(90 days)
The Nuclear Associates VacuDAP - Model 2000, 2001 is intended to measure the radiation output of diagnostic X-ray generating machines during imaging of patients in both radiography and fluoroscopy. The instrument measures and displays Dose Area Product, a parameter that can be related to patient dose by a Medical Physicist. The Dose Area Product measurement includes the influence of dose rate, screening time and used field quantity variables. The instrument accumulates Dose Area Product values until manually reset by the user.
The basic unit VacuDAP 2000 consists of the square ionization chamber and the chamber electronics including the high voltage generation, amplifier, microcontroller and a 8-digit display. These components are designed as a compact unit. The VacuDAP 2001 is completed display. These control (terminal) which makes it possible to operate from everywhere. Optional a printer is available. The X-ray generates an electric charge in the ionization chamber which is measured by the electronic evaluator as chamber current. The microcontroller calculate the dose area product and dose area product rate including the factor of the chamber. The results are transmitted to the serial interface on request of the terminal microcontroller. The measuring operation is working irrespective of the data displayed and is cumulating until the electronic evaluator is reset.
The provided documentation for the Victoreen VacuDAP, Models 2000 and 2001, is a Premarket Notification [510k] Summary. This type of submission focuses on demonstrating substantial equivalence to a predicate device rather than presenting detailed clinical study results to meet specific acceptance criteria through rigorous performance evaluation.
Therefore, the document does not contain the detailed information required to fill out all sections of your request regarding a study proving the device meets acceptance criteria. Here's what can be extracted and what is missing:
1. A table of acceptance criteria and the reported device performance
The document provides a "Specification Comparison Table" that lists key features and their performance for both the new device (VacuDAP Model 2000, 2001) and the predicate device (Dose Area Product Meter, Model 07-205). These specifications are implicitly the "acceptance criteria" for demonstrating substantial equivalence, where the new device's performance needs to be comparable or better than the predicate.
| Feature | Acceptance Criteria (Predicate Device Performance) | Reported Device Performance (New Device) |
|---|---|---|
| System accuracy | better than ± 20% | max. ± 20% |
| Interface | RS232 | RS485 |
| Relative Humidity | 95%RH non-condensing | 75% |
| Sensitivity | $3 \times 10^{-3} - 3 \times 10^{2} Gycm^2 S^{-1}$ | $8 \times 10^{-8} As / Gycm^2$ |
| Al equivalent/filter effects | 0.5mm | 0.4mm |
| Energy Range | 50 to 150kV | 50 to 200kV |
| Chamber Power | 90VAC to 132VAC | |
| 180 VAC to 264VAC @10VA | 12VDC / 250mA | |
| Terminal Power | Info unavailable | 12/150mA |
Assessment of Performance against Criteria:
The new device (VacuDAP) meets or exceeds the predicate device's performance for several key parameters:
- System accuracy: Max. ± 20% is comparable to "better than ± 20%".
- Dap range and rate: The new device has a significantly wider range and higher rate capability.
- Light Transmission: The new device has higher light transmission.
- Al equivalent/filter effects: The new device has a lower filter effect (0.4mm vs 0.5mm).
- Energy Range: The new device has a wider energy range (50 to 200kV vs 50 to 150kV).
- Sensitivity: A direct numerical comparison is difficult due to different units ($As/Gycm^2$ vs $Gycm^2 S^{-1}$), but the text mentions the new device has "a higher sensitivity".
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document does not provide any details on a specific test set, its sample size, or data provenance. The calibration section mentions that "The measuring results have been compared against a reference instrument calibrated by the Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)." This implies some form of testing or comparison was done, likely in Germany, but no specifics about the dataset are given.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
This information is not provided in the document, as it's not a clinical study involving human interpretation of medical images or data requiring expert consensus. The device measures physical parameters (Dose Area Product). The "reference instrument calibrated by the Physikalisch-Technische Bundesanstalt" served as the ground truth.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
This information is not applicable and not provided as there is no human interpretation or subjective assessment that would require an adjudication method.
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 as the VacuDAP is a device for measuring radiation output and is not an AI-assisted diagnostic tool that would involve human readers or image interpretation.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
A "standalone" performance evaluation was implicitly performed during factory calibration. The document states: "Factory calibration of the product is limited to calibration of the ionization chamber with a radiation source. The measuring results have been compared against a reference instrument calibrated by the Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)." This describes the device's performance in measuring known radiation outputs against a traceable standard, which is essentially a standalone performance assessment for a measurement device. However, specific performance metrics from this calibration (e.g., accuracy, precision) beyond the "max. ± 20%" system accuracy are not detailed in the summary.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The ground truth for evaluating the VacuDAP's performance was established using a reference instrument calibrated by the Physikalisch-Technische Bundesanstalt, Braunschweig (Germany). This represents a highly accurate and traceable physical standard for dose area product measurement.
8. The sample size for the training set
This information is not applicable and not provided. The VacuDAP is a physical measurement device, not a machine learning or AI algorithm that requires a training set.
9. How the ground truth for the training set was established
This information is not applicable and not provided, as there is no training set for this type of device.
§ 892.1680 Stationary x-ray system.
(a)
Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate and control x-rays for examination of various anatomical regions. This generic type of device may include signal analysis and display equipment, patient and equipment supports, component parts, and accessories.(b)
Classification. Class II (special controls). A radiographic contrast tray or radiology diagnostic kit intended for use with a stationary x-ray system only is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.