Search Results

Bindex measures apparent cortical bone thickness at the proximal tibia and can be used in conjunction with other clinical risk factors or patient characteristics as an aid to the physician in the diagnosis and other medical conditions leading to reduced bone strength and in the determination of fracture risk.

The Bindex Bl-2 system consists of handheld ultrasound transducer and software. Bindex Bl-2 is connected to the USB port of a computer and controlled with computer software. Bindex Bl-2 is used for measurement of cortical bone thickness and it provides Density Index (DI), a parameter which estimates bensity at the hip as measured with DXA. For measurements, gel is applied on skin and ultrasound transducer is manually placed on the measurement location. Standardized measurement location is at proximal tibia (1/3 length of tibia). Transducer is manually oriented perpendicularly to the cortical bone to achieve accepted measurement. Measurement is repeated five times at each measurement location. Finally, transducer is disinfected by wiping gel off with isopropyl alcohol moistened cloth.

The provided document is a 510(k) summary for the Bindex BI-2 device, which measures apparent cortical bone thickness. The device received substantial equivalence based on its similarity to a predicate device (Bindex BI-100). The document focuses on demonstrating substantial equivalence rather than presenting an exhaustive de novo clinical study with specific acceptance criteria and detailed device performance metrics against a clinical ground truth.

Here's an analysis based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly present a table of acceptance criteria with corresponding device performance for clinical accuracy in the traditional sense of a de novo study. Instead, it relies on demonstrating that the Bindex BI-2 (subject device) is substantially equivalent to the Bindex BI-100 (predicate device), for which previous clinical and pre-clinical data supports its safe and effective use.

The "acceptance criteria" here are implicitly related to the predicate device's established performance and the subject device's ability to demonstrate equivalence in technical and functional aspects. The performance data presented are primarily related to engineering and safety testing, not direct clinical diagnostic performance metrics (like sensitivity, specificity, accuracy against a gold standard for bone strength or fracture risk).

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

The document does not describe a separate "test set" in the context of a de novo clinical study with human subjects for the Bindex BI-2. Its performance demonstration relies on showing equivalence to the predicate device.

• Clinical Studies: The document states, "The same clinical and pre-clinical data supports the safe and effective use of Bindex Bl-100, to which substantial equivalence is shown." This implies that the clinical data for the predicate device (Bindex BI-100) serves as the basis for clinical effectiveness.
• Engineering Tests (Biocompatibility, Electrical, EMC, Mechanical, Acoustic): These tests were conducted on the Bindex BI-2 itself, but sample sizes for these specific engineering tests are not provided (e.g., number of devices dropped, number of units tested for EMC). The provenance is implied to be internal testing by Bone Index Finland, Ltd.

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

Not applicable for this submission. The submission is a 510(k) for substantial equivalence to a predicate device, not a de novo clinical study establishing new clinical ground truth for a novel device. The document references "other clinical risk factors or patient characteristics" as aids to diagnosis for the physician, suggesting the device provides data to be used in conjunction with a physician's expert judgment, rather than replacing it or having its output directly adjudicated by a panel.

4. Adjudication Method for the Test Set

Not applicable. No new clinical test set requiring adjudication is described for the Bindex BI-2 device in this submission.

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. The Bindex BI-2 is described as a medical device (bone sonometer) that measures "apparent cortical bone thickness" and provides a "Density Index (DI)." It is not an AI-based diagnostic image interpretation system with a "human-in-the-loop" component in the way that an MRMC study would typically evaluate. The device provides quantitative measurements to aid a physician, not AI-assisted readings of complex medical images.

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

The Bindex BI-2 operates as a standalone measurement device. It directly measures cortical bone thickness using ultrasound. The output (thickness, Density Index) is a quantitative measurement, not an "algorithm-only" interpretation in the sense of a machine learning model. The device itself is the "standalone" entity that performs the measurement. However, its output is intended to be used by a physician "in conjunction with other clinical risk factors or patient characteristics."

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

For the Bindex BI-2 itself, the ground truth for its technical performance (e.g., accuracy of thickness measurement) is not explicitly detailed in this summary. Instead, the submission relies on the established "safe and effective use" of the predicate device (Bindex BI-100). The predicate device's indications for use mention "diagnosis of osteoporosis" and "determination of fracture risk," implying that its effectiveness was likely demonstrated against clinical endpoints such as bone mineral density (often measured by DXA, as suggested by the BI-2 providing a parameter estimating density at the hip as measured with DXA), or potentially fracture outcomes data, for which ultrasound measurements serve as a surrogate.

The Bindex BI-2's output (Density Index) "estimates density at the hip as measured with DXA," suggesting DXA as a clinical ground truth for the predicate's or implied target value.

8. The Sample Size for the Training Set

Not applicable for a training set in the context of machine learning. The device is a measurement instrument, not an AI model that requires a training set. If "training set" refers to the data used to develop the algorithms for the predicate device, that information is not provided in this summary.

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

Not applicable, as there is no mention of an algorithm training set in the context of machine learning.

Ask a specific question about this device

Bindex measures apparent cortical bone thickness at the proximal tibia and can be used in conjunction with other clinical risk factors or patient characteristics as an aid to the physician in the diagnosis of osteoporosis and other medical conditions leading to reduced bone strength and in the determination of fracture risk.

