(626 days)
The SEM Scanner (Model 200) is intended to be used by healthcare professionals as an adjunct to standard of care when assessing the heels and sacrum of patients who are at increased risk for pressure ulcers.
The SEM Scanner (Model 200) is a hand-held, portable device that consists of a single electrode sensor, an integrated pressure sensor, and hardware and software to run a user interface device screen that displays the device status, battery status, SEM Value, and SEM Delta ("SEM Δ"). The SEM Scanner (Model 200) is pre-calibrated. The SEM Scanner (Model 200) is provided with an inductive charging mat and power supply for recharging the device unit.
The SEM Scanner (Model 200) assesses changes in electrical capacitance of tissue and expresses the result in a SEM Value of 0.3 to 3.9. SEM is a unitless number (not an International System of Unit). The SEM Scanner (Model 200) displays a △ (delta) value after taking a minimum of three (3) SEM Values readings. A minimum of four readings were taken to obtain a result during the supporting clinical studies. The reported SEM A is used as an adjunct to the standard of care when assessing the heels and sacrum of patients who are at increased risk for pressure ulcers.
Here's a breakdown of the acceptance criteria and study details for the SEM Scanner (Model 200), based on the provided text:
Description of Acceptance Criteria and Proving Study
The SEM Scanner (Model 200) is intended to be used by healthcare professionals as an adjunct to standard of care for identifying patients at increased risk for pressure ulcers at the heels or sacrum. The primary effectiveness was evaluated based on the device's ability to detect positive and negative instances related to pressure ulcer development.
1. Table of Acceptance Criteria and Reported Device Performance
| Criteria Category | Criteria Description | Acceptance Value | Reported Device Performance and Confidence Interval | Met? |
|---|---|---|---|---|
| Effectiveness | Positive Detection (Sensitivity): Observation of two or more SEM Δ >0.5 from three consecutive series of SEM Scanner readings prior to pressure ulcer diagnosis by clinical judgment of the Specialist. A sensitivity of at least 0.70 (70%) is defined for positive detection success. | ≥ 0.70 (70%) | 87.4% (95% CI: 77.8%, 96.7%) | Yes |
| Negative Detection (Specificity): Observation of two or more SEM Δ <0.5 from three consecutive series of SEM Scanner readings prior to no pressure ulcer diagnosis by clinical judgment of the Specialist. A specificity of at least 0.55 (55%) is defined for negative detection success. | ≥ 0.55 (55%) | 33.0% (95% CI: 27.6%, 38.7%) | No | |
| Safety | Percentage of device-related adverse events reported in the study. A continued demonstration of no reports of device-related adverse events. | 0% | 0% (No reports of adverse events related to use of the SEM Scanner device units) | Yes |
| Biocompatibility | Skin-contacting materials tested to be biocompatible, not causing irritating, sensitizing, or cytotoxic effects. | No irritating, sensitizing, or cytotoxic effect | Testing conducted per ISO 10993-5:2009 and ISO 10993-10:2010 confirmed: "The device did not cause an irritating, sensitizing or cytotoxic effect upon the skin." | Yes |
| Cleaning/Disinf. | Device withstands repeated exposure to cleaning and disinfection agents without wear-induced failure or degradation. | Maintains functional performance | "Wear testing was conducted to assess wear-induced failure of the device components and potential degradation of the seal material or functional performance due to exposure to cleaning agents used during cleaning and disinfection." (The results implicitly met the criteria as there were no stated issues). | Yes |
| EMC/Electrical S. | Conformance to specified electromagnetic compatibility and electrical safety standards. | Conformance to IEC 60601-1, EN 60601-1-2, EN 60529-1 | Testing confirmed EMC and electrical safety of the device in accordance with IEC 60601-1 (3rd edition), EN 60601-1-2:2001/A1:2006, and EN 60529-1:1992, including specific test parameters for electrostatic discharge, radiated immunity, transient/burst, surge, conducted disturbances, magnetic field immunity, voltage dips, and radiated/conducted emissions. | Yes |
Note on Specificity: While the device did not meet the specificity endpoint of 55%, the FDA still granted the De Novo request, concluding that the probable benefits (high sensitivity) outweigh the probable risks, especially considering its intended use as an adjunct tool.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Test Set): 182 subjects contributed to the Intent-to-Treat (ITT) data analysis. These 182 subjects had 437 individual anatomical locations (heels and sacrum) assessed.
