2 The technology


2.1 SEM Scanner 200 is a portable, hand-held skin assessment device. It detects an increased risk of pressure ulcers developing by identifying early pressure-induced tissue damage at the heel and sacrum. Published evidence suggests that damage to underlying soft tissues can happen 3 days to 10 days before tissue damage shows at the epidermis (Moore et al. 2017). Tissue inflammation is the first response to damage and causes increased dilation and permeability of surrounding blood vessels. This leads to leakage of plasma and fluid, creating a layer of subepidermal moisture. As damage increases, so does the level of subepidermal moisture. SEM Scanner 200 measures variation in subepidermal moisture across a small area. Healthy tissue has little variation, whereas inflamed or dead tissue has more variation. The variation is reported as a 'delta' value, with healthy tissue giving a low numerical reading and inflamed or dead tissue giving a higher numerical reading. A subepidermal moisture delta value of 0.6 or more is thought to represent clinically significant levels of tissue damage.

Innovative aspects

2.2 SEM Scanner 200 uses a novel method of identifying subepidermal moisture in the tissue of the heels and sacrum. SEM Scanner is the only CE marked device that assesses the anatomical risk of pressure ulcer formation before pressure-induced damage happens.

Intended use

2.3 SEM Scanner 200 is intended to be used on the heels and sacrum of people who are at risk or at high risk of developing a pressure ulcer. Risk categories are defined in NICE's guideline on pressure ulcers: prevention and management.

2.4 SEM Scanner 200 is used by healthcare professionals on hospital admission, during the patient's stay and on discharge. Users need training to use the device and interpret the results. For information on how to use the technology see the SEM Scanner 200 information for use document.


2.5 SEM Scanner 200 costs £5,835 per device.

For more details, see the website for SEM Scanner 200.

  • National Institute for Health and Care Excellence (NICE)