Design Process for a Birthing Bed, Based on User Hierarchy: Promoting Improvement in User Satisfaction

Abstract

The medical device design process has a responsibility to define the characteristics of the object to ensure its correct interaction with users. This study presents a proposal to improve medical device design processes in order to increase user acceptance by considering two key factors: the user hierarchy and the relationship with the patient’s health status. The goal of this study is to address this research gap and to increase design factors with practical suggestions for the design of new medical devices. The results obtained here will help medical device designers make more informed decisions about the functions and features required in the final product during the development stage. In addition, we aim to help researchers with design process didactics that demonstrate the importance of the correct execution of the process and how the factors considered can have an impact on the final product. An experiment was conducted with 40 design engineering students who designed birthing beds via two design processes: the traditional product design process and the new design process based on hierarchies (proposed in this study). The results showed a significant increase in the user acceptance of the new birthing bed developed with the hierarchical-based design process.

1. Introduction

User-centered design in healthcare has been applied in different studies; however, research on this topic is limited. Few articles focus on future design guidelines, methods to improve the patient experience, or the specific needs of patients within hospitals [1]. Best practices in the medical device industry increasingly seek informed innovation process developments. With the understanding of all stakeholders, industry leaders seek to maximize the effectiveness of their devices while reducing patient risk and the cost of execution to provide comprehensive solutions for both health and business [2]. Companies must be rigorous in their search for innovation, seeking the ultimate goal of developing new products more effectively and efficiently [3]. Profitable and systematic approaches are necessary for product development. They guarantee safe and effective devices for users, economic successes for manufacturers, and reliable and profitable investment for consumers [4].

The correct patient care is based on the medical devices that are available; currently, clinical professionals have to adapt to the functionality of devices to avoid errors and patient risk. The reports of errors in medical devices have emphasized the implementation of user-centered design processes [5]. Research conducted in the US and the UK suggests that much usage error is the result of poor device design [6] that is not suited to user needs. Unfortunately, many investigations into medical errors are superficial, and they do not report these errors in depth. Usually, the fault lies with the user of the device. There is a link between poor device design and what was traditionally classified as user error. The FDA and courts of law recognize the importance of poor device design in contributing to such “misuse.” To reduce mistakes, designers must follow a user-centered engineering approach to keep user needs in mind throughout the design process [6].

1.1. Design Process

Design is the human power to conceive, plan, and realize all of the products that serve humans to achieve their individual or collective goals [7]. The design of medical devices begins with a brief: a problem to be solved. For a new device to hit the market and to reach the clinical setting, certain procedures such as verification/validation must be conducted. In addition, the integration of human factors into the design process reduces risk and improves patient safety. Design control is a fundamental requirement for attaining regulatory approval internationally, as it ensures that any decision made during the process is verifiable to improve the ability of designers and auditors to determine the safety and efficacy of a product. This framework is what informs United States’ (US) federal regulation 820.30 for design control [8].

Traditional design processes focus on prioritizing evaluation criteria and shaping use-value. They may not address all of the interactions between systems such as users and contexts or meet general design expectations [9]. Traditional design approaches have been accused of failing to involve users in the design process, compromising business opportunities and user experience and interaction. Eilkinson and De Angelli explain that considering users to be individuals with their own individual needs, capabilities, and desires throughout the design process increases user acceptance [10].

In a typical design process, designers must consider the complexity of the context and the users of the product. They must balance the conflicting needs of end users with business approaches that influence the entire design process. However, in the case of medical device design, this problem is further complicated, as detailed investigations of user needs and end-use environments remain difficult to develop. It is often unclear how the design process can be improved, and it is unclear how improvements in these domains could affect the usability of the final product itself or how end users might or might not accept the product. These challenges necessitate the further study of medical device design [11]. There are two directions by which designers approached product concepts in the past: the marketing perspective and the engineering perspective. Marketers focused on product attractiveness, while engineers concentrated on appropriate product features. Methods and approaches that support product development teams early in the process include the Kano model or joint analysis, in which the perspectives of engineers and salespeople complement each other. What these two methods have in common is the fact that their objective is to identify the current or obvious client desires and needs [12].