- Data Provenance:
- Country of Origin: Nine (9) US centers and three (3) UK centers. 77.8% of subjects were from US centers and 22.2% from UK centers.
- Retrospective or Prospective: Prospective, multi-site, longitudinal, blinded study.
3. Number of Experts and their Qualifications for Ground Truth
- Number of Experts: Multiple "Specialists" at each participating site.
- Qualifications of Experts: The "Specialist" was assigned to nursing staff who were the facility's experts on wound care. Their "clinical judgment of the wound/tissue viability experts" served as the gold standard.
4. Adjudication Method for the Test Set
The ground truth was established by the "clinical judgment of the wound/tissue viability experts" (Specialists). The study design implies a single expert's judgment for each case, as it refers to "the clinical judgment of the Specialist" being the "gold standard." There is no explicit mention of an adjudication process (like 2+1 or 3+1 consensus) among multiple experts for individual cases or the ground truth.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study
No, a Multi Reader Multi Case (MRMC) comparative effectiveness study was not done in the traditional sense of comparing human readers' performance with and without AI assistance to quantify improvement.
The study did compare the SEM Scanner to Standard of Care, Visual Skin Assessment (VSA), but not in a way that directly measures the effect size of how much human readers improve with AI vs. without AI. Instead, it assessed the device's diagnostic performance (sensitivity and specificity) against the gold standard (Specialist's clinical judgment/VSA). The "Generalists" used the SEM Scanner, but their performance with the device was compared against the Specialists' judgment rather than comparing their own performance with and without the device.
6. Standalone (Algorithm Only) Performance
No, a standalone (algorithm only without human-in-the-loop performance) study was not conducted. The device is explicitly intended "to be used by healthcare professionals as an adjunct to standard of care." The study involved "Generalists" taking SEM Scanner readings, and these readings were interpreted in the context of clinical judgment. The acceptance criteria for sensitivity and specificity are based on the device's readings (SEM Δ values) correlating with the Specialist's clinical judgment of the presence or absence of pressure ulcers.
7. Type of Ground Truth Used
The ground truth used was expert consensus / clinical judgment. Specifically, it was "the clinical judgment of the wound/tissue viability experts" (Specialists) who continued "standard of care" evaluations, including pressure ulcer diagnosis based on Visual Skin Assessment (VSA).
8. Sample Size for the Training Set
The document does not specify a training set sample size. The entire clinical study described (189 subjects, 182 ITT for analysis) appears to be the primary dataset used for evaluating the device's performance against predefined endpoints, not specifically for training an algorithm that then undergoes separate testing. Given that the device assesses changes in electrical capacitance and displays a value (SEM Δ) rather than providing a "diagnosis" from an AI algorithm, it's unlikely to have a separate "training set" in the machine learning sense. The device's operational parameters (e.g., the threshold for SEM Δ > 0.5) were likely established through earlier engineering or pre-clinical work, but a formal clinical training set is not mentioned.
9. How the Ground Truth for the Training Set Was Established
As a separate "training set" is not explicitly mentioned for an AI/algorithm in the provided text, the method for establishing ground truth for such a set is also not described. The clinical study described served as the validation for the device's performance based on its inherent mechanism and pre-established thresholds.
{0}------------------------------------------------
DE NOVO CLASSIFICATION REQUEST FOR SEM SCANNER (MODEL 200)
REGULATORY INFORMATION
FDA identifies this generic type of device as:
Pressure ulcer management tool. A pressure ulcer management tool is a prescription device intended for patients at risk of developing pressure ulcers. The device provides output that supports a user's decision to increase intervention. The device is an adjunct tool for pressure ulcer management that is not intended for detection or diagnostic purposes.
NEW REGULATION NUMBER: 21 CFR 876.2100
CLASSIFICATION: Class I (Exempt from premarket notification review, subject to limitations in 21 CFR 876.9)
PRODUCT CODE: QEF
BACKGROUND
DEVICE NAME: SEM Scanner (Model 200)
SUBMISSION NUMBER: DEN170021
DATE DE NOVO RECEIVED: April 3, 2017
SPONSOR INFORMATION:
Bruin Biometrics, LLC 10960 Wilshire Blvd., # 950 Los Angeles, CA 90024
INDICATIONS FOR USE
The SEM Scanner (Model 200) is intended to be used by healthcare professionals as an adjunct to standard of care when assessing the heels and sacrum of patients who are at increased risk for pressure ulcers.
