Smart medical beds in patient-care environments of the twenty-first century: a state-of-art survey

In accordance with the aforementioned results, a growing number and variety of medical beds has been found in this period, with increased mechanical and autonomous functions, reaching up to novel devices, like a continuous-use bed that turns into a wheelchair for disabled patients [7], and models with embedded networking, communication, monitoring and integrated alarms [8] (i.e. Stryker iBed Awareness). The global market for medical beds has become, as a result, vastly more competitive in the past decades [9], and the continuing trend of specialization into different sub-groups of patients and environments is evident: apart from bariatric (i.e. Joerns Bari10A and Hill-Rom Excel Care ES) and domiciliary beds, new product lines, aimed at the aid of the elderly (Japan’s Paramount Bed Co. Ltd. Rakusho Series) or pediatric patients appear more prominently, while other models (for instance Merivaara Carena) display features directed at many of these populations under a single model.

Following the trend of all medical devices, the integration of more-developed technologies into electric medical beds became the most significant in this period, resulting in examples with multi-language speech synthesis for patient-caregiver communication (Stryker InTouch), and recommending [10], and even implementing speech-recognition functions for their control (Vallitech-2015). With significant embedded capabilities and autonomy, user interfaces (detailed in section “User interfaces”) continue to stand out as relevant weighting factors in the evaluation of these products. A patent of 2005 shows multiple potential configurations for side-rail integrated controls [10], and a subsequent patent of 2010 updates these alternatives with touchscreen functions, for both patient and caregiver use [11]. In 2004, a patent displaying a bed with wireless connectivity, high-complexity user interfaces, and incorporating patient-blocking functions, foot pedals, and automated functions was presented [8]. The TotalCare SpO₂RT bed, from Hill-Rom, as well as Stryker’s InTouch Care bed and SizeWise’s Navigator models, show integrated touchscreens and dedicated graphical user interfaces as part of their developments. Upgraded, comprehensive front panels and alternate controls continued to proliferate in this period, and the redundancy of controls became a standard feature (for instance, visible in Haelvoet Olympia Hospital and Linet Eleganza Smart models). Improved ergonomics and risk-reducing articulations have also been included into new devices, modifying the hip-section articulation when the backrest is lifted (TotalCare SpO₂RT model), and/or compensating the position of the patient in its environment (Stryker S3 Med/Surg Bed).

Over the past years, trends and most relevant innovations to medical beds have been notably related to design aspects, referred to materials (more hygienic and resistant), population-specific models, ergonomic manual commands, and morphological changes associated to updated mobility-options (elevation, front-back and lateral inclination, etc.), updated side-rails, patient-support structures, castors (fifth castor for enhanced transport), while embedded with the aforementioned new technologies.

In the competitive scenario presented in previous sections, aesthetic and comprehensive design features stand out as a differentiating factor between products. These features, prominently represented by the side-rails and panels, also serve in adapting the beds to different environments and populations. An analysis of these products, and their means of diffusion, allowed inferring a set of values and responses that this new generation of smart beds aims to provoke:

In sum, the following trends, exemplified in Fig. 2, have been associated to the design of smart beds:

Regulatory frameworks have an impact on the design-process and requisites expected of different families of devices in order to reach their potential users. In the sector of medical beds, there have been advances in this field between 2000 and 2016. After the development of particular standards for electric medical beds in the late 90’s [4], the first decades of the twenty-first century have seen the convergence of these standards into a unified reference. ISO/IEC standard 60,601–2-52:2009 (basic safety and essential performance of medical beds) [12] was issued in 2009 as a combination of previous standards IEC 60601–2-38:1996 (requirements for the safety of electrically operated hospital beds) [13], and EN 1970:2000 (adjustable beds for disabled persons: requirements and test methods). This document, which covers issues like safe working loads, mechanical and electrical safety, ergonomic requisites and risk-management strategies as a consolidated reference among five scenarios for medical beds (from hospital to nursing and home environments) [12], was first amended in 2015 [14], and falls within the updated scope of IEC 60601 [15].

The current number of developers and manufacturers of medical beds, their associated products and accessories, as well as healthcare-management technologies, falls easily within the hundreds. Significant market actors, as described by medical-bed market surveys [9, 16], include Hill-Rom, Linet, ArjoHuntleigh, Stryker, Paramount Bed Co. Ltd. and Invacare.