According to Ulrich and Eppinger, both authors have considered hierarchical analyses in their design processes, such as the hierarchy of needs. The concept development process involves a distinction between customer needs and product specifications; this distinction is subtle but essential. According to this methodology, the authors propose five steps to identify client needs, among which are collect, interpret, and organize the needs into a hierarchy of primary, secondary, and tertiary and ensure that this is reflected in the end product. The primary needs are the most general, while the secondary and tertiary needs express more detail. The procedure for organizing the hierarchy is intuitive, survey-based, and practical and is limited to only a tiny group of needs that result in complex or costly technical trade-offs in product design [13].

Hierarchical task analysis (HTA) is a central ergonomic approach based on performance theory. It represents a hierarchy of system sub-goals for an extensive analysis [14]. Hierarchical task analysis (HTA) is one of the most widely used methods [15]. Under this method, tasks are ranked under the health status and care needs criteria, basing the hierarchies on user needs and user types. There are several models of design processes. Models are continually changing, yet the foundation of the design process is constant. There are two well-known models: one proposed by Pahl and Beitz and the other developed by Stuart Pugh. Both are configured around engineering design, as they are used for the development of medical devices. Both posit that medical devices are products that have to be manufactured because at the end of the day, they are needed and have a more technical vision. Pahl and Beitz’s model allows the designer to become fully aware of the needs and environments within which they operate; it also gives the designer time to discuss their design with the end-users before the conceptual design phase. Pugh’s model fundamentally assumes that the process begins at one end and progresses straight to the final result; Pugh incorporates manufacturing into the design process. While these models are essential, they focus on visualizing the process but not the activities [16].

Since 1990, designers have explored design thinking and practice. The pioneers of this were the IDEO design studio at the Stanford University School of Design; they tried to map the process in different ways: rounds, cycles, double diamond, etc. However, there are two fundamental values or principles that they could not avoid: design thinking must primarily be human centered, beginning with the user’s needs and then proceeding to the creative stage [17].

The design process has been described as a problem-solving activity [18]. This is typical of the first generation of design methods. The idea of human needs and the subdivision of the process were the natural way to approach a design problem, as described in Figure 1.

Today, the traditional design scheme is implemented in product design [19]. This method is a linear process consisting of researching the design requirements, defining concepts, developing the design of the product itself, manufacturing it, and launching it on the market, as shown in Figure 2. However, such a scheme has notable shortcomings, notably the lack of definitions for prototypes based on adaptation to the requirements and needs of its end user and the lack of an evaluating stage for the usability of the product itself.

For Rodríguez Morales [20], the traditional design process, also understood as form-oriented design, has the creation of mass-produced functional objects based mainly on quantitative data as its main objective.

On the other hand, the user-centered design process presents an alternative path where, beyond defining design requirements, designers seek to understand and explain the actual users of the products to be designed and their needs and context of use. Once these variables are established, user testing allows the design to be redefined based on the end-user requirements and prototypes produced before manufacturing, as shown in Figure 3.

User-centered design focuses on generating practical and attractive proposals for its users and on creating aesthetically pleasing and functional objects. Its main objective is to provide a great user experience, basing its indicators on quantitative data and in-depth ethnographic studies of the profiles of users who interact with the product under development and the understanding of the requirements that may be needed [21].

Based on the above, we can conclude that user-centered design seeks to generate products that improve the quality of life of the user by exploring their ethnographic diversity. Thus, the user-centered process aims to drive innovation and tends towards smaller consumption niches [22]. This method of implementing the design process provides humanistic aspects, commercial objectives, and a renewed vision of the execution process for designers.

Traditional design processes mainly address the typification of users in three groups. Eason (1987) identifies the three categories of users as primary (those who frequently use the system), secondary (those who occasionally use the system), and tertiary (all users who are affected by the introduction of the system or influencing its purchase). Identifying all of the possible users allows designers to make reasonable decisions about their degree of involvement in a project to be successful. However, he/she does not specify that the hierarchies of the three groups can constantly change during the product’s end-use, as is the case with a medical device [23].