LIMITATIONS
The sale, distribution, and use of the SEM Scanner (Model 200) are restricted to prescription use in accordance with 21 CFR 801.109.
{1}------------------------------------------------
WARNING: The standard of care should be followed for reducing the risk of developing pressure ulcers. Readings from the SEM Scanner 200 can be used to support increased intervention, but should never be to the basis for decreasing intervention.
WARNING: This device is not intended to be used for detecting or diagnosis of pressure ulcers.
WARNING: To prevent the spread of infection, the SEM Scanner 200 should be properly cleaned and disinfected according to the instructions provided in this Instructions for Use after it is used on a patient.
WARNING: Should the device come in contact with non-sterile surfaces (for example, if it falls on the floor) it should be cleaned and disinfected before obtaining another patient reading.
PLEASE REFER TO THE LABELING FOR A COMPLETE LIST OF WARNINGS, PRECAUTIONS AND CONTRAINDICATIONS.
RATIONALE FOR EXEMPTION
Section 510(1) of the FD&C Act (21 U.S.C. 360(1)) provides that a class I device is not subject to the premarket notification requirements under section 510(k) of the FD&C Act unless the device is of substantial importance in preventing impairment of human health or presents a potential unreasonable risk of illness or injury. FDA has determined that the device does meet these criteria and, therefore, premarket notification is not required for the device.
General controls provide reasonable assurance of safety and effectiveness, if device manufacturers comply with such requirements, which includes current good manufacturing practice requirements (21 CFR part 820), including design controls (820.30) due to the inclusion of software, and general labeling (21 CFR part 801). Examples exceeding the limitations of exemption could include indications for diagnostic purposes, clinical decision making, carly detection of pressure ulcers, measurement of sub-epidermal moisture, supporting a user's decision to decrease intervention, or the device operates using a different fundamental scientific technology.
DEVICE DESCRIPTION
The SEM Scanner (Model 200) is a hand-held, portable device that consists of a single electrode sensor, an integrated pressure sensor, and hardware and software to run a user interface device screen that displays the device status, battery status, SEM Value, and SEM Delta ("SEM Δ"). The SEM Scanner (Model 200) is pre-calibrated. The SEM Scanner (Model 200) is provided with an inductive charging mat and power supply for recharging the device unit.
The SEM Scanner (Model 200) assesses changes in electrical capacitance of tissue and expresses the result in a SEM Value of 0.3 to 3.9. SEM is a unitless number (not an International System
{2}------------------------------------------------
of Unit). The SEM Scanner (Model 200) displays a △ (delta) value after taking a minimum of three (3) SEM Values readings. A minimum of four readings were taken to obtain a result during the supporting clinical studies. The reported SEM A is used as an adjunct to the standard of care when assessing the heels and sacrum of patients who are at increased risk for pressure ulcers.
Image /page/2/Picture/1 description: The image shows two medical devices on a white background. The device on the left is a gray and white handheld device with a screen that reads "bruin BIOMETRICS SEM". An arrow points to the action button on the top of the device, which turns the device on and off and resets readings. The device on the right is a white device with a red button in the center.
- Figure 2. SEM Scanner (Model 200) Top View Figure 2. The electrode on the bottom showing Display and Action Button of the SEM Scanner (Model 200)
Image /page/2/Picture/3 description: The image shows a gray and cream-colored device on a white background. The device has a smooth, rounded shape with a gray top and a cream-colored bottom. There are small, raised dots on the side of the cream-colored part. The device appears to be resting on a small, circular base.
Figure 3. SEM Scanner (Model 200) Side View
{3}------------------------------------------------
Image /page/3/Figure/0 description: The image shows a Bruin Biometrics device with a screen displaying various information. The screen shows the SEM value as 0.0, a delta symbol, and a status indicator that reads "Ready". There is also a battery gauge and a pressure indicator with yellow and green bars, indicating pressure levels.
