document lists "Key Performance Specifications/Characteristics" as "Immobilization of patient's head or head and neck." However, it doesn't quantify this performance.

Here's an interpretation based on the provided text, focusing on the types of verification activities performed, which imply the acceptance criteria were related to meeting harmonized standards and ensuring user safety and device function.

The following points (2-9) are not applicable or cannot be answered based on the provided document, as it pertains to a physical immobilization device and not an AI/imaging diagnostic tool.

2. Sample size used for the test set and the data provenance: Not applicable. This document does not describe a clinical study with a patient image test set. The verification activities are related to device testing (e.g., mechanical, electrical, material).

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts: Not applicable. No "ground truth" in the context of diagnostic imaging or AI performance is established or discussed.

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-assisted diagnostic device.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done: Not applicable. This is a physical device, not an algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.): Not applicable.

8. The sample size for the training set: Not applicable. No training set for an algorithm is mentioned.

9. How the ground truth for the training set was established: Not applicable.

Ask a specific question about this device