According to the Federal Drug Administration, there is a definition for the design standards for medical devices. The current design process combines engineering disciplines, government regulatory agencies (national and international), independent certification, and compliance companies. The objective of these techniques is to ensure that a new product meets user expectations and that it is safe and effective in providing its stated benefits [24].

A 2020 study by Bikina et al. of Kwangwoon University in Seoul, Korea, analyzed 88 scientific sources related to the usability and UX of medical device design. The studies examined the concept of medical device usability from three points of view: patients, physicians/medical staff, and caregivers. The primary documents were up to international standards. The authors presented the principal UX analysis methodologies. The three main future challenges for human factors in medicine are user–product interaction, the technology and medical device design process, and aspects of clinical research. They concluded that usability can be considered a subset of UX. Second, assessments can be applied differently for medical devices and consumer goods. Third, usability can be evaluated differently, depending on the type of product. Fourth, there is a distinctive difference in the evaluation of the usability of medical devices compared to consumer goods [25].

A 2001 study by Maguire at the Research Institute at Loughborough University analyzed the importance of human-centered design systems and processes to achieve them. Adopting the framework of ISO 13407, each procedure was considered along with a set of usability methods to support it. Usability is now widely recognized as being critical to an interactive system or product [26]. An analysis of the literature shows that the main benefits of user participation in the design and engineering of a medical device include relevant information about the user perspectives, which improves the design of the user interface as well as the functionality, usability, and quality of medical devices [19]. The application of human factors, standards, and the practices of user centered design remains a priority in the industry for the development of safe, effective, and usable medical devices. Despite the challenges, the industry respects the rules and values user recommendations [8].

Participatory design aims to develop products with the participation of end users in order to capture information and user feedback at each stage of the design and development process. These participatory design approaches try to better understand real users. Designing easy to use products is essential [10]. Studies have shown that user research can be conducted in a rigorous way, and this type of research is necessary if we are to demonstrate the benefits of adopting user-centered principles for medical device developers. When developing any new medical device, the user requirements must be correctly specified. This will increase the likelihood of producing a device that is also easy and satisfying to use. These processes are a risk from a business point of view, as developing a new medical device is expensive. Therefore, it is essential that the correct device is developed and that this device is safe and meets the needs of users [27].

The application of human factors (HF) to the design of medical devices is indispensable for the development of new products The publication of ISO 62366:2008 Medical devices: Application of usability engineering to medical devices (ISO 62366:2008) details how developers must formally address usability. Any medical device that is marketed must be safe (ISO 14971:2007), and developers must demonstrate evidence of the device’s clinical efficacy [28]. Currently, there are different design methodologies and processes that highlight the value of user knowledge and indicate the importance of involving them during the design process of a new product, for example, the user-centered design process (UX council), design thinking (IDEO), the medical device design process (FDA), the double diamond design process (Design Council), the user interaction design process (interaction design foundation), and many others [29].

In the article “Hospital Bed Designs” by N. Wiggermann et al., they mention a user-centered design process. However, their design process does not consider or make mention of users hierarchically or fluctuations in the patient’s health status [30], which could be important factors to consider when making design decisions during development. Ignoring these factors could lead to errors of use and reduce user acceptance.

The users of medical devices must be defined and classified effectively, according to a 2008 study by Ghulam et al., in which they reviewed 556 articles, with the results showing that the involvement of different user types was only present in 29 studies. They found that health users are not the only users, and that the definition and classification of users was unclear. They concluded that medical device users are heterogeneous and are composed of different classes, groups, and types that have different needs and requirements. Without acknowledging this problem, the development of medical devices will be less effective [31]. An example is shown in Figure 4. This figure represents how many users could be involved in a birthing procedure.