Figure 4. SEM Scanner (Model 200) Display (V3.60)
| Item | Function |
|---|---|
| Action Button | Clears SEM readings and turns the Scanner unit ON/OFF. |
| Battery Gauge | Battery icon indicating current battery state of charge |
| △ (Delta) | Calculated difference between the minimum and maximum SEMValues in the set of readings taken |
| SEM | Display of SEM Value for the last completed reading |
| Pressure Indicator | Bars indicating the applied pressure while taking a SEM reading. Thecolor changes from yellow to green to yellow as applied pressureincreases. Green bars indicate the correct pressure is applied to take theSEM reading and the SEM Value will show on the screen. |
| Status Indicator | Number of acquired readings, status indicator, or error messages |
| Table 1. Legend for Figure 4 |
A SEM Value of zero (0.0) shown on the display screen represents when the device is not measuring or when SEM readings are cleared out from the screen.
Product Specifications
| Product Feature | Specification |
|---|---|
| Capacitance Range | (b) (4) |
{4}------------------------------------------------
| Product Feature | Specification |
|---|---|
| Method of Taking a Reading | Reading is triggered when pressure is applied to the electrodes |
| Battery Source | Operates on a rechargeable lithium ion polymer batter Continuous operation for at least 3 hours Charges using inductively coupled energy transfer in a fully enclosed charging system Includes a temperature detection component that will stop the battery from charging if the battery temperature threshold is exceeded |
| Device Unit Enclosure (“Packaging System”) | Integrated housing enclosure for the electrical components No external connectors No exposed electrically live element IPX1 water ingress protection |
| Electrode System Package Support | Includes an elastomer support for the electrode |
| Environmental Requirements | Device operates over the range of 15 to 35°C at 5 to 90% humidity (non-condensing) |
SUMMARY OF NONCLINICAL/BENCH STUDIES
BIOCOMPATIBILITY/MATERIALS
The skin-contacting materials, such as the elastomer membrane, rubber, and polyimide materials, were tested to be biocompatible for the intended use of the device. Testing was conducted following FDA's guidance "Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process"," issued June 16, 2016. Testing included:
- ISO 10993-5:2009, Biological evaluation of medical devices Part 5: Tests for In . Vitro cytotoxicity
- ISO 10993-10:2010, Biological evaluation of medical devices Part 10: Tests for . irritation and delayed-type hypersensitivity
The device did not cause an irritating, sensitizing or cytotoxic effect upon the skin.
{5}------------------------------------------------
SHELF LIFE/REPROCESSING
Cleaning and Disinfection Testing
The device is nonsterile. Cleaning and disinfection testing was conducted following FDA's guidance document "Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling," issued March 17, 2015.
Wear Testing - Repeat Exposure to Cleaning and Disinfection Agents
Wear testing was conducted to assess wear-induced failure of the device components and potential degradation of the seal material or functional performance due to exposure to cleaning agents used during cleaning and disinfection.
ELECTROMAGNETIC CAPABILITY & ELECTROMAGNETIC SAFETY
Electromagnetic Compatibility (EMC) and Electrical Safety verification testing were conducted to confirm the EMC and electrical safety of the device. Testing was conducted in accordance with:
- IEC 60601-1 (3rd edition). Medical Electrical Equipment General Requirements . for safety and essential performance
- EN 60601-1-2:2001/A1:2006, Medical electrical equipment. General . requirements for basic safety and essential performance. Collateral standard. Electromagnetic compatibility. Requirements and tests
| Test Description | Test Parameter |
|---|---|
| Electrostatic discharge | ±6 contact discharge± kV air discharge |
| Radiated, Radiofrequency,Electromagnetic Field Immunity | Radiated Immunity, 3 V/m, 80 – 2500 MHz,80% AM at 1 kHz |
| Electrical Fast Transient/Burst | AC power ports, ±2 kV |
| Surge Immunity | AC power ports, ±1 and ±2 kV |
| Immunity to Conducted Disturbances,Induced by Radiofrequency Fields | AC power ports, 0.15-80 MHz, 3 Vrms, 80%AM at 1 kHz |
| Power Frequency Magnetic FieldImmunity | 3 Arms/m |
| Voltage Dips and Short InterruptionImmunity | AC power linesReduction 30%, 25 periodsReduction 60%, 5 periodsReduction 100%, 0.5 periodsReduction 100%(b) (4) periods |
- · EN 60529-1:1992, Degrees of protection provided by enclosures (IP Code)
{6}------------------------------------------------
| Test Description | Test Parameter |
|---|---|
| Radiated Emissions - CISPR 11 | Class A |
| Conducted Emissions (AC Mains) -CISPR 11 | Class A |
Electrical safety testing per EN 60529-1 was also conducted to verify the degree of protection provided by the enclosure against access of persons to hazardous parts, water, and solid foreign objects.
