Designing Intensive Care Unit Beds to Relieve Coma-Related Skin Ulcers, Enhancing Comfort and Care

The study was designed to address the practical challenges encountered in developing an intensive care unit (ICU) bed specifically for the prevention of pressure ulcers in comatose patients. The research was carried out in three main stages, each building on the findings of the previous phase and integrating both literature and empirical work.

Stage One: Review and Assessment of Current ICU Beds

Initially, gathered detailed technical information and user feedback on a range of currently available ICU beds, both from hospital procurement records and published clinical studies. This stage involved not only examining product manuals and manufacturer data but also observing actual use in two different hospital ICUs. Particular attention was paid to the adjustment mechanisms, mattress types, and how pressure distribution is managed under typical patient loads. In addition, informal interviews with clinical nurses and caregivers were conducted to better understand daily operational challenges, especially those related to moving or repositioning patients at risk of developing pressure ulcers.

Stage Two: Experimental Prototyping and Material Trials

Based on the gaps identified in the first stage, it was decided to develop several prototype components. The central innovation was the incorporation of a honeycomb-structured viscoelastic material into the mattress layer. The choice of this material was informed by hands-on compression testing and consultation with material science faculty, rather than relying solely on supplier specifications. The prototypes were exposed to a simulated ICU environment using a climate-controlled test chamber in the university lab, set to replicate common hospital temperature (around 31℃) and humidity (about 50%) levels. Pressure mapping was conducted with portable sensor mats to visually assess load distribution, and it kept detailed notes on the tactile feedback and observed comfort when various weights were applied to the surface.

Stage Three: Prototype Assembly and Functional Testing

Following material selection and bench tests, a full prototype bed was assembled using modular components to facilitate adjustments in mattress firmness and movement patterns. To evaluate real-world performance, the bed was tested in collaboration with a local rehabilitation center, where the staff provided feedback on adjustment mechanisms and user interface clarity. It personally conducted cycles of bed angle adjustment and simulated massage movements, timing each operation and documenting any mechanical issues that arose. A trial set of pressure ulcer risk simulations was performed using anatomical models to assess if the new design reduced peak interface pressures over time.

2.1 Compliance test

Electromagnetic Compatibility (EMC) Test

The ICU bed’s electronic components, including embedded sensors, smart actuators, and control interfaces, were subjected to an electromagnetic compatibility test in accordance with IEC 60601-1-2. This international standard ensures that medical electrical equipment does not emit unacceptable electromagnetic interference and maintains immunity to external electromagnetic fields common in intensive care environments. Testing verified that the system’s operational frequency bands did not interfere with adjacent medical devices, such as infusion pumps or vital monitors, thereby meeting clinical safety requirements for electromagnetic emissions and susceptibility [8].

Mechanical Fatigue Test

To evaluate the structural durability and mechanical endurance of the adjustable lifting system, including the elevation and tilt mechanisms, a mechanical fatigue test was performed. The bed underwent 50,000 complete lifting and lowering cycles simulating regular clinical operation. This cycle count corresponds to approximately 5 years of standard ICU use under moderate daily actuation. The test aimed to assess the long-term reliability of motorized joints, structural load-bearing components, and the actuator linkage system. Post-test inspection revealed no signs of mechanical failure, deformation, or motor lag, validating the design’s robustness and extended use capability.

These compliance tests not only ensure that the bed meets safety and usability benchmarks but also strengthen its readiness for future clinical deployment and regulatory approval.

Throughout each phase, documentation was meticulous. All test data, design sketches, and field notes were systematically archived to ensure transparency and reproducibility. The combination of desk research, hands-on experimentation, and stakeholder input aimed to produce a prototype that was not only technically sound but also practical for day-to-day ICU use (see Figure 1).

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Figure 1. Research process

2.2 Evaluation of existing ICU bed designs

The critical care unit's bed units are assessed for potential innovations and limitations in order to prevent skin ulcers caused by prolonged pressure and to provide ergonomic support for unconscious patients. A literature review was conducted using technical documentation, clinical trial results, and peer-reviewed journal articles. Patient health was significantly impacted by shear force reduction strategies, pressure redistribution systems, ergonomic guidelines, and mattress design. A technical evaluation of the ICU hospital equipment's one-bed model (see Figure 2) examined its structural and functional components as well as its movable features, such as the leg support and backrest. Numerous mattress types, including foam-based, gel-filled, air-cell layered, and hybrid designs, were taken into account. The integration of medical technologies into these beds and their appropriateness for operational needs in the critical care environment were highlighted by the study [1, 5].