The lack of knowledge about the focus on users in the design processes and the strict regulations for the design of medical devices have overshadowed the importance of implementing ergonomic factors during the design process [19]. Such is the case for birthing beds. Although they are the product of a professional design process, they often lack factors that should be thoroughly investigated during development. One of these factors is the importance of hierarchy of the users who will be interacting with the product, whose interaction with the object will be influenced by fluctuations in the patient’s health status [32].

An experimental study was conducted in the design of a new birthing bed to evaluate the results of each process and to seek a final comparison of the design proposals in order to determine whether or not a design process based on hierarchies increased the satisfaction of the final users. In this project, we considered a class 1 medical product that does not represent a potential risk of disease or injury and has a frequent and specific use for a single condition. For this reason, we chose a birthing bed since it has a complex design, around which many activities take place, and in which one of the main factors within the hospital context is medical equipment that helps conduct the work, with the birthing bed being an example of a piece of equipment around which activities are carried out to allow efficient work [33].

1.2. Birthing Bed

When a medical device designer starts designing a new product, they need to understand the problem and what the emotions of the users are. Empathy, which is the ability to share experiences, is a priority. What is it like to be on the receiving end of a pelvic exam? Uncomfortable and daunting. It is even worse in emergency rooms, where 6.3 million pelvic exams are performed annually and where gynecological beds are rarely available [17]. Creating an efficient delivery environment in a hospital setting entails meeting the needs of medical technical safety and ensuring a physiological and emotionally safe environment for women during labor. The psychosocial environment has fundamental effects on the women’s birthing experience, and the design aspects of the delivery room indirectly influence maternal and neonatal outcomes. The study concludes that maternity facilities must incorporate a personalized, woman-centered approach to delivery. More research is required on how this approach could be implemented in maternity care facilities to reduce power imbalances and increase women’s sense of organization and satisfaction with childbirth [34].

A hospital bed, for example, is generally located at the center of the delivery room. This position is common although this is largely due to practicality, as doctors may need to access the woman who is giving birth in case an intervention is required. The bed being in the center of the room is an approach that contributes to the feeling of vigilance in the delivery room. Placing the bed in the center also makes the woman feel that this is where she “should” give birth [35]. This traditional childbirth environment affects women’s labor experiences. A common feature of the modern birth space is the bed. Knowledge about the use of the bed and about the perceptions and attitudes of women in labor and doctors is limited [35]. The modern hospital bed is a sophisticated medical device, and its users represent a diversity of skills and needs. To develop a new bed, a company studied users over almost 500 h of observation in 29 hospital units. The different needs and capabilities of users are a complex challenge for the design of a new hospital bed [36]. Therefore, in their study, they did not refer to the hierarchical fluctuation of the users.

At present, the obstetric team does not meet the proper requirements for the adequate care of pregnant patients in the labor room or in the expulsion room. In the different stages of delivery, equipment deficiencies cause various conditions in patients [35].

An industrial designer or a medical device designer should be prepared by their fundamental training in school. Since traditional design processes are not enough to face the challenge of designing a birthing bed, both must be familiar with the importance of ergonomic factors in the design process, mainly in user-centered design [33]. However, neither the traditional design process nor user-centered design specifies the importance of defining user hierarchies and their correlation with the possible health status of the patient.

1.3. Project Description

This research compares the improvements obtained in a design process based on hierarchies compared to the traditional design process. It has been proven that multiple medical errors within hospitals could be solved with prevention activities that reduce risks for people and the unnecessary expenditure of resources. Preventive medicine should prioritize health policies and the proper design of devices, as set by quality standards in the medical field [18].

This study focuses on studying the design process of birthing beds by taking the several users around the object, the types of users, the hierarchy of users in the use of the bed, and the fluctuation of the patient’s health status, which causes constant changes in the hierarchy of users, into account to improve the design of the birthing bed and meet the needs of each user during the delivery process. Additionally, this process is based on the education of process design and is based on the hierarchies of the users. In the final year of an engineering design bachelor’s degree, a group of students demonstrated the impact of didactic information on their project performance, which was evaluated through the resultant prototypes [37].