MAGNETIC RESONANCE (MR) COMPATIBILITY
The SEM Scanner (Model 200) has not been tested for MR Compatibility and should not be used in an MRI suite.
SOFTWARE
The agency considers the software to be a minor level of concern (LOC) because inadvertent software errors (e.g., failures or latent design flaws) are unlikely to cause any injury to the patient or operator.
All of the elements of software information as outlined in FDA's guidance documents "Guidance for the Content of Premarket Submissions for Software Contained in Medical Devices" (issued May 11, 2005) were provided.
Overall, the software documentation included in the De Novo request is in sufficient. detail to provide reasonable assurance that the software will operate in a manner described in the specifications.
SUMMARY OF CLINICAL INFORMATION
A total of 12 study sites. nine US centers and three UK centers, participated in this prospective. multi-site, longitudinal, blinded study. In total, 77.8% of the enrolled subjects were from US centers and 22.2% were from UK centers. This study enrolled a total of 189 subjects, who had provided their written informed consent or by verbal/ written consent of the subjects' legally authorized representative, from April through November 2016.
The study was carried out by a clinical study team at each participating site comprised of a Principal Investigator, Study Coordinator, and individuals acting in study roles of "Generalists" and "Specialists." Daily assessments were limited to up to two assessors within each assessment team. Comprising one team, the "Specialist" was assigned to nursing staff who were the facility's experts on wound care to continue "standard of care" evaluations. The "gold standard" in this case is the clinical judgment of the wound/tissue viability experts.
{7}------------------------------------------------
Comprising a second team, the "Generalist" included individuals who did not provide pressure ulcer care to the enrolled subjects and consisted of a wider range of healthcare providers: wound experts, ward nurses, nursing assistants, or medical assistants.
Blinding between assessment teams, the Specialists, was employed. The Study Coordinator acted as the "gate-keeper" to help maintain blinding. In addition to blinding between Specialists and Generalists, the study was also blinded to staff at BBI during enrollments by an independent consultant to BBI (PhD Epidemiologist) managing the Medrio database, an electronic data capture system. The purpose of this study was to compare the SEM Scanner to the current Standard of Care, Visual Skin Assessment (VSA), in identifying patients with tissue at increased risk of developing pressure ulcers at the heels or sacrum.
Enrolled subjects were expected to be evaluated once daily throughout the observation period for a minimum of 6 days to maximum of 21 days upon enrollment or until earlier exit from the study. The minimum of 6 days was selected to optimize the probability of observing an early pressure ulcer should one develop. The maximum of 21 days was selected to set expectations for the study sites on the upper bound for length of participation. The total number of evaluation days include the day of enrollment (day 0).
Daily assessments were performed at the sacrum and both heels unless the anatomical location(s) were not assessable. Daily assessments included:
- Specialist Risk Assessments .
- Specialist Skin Assessment (including pressure ulcer diagnosis) .
- . Generalists SEM Scanner Readings
- . Prevention/Intervention Questionnaire
Primary Endpoint:
Positive Detection is defined as observations of two or more SEM Δ >0.5 from three consecutive series of SEM Scanner readings prior to pressure ulcer diagnosis by clinical judgment of the Specialist. A sensitivity of at least 0.70 is defined for positive detection success as a measure of the primary effectiveness performance.
Negative Detection is defined as observations of two or more SEM Δ <0.5 from three consecutive series of SEM Scanner readings prior to no pressure ulcer diagnosis by clinical judgment of the Specialist. A specificity of at least 0.55 is defined for negative detection success as a measure of the primary effectiveness performance.
Safety Endpoint
For product safety, the measure of analysis was on the percentage of device-related adverse events reported in this study. A continued demonstration of no reports of device-related adverse events experienced by subjects and device users from direct use of the device is defined as a safety endpoint success.