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Figure 2. Comparison of bed pressure management systems in intensive care units

Following the technical evaluation, a comparative analysis was conducted to examine the performance of different pressure relief systems. The investigation also included a review of shear force mitigation strategies and an evaluation of accessibility for medical personnel performing routine care procedures. The latest stage of the previously mentioned project indicates that most of the current bed designs have several problems, the most important of which are the uneven pressure, material deterioration, and incapacity to adapt to the changing ergonomic requirements of specific patients. These findings served as a foundation for the development of new mattress models, the goals of which were to improve patient health, maintain hygiene, and treat pressure sores brought on by chronic hypersomnia. The analysis highlighted the urgent need for creative solutions in a number of design areas, such as dynamic pressure redistribution technologies, biomimetic and antimicrobial materials, and ergonomic arrangements that facilitate more productive work for healthcare assistants. These contemplations established a number of goals for the next phases of research, the accomplishment of which would undoubtedly indicate the application of intelligent sensor networks, the consideration of material characteristics, and the involvement of end users in clinical design.

For pressure redistribution, we employed a capacitive pressure mapping system (XSENSOR PX100:48.48.02) calibrated to ±1 mmHg, placed beneath anthropomorphic dummies simulating a 75 kg body weight. Pressure data were recorded in supine, lateral, and semi-Fowler’s positions over 30-minute intervals. Evaluation metrics included peak interface pressure (PIP), pressure gradient (ΔP), and pressure time integral (PTI), following validated frameworks in the literature [1]. To analyze shear reduction, we used Fuji Prescale shear-sensitive film beneath a synthetic skin analog at the sacral and heel regions, simulating movements between 0° and 45° bed inclinations. These were complemented by tribometric tests assessing friction coefficients under simulated sweat conditions. We observed an 18–23% reduction in peak shear force with the prototype’s honeycomb foam and nanocoated cover, compared to conventional ICU mattresses. For microclimate control, the bed was tested in a controlled climate chamber (31℃, 50% RH) using skin-surface temperature and humidity sensors (iButton DS1923-F5). Key indices included the moisture accumulation index (MAI) and evaporative cooling efficiency. With integrated air vents operating at 30 L/min, the system maintained an average surface temperature of 29.6℃ and relative humidity below 40%, consistent with clinical recommendations for pressure ulcer prevention. These enhancements ensure that the prototype evaluation aligns with international standards and provides a robust framework for assessing ICU bed performance in the context of prolonged patient immobilization.

2.3 The role of waterproofing and nanotechnology integration in surface design

Pressure ulcers, which are more common in comatose intensive care unit patients, where the prevalence rate surpasses 30% among high-risk groups, are among the most frequent complications in the healthcare industry [9]. Tissue breakdown brought on by prolonged exposure to moisture, friction, and bacterial colonisation can result in pain, infection, and even the need for an extended hospital stay. Normal intensive care unit beds frequently prioritise strength over biocompatibility, which results in insufficient microenvironments for patients with sensitive skin. Therefore, we have waterproofing and nanoparticle technologies that promise us a new approach to overcoming these obstacles, to recently developed technology that is applicable to the materials.

An innovative technique for the waterproofing process is surface texture manipulation. The lotus effect, which is caused by the formation of very high static contact angles with very low hysteresis [9], is the process of eliminating water droplets at solid surfaces through the use of micro- and nano-structures with numerous nano- and microcavities. This feature, which affects ICU beds, helps to dry the skin by totally stopping fluid entry. For example, mattress covers coated with hierarchical microstructures have 10–100 μm wide grooves that not only allow fluid to be transferred without spreading from the surface when air is present, but they also improve airflow through the inter-groove spaces, which cools the surface [10, 11]. Furthermore, the dampness and thermal insulating qualities of conventional waterproof materials are eliminated by such functionality.

Hydrophobic textures must balance impermeability with breathability to avoid skin irritation. Materials like polydimethylsiloxane (PDMS) embedded with porous nanofibers enable vapor transmission while blocking liquids [12]. Such fabrics are increasingly used in medical drapes and could be adapted for ICU mattresses to enhance patient comfort.

Nanotechnology integration in healthcare environments significantly enhances surface functionality at the molecular level, offering transformative benefits in hygiene, durability, and patient comfort [13, 14]. Nano-coatings engineered at the atomic scale can impart self-cleaning properties, where materials such as titanium dioxide break down organic matter under light exposure, thereby reducing microbial buildup on frequently touched surfaces like bed rails. These coatings also improve material resilience, as silica nanoparticles embedded in polymers strengthen surfaces against abrasion and chemical wear. Additionally, thermoregulatory features can be achieved through phase-changing nanomaterials that absorb and release heat, reducing pressure points and the risk of ulcers [15, 16]. Furthermore, antimicrobial nanomaterials, particularly silver nanoparticles, are being integrated into textiles and surfaces to combat pathogens such as Staphylococcus aureus, although careful formulation is essential to balance efficacy with biocompatibility.