2. Materials and Methods

A cross-sectional comparative study was conducted with a convenience sample consisting of two groups of students from the Design and Innovation Engineering Department at the Universidad Panamericana of Guadalajara, Mexico. A total of 40 students who were in the 5th semester of their degree participated, and 88% were women while 12% were men. To check whether a hierarchical design process improves the final product, the students were asked to design a bed for natural births.

The study was conducted in three stages:

• Stage A—Traditional Design Process
• Stage B—Hierarchal Design Process
• Stage C—Comparison of Levels of Acceptability of the Proposals

2.1. Stage A: Traditional Design Process

The objective was to determine the design characteristics and to evaluate if the students identified potential users. They conducted three different activities:

(a)

Dynamics of creativity, in which they generated concepts from different sources of inspiration. Each team developed ten design proposals.

(b)

Article research, in which they were asked to investigate databases of scientific texts to add information from previous results and to improve their previous proposals. We selected three proposals per team.

(c)

Field research, in which five teams selected for their performance in the previous activities by identifying the number of users around the birthing bed, the equipment inside the room, times and movements, the movement hierarchy, and the birthing bed’s functions. Participants generated three proposals per team after taking this information into account.

This process allowed us to analyze the proposals based on the considerations of the product’s users and the inclusion of 13 criteria: safety, convenience, efficiency, attractiveness, shape, color, adaptability, ease of use, material suitability, comfort, consideration of needs, easiness to use, agreeability to use, and user feelings toward the inclusion of their particular needs during design.

2.2. Stage B: Hierarchy Design Process

Regarding the proposals obtained in Stage A, we produced new designs integrating the design process based on hierarchies, as shown in Figure 5. The objective of this stage was to modify the previously elaborated upon proposals based on the analysis of the various users who interact with the birthing bed. A total of 20 students participated in this stage.

At the beginning of this stage, an information session was held on the hierarchical approach. We followed the scheme depicted in Figure 5 and explained the importance of correctly identifying the number and type of users involved around the stretcher during the delivery process. With this information, they analyzed 32 birthing videos collected through the online YouTube platform. The videos were selected based on their duration and type of shot. The information they had to obtain from the videos was user type, number of users, the labor position of the woman on the birthing bed during the expulsion process, and the interactions between each of those factors [19].

Subsequently, they indicated several possible scenarios and analyzed each user’s tasks again, depending on the stage of labor and the patient’s health status.

2.3. Comparison of Acceptable Levels of the Proposals

This stage aimed to compare the level of acceptance of the models designed with a traditional design process and with the models designed with a design process based on user hierarchies, as shown in Figure 6.

The evaluation was conducted by 453 participants, corresponding to 11 user profiles: pregnant mother, father, obstetrician–gynecologist, nurse, maintenance staff, technical staff, anesthesiologist, pediatrician, newborn, midwife, and parents from a sample of 40 subjects per profile.

A survey was designed using a Likert scale to evaluate the best proposals from Stages A and B that considered the quality of the graphic representation of the ideas from the proposal justification. The survey was conducted online, evaluating the 13 design factors considered at the beginning of the process: safety, convenience, efficiency, attractiveness, shape, color, adaptability, ease of use, material suitability, comfort, consideration of needs, easiness to use, agreeability to use, and user feelings toward the inclusion of their particular needs during design.

The survey was given to eleven different user groups, comparing the proposals made in pairs. For the statistical analysis, the Friedman [38] test was used, which allowed a comparison of results. Friedman’s test is a quadratic statistic that helps in studies where the direction of deviations between treatments and alternative hypotheses is not known [39].

3. Results

3.1. Results Stage A

The results were 130 sketches, from which the teachers discarded all of the proposals that did not meet the requirements and those of low-quality idea representation in each step.

3.1.1. Step 1: Dynamics of Creativity

A total of 68 different characteristics were identified, in which only 22 were repeated at a percentage by 10% or more by the participants, as shown in Figure 7.