Inclusion Criteria
-
- Greater or equal to 55 years of age
{8}------------------------------------------------
-
- At risk of developing a pressure ulcer at time of enrollment as defined by one or more of the following:
- a. PU Risk Score Braden < 15; Waterlow > 10; or Norton < 18
- b. Poor mobility; e.g., Braden mobility subscore ≤ 2; Waterlow mobility subscore 2; Norton mobility subscore < 2; or poor mobility according to clinical judgment (chair- or bed-bound)
- c. Poor nutrition: e.g., Braden nutrition subscore < 2; Waterlow nutrition subscore 2; or poor nutrition according to clinical judgment
- d. Medical procedure (e.g. surgery, x-ray, etc.) involving immobility and inability to change position lasting 4 hours or longer
-
- Evaluable by the study team for a minimum of 6 consecutive days upon enrollment
-
- Willing and able to provide informed consent (or by proxy)
Exclusion Criteria
-
- Unhealed (including newly diagnosed) pressure ulcer at any anatomical site at the time of enrollment
-
- Broken skin at the sacrum and both heels that prevents collection of SEM Scanner readings from all three anatomical locations; possible assessment at only one or two locations is not grounds for exclusion
-
- Moisture lesion or incontinence associated dermatitis at the sacrum
-
- Physical, structural, or other limitations preventing assessments required in this study (e.g., suspected or actual injury preventing turning)
-
- Presence of any condition(s) or injury(ies) which compromises the subject's ability to complete this study
-
- Per clinical decision of the study Investigator, diminished decision-making capacity which might impact compliance or completion with study procedures
-
- Patient modesty concerns on the part of the subject (or their proxy) that might impact collection of SEM Scanner readings at the anatomical location (heels and sacrum) to be assessed
Loss to Follow Up
No subjects withdrew from the study.
Protocol Deviations
There were no protocol deviations due to inclusion/exclusion criteria or withdrawal criteria.
At the West Coast site, there were 4 procedural protocol deviations related to missing SEM Scanner readings. The deviations regarding missing SEM Scanner readings occurred because obtaining the readings would have compromised subject safety, or the subject's concerns regarding modesty.
At the East Coast site, there were 34 procedural protocol deviations related to missing SEM Scanner readings and 27 procedural protocol deviations related to missing date of wound diagnosis. The deviations regarding missing SEM Scanner readings occurred because obtaining the readings would have compromised subject safety, or the subject's concerns regarding modesty. The deviations regarding date of wound diagnosis occurred because the nursing facility
{9}------------------------------------------------
where the study procedures took place often did not record the date of wound diagnosis in their records.
Specifically, 182 patients were listed as Intent to Treat (ITT). Of those, 170 Patients were included in the sensitivity and specificity calculations with 48 pressure ulcers forming across 36 Patients.
Within the 12 sites included in the study, the trials were completed in:
-
- Orthopaedic Trauma: 14% (n=26 subjects)
-
- Medical Surgery: 27% (n=50 subjects)
-
- Long Term Care: 32% (n=58 subjects)
-
- ICU: 9% (n=17 subjects)
-
- Rehab: 4% (n=7 subjects)
-
- Neurologic Care: 8% (n=15 subjects)
-
- Other/Mixed: 5% (n=9 subjects)
Results – Primary Endpoint ITT
Of the 189 subjects, a total of 182 subjects with 437 anatomical locations were used to derive clinical validity of the SEM Scanner △ values contributed to the intent-to-treat (ITT) data analysis performed per this study's Statistical Analysis Plan (SAP). Table 1 reflects the distribution of pressure ulcers identified by VSA per Specialist' judgment that went into the ITT analysis.
| ITT (N = 182**) | ||||||
|---|---|---|---|---|---|---|
| All | Sacrum | Heels | ||||
| PU Classification, n = 48* | n | % | n | % | n | % |
| Stage I | 32 | 66.7% | 12 | 25% | 20 | 41.7% |
| Stage II | 3 | 6.3% | 3 | 6.3% | 0 | 0.0% |
| Stage III - IV | 0 | 0.0% | 0 | 0.0% | 0 | 0.0% |
| Unstageable | 2 | 4.2% | 0 | 0.0% | 2 | 4.2% |
| sDTI | 11 | 22.9% | 1 | 2.1% | 10 | 20.8% |
Table 1. Pressure Ulcer (PU) Classification Included in ITT Analysis
Source: Table 8b in SEM200-008 Final Study Report
Sacrum PUs w/insufficient SEM valid series for comparison: (b) (4)
(b) (4) and (b) (4) pressure ulcers because of non-analyzable data; not part of ITT
48 PUs developed in the Intent-to-Treat population (26% incidence in the ITT population) with a number of patients developing at least 1 PU at separate anatomical sites. Therefore the 48 PUs developed on 36 patients.