The Bindex system includes ultrasound pulser, transducer and software. Bindex is connected to the USB port of a computer and controlled with computer software. Bindex is used for measurement of cortical bone thickness and it provides Density Index (DI), a parameter which estimates bone mineral density at the hip as measured with DXA. For measurements, gel is applied on skin and ultrasound transducer is manually placed on the measurement location. Standardized measurement location is at proximal (1/3 length) of tibia. Transducer is manually oriented perpendicularly to the surface of the cortical bone to achieve accepted measurement. Measurement is repeated five times at each measurement location. Finally, transducer is disinfected by wiping gel off with disinfective solution moistened cloth or tissue.

Here's a breakdown of the acceptance criteria and the study proving the device meets them, based on the provided text:

Acceptance Criteria and Device Performance

The core of the device's effectiveness lies in its ability to aid in the diagnosis of osteoporosis and determination of fracture risk, performing comparably to the predicate device and being able to identify osteoporotic and non-osteoporotic subjects correctly with certain thresholds.

Device Study Details

2. Sample Sizes and Data Provenance

• In vitro and In vivo Proof of Concept:
  • Bovine cortical bone samples (n=6)
  • Human volunteers (n=20)
  • Provenance: Not explicitly stated for these initial proof-of-concept studies, but the reference to Karjalainen et al. 2008 suggests academic research.
• Clinical Studies:
  • Study 1 (Initial Clinical Testing): Sample size not explicitly given for the study that introduced DI (Karjalainen et al. Osteoporos Int 2012).
  • Study 2 (Finnish Population): 572 subjects.
    • Provenance: Finland; Karjalainen J. et al. Osteoporos Int 2016. This was a prospective study used to determine diagnostic thresholds.
  • Study 3 (U.S. Study): 560 subjects.
    • Provenance: United States; Schousboe et al. 2016. This study validated the thresholds developed in the Finnish study. It's likely prospective given the validation nature.

3. Number of Experts and Qualifications for Ground Truth

The document does not explicitly state the number or specific qualifications of experts used to establish ground truth for the test set. However, it heavily references DXA (Dual-energy X-ray Absorptiometry), which is the established gold standard for osteoporosis diagnosis. The criteria for osteoporosis classification (T-score threshold of -2.5) are based on World Health Organization (WHO) definitions and guidelines from the International Society of Clinical Densitometry (ISCD). This implies that ground truth was established by clinical diagnosis using DXA, interpreted by qualified medical professionals (e.g., radiologists, endocrinologists, or other specialists involved in bone health), rather than by individual experts marking images for AI.

4. Adjudication Method for the Test Set

Not applicable. The primary ground truth for clinical studies was established by DXA measurements and WHO/ISCD criteria for osteoporosis, not by human expert agreement on device output in a read-out session that would require adjudication.

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

No, a traditional MRMC study as understood in image interpretation (comparing human reader performance with/without AI assistance) was not performed. This device is a measurement tool (bone sonometer) that provides a quantitative output (Density Index) rather than creating images for human interpretation. Its effectiveness was evaluated by comparing its diagnostic capability (identifying osteoporotic patients, fracture risk prediction) to the DXA gold standard and to the predicate device.

The study aimed to show that the Bindex could reduce the need for DXA examinations by identifying a subset of patients who wouldn't need one (where Bindex's "yellow area" means they would). Approximately 30% of patients would still need a DXA. This indicates an effect on follow-up testing, but not a direct improvement in human reader performance on a given test.

6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study

Yes, the primary effectiveness endpoint evaluation describes the performance of the Bindex device (algorithm) itself in making classifications related to osteoporosis, in conjunction with DXA. While the phrase "in conjunction with other clinical risk factors or patient characteristics as an aid to the physician" implies physician involvement, the performance claims ("identify 90% of osteoporotic and non-osteoporotic subjects correctly," "similar fracture prediction capability") are attributed to the device's DI and Ct.Th. values, reflecting its standalone diagnostic potential within a clinical framework. The device is a "bone sonometer" providing a numerical output, not an AI interpreting complex images for human assistance.

7. Type of Ground Truth Used

• Clinical Studies: Clinical diagnosis of osteoporosis based on DXA measurements and World Health Organization (WHO) T-score criteria, as defined by the International Society of Clinical Densitometry (ISCD). This is the gold standard for osteoporosis diagnosis.
• In vitro and In vivo Proof of Concept:
  • In vitro: Caliper measurements of bovine bone samples.
  • In vivo: Peripheral Quantitative Computed Tomography (pQCT) measurements of human volunteers.

8. Sample Size for the Training Set

The document does not explicitly state the sample size of a "training set" for the device's algorithm. It describes clinical studies where thresholds were determined and validated.

• The Finnish study (n=572) was where the thresholds were "determined." This population effectively served as the development/training dataset for establishing the Density Index (DI) thresholds for osteoporosis classification.
• The U.S. study (n=560) was then used for validation of these predetermined thresholds.

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

For the "training" (threshold determination) set in the Finnish study (n=572), the ground truth for osteoporosis was established by conventional DXA measurements and the application of WHO/ISCD guidelines for osteoporosis diagnosis (T-score threshold of -2.5). This means patients in this cohort underwent DXA scans, and their osteoporosis status was determined based on the globally accepted clinical standard. The Bindex's DI and Ct.Th. values were then correlated with this established DXA-based ground truth to define clinical thresholds for the device.

Ask a specific question about this device