(160 days)
The MolecuLight i:X is a handheld imaging tool that allows clinicians diagnosing and treating skin wounds, at the point of care, to
(i) View and digitally record images of a wound,
(ii) Measure and digitally record the size of a wound, and
(iii) View and digitally record images of fluorescence emitted from a wound when exposed to an excitation light.
The fluorescence image, when used in combination with clinical signs and symptoms, has been shown to increase the likelihood that clinicians can identify wounds containing bacterial loads >10^4 CFU per gram) as compared to examination of clinical signs and symptoms alone. The MolecuLight i:X device should not be used to rule-out the presence of bacteria in a wound.
The MolecuLight i:X does not diagnose or treat skin wounds.
The MolecuLight i:X Imaging Device is a handheld medical imaging device comprised of a high-resolution color LCD display and touch-sensitive screen with integrated optical and microelectronic components. MolecuLight i:X uses its patented technology to enable real-time standard digital imaging and fluorescence (FL) imaging in wounds and surrounding healthy skin of patients as well as wound area measurements.
The MolecuLight i:X is a handheld imaging tool that helps clinicians identify wounds containing elevated bacterial loads. The provided text outlines the acceptance criteria and the study that supports the device's claims.
1. Table of Acceptance Criteria and Reported Device Performance
The provided documentation does not explicitly state "acceptance criteria" as a set of predefined thresholds that the device had to meet for clearance. Instead, it presents performance metrics from a clinical study, which implicitly serve as evidence for addressing the added labeling claims. The key performance metrics are related to the device's ability to guide wound sampling for detecting bacterial burden.
Derived Acceptance Criteria (based on the device's claims and study outcomes) and Reported Device Performance:
| Acceptance Criteria (Implicit from device claims) | Reported Device Performance |
|---|---|
| Clinical Efficacy: Increased likelihood for clinicians to identify wounds with bacterial loads >10^4 CFU/g when using fluorescence imaging vs. clinical signs alone. | Sensitivity to Detect Elevated Bacterial Load ($\ge 10^4$ CFU/g): |
- SoC-guided sample: 87.2% (95% CI: 77.7%, 93.7%)
- FL-guided sample: 98.7% (95% CI: 93.06%, 99.97%)
P-value: P = 0.012 (FL-guided sampling was significantly more sensitive)
Ability to detect a higher number of bacterial species:
- Mean number of species by FL-guided Biopsy: 3.026 (SD 1.667)
- Mean number of species by SoC-guided Biopsy: 2.231 (SD 1.528)
- Difference: 0.795 (SD 1.804)
P-value: P 10^4 CFU per gram" were the key threshold. Pathogen identification was also a part of the ground truth.
- Non-Clinical Testing: The ground truth for demonstrating red fluorescence production for specific bacterial species was based on sub-culturing on Porphyrin Test Agar (PTA) and direct observation of fluorescence using the MolecuLight i:X.
8. The Sample Size for the Training Set
The document primarily discusses a retrospective analysis for clinical validation and in-vitro testing. It does not mention a separate training set size for any specific AI/algorithm development, as the device's core functionality appears to be based on known autofluorescence properties of bacteria rather than a deep learning model trained on large datasets for complex pattern recognition. The study mentioned ([K191371](https://510k.innolitics.com/search/K191371)) was used to support subsequent claims, implying this may have provided data for initial claims.
9. How the Ground Truth for the Training Set Was Established
As no explicit training set for a machine learning algorithm is detailed, the method for establishing ground truth for such a set is not provided. The non-clinical testing described involves culturing specific bacterial species to verify their autofluorescent properties, which would serve as a 'ground truth' for the physical principle the device leverages.
§ 878.4550 Autofluorescence detection device for general surgery and dermatological use.
(a)
Identification. An autofluorescence detection device for general surgery and dermatological use is an adjunct tool that uses autofluorescence to detect tissues or structures. This device is not intended to provide a diagnosis.(b)
Classification. Class II (special controls). The special controls for this device are:(1) In vivo testing under anticipated conditions of use must characterize the ability of the device to detect autofluorescent signals from tissues or structures consistent with the indications for use.
(2) The patient-contacting components of the device must be demonstrated to be biocompatible.
(3) Performance testing must demonstrate the electromagnetic compatibility and electrical, mechanical, and thermal safety of the device.
(4) Software verification, validation, and hazard analysis must be performed.
(5) Performance testing must demonstrate the sterility of patient-contacting components of the device.
(6) Performance testing must support the shelf life of device components provided sterile by demonstrating continued sterility and package integrity over the labeled shelf life.
(7) Performance testing must demonstrate laser and light safety for eye, tissue, and skin.
(8) Labeling must include the following:
(i) Instructions for use;
(ii) The detection performance characteristics of the device when used as intended; and
(iii) A shelf life for any sterile components.