3.1.2. Step 2: Article Research

The repeated design characteristics were primarily identified according to the elements in the previous step. A study was conducted that resulted in 22 different aspects, 17 of which were present at a frequency greater than 10%. This can be seen in Figure 8.

3.1.3. Step 3: Field Research

From the information collected in the fieldwork and considering the characteristics obtained from step 2, 15 new proposals were designed, with the three best proposals from each team being chosen to be analyzed.

This time, the number of characteristics was 21, which were repeated in more than one concept, as represented in Figure 9.

With these three steps, Stage A of the study, which focused on designing under the traditional process, was complete; Figure 10 shows the final designs from this stage.

The number of characteristics identified was reduced to 20, of which 13 were repeated in more than one concept. Five different types of users were identified: pregnant mother, father, obstetrician–gynecologist, nurse, and anesthesiologist.

3.2. Results Stage B

Table 1. Examples of video analysis, task analysis, and user hierarchy.

Video Screen Shot and source	User	Hierarchy	Task Analysis
Video no. 25	Mother	2	Leaning almost sitting, feet supported
	Family	5	Accompaniment
	Specialist	1	Delivery, cleaning the baby
	Pediatrician	4	Delivery assistance, baby cleaning, mom cleaning
	Baby	3	Cleaning mother´s baby

represents all of the users classified according to who had the most significant interaction with the product.

Table 2. Users that appear in the videos during the delivery phase.

	Appearance in the Videos
Users	Percentage	Number of Videos
Specialist, Mother, Baby, Nurse, Family member	100	32
Pediatrician	68.8	22
Technician	31.3	10
2nd Family member	15.6	5
3nd Family member	28.1	9
2nd Nurse	6.2	2
4nd Family member	3.1	1
2nd Doctor	3.1	1
2nd Technician	188	6
3nd Nurse	9.4	3

represents the analysis of the videos that allowed us to identify these characteristics in each of them; the average number of users was between six and eight people depending on the activity. Additionally, the frequency with which users appear in the videos is shown according to their greater or lesser extent of their interaction with the birthing bed.

Figure 11 represent a top view of different the user positions observed in the videos. It shows the specialist at the bottom of the bed, the nurse assisting, and the specialist or family members on both sides of the birthing bed.

Figure 12 represents the positions that are used by mothers the most to have their babies. The most used ones were reviewed since it was found that a specific position allows nurses better access from the side of the bed, giving them more space to conduct their tasks.

3.2.1. Future Scenarios

The students were shown examples of possible scenarios where the patient could have a health problem during labor and how this could affect user fluctuation and interactions around the birthing bed [39].

Scenario design is one of the most used techniques in the activity known as prospective. This is a tool to reduce the level of uncertainty that affects decision making in the medium and long term [40].

The design of frameworks is a fundamental concept that is intended to guide the construction of a structure that leads us to the most optimal solution to a problem. The number of possible scenarios or frameworks that could be generated in each situation was explained to the students; this was exemplified with a permutation combinatorial calculation analysis, as is show in Figure 13 [39].

Once this information was shown to students, the following scheme, Figure 14, was designed to exemplify the possible movement of hierarchies depending on complications during delivery with a graphic to reinforce the learning of the subject based on the study of multiple frameworks [41].

Several possible scenarios were described to the students, and they were asked to perform an analysis of each user’s tasks, depending on the different possible patient complications.

With the data mentioned above, the participants were asked to design a new birthing bed. As a result, they developed 15 proposals, of which the teachers chose the best five, which are shown in Figure 15.

The design proposals were analyzed to identify the most frequently mentioned characteristics and all the users involved during the delivery who interacted with the birthing bed.

Figure 15 shows the results of the final designs of Stage B.

The features that were included in these models are shown in Figure 15.

3.2.2. Analysis

Figure 16 represents the results of twenty design characteristics that were identified by more than 10% of participants and the eleven different types of users: pregnant mother, father, obstetrician-gynecologist, nurse, cleaning staff, technical staff, anesthesiologist, pediatrician, neonate, midwife, and another relative.

