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The Tonometer Easyton is indicated for the measurement of intraocular pressure in human eyes.

The principle of EASYTON measurement is based on simultaneous use of the two types of measuring actions – static and dynamic. Both actions are carried out by the vibrator's rod on the eyelid. Static action is carried out during the time of measurement and determined by the weight of the vibrator. Dynamic exposure represents itself during the vibrating action with frequency: about 150 HZ and amplitude: the millimeter hundredth parts and tactile is felt as soft vibration. Vibrator's rod is elastically movable in its axial direction and is set in oscillatory motion by electromagnetic way. While carrying out the measurement, the rod is put up on the eyelid, sagging (pressing the eyelid down with its weight about 10g and is fixed on sclera or an eye cornea forming elastic system of eye-vibrator with total mechanical rigidity. This system is disturbed from the equilibrium state by the rod's short term electromagnetic removal. In a system within tan equilibrium state restoration there are arising free damped vibration. Functional connection between elastic system rigidity and the period of is own vibration is known. This period is measured by the tonometer and is used for IOP calculation being shown on the display.

The information provided describes the performance study for the Intraocular Pressure Tonometer EASYTON.

1. Table of Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the statement "not more than 5% of the paired differences between the reference tonometer reading and the test tonometer reading for each pressure range are greater than the tolerance for that range," where the tolerance is defined as ±2 mmHg for IOP from 7 to 23 mmHg and ±5 mmHg for IOP more than 23 mmHg (as stated in the technical specifications).

Here's a summary of the reported device performance from the provided text:

Summary of Studies and Performance (from table on page 15):

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

The studies were prospective comparative studies using human subjects.

• "Low stiffness eyelids study" (Caucasian population): 156 patients (eyes)
• "Epicanthus study" (Asian population): 150 patients (eyes)
• "Rigid stiffness eyelids study" (Indian population): 78 patients (155 eyes) - Note: The discrepancy between patients and eyes might indicate bilateral measurements or a typo. Assuming 155 eyes were tested.

Data Provenance:

• Russia (Moscow, Russia): Glaucoma Community of Russia, IPO (Caucasian population with low stiffness eyelids)
• Kazakhstan (Karaganda, Kazakhstan): Regional Medical Center and TENSV Clinic, LLP (Asian population with epicanthal fold of the eyelid)
• India (Gurgaon, New Delhi, India): Hospital Park (Indian population with rigid stiffness of eyelids)

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 involved in establishing the ground truth measurements for the test set. However, the ground truth was established using the Goldman Applanation Tonometer, which is a widely recognized standard in ophthalmology and would typically be operated by ophthalmologists or trained technicians.

4. Adjudication Method for the Test Set

The document does not describe an adjudication method for the test set. The study compares the Easyton measurements directly against the Goldman Tonometer measurements.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No multi-reader multi-case (MRMC) study is described. The studies focus on comparing the device's measurements against a reference standard across different patient populations and anatomical features, rather than evaluating human reader performance with and without AI assistance.

6. Standalone (Algorithm Only) Performance Study

The provided information describes the performance of the device itself (Easyton Tonometer) against a reference standard (Goldman Tonometer) in human subjects. This is a standalone performance study of the device.

7. Type of Ground Truth Used

The ground truth used was comparative measurements from a reference device, specifically the Goldman Applanation Tonometer. This is considered a clinical reference standard for intraocular pressure measurement.

8. Sample Size for the Training Set

The document does not provide information about a separate training set or its sample size. The studies described appear to be testing (validation) studies. The device's measurement principle (functional connection between elastic system rigidity and the period of its own vibration, with IOP calculation based on measured vibration frequency) suggests a physical-based measurement rather than a machine learning model that would require a distinct training set. If machine learning was involved in the device's core algorithm, details about its training set are not provided.

9. How the Ground Truth for the Training Set was Established

As no training set is described, the method for establishing its ground truth is not provided.

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