{10}------------------------------------------------
| ITT(N=182) | ||
|---|---|---|
| Gender | n | (%) |
| Male | 85 | (46.70%) |
| Female | 97 | (53.30%) |
| Race | ||
| White or Caucasian | 121 | (66.48%) |
| Black/ African American | 8 | (4.40%) |
| Asian | 44 | (24.18%) |
| American Indian/ Alaskan Native | 1 | (0.55%) |
| Pacific Islander/ Native Hawaiian | 2 | (1.10%) |
| Unknown | 2 | (1.10%) |
| Other | 4 | (2.20%) |
| Ethnicity | ||
| Non-Hispanic/ Latino | 158 | (86.81%) |
| Hispanic/ Latino | 8 | (4.40%) |
| Unknown | 12 | (6.59%) |
| Does not wish to provide | 4 | (2.20%) |
| Fitzpatrick Skin type | ||
| Type I (0-7) | 60 | (32.97%) |
| Type II (8-16) | 67 | (36.81%) |
| Type III (17-25) | 43 | (23.63%) |
| Type IV (26-30) | 5 | (2.75%) |
| Type V-VI (over 30) | 4 | (2.20%) |
| Missing | 3 | (1.65%) |
Table 2. Demographic Characteristics of Study Subjects
Table Source: Table 2 in database of SEM200-008 Final Clinical Study Report
Sensitivity and specificity data presented in Tables 3a and 3b show how the SEM Scanner 200 compares to visual skin assessment in identifying patients with tissue at risk of developing pressure ulcers at the heels or sacrum.
In the 008 study, healthcare providers assessed 437 individual anatomical locations from 182 subjects in the ITT. These locations were classed as shown in Table 3a. Results from the 008 clinical study results from each assessed anatomy were classed as:
- True positives - a visible pressure ulcer and a localized SEM Δ of 0.6 or above ("abnormal levels of SEM"). Table 3a shows 42 anatomical sites in this category.
- True negatives no visible pressure ulcer and a localized SEM A below 0.6 ("flat ● values"). Table 3a shows 128 anatomical sites in this category.
{11}------------------------------------------------
- False negatives a visible pressure ulcer and a localized SEM △ below 0.6 ("flat values"). ● Table 3a shows 6 anatomical sites in this category.
- False positives no visible pressure ulcer and a localized SEM Δ of 0.6 or above . ("abnormal levels of SEM"). Table 3a shows 261 anatomical sites in this category.
No subjects were enrolled in the study who were not at risk for developing PU. Performance of this device on subjects who are not at risk of developing PU was not conducted in this study nor considered in the sensitivity and specificity calculations.
Table 3a: Final results for individual anatomical locations for SEM Scanner from the 008 study
| True Positive = 42 | False Positive = 261 | All positives69% |
|---|---|---|
| False Negative = 6 | True Negative = 128 | All negatives31% |
| Total anatomicallocations437 | Total patients in ITTpopulation182 |
In order to appropriately account for the within subject correlation in the estimates of the 95% confidence intervals for sensitivity and specificity, the bootstrap method used. The bootstrap method was applied by sampling, with replacement, from the original dataset. The sampling was done on a per subject basis such that all records for a randomly chosen subject were extracted. One thousand datasets were generated using this method, each with the same number of subjects as the original dataset.
Estimates of sensitivity and specificity were then calculated across datasets by taking the median value. The confidence limits were generated from the 2.5th and 97.5th percentiles. This resulted in the following estimates (Table 3b).
Table 3b. Range of SEM △ and Confidence Intervals Using Bootstrap Method
| SEM Δ | Sensitivity1 | Specificity1 | ||||
|---|---|---|---|---|---|---|
| n | % | 95% CI | n | % | 95% CI | |
| >0.5 | 42 | 87.4% | 77.8%, 96.7% | 124 | 33.0% | 27.6%, 38.7% |
Sensitivity and specificity analysis was performed following an analysis rule of 2 of 3 consecutive observations of a SEM Δ of 0.6 or above ("SEM positive") or SEM Δ of 0.5 or less ("SEM negative") from a five-day window from study exit or when a pressure ulcer is identified by visual skin assessment. This analysis rule was defined before study analysis was performed.
