(149 days)
The Achilles ultrasonometer measures ultrasound variables of the os calcis to provide a clinical measure called Stiffness Index. The Stiffness Index indicates risk of osteoporotic fracture in postmenopausal women comparable to bone mineral density (BMD) as measured by X-ray absorptiometry at the spine or hip.
Stiffness index results expressed as t-scores are used to assist the physicians in the diagnosis of osteoporosis in the same way as are t-scores or obtained by x-ray absorpiometry. Either the stiffness index t-score or x-ray absorpiometry t-score can be utilized by a physician, in conjunction with other clinical risk factors, to provide a comprehensive skeletal assessment.
The stiffness index has a precision error in older women comparable to that of x-ray absorpiometry, which makes it suitable for monitoring bone changes.
Achilles EXPII measures ultrasound variables of the os calcis to provide a clinical measure called Stiffness Index. The Stiffness Index indicates risk of osteoporotic fracture in postmenopausal women comparable to bone mineral density (BMD) as measured by X-ray absorptometry at the spine or hip.
GE Healthcare's Achilles EXPII Bone Sonometer measures ultrasound variables of the os calcis to provide a Stiffness Index. This index indicates the risk of osteoporotic fracture in postmenopausal women, comparable to bone mineral density (BMD) measured by X-ray absorptiometry at the spine or hip. The device's performance was compared to its predicate device, the Achilles Express.
Here's an analysis of the acceptance criteria and the study that proves the device meets them:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria / Performance Metric | Reported Device Performance (Achilles EXPII vs. Achilles Express) |
|---|---|
| Equivalence in Stiffness Index results | Stiffness Index results from Achilles EXPII shown to be equivalent to Achilles Express in vivo. |
| Correlation (R value) of Stiffness Index values | High correlation (R=0.97) between the two devices. |
| Significant differences in Stiffness values | No significant differences found. |
| Precision error in older women | Comparable to that of X-ray absorptiometry. |
2. Sample size used for the test set and the data provenance
The document mentions "A clinical study GE3120 was performed". However, the sample size for this clinical study and the data provenance (e.g., country of origin, retrospective or prospective nature) are not provided in the provided text.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The provided text does not mention the use of experts or the establishment of ground truth in the context of radiologists or similar qualified professionals guiding the clinical study. The study focuses on comparing the device's output (Stiffness Index) with its predicate.
4. Adjudication method for the test set
The provided text does not describe any adjudication method like 2+1 or 3+1. The study appears to be a direct comparison of measurements between two devices.
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 an MRMC comparative effectiveness study in the context of human readers and AI assistance. The Achilles EXPII is a diagnostic device for measuring bone health, not an AI-assisted interpretation tool for human readers. Therefore, an effect size of human reader improvement with/without AI is not applicable and not mentioned.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This device functions as a standalone device (an ultrasonometer) that measures physical properties to calculate a Stiffness Index. Its performance, as described, is independent of human interpretation or input for the primary measurement itself, though physicians use its output in conjunction with other clinical factors. The comparison made in the study (device vs. predicate device) is a standalone performance comparison.
7. The type of ground truth used
The "ground truth" in this context is the Stiffness Index values obtained from the predicate device, the Achilles Express Ultrasonometer. The study aimed to demonstrate that the Achilles EXPII’s measurements are equivalent to those of the legally marketed predicate. The predicate device itself (Achilles Express) would have been validated against a clinical truth, likely Bone Mineral Density (BMD) as measured by X-ray absorptiometry, which is mentioned as the comparative standard for the Stiffness Index in general.
8. The sample size for the training set
The provided text does not mention a training set in the context of machine learning or AI models. The Achilles EXPII is a measurement device, not explicitly based on a machine learning model that requires a training set.
9. How the ground truth for the training set was established
As there's no mention of a training set in the provided documentation, this question is not applicable.
§ 892.1180 Bone sonometer.
(a)
Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture risk. The primary components of the device are a voltage generator, a transmitting transducer, a receiving transducer, and hardware and software for reception and processing of the received ultrasonic signal.(b)
Classification. Class II (special controls). The special control for this device is FDA's “Guidance for Industry and FDA Staff; Class II Special Controls Guidance Document: Bone Sonometers.” See § 892.1(e) for the availability of this guidance document.