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The SENSIMED Triggerfish® is a prescription device indicated to detect the peak patterns of variation in intraocular pressure over a maximum period of 24 hours to identify the window of time to measure intraocular pressure by conventional clinical methods. The SENSIMED Triggerfish® is indicated for patients 22 years of age and older.

Device Description

SENSIMED Triggerfish® diurnal recording system (hereinafter "STF") is a small patient-worn electronic device intended for use in the home and clinic settings for recording diurnal patterns of IOP fluctuations. The components of the STF are as follows: a hydrophilic, single-use soft contact lens with a strain gauge sensor, antenna with a telemetry chip embedded within it, allowing for continuous wireless recording of changes in ocular dimension, an external adhesive antenna worn around the eye is used to send power to, and receive measurement data from, the embedded system, a pocket-sized, battery-operated recorder worn by the patient during the 24-hour recording session, which is connected to the external adhesive antenna by a data cable. Additional components: charger to recharge the Recorder, Bluetooth universal serial bus (USB) adapter for communication between Recorder and doctor's personal computer (PC), and software for initiation recording sessions, and retrieval & display of the recorded data. The operating principle of the STF is based on the measurement of circumferential changes of the eye ball at the corneoscleral interface by an active strain gauge embedded into the periphery of a soft silicone contact lens ("ocular telemetry sensor"). During the 24-hour recording session, the sensor wirelessly transfers the data to the recording system. At the end of the recording session, all data can be transferred to the PC for review and analysis by a healthcare professional.

AI/ML Overview

The SENSIMED Triggerfish® is a prescription device indicated to detect the peak patterns of variation in intraocular pressure over a maximum period of 24 hours to identify the window of time to measure intraocular pressure by conventional clinical methods. It is indicated for patients 22 years of age and older.

Here's an analysis of the acceptance criteria and the studies that prove the device meets these criteria:

1. Table of Acceptance Criteria and Reported Device Performance:

Acceptance Criteria (from "Special Controls")	Reported Device Performance
1. Clinical performance data must demonstrate that the device and all of its components perform as intended under anticipated conditions of use. The following performance characteristics must be demonstrated:
a. ability of the device to detect diurnal changes	Study TF-1005: Demonstrated repeatability of the mean 24-hour STF profiles in 31 glaucoma and glaucoma suspect subjects, with a strong intraclass correlation (ICC) (0.99) between the mean profiles from two different sessions one week apart. This indicates consistent detection of diurnal patterns. Study TF-1009: Showed that a positive slope was detected on STF profiles in the transition period from wake to sleep (W/S slope) in the study population. Although the results are inconclusive for quantitative characterization of W/S slopes, they show the ability of the device to qualitatively capture "larger and slower patterns" (diurnal changes). A strong correlation (r=0.956, p<0.001, Pearson correlation) was observed between the mean 24-hour STF curve from one eye of 30 healthy subjects and the mean 24-hour IOP curve collected from the fellow eye, further supporting the link between STF output patterns and IOP changes.
b. tolerability of the system at the corneoscleral interface in the intended use population.	Study TF-1005: The mean duration of STF wear was 24.0 ±0.5 hours in the first session and 24.0±0.3 in the second session, equating to 80 24-hour exposures. Six device-related slit lamp findings of moderate or severe intensity occurred in 4 subjects (5.1% of evaluable eyes), with ocular hyperemia being the most common. All resolved with no clinical sequelae (mean time to resolution: 24.5±11.8 hours). No serious adverse events were reported. Comparison of VAS scores by group over two sessions yielded no significant difference (p=0.336), indicating acceptable comfort levels. Study TF-1009: Average subject tolerability was 3.7 on a 5-point scale (5 high acceptance; 1 low acceptance). Seven eyes (21.2%) displayed moderate corneal staining, and 1 eye (3.0%) and 3 eyes (9.1%) displayed moderate to severe injection (ocular hyperemia), respectively. No serious adverse events were reported.
2. Non-clinical testing must validate measurements in an appropriate non-clinical testing model to ensure ability to detect changes in intraocular pressure.	Two ex vivo porcine eye studies were performed. The first demonstrated a strong correlation (r=0.992) between the wired contact lens strain gauge sensor output and control manometric pressure, indicating detection of changes in volume corresponding to physiological IOP changes. The second study, using the telemetric (wireless) sensor, demonstrated the ability to detect dimensional changes with high sensitivity (detecting small simulated pressure pulsations) and high correlation (r²=0.9935) to simulated IOP changes.
3. Patient-contacting components must be demonstrated to be biocompatible.	The ocular telemetry sensor is embedded in silicone elastomer, demonstrated to be biocompatible per ISO 10993-1:2009 for mucosal membrane contacting devices with limited contact. Cytotoxicity (ISO 10993-5:2009), irritation, and sensitization (ISO 10993-10:2010) tests were conducted. Chemical analysis of leachables and extractables showed organic substances below the limit of quantification. The antenna's medical-grade foam and hypoallergenic adhesive tape were deemed biocompatible based on long history of safe use and cytotoxicity testing (ISO 10993-5:2009).
4. Any component that is intended to contact the eye must be demonstrated to be sterile throughout its intended shelf life.	The contact lens with embedded telemetry sensor is packaged to ensure a Sterility Assurance Level (SAL) of 10⁻⁶. Sterilization process was validated in accordance with ISO 11737-2:2009. Shelf life testing for 24 months was performed following real-time storage at ambient conditions, in accordance with ISO 11607-1:2006 and ISO 11737-2:2009.
5. Software verification, validation and hazard analysis must be performed.	The software is considered a minor level-of-concern. The application included: Software Description, Device Hazard Analysis, Software Requirements Specifications, Architecture Design Chart, Design Specifications, Traceability Analysis/Matrix, Verification and Validation testing, and Revision Level History. These documents were deemed sufficient.
6. Performance testing must demonstrate the electromagnetic compatibility and electromagnetic interference of the device.	Verification testing was performed according to IEC 60601-1-2:2007, including compliance with US National differences. Electromagnetic compatibility was supported by demonstrating compliance with IEC 60601-1-2:2014 for the home healthcare environment, including evaluation of potential interference to and by the STF device from Bluetooth communication.
7. Performance testing must demonstrate electrical safety of the device.	Verification testing was performed according to IEC 60601-1-2:2007, including compliance with US National differences.
8. Labeling must include the following: - Warning against activities and environments that may put the user at greater risk. - Specific instructions for the safe use of the device. - A summary of non-clinical testing information to describe EMC safety considerations. - A summary of safety information obtained from clinical testing. - Patient labeling to convey information regarding appropriate use of device.	The labeling satisfies 21 CFR 801.109 and principles in FDA's "Medical Device Patient Labeling" guidance. The user manual includes a complete list of contraindications, warnings, precautions, possible complications, description of components, principle of operation, user controls, operating/maintenance instructions, and a listing of observed AEs. The patient labeling includes relevant contraindications, warnings, precautions, observed/probable complications, directions/considerations for recording sessions, and a description of the device and its indications for use.