The global market of electric and smart medical beds, both for healthcare facilities and residential use, reaches its highest degree of development in the United States and Europe, with the Asian market showing great potential for growth in the following years, and within this market, pressure-relief surfaces and beds are among the most prominent sub-groups [9]. Figure 3 shows the global distribution of the reviewed companies (accessed 04/2018).

Table 3 shows a set of stand-out curent medical-bed properties found on the reviewed systems, ranging from homecare to intensive-care solutions, detailing aesthetic-morphological properties (section “Changing (and keeping) the face of the medical bed”) and special functions that are available in these devices, stemming from the integration of multiple technological solutions into one device (section “Market expansion and technological availability”). As a group, these devices directly highlight the different specific purposes that medical beds can be intended for (see “description”), as well as the increased level of technology embedded into them over time. These features are divided in the table, according to their relation to the device itself, the user (caregiver or patient), or the healthcare environment.

Features mentioned in the table (i.e. bed-exit alarms, obstacle detection, advanced motion options, therapy routines, patient and bed history logging, integrated scale, head-of-bed angle monitoring and measurements, patient-blocking, local and remote information on patient conditions, integrated accessory-controls), are all relevant in their own right, but most impactful when controlled under a single patient-care interface. Most of these features are shared among models, and not only isolated cases, representing the increased expectations that their users have developed.

As indicated in section “Changing (and keeping) the face of the medical bed”, design highlights, including patient and caregiver ergonomics and environmental adaptations for clinical and/or residential settings, are most significant and prominently present across the growing family of smart beds. Similarly, access to pre-programmed positions, dedicated accessories and optional features are also largely visible. For instance, 85% of the models highlighted in Table 2 include positions like cardiac chair and automatic CPR (cardiopulmonary resuscitation), and 95% have dedicated accessories like specialty mattresses, IV-holders and options for a fifth castor. From the perspective of robustness and safety, battery backup and eased CPR release, mentioned in Table 3, provide for fast responses to emergencies under power-failure conditions, another functionality mentioned in the current standard.

Supplementing design features, customization of finishings, materials, colors and side-rail styles for a single model are also distinct, but present to a lesser extent (corresponding to a 60% of the models in Table 2), while proving a meaningful addition to the design of dedicated, more patient-conscious environments. Finally, adjustable bed sections (frame width and length), particularly useful for bariatric patients, have become a widespread feature, found in the form of integrated mechanics, or as optional additions, across all models from Table 2.

As a result of this analysis, it has become evident how user interfaces in medical beds have progressively diversified in this period. Starting with wired hand-held controls (which persist in most models, for instance Joerns UltraCare XT), interfaces have advanced up to solutions with redundant side-rail integrated controls (exterior and interior, i.e. ArjoHuntleigh Enterprise 9000), remote controls, foot-pedals, integrated numeric displays and touchscreens (mostly directed to caregiver control), and variants like hanging controls reachable by the patient (see Linet Eleganza Smart and Haelvoet Olympia). Figure 4 shows examples of these alternatives, supplementing handheld and side-rail controls, which are also visible in Fig. 2. Additionally, current inventions contemplate new integrations between these technologies for future devices [10, 17].

Smart medical-bed interfaces count on the aforementioned, now-standard features like patient blocking, nurse-call functions, networking and interaction with other devices and accessories (i.e. air-pressure mattresses), and redundancy through multiple controls is available for most options, favoring robust and reliable operation. Based on years of interdisciplinary experience, currently-enforced standards have regulated requisites for these interfaces (indicators, size, means of operation) [12]. The addition of advanced graphical means and touchscreens with dedicated user interfaces is currently present in a select number of beds, however (20% of the highlighted cases in this article), while it provides eased access to features like alarm setup and monitoring, and is essential to the control of a growing number of states and functions in smart beds, like bed-history functions. For this reason, their presence is expected to increase in the future.