The designs that were presented evolved satisfactorily, and the teams detected all of the users involved. They analyzed the needs of each one, increasing the complexity of the problem. The final proposals had design elements that were focused on the solution of these problems.

3.3. Stage C

Based on the survey results, an average of the score acquired in each category was calculated. The results are shown in

Table 3. Evaluation of the design proposals for the birthing beds in Stage A and Stage B.

Stage A		Stage B
Model	Mean	Model	Mean
A1	51.12	B1	51.51
A2	41.97	B2	55.79
A3	55.21	B3	54.48
A4	49.67	B4	50.99
A5	40.67	B5	56.45

and helped to determine which birthing bed obtained the best scores.

3.3.1. Analysis

The Friedman test was applied to check whether the differences found between the two design stages were statistically significant since those were ordinal data. The results indicate that the Stage B scores were higher. They are shown in

Table 4. Comparison between the characteristics of the designs of birthing beds (n = 453).

Characteristics	Stage A		Stage B		Friedman Test
	Mean	s. d.	Mean	s. d.
Safe	3.81	1.05	4.27	1.00	52.25 ***
Convenient	3.74	1.09	4.02	1.05	22.37 ***
Efficient	3.73	1.14	4.07	1.02	17.75 ***
Atractive shape	3.77	1.14	4.23	1.02	48.13 ***
Color	3.74	1.22	4.32	0.98	70.00 ***
Adaptable	3.78	1.14	4.17	0.99	23.22 ***
Technology easy to use	3.87	1.12	4.11	0.96	8.73 **
Suitable material	3.89	1.11	4.13	0.94	15.02 ***
Comfort	3.65	1.21	4.27	1.11	43.84 ***
Consideration of needs	3.77	1.26	4.1	0.98	34.59 ***
Easy to use	3.74	1.19	4.23	0.99	32.00 ***
I would agree to use it	3.68	1.23	4.09	1.1	33.53 ***
Consider my special needs	3.54	1.24	3.92	1.15	28.45 ***

** p < 0.01; *** p < 0.001.

.

In Stage C, the results of Stage A, which was based on the traditional design process, were compared with the results from Stage B, the hierarchy-based design process, which are shown in Figure 17.

3.3.2. Conclusion Stage C:

Figure 18 represents the conclusion of the comparison of the proposals from Stage A and Stage B and show how the Stage B designs had better user acceptance based on different factors.

4. Discussion

The research results reveal that the hierarchy-based design process effectively increases user acceptance more than the traditional design process; however, some factors should be considered for future projects. Among them, the survey presented to users with the final designs should also be presented during the proposal stage, with the rendering and color level of all designs being the same in order to give uniformity to all of the designs so that the user can more objectively choose the best design based solely on the design itself.

Stage B, the hierarchical design process, presented better results than traditional design; however, it is a longer process, but the increment of work/time represents an area of opportunity for the hierarchical design process.

It is essential to mention that Stage B follows Stage A, which could be a risk in terms of the experiment because some might argue that the results of the first stage could help improve the results of Stage B. This could be discussed further in the future with more experiments.

The experiment was developed with 40 Mexican students, of which the majority were women (88%). An information gap was detected with the male participants, showing an evident cultural issue when they were watching the birthing bed due to the graphic content of the videos since Mexican males are not familiar with this kind of content. For the majority, both women and men, it was their first time observing this type of procedure. This caused shock that could generate an area of opportunity for design, as it generated more empathy when designing their products.

Research articles do not decide who the users of medical devices are. Different authors analyze products with engineering models and the design process but still do not agree on the users, making it difficult for the designer to conduct the design process; some studies divide users into primary, secondary, and subgroups [42]. Some authors only indicate two groups: those who are health professionals and those who are not [43]. Others only identify two groups of users: women and men [31]. Others speak about the patient as the last consumer [4]. Once each medical product user has been detected, it is necessary to evaluate the hierarchy of those using the product—not only the hierarchy of use at the beginning but throughout the patient’s health process, since depending on the health stage, the movement of users around the object may constantly fluctuate, changing the hierarchy of use and, at the same time, demanding different functions and characteristics from the product for each user at each stage.