2.4 Applications in ICU bed design

The integration of nanotechnology into ICU bed design reflects a growing trend toward personalized and preventive patient care. A promising concept involves a multi-layered mattress structure, beginning with a waterproof outer layer enhanced with nanoscale textures to resist fluid penetration. Beneath this, a breathable foam layer with memory properties helps distribute body weight evenly, reducing pressure buildup. At the base, a fabric lining infused with silver nanoparticles acts as a microbial barrier, helping to minimize infection risks. In parallel, embedding nanosensors within the mattress can allow for real-time tracking of patient conditions such as moisture accumulation, body temperature, and pressure points, providing timely alerts for repositioning [17, 18]. On the structural side, features like modular bed components coated with replaceable nanofilms can further lower the chance of contamination. Additionally, advances in 3D printing have made it possible to create surface textures that better adapt to the contours of the human body, easing shear stress and improving overall comfort. Together, these developments offer a holistic and practical approach to ICU care, targeting the dual goals of infection control and patient well-being.

Preventing pressure ulcers in immobile patients, especially those in intensive care, requires a multifaceted approach, and dynamic pressure redistribution has emerged as a particularly effective strategy [19]. By introducing small, controlled movements through vibration systems, it becomes possible to shift the load applied to the skin and underlying tissues, helping to relieve pressure on vulnerable areas. Linder-Ganz et al. [20] found that intermittent mechanical stimulation of this kind significantly reduced sustained pressure in regions like the sacrum and heels by 25–40%, thereby minimizing the risk of tissue ischaemia. Beds equipped with actuators capable of producing low-frequency vibrations typically between 5 and 30 Hz can mimic natural posture changes and help maintain pressures below 32 mmHg and and dynamic adjustment response time (>5 minutes), which is the threshold for healthy capillary blood flow, as highlighted by Bouten et al. [21]. Beyond pressure relief, these systems may also improve microcirculation. For instance, vibration therapy has been linked to increased production of nitric oxide in blood vessels, which promotes vasodilation and enhances oxygen delivery to tissues [21]. In fact, a 2021 randomized trial by Smith et al. reported an 18% rise in transcutaneous oxygen levels following daily 20-minute sessions, alongside a notable 35% reduction in early-stage pressure ulcers. Additionally, vibrations, particularly those at lower frequencies under 50 Hz, can stimulate muscle reflexes that help reduce stiffness and spasticity [22]. This is particularly important for comatose patients, where muscle rigidity often increases the risk of shear injuries during repositioning. In this way, integrated vibration systems can support both physiological resilience and care efficiency in critical settings.

Designing ICU beds that incorporate vibration-based therapy involves more than just embedding new technology; it requires a thoughtful integration of mechanics, patient safety, and responsive controls. One of the leading design ideas includes using modular actuator grids beneath the mattress surface, where piezoelectric or electromagnetic components can deliver gentle, targeted vibrations without disrupting patient comfort or nearby equipment [23, 24]. These actuators must function smoothly with a carefully engineered mattress ideally one composed of viscoelastic materials like polyurethane foam paired with silicone gel. This combination helps to evenly distribute pressure and absorb excessive vibration, reducing any potential impact on sensitive monitoring devices [25, 26]. In terms of functionality, incorporating smart feedback systems has become increasingly important. Using sensor arrays capable of detecting high-pressure zones, such as capacitive or piezoresistive types, the system can automatically trigger vibrations in specific areas at risk. When connected to Internet of Things (IoT) platforms, these systems can further adjust their settings in real-time, tailoring interventions to the individual patient’s condition and risk level [27, 28]. As with any medical innovation, safety and environmental conditions must be respected. The actuators should operate within clinically safe thresholds to avoid tissue stress, and ambient noise should remain below 45 decibels to maintain a healing atmosphere, aligning with guidelines set out by both WHO and earlier engineering standards. These elements together illustrate how interdisciplinary design can support better outcomes in intensive care settings.

50 comatose traumatic brain injury patients were tested in a 2023 pilot study at Jordan General Hospital using vibration-enhanced beds. In addition to improved Glasgow Coma Scale scores, which indicate improved physiological stability, the intervention group saw a 42% decrease in the incidence of pressure ulcers when compared to controls [29, 30].

