(266 days)
Dopplex Ability is indicated for use on adult subjects at risk of having or developing peripheral arterial disease (PAD).
Dopplex Ability is intended for rapid measurement of ankle-brachial pressure index (ABPI) or ankle-brachial index (ABI) in adults and pulse volume recording (PVR) / volume plethysmography.
It is suitable for use in woundcare assessment, for assessing symptomatic PAD, and as a screening device for PAD. It may also be used on patients with venous or arterial ulcers prior to the application of compression therapy. Dopplex Ability can be used on patients with unilateral lower limb amputation.
Dopplex Ability is intended to measure a patient's Ankle Brachial Index (ABI) and provide PVR. This is done through an automated process.
The operator places the four colour coded cuffs on each of the patient's limbs as described in the instruction for use and connect to the device.
When connected the operator pushes soft touch button to start measurement, the device then will automatically control the inflation / deflation of the cuffs on each limb and monitor minute variations in individual pressures to determine values to be used for the calculation of the ABI values for both the left and right hand of the patient.
Dopplex Ability uses pneumo-plethysmography uses obtain physiological measurements from patient's limbs. Measurements are conducted as a single occurrence on all four limbs, eliminating any requirement to rest the patient between measurements.
The test period takes approximately 3 minutes. The ABI indices are calculated using an in house algorithm.
ABI values are displayed on the LCD and can also be printed. In addition, records are generated of the Pulse Volume Waveforms (PVR), which may also be displayed on the LCD and can be printed.
Here's an analysis of the acceptance criteria and study information for the "Dopplex Ability" device, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The provided text does not explicitly state numerical acceptance criteria in a dedicated table format. Instead, it describes the study design and concludes that the device performs as well as the predicate. The performance is demonstrated through a comparison with a predicate device.
| Acceptance Criterion (Assumed) | Reported Device Performance (from text) |
|---|---|
| Safety and Effectiveness | "The non clinical and clinical data detailed within submission demonstrates that the device is safe and effective and performs as well as the legally marketed Predicate device, identified in this summary." |
| Measurement of ABPI / ABI and PVR (equivalent to predicate) | "Clinical data submitted demonstrates the submission device to provide the performance as indicated for use by a comparison of measured indices using both devices." |
| "The predicate device has been used in comparison bench testing and clinical assessment to evaluate and demonstrate the equal capability of both devices to measure ABI." | |
| Improved Functionality (single occurrence measurement on all four limbs) (beyond predicate capability) | "With respect to Dopplex Ability to function to measure all four limbs as a single occurrence, the submission device provides improved functionality above that of the legally marketed predicate device without addition concerns regarding safety and effectiveness." This implies the acceptance of this improved function without compromising safety/effectiveness compared to the predicate. |
2. Sample Size Used for the Test Set and Data Provenance
The document states:
- "The predicate device has been used in comparison bench testing and clinical assessment to evaluate and demonstrate the equal capability of both devices to measure ABI."
- "Clinical data submitted demonstrates the submission device to provide the performance as indicated for use by a comparison of measured indices using both devices."
However, the specific sample size for the test set (number of patients or measurements) is not explicitly mentioned in the provided 510(k) summary.
Data Provenance: The document does not specify the country of origin for the clinical data. It also does not explicitly state if the study was retrospective or prospective. Given the nature of a 510(k) submission and the description of "clinical assessment" to demonstrate "equal capability," it is most likely a prospective clinical study designed for this comparison.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not provide information on the number of experts used or their qualifications for establishing ground truth for the test set. The study design described is a comparison of the new device (Dopplex Ability) to a predicate device (Vascular Assist), rather than a comparison to expert-derived ground truth as such. The predicate device's measurements are effectively treated as the "reference standard" for comparison.
4. Adjudication Method for the Test Set
The document does not specify an adjudication method. Since the study focuses on quantitative measurement agreement between two devices rather than subjective interpretation, a formal adjudication process for "ground truth" might not have been applicable in the traditional sense. The comparison likely involved statistical methods to assess agreement (e.g., Bland-Altman analysis, correlation).
5. If an MRMC Comparative Effectiveness Study Was Done, and Effect Size
The provided text does not indicate a Multi-Reader Multi-Case (MRMC) comparative effectiveness study. The study described is a comparison of two devices (Dopplex Ability vs. Vascular Assist) rather than comparing human readers with and without AI assistance. Therefore, there is no mention of an effect size for human reader improvement with AI.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
Yes, the study primarily describes standalone performance of the Dopplex Ability device itself, comparing its measurements to those of the predicate device. The device is described as an "automated process" where "the device then will automatically control the inflation / deflation of the cuffs on each limb and monitor minute variations in individual pressures to determine values to be used for the calculation of the ABI values." The "in house algorithm" calculates the ABI values. While a human initiates the test and places cuffs, the core measurement and calculation are automated.
7. The Type of Ground Truth Used
The "ground truth" for the test was the measurements obtained by the legally marketed predicate device (Vascular Assist). The study's objective was to demonstrate that the Dopplex Ability device's measurements of ABI and PVR were "equal" or provided "the performance as indicated for use by a comparison of measured indices using both devices."
8. The Sample Size for the Training Set
The document does not specify a sample size for a training set. The device performs quantitative measurements based on pneumo-plethysmography and an "in house algorithm" for ABI calculation. While such algorithms might be developed and "trained," the summary only describes the clinical validation against the predicate, not the internal development or training process.
9. How the Ground Truth for the Training Set Was Established
Since a training set sample size is not provided, the method for establishing its ground truth is also not described in this document.
§ 870.2780 Hydraulic, pneumatic, or photoelectric plethysmographs.
(a)
Identification. A hydraulic, pneumatic, or photoelectric plethysmograph is a device used to estimate blood flow in a region of the body using hydraulic, pneumatic, or photoelectric measurement techniques.(b)
Classification. Class II (performance standards).