This indicates an information gap that requires further study. Suppose the designer of the medical device does not recognize all of the users. In that case, they would not be able to classify them, thus reducing the acceptability of the product, leading to a design process focused on the function alone, bringing t products with a high risk of poor usability to the market, which will undoubtedly result in the product being a commercial failure. More importantly, however, they could harm the patient or make incorrect diagnoses.

5. Conclusions

This study focuses on pointing out the importance of a new design processes for medical devices that can improve the characteristics of the product design and thereby increase user satisfaction. The main contribution of this new process focuses on showing medical device designers the importance of considering the hierarchy of users around a medical product and considering the fluctuation of the patient’s health status, since, depending on the progression of the disease, the patient needs the attention of various users. In turn, the final users need to solve specific problems in each phase, and a design needs to be prepared for each user’s particular needs around the birthing bed and the patient.

The results obtained here will help medical device designers and healthcare professionals understand the main trends in medical research and improve the design process. In addition, they will help increase the level of satisfaction among users of medical devices [44].

The final results showed a significant difference in the acceptance of the products of Stage B (design based on hierarchies) expressed by users. In the birthing bed design process, different aspects were considered during the development process. However, the users showed a significantly greater preference for the design that concentrated on the satisfaction of their individual needs, that is, the proposals from Stage B.

The students participating in the current study concluded that a hierarchy-based design process enables the designer to understand the user’s needs better and integrate them during the design process of a new birthing bed. It generates an increase in acceptance by the users, unlike the traditional design process.

As evidenced by this study, the consideration of the needs of the different stakeholders is fundamental for the design process of a medical device to capture the information that will determine the final characteristics of the design and the better integration of aesthetic factors: ergonomic, functional, and their correct correlation with the context.

The user-centered design process describes the phases throughout a design development lifecycle, all while focusing on gaining a deep understanding of who will use the product, how, and when, allowing for a better understanding of the design process and its control at any stage and as an interactive process, keeping researchers and designers aware of the real needs of all of the users who will interact with the final device.

A design process based on evidence [45] or theoretical and field research helps to develop products in the design process by increasing functionality and decision-making. A design process supported by user-centered design increases the value of user involvement [46] and their importance by considering multiple scenarios that could occur if the patient’s health deteriorates during the use of the object. The constant fluctuation of users during childbirth should be significant and indispensable information for medical device designers and must be considered during the design process. This information will help develop designs that significantly increase the acceptance of the object for final users.

Derived from this study, the five final designs from Stage B were sent to participate in the National Design Prize, México 2020, design contest, with the students who designed B5 achieving the honorable mention award and with designs B1, B2, and B4 being selected as finalists. Figure 19 represents the images of the chosen concept.

Two functional prototypes were donated to indigenous communities from the Lacandon jungle in Chiapas, Mexico, as shown in Figure 20. They sent it through the IXIM association to the “Casa Madre Tierra” association to be evaluated in the Tzeltal and the Tzotzil communities; the investigation is ongoing, and we are collecting information from midwives, intending to design a second prototype that is even more adapted to the needs of these communities. We aim to manufacture it at an industrial level and take it to more than 800 registered midwives in the Lacandon area and perhaps also to the border area between Mexico and the USA to support the problems relating to childbirth in migrant communities.

6. Patent

Currently the B5 design proposal is at the patenting stage and was the winner of the call for the “Jalisco Program for the Promotion of Intellectual Property” (PROPIN) 2021, issued by the State Council of Science and Technology of Jalisco (COECYTJAL) in collaboration with the Jalisco Science and Technology Innovation Secretariat (SICYT).

7. Ethical Considerations

The students were informed about their participation in the study, but they were unaware of the analysis conducted on their sketches so as not to modify the experiment. Likewise, users were informed about their voluntary participation in the study and how the results would be handled. At the end of the project, they were informed of the results.