Clinical profile of the SEM Scanner — Modernizing pressure injury care pathways using Sub-Epidermal Moisture (SEM) scanning

Figures & data

Figure 1. (a): The SEM Scanner 200 (b): The Provizio® SEM Scanner

Figure 2. Wall to patient/user and the isolation barrier enabling reinforced insulation between the SEM Scanner and the patient

Figure 3. Claims-Data-Value Framework- Evidence pyramid in the development of SEM Scanner technology

Figure 4. Receiver operating characteristic curve for performance of algorithms A and B relative to the gold standard of skin and tissue assessment in combination with clinical judgment. Receiver operating characteristic curve illustrating diagnostic sensitivity and specificity of the SEM Scanner algorithms in early detection of deep and early stage pressure-induced injury. AUC, area under the curve. CI, confidence Intervals. Figure adapted from Gershon et al, 2021 .[45]

Table 1. Foundational studies of the SEM Scanner evaluated by the Food and Drug Administration (FDA) prior to regulatory De Novo approval

Title	Inter-operator and inter-device agreement and reliability of the SEM Scanner^[51]	Evaluating the sensitivity, specificity, and clinical utility of algorithms of spatial variation in sub-epidermal moisture (SEM) for the diagnosis of deep and early-stage pressure-induced tissue damage^[45]	A blinded clinical study using a subepidermal moisture biocapacitance measurement device for early detection of pressure injuries^[44]
Primary Objective	To evaluate the repeatability of the SEM Scanner readings between operators and multiple devices	The aim was to evaluate the ability of an objective test, the SEM, to discriminate between participants with confirmed PIs with intact skin versus those with no pressure damage.	Demonstrate the sensitivity and specificity of the SEM Scanner for detection of early pressure injuries in patients before pressure injuries are diagnosed through clinical judgment.
Secondary Objective	NA	The secondary aim was to gather data about characteristics of damaged versus healthy tissue and develop, post hoc, a clinically useful algorithm with robust sensitivities and specificities that can be further evaluated longitudinally and deployed in clinical practice.	Determine the average number of days between diagnosis of early pressure injuries using the SEM Scanner and diagnosis of pressure injuries through clinical judgment.
Design:	Non-interventional, single site, comparative, repeatability, and reliability study.	Multi-site, dual arm, cross-sectional, observational, retrospective study.	Multi-site, longitudinal cohort.
Primary Endpoint	Determination of intraclass correlation (ICC)	Evaluate spatial SEM measures between healthy and confirmed injured tissue (Stage I–II pressure injuries or suspected DTI).	A Positive Detection was defined as, ‘Observation of two or more SEM deltas ≥0.6 from three consecutive series of SEM Scanner readings prior to pressure injury diagnosis by clinical judgment of the Specialist’ Negative detection was defined as, ‘Observations of two or more SEM deltas <0.6 from three consecutive series of SEM Scanner readings prior to no pressure injury diagnosis by clinical judgment of the Specialist’ For the purposes of endpoint analysis, a ‘Valid Series’ of SEM Scanner measurements was considered when three days of SEM Scanner measurements were performed with no more than one day missing between these three days of measurements. A ‘Valid Series’ comprised no more than four observation days of SEM Scanner measurements.
Secondary Endpoint:	NA	Sensitivity and specificity tables and receiving operator characteristics (ROC) curves were analyzed to compare the diagnostic accuracies of gold standard STAs with the SEM test.	The measure for secondary endpoint was the Number of Days between pressure injury diagnosis by clinical judgment of the Specialist and the first day of SEM Scanner delta >0.5 (‘time to detection’). The number of days was calculated only for anatomical locations that demonstrate Positive Detection Success as defined by the Primary Study Endpoint. The average number of days was determined separately for sacrum and for heels.
Safety Endpoint:	NA	Adverse event and serious adverse reporting was included in the protocol. However, no device relate adverse events were reported during the course of the study	Adverse event and serious adverse reporting was included in the protocol. However, no device related adverse events were reported during the course of the study.
Study Population:	Healthy volunteers	Participants with a Stage I or Stage II PI/PU or an sDTI (Arm I) were recruited under protocol SEM200-03 (Quorum Review IRB File # 28,891/2). Participants unaffected by PI/PUs (Arm II) were recruited under protocol SEM200-004 (Quorum Review IRB File # 29,154/1).	Participants were tracked from enrollment with no observed PI to discharge. Discharge was precipitated by any of three events: (a) confirmation of a pressure injury by an expert ‘Specialist’; (b) discharge from the facility after a minimum of 6 days of observation; or (c) satisfying the maximum enrollment of 21 days.
Inclusion Criteria:	1. Participants are ≥ 18 years of age. 2. Participant or proxy is willing and able to provide written consent. 3. Participant is agreeable to having SEM Scanner readings performed	1. Participants ≥55 years of age 2. Participant or proxy is willing and able to provide informed consent 3. Participant is agreeable to having skin assessments and SEM readings performed 4. Participant has a PI (Stage I or II, or suspected DTI) (Protocol – 003)5. Participant is healthy and unaffected by PI (Protocol −004)	1. Greater or equal to 55 years of age 2. At risk of developing a pressure injury at time of enrollment as defined by one or more of the following: a. PI 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 3. Evaluable by the study team for a minimum of 6 consecutive days upon enrollment 4. Willing and able to provide informed consent (or by proxy)
Exclusion Criteria	1. Participant has broken skin or scar tissue at the sacrum, left heel, or right heel. 2. Participants for whom the physical act of performing the inspections and measurements required in this study are contra-indicated. 3. Participants with any one of the four (4) anatomical sites in question are not amendable to scanning (e.g. cast or medical device present such that the sacrum or heels are not accessible). 4. Participants or legal representatives who are unable to understand the aims and objectives of the trial.	1. Participant has broken skin at the anatomical locations being assessed 2. Participants with limited physical capacity or accessibility to the anatomical locations that would prohibit clinical evaluations and measurements to be performed. 3. Participants or legal representatives who are unable to understand the aims and objectives of the study. 4. Presence of any condition(s) that seriously compromise the participant’s ability to complete this study. 5. Participant has been told by a physician that he/she has any one of the following: rheumatoid arthritis, gout or an autoimmune disorder. 6. Participant is on systemic or topical corticosteroids. Participants using topical corticosteroids are excluded only if medication is placed on any of the anatomical locations being assessed.	1. Unhealed (including newly diagnosed) pressure injury at any anatomical site at the time of enrollment. 2. 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. 3. Moisture lesion or incontinence associated dermatitis at the sacrum. 4. Physical, structural, or other limitations preventing assessments required in this study (e.g. suspected or actual injury preventing turning). 5. Presence of any condition(s) or injury(ies) which compromises the participant’s ability to complete this study. 6. Per clinical decision of the study Investigator, diminished decision-making capacity which might impact compliance or completion with study procedures. 7. Patient modesty concerns on the part of the participant (or their proxy) that might impact collection of SEM Scanner readings at the anatomical location (heels and sacrum) to be assessed.
No. of Sites	1 study center in the United States (Los Angeles Area)	14 facilities in Los Angeles (LA), California, US and at two facilities in Virginia Beach (VB), VA, US.	12 inpatient facilities (six acute care and three post-acute care settings in the United States [77.8%; n = 147] and three acute care settings in the United Kingdom [22.2%; n = 42])
No. of Participants	31 participants.	175 participants: 59 participants with PI/PUs on the heel (33.7%); 63 participants with PI/PUs on the sacrum (36%); three participants with PI/PUs on the thoracic spine, right trochanter and right ischium (1.7%), one each, respectively; and 50 participants unaffected by PI/PUs (28.6%).	189 participants (46.7% males and 53.3% females) were enrolled, primarily from US sites (77.8% US vs 22.2% UK, respectively). Seven participants’ data were not analyzable, resulting in an Intention To Treat population of 182.
Key Results	This study demonstrates the high reliability and good agreement of the SEM Scanner across different operators and different devices. Given the limitations of current methods to prevent and detect PIs, the SEM Scanner shows promise as an objective, reliable tool for indicating a high risk for PIs.	SEM technology using anatomy specific data informs HCP’s that PI prevention intervention decisions can be made before visible signs of tissue damage on the skin surface. The test of SEM, where a SEM Delta ≥0.6 indicates increased risk of PI, using an anatomically specific mapping method significantly exceeds the accuracy of current clinical judgment alone and is clinically applicable in the real world.	The SEM Scanner supports HCPs to identify specific anatomical areas at increased risk of PI/PU development 5 days (Median) earlier than visual skin assessment.