Available as integrated functions for commercial beds and research proposals, patient monitoring is the most extended group among comprehensive proposals for the care of high-risk or long-term patients. Varied systems for fall [18] and agitation detection, around the bed, can be valuable additions to the medical bed, allowing for patient-aware care environments and active sensor-networks [19]. Similarly, pressure-distribution matrices over the support surface of the bed allow a comprehensive analysis on patient position, and may reduce the risk of developing pressure ulcers [20]. Based on acquired data concerning the state of the patient or device, these monitoring proposals can either show the detected state [21], emit alarms [18], or act autonomously against detected hazards [22, 23]. Patient-motion sensors, in contact with the subject, can perform similar tasks concerning the detection and alert of lack of mobility (Leaf Healthcare Inc. developed one such device), as isolated additions.

Integrated, non-invasive vital-sign acquisition from the bed has also been a matter of research over the past years. A consumer-ready device [24] can be placed under the mattress, and acquire heart and breathing rates, as well as estimate patient motion and register caregiver-response time. Outside the medical bed, entertainment systems with infrared sensors have been valued and are being studied for non-invasive heart rate detection [25].

Head-of-bed angle indication and logging is important for the prevention of secondary conditions associated to immobility, and requisites concerning its state vary depending on the condition of the patient (prevention of pressure ulcers requires low angles, and risk of aspiration in intubated patients requires head-rest angles of over 30 degrees, according to the experience of nursing and medical staff) [26]. While incorporated into high-end current devices, the addition of this functionality to manual devices through MEMS [27] sensors is a low-cost addition with great positive potential [28]. Many current technologies are, likewise, sufficiently developed to allow for low-cost derived solutions, integrating these into less-developed healthcare environments.

Finally, patient-motion assistance is another field of research that is valued for the care of the older and disabled patients, with research solutions [29], as well as consumer-ready devices incorporating such features, so that the device supports patient motion, instead of replacing it.

Directed to the treatment of subjects with temporary or permanently-restricted mobility, medical beds benefit from past and current accessibility inventions and developments, both in terms of their actuation-means, as well as in terms of their user-interfaces.

Among these solutions, environmental control units (ECU, see [30] for a review on incipient models of the late 90’s) currently stand out as available additions to the medical bed environment, controlling some medical beds. These systems are among the most used accessibility-technologies by patients with spinal cord injury [31]. Basic inputs to ECUs include accessibility switches, sip-puff controls and pressure sensors (see [32]), and their impact on the quality of life of patients is a matter of research [33]. Over the past decades, this concept has been considered by research solutions for healthcare facilities, with inventions aiming at supplementing bed control [17]. Speech control, for instance, is considered and implemented on a limited number of cases, as an accessory ECU (as the one developed for the Pro Bed Medical Technologies Freedom Bed) or incorporated into some devices [34]. The promise of speech control for these devices is not new, with a patent from 1991 describing an ECU for a hospital bed and its environment [35]. The effectiveness of speech recognition, however, was more limited at that time, as compared to current models and consumer-ready systems.

Another example is the development of Brain-Computer Interfaces [36], powerful technologies for the aid of critically impaired patients, which are seen as possible inputs for ECUs and medical beds with basic actuating functions. This promising technology, however, presents specific difficulties [37] and is under development, limiting its current reach.

Surrounding the medical bed, the integration of information-technologies into the patient-care environment has changed the way patient-information and treatments are handled. Updated user interfaces, dedicated to patients and caregivers, have emerged over the past decade, both as consumer-ready solutions [38] and research projects [34], covering the management of patient records, and control over the near environment (like TV, lights, etc.). As medical beds become smarter, interaction with these smart environments becomes a possibility [8].

A growing trend looks to change the experience of the healthcare environment for patients, providing new means of communication and entertainment at their reach, particularly aimed at patients with restricted mobility (acute, recovering, and long-term patients). These proposals integrate connectivity and a higher control over the environment, while including informative resources (tutorials [38], etc.) concerning different conditions. Even when not including control over the bed itself, these “Interactive Patient-Care Systems” [39] may integrate a touchscreen through adjustable stands (e.g. Siemens HiMed Cockpit, visible in Fig. 5).

The development of personalized healthcare and medical devices for injuries and chronic diseases has been deemed as one of the most impactful and feasible challenges to be tackled by biomedical engineers in the near future [40], and the evolution of medical beds and devices in the immediate surroundings of the patient is instrumental to these advances. The core of these projects stems from a thorough vision concerning the patient’s experience of this environment, valuing the possibility of empowering patients on their own care, through a more fluid interaction with their surroundings.