Search Results

The DXL Calscan™ Bone Densitometer estimated bone mineral density (BMD) (g/cm²) for the region of the heel (os calcis). By comparing estimated BMD to a (grim ) for the region of the Rose (a T-score is calculated so that the physician, at his or her discretion, may assess fracture risk.

The DXL Calscan™ Bone Densitometer estimates Bone Mineral Density (BMD) of the Os Calcis. THE DAL Calstan - Bone Densitometor Societator Sectionetry (DEXA). Heel width, measured by a The lectificiously is based on Dual Enorgy Artay Arage in the effects from soft and adipose tissues.

Here's an analysis of the provided text regarding the DXL Calscan Bone Densitometer's acceptance criteria and study information:

Summary of Device Acceptance Criteria and Performance

Study Information

1. Sample sizes used for the test set and the data provenance:

   • The provided text does not specify the sample sizes used for the in vitro or in vivo precision and accuracy studies.
   • Data provenance: Not explicitly stated (e.g., country of origin, retrospective or prospective). The company is Swedish (Demetech AB, Solna, Sweden), so it's possible studies were conducted in Sweden, but this is not confirmed.

2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

   • The document does not provide information on the number or qualifications of experts used to establish ground truth for the in vivo studies.
   • For in vitro studies, the "actual hydroxyapatite content" likely serves as a direct reference, not requiring expert consensus in the same way.

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

   • The document does not describe an adjudication method.

4. 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:

   • No MRMC comparative effectiveness study is mentioned. This device is a bone densitometer, which directly measures BMD and does not involve human interpretation of images per se that would typically require an MRMC study or AI assistance for human readers.

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

   • Yes, the performance metrics (accuracy, precision, CV%) are for the DXL Calscan™ Bone Densitometer itself, which is an automated device for measuring BMD. These are standalone performance metrics.

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

   • For the in vitro accuracy study, the ground truth was "actual hydroxyapatite content."
   • For the in vivo precision study, the ground truth for precision is typically the repeated measurement itself, a comparator for accuracy is not explicitly stated but would ideally be a gold standard BMD measurement technique.

7. The sample size for the training set:

   • The document does not specify a training set sample size. This is common for predicate-based 510(k) submissions, especially for a device performing direct physical measurements rather than learning complex patterns from a large dataset like an AI algorithm.

8. How the ground truth for the training set was established:

   • The document does not specify how a ground truth for a training set was established, nor does it indicate the use of a distinct "training set" in the context of machine learning. The studies described are performance validation studies.

Ask a specific question about this device

To estimate bone mineral content (BMC, grams) and bone mineral density (BMD, grams/cm²).

The DexaCare® G4 is a cost effective, table top bone densitometer. The DexaCare® G4 is a modification of the predicate Osteometer MediTech DTX-200 device listed in 510(k) K964562. The DexaCare® G4 candidate device is a dual energy system, where the measured object, in this case the forearm, by the software, is divided into two compartments, bone and soft-tissue. Having two energies, and two compartments (unknowns) it is possible to establish and solve two formulae with two unknowns. The X-ray generator is driven at 55kV, with a current of 300pAmps. The beam is filtered with Tin (Sn), using the K-Edge of this material to enhance the separation of the low and the high energy. The average energy peaks are approximately 29 keV, and 46 keV respectively. A highly stable X-ray output, together with a source collimation of 1 mm and a pixel resolution of 0.4mm X 0.4mm, yields images of very high quality. The detector is a sandwich construction, using solid state photodiodes consisting of two diodes with scintillation material. The two energies are separated by the sandwich construction. The X-ray beam meets the first scintillator, where predominantly the low energy is detected, and then it meets the second scintillator, where the rest of the energy is detected. The typical time to estimate bone mineral content and bone mineral density is approximately four minutes. The effective patient dose is estimated to be 0.1 micro Sievert per scan.

Here's a breakdown of the acceptance criteria and study details for the DexaCare® G4 device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The submission primarily focuses on demonstrating substantial equivalence to a predicate device rather than setting explicit numerical acceptance criteria for independent performance. The "acceptance criteria" can be inferred as showing comparable performance to the predicate device, specifically regarding the correlation and lack of significant difference in BMC and BMD measurements.

2. Sample Size and Data Provenance

• Test Set Sample Size: 16 subjects.
• Data Provenance: Retrospective for the purpose of demonstrating equivalence, and conducted in-house at Osteometer MediTech, Inc. in Hawthorne, CA, USA. This indicates the data was collected specifically for this validation study, not from a broad population in multiple countries.

3. Number of Experts / Qualifications for Ground Truth

Not applicable. This study does not involve expert readers establishing ground truth for diagnostic accuracy, but rather compares quantitative measurements from two devices.

4. Adjudication Method

Not applicable. The study involves direct measurements of BMC and BMD, followed by statistical comparison (paired t-test, linear regression), not interpretation needing adjudication.

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

No, an MRMC comparative effectiveness study was not performed. The device is a bone densitometer producing quantitative measurements, not a system that assists human readers in interpretation.

6. Standalone Performance Study

Yes, a standalone study was performed. The study compared the measurements of the DexaCare® G4 directly against measurements from the predicate DTX-200 devices without human-in-the-loop interpretation being evaluated. The algorithm's output (BMC and BMD) was directly compared.

7. Type of Ground Truth Used

The "ground truth" in this context is the quantitative measurements (Bone Mineral Content and Bone Mineral Density) obtained from the predicate DTX-200 device. The study aims to show that the new device's measurements are essentially the same as those from the established predicate device.

8. Sample Size for Training Set

No information is provided regarding a separate training set. The study describes a clinical validation study on 16 subjects. Given the nature of a bone densitometer (a measurement device as opposed to an AI diagnostic assistant that requires extensive image-based training), it's highly probable that traditional calibration procedures were used rather than a "training set" in the machine learning sense. The document states: "The DexaCare® G4 uses a line-by-line calibration system to ensure good precision."

9. How Ground Truth for Training Set Was Established

Not applicable, as no training set in the AI sense is specifically mentioned. Calibration for the device would typically be established using phantoms with known bone mineral content/density values, following industry standards for bone densitometry. However, the document does not detail the specific methods for establishing the accuracy of the calibration system itself.

Ask a specific question about this device