Figure 5. Receiver operating characteristic curve for performance of the SEM Scanner relative to the gold standard of skin and tissue assessment in combination with clinical judgment. Receiver operating characteristic curve illustrating diagnostic sensitivity and specificity of the SEM Scanner in early detection of deep and early stage pressure-induced injury. AUC, area under the curve. CI, confidence Intervals. Figure reprinted with permissions from Okonkwo et al, 2020 .[44]

Figure 6. Pressure injury (PI) incidence reduction rates using the SEM Scanner as an adjunct in daily PI care practice

Table 2. Regulatory approval of the SEM Scanner series – SEM Scanner 200 and the Provizio® SEM Scanner

Regulatory Body	Target Country	Device Classification	Status
EU Medical Device Directive (MDD) & EU Medical Device Regulation (MDR)	European Union	Class IIa	Approved
EU Medical Device Directive (MDD) & EU Medical Device Regulation (MDR)	United Kingdom	Class IIa	Approved
Food and Drug Administration (FDA)	United States of America	Class I DeNovo	Approved
Health Canada Medical Device License (MDL)	Canada	Class II	Approved
Therapeutic Goods Administration (TGA)	Australia	Class IIa	Approved
Medicines and Medical Devices Safety Authority (Medsafe)	New Zealand	Class IIa	Approved

Gershon S, Okonkwo H. Evaluating the sensitivity, specificity and clinical utility of algorithms of spatial variation in sub-epidermal moisture (SEM) for the diagnosis of deep and early-stage pressure-induced tissue damage. J Wound Care. 2021;30(1):41–53.

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Clendenin M, Jaradeh K, Shamirian A, et al. Inter-operator and inter-device agreement and reliability of the SEM Scanner. J Tissue Viability. 2015;24(1):17–23.

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Okonkwo H, Bryant R, Milne J, et al. A blinded clinical study using a subepidermal moisture biocapacitance measurement device for early detection of pressure injuries. Wound Repair Regen. 2020;28(3):364–374.

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