2. Sample Size Used for the Test Set and Data Provenance:

Study TF-1005 (Safety and Tolerability):
- Sample Size: 41 subjects enrolled (22 glaucoma suspects, 19 with POAG). 40 subjects completed the study. Data equates to 80 24-hour exposures to STF.
- Data Provenance: Single-center, prospective, open-label study conducted in the US.
Study TF-1009 (Safety and Performance):
- Sample Size: 33 subjects enrolled. Data for 29 subjects was included in the primary analysis set for performance. Data from all 33 subjects were included for safety analysis.
- Data Provenance: Single-center, prospective, open-label study conducted in the US at a sleep laboratory facility.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:

The document does not explicitly state the number or qualifications of experts used to establish ground truth for the test sets.

For clinical studies (TF-1005 and TF-1009), standard ophthalmic examinations were conducted by healthcare professionals. Tonometry measurements (pneumatonometry) were used in Study TF-1009 to provide reference IOP data.
The "ground truth" for the device's primary indication (detecting peak patterns of variation in intraocular pressure over a maximum period of 24 hours to identify the window of time to measure intraocular pressure by conventional clinical methods) is implicitly tied to these clinical assessments and the correlation of STF patterns with actual IOP fluctuations (as measured by tonometry).
However, the document does not mention an independent panel of experts reviewing cases to establish a definitive ground truth for each case in the test set, as might be done for diagnostic imaging studies. The focus is on the device's ability to capture physiological changes and its correlation with conventional IOP measurements.

4. Adjudication Method for the Test Set:

The document does not describe any formal adjudication method (e.g., 2+1, 3+1) for establishing ground truth from multiple experts for the clinical studies. The clinical studies primarily gathered data on direct device performance, safety events, and correlation with existing clinical measurements (जैसे, tonometry).

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:

This is not applicable. The SENSIMED Triggerfish® is a diurnal pattern recorder system, not an AI-assisted diagnostic tool that aids human readers in interpreting medical images or data. Therefore, an MRMC study comparing human reader performance with and without AI assistance was not conducted or relevant for this device.

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

Yes, the SENSIMED Triggerfish® operates as a standalone device in its primary function of recording diurnal patterns of ocular dimension changes. The "algorithm only" performance is represented by its ability to capture these patterns and correlate them with IOP fluctuations. The device continuously records data without immediate human intervention in the data acquisition phase. The output is then reviewed and analyzed by a healthcare professional.

7. The Type of Ground Truth Used:

Clinical Studies (TF-1005 & TF-1009): The "ground truth" for evaluating the device's performance was primarily derived from:
- Clinical Observations and Assessments: Ophthalmic examinations, adverse event reporting, and patient-reported discomfort levels (VAS, questionnaires).
- Conventional IOP Measurements (Tonometry): In Study TF-1009, pneumatonometry measurements were taken every 2 hours in the non-STF eye to provide a reference for IOP changes. Correlation with these tonometry measurements helped establish the link between STF output patterns and IOP changes.
- Physiological Phenomena: The ability to detect wake-to-sleep (W/S) slopes and ocular pulse frequency (compared to heart rate) were used as performance indicators, representing established physiological changes.
Non-Clinical/Bench Studies:
- Controlled Manometric Pressure: In ex vivo porcine eye studies, changes in ocular volume were induced by syringe and measured by control manometric pressure, serving as the ground truth for evaluating the sensor's ability to detect dimensional changes.

8. The Sample Size for the Training Set:

The document describes clinical studies that served for validation and performance assessment. It does not explicitly mention a separate "training set" in the context of machine learning model development. This device appears to be based on physical sensing principles (strain gauge) rather than a complex machine learning model that would require a distinct training set for algorithm development. The non-clinical and clinical studies appear to be for validation of the device's physical and clinical performance.

9. How the Ground Truth for the Training Set Was Established:

As there's no explicit mention of a "training set" for a machine learning algorithm, the concept of establishing ground truth for such a set is not applicable here. The device's functionality relies on direct measurement of physical changes. The "ground truth" in the validation studies (both non-clinical and clinical) was established using controlled experimental setups (ex vivo porcine eyes with manometric pressure) and conventional clinical measurements (ophthalmic exams, tonometry) to assess the device's ability to detect and correlate with known physiological phenomena and IOP changes.

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