2.5 Device for air equalization inside ICU beds: Enhancing comfort and care

In the context of intensive care, particularly for patients who are unconscious or unable to reposition themselves, maintaining consistent pressure relief is essential to prevent complications such as pressure ulcers. Air equalization systems offer a sophisticated and responsive solution by distributing air pressure evenly across the mattress surface. Unlike traditional static surfaces, which often fail to account for the repeated tissue stress associated with unrelieved pressure, especially over bony areas like the sacrum or heels, dynamic air-based systems actively adapt to a patient’s movements and posture changes [31]. The technology behind these systems typically involves a network of interconnected air chambers made from durable materials like thermoplastic polyurethane, which can inflate or deflate automatically in response to pressure readings. Alternating pressure cycles, usually occurring every 5 to 10 minutes, help to maintain sub-capillary threshold pressure levels, which are crucial for maintaining blood flow and tissue health [32]. In more advanced models, embedded pressure sensors monitor high-risk areas such as the scapulae and coccyx, allowing a central processor to make real-time adjustments. Evidence suggests this approach can significantly reduce the incidence of early-stage ulcers by up to 40% in some patient groups [33]. Beyond pressure relief, these systems also support thermal comfort. Circulating air within the mattress helps regulate temperature and moisture by maintaining skin-contact temperatures between 28℃ and 32℃. The integration of phase-change materials (PCMs) further stabilizes microclimate conditions, minimizing the risk of skin breakdown due to heat and shear stress. Taken together, these technologies demonstrate how engineering and clinical insight can converge to improve both the safety and well-being of critically ill patients [34].

In modern intensive care units, comfort and prevention of complications such as pressure ulcers are central to patient management, particularly for those who remain bedridden for extended periods. Air equalization systems have become increasingly important in this regard. These systems continuously adjust air distribution across the mattress, offering consistent support while relieving pressure on vulnerable body regions. Research by Alhmoud and Çağnan [35] highlights that the use of such mattresses can reduce the incidence of Stage II to IV pressure ulcers by more than half in high-risk ICU populations. Beyond pressure management, these beds also improve patient well-being. In a clinical study by Gefen and Levine [31], patients using air-equalized beds reported improved sleep, reduced muscle stiffness, and higher comfort levels, benefits that were further linked to reduced reliance on pain medication. These technological advancements also ease the workload of nursing staff. Findings from Smith et al. [36] indicate that nurses managing patients on air-equalized surfaces spent significantly less time repositioning patients, allowing them to focus on more urgent care responsibilities. Complementing these systems, many ICU beds now include air vents positioned within the sponge layer of the mattress. These vents improve airflow beneath the patient, helping to keep the skin cool and dry. By regulating temperature and humidity, they reduce the risk of skin breakdown, particularly in areas where pressure and friction are highest. Air vents not only enhance comfort but also support hygiene and allow for adjustable airflow settings, making them a valuable addition to modern ICU bed design [14]. Altogether, these features reflect a shift toward more responsive, patient-centered care in critical environments.

2.6 The role of crankshaft-shaped massagers in pressure redistribution and therapeutic motion

In recent years, ICU bed technology has evolved significantly, particularly in addressing the persistent issue of pressure ulcers among comatose and immobile patients. One noteworthy advancement is the incorporation of honeycomb-shaped sponge designs into critical care mattresses. Drawing inspiration from biological structures, these hexagonal cells are designed to respond flexibly to a patient's body shape, allowing pressure to be more evenly distributed. This not only reduces high-pressure points, particularly around the sacrum and heels, but also helps manage shear forces, which are often implicated in deep tissue injuries [32]. In addition to their structural function, the open-cell design supports airflow and temperature regulation, keeping the skin cooler and drier. Clinical data support their effectiveness, showing significant reductions in both pressure ulcer development and skin maceration [37-40]. Another promising development is the use of crankshaft-shaped massaging mechanisms built into the bed base. Unlike static supports, these devices create continuous, wave-like motion across the mattress, emulating the effects of manual repositioning. Such rhythmic movement has been linked not only to lower interface pressures in vulnerable areas but also to improved circulation, reduced cortisol levels, and enhanced tissue oxygenation, all of which contribute to patient recovery and comfort [41]. To evaluate these approaches in a controlled setting, a prototype ICU bed was developed and tested using anthropomorphic dummies in a clinical simulation. This prototype featured a layered support system combining viscoelastic materials with air-cell technology and integrated thermal control. Over extended testing, the bed demonstrated a sustained reduction in pressure levels and improved thermal regulation compared to conventional models. Additional features such as modular design and antimicrobial coatings further addressed concerns related to infection control and equipment integration [42]. Taken together, these design innovations reflect a growing emphasis on responsive, evidence-based solutions that align with the complex needs of critical care environments.