{12}------------------------------------------------
The study was successful in meeting the sensitivity endpoint of at least 70% for positive detection success. ITT study results demonstrated a sensitivity of 195% CI: (6) (4% -(b) (4) %) for detecting pressure ulcers between the SEM Scanner and clinical judgment per visual skin assessment.
The ITT study results showed a specificity of (97% (95% CI (4) (4) % - (6) (4) %) in this study. This did not meet the specificity endpoint of at least 55% for negative detection success.
Safety Endpoint Results
Of the 189 patients enrolled in this study, there were zero (0%) reports of adverse events related to use of the SEM Scanner device units, which meets the safety endpoint of the study. In total, adverse events from five subjects were reported in this study. Four of the five events were categorized as unrelated, and the remaining one event was because of underlying disease.
Interpretation of the △ Symbol:
-
A A < 0.6 (0.5 and below) at an anatomical site may suggest the tissue is not at increased risk for pressure ulcers
-
A △ > 0.6 (0.6 and above) at an anatomical site may suggest increased risk for pressure ulcers ("positive")
The A value should be considered in conjunction with other measures of standard of care and clinical judgment.
Pediatric Extrapolation
In this De Novo request, existing clinical data were not leveraged to support the use of the device in a pediatric patient population.
LABELING
Labeling meets the requirements for prescription use in accordance with 21 CFR § 801.109. Labeling for the device includes the following:
- Instructions on how to operate the device with explanations of user-interface features.
- Instructions to clean and disinfect the device between each patient.
- . A contraindication that the device is not to be used on open wounds, in order to reduce the potential for cross-contamination between patients.
- . A statement indicating that the device is not intended to be used as a standalone device. but rather as an adjunct to clinical judgment. Any decision to intervene or not should be based solely on the experience and expertise of the clinician.
- Information on electrical safety and electromagnetic compatibility.
{13}------------------------------------------------
RISKS TO HEALTH
The risks associated with the pressure ulcer management tool are adverse tissue reaction, transmission of infection between patients, electromagnetic interference with patient monitoring equipment, and electrical shock. The severity and incidence of these risks to health are relatively low due to the very limited patient contact with the device. As such, general controls are sufficient to mitigate these risks and reasonably assure safety and effectiveness. General controls include but are not limited to good manufacturing practice requirements (21 CFR part 820), including design controls (820.30) due to the inclusion of software, and general labeling (21 CFR part 801).
BENEFIT-RISK DETERMINATION
The SEM Scanner Model 200 is a hand-held, portable device that consists of a single electrode sensor, an integrated pressure sensor, and hardware and software to run a user interface device screen. The risks to health associated with SEM Scanner Model 200 include adverse tissue reaction, transmission of infection between patients, electromagnetic interference with patient monitoring equipment, and electrical shock, none of which occurred in the clinical trial. These risks are considered low and can be mitigated with general controls.
The performance characteristics of this device reveals a sensitivity of 87% and a specificity of 33% in a population at risk for pressure ulcers. These outcomes demonstrate a clinical benefit as an adjunct to standard of care to help identify patients at increased risk for pressure ulcer where further interventions can be beneficial. As stated in the warnings in the labeling, readings from the device should never be used to support reduced intervention compared to standard of care
Patient Perspectives
This submission did not include specific information on patient perspectives for this device.
Benefit/Risk Conclusion
In conclusion, given the available information above, for the following indication statement:
The SEM Scanner (Model 200) is intended to be used by healthcare professionals as an adiunct to standard of care when assessing the heels and sacrum of patients who are at increased risk for pressure ulcers.
The probable benefits outweigh the probable risks for the SEM Scanner (Model 200). The device provides benefits and the risks can be mitigated by the use of general controls.
{14}------------------------------------------------
CONCLUSION
The De Novo request for the SEM Scanner (Model 200) is granted and the device is classified as follows:
Product Code: QEF Device Type: Pressure ulcer management tool Class: I (Exempt from premarket notification review, subject to limitations in 21 CFR 876.9) Regulation Number: 21 CFR 876.2100
§ 876.2100 Pressure ulcer management tool.
(a)
Identification. A pressure ulcer management tool is a prescription device intended for patients at risk of developing pressure ulcers. The device provides output that supports a user's decision to increase intervention. The device is an adjunct tool for pressure ulcer management that is not intended for detection or diagnostic purposes.(b)
Classification. Class I (general controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 876.9.