Improved Suction Efficiency and User Satisfaction With a Novel Portable Manual Suction Device: A Simulation-Based Pre-Hospital Study

Abstract

Introduction

Effective airway suction is critical in prehospital care, yet many portable devices still provide limited suction performance and are poorly designed ergonomically. This study developed and evaluated a portable manual suction device intended to improve both operational performance and operator usability during simulated airway management.

Methods

In this simulation-based developmental study, all suction trials were conducted in a controlled laboratory setting using standardized simulated airway fluids and predefined environmental conditions. Suction performance was assessed using three standardized fluids. Performance outcomes included suction time, aspirated volume, and calculated efficiency. User satisfaction was measured using a validated scale ranging from 10 to 50 points. All analyses were performed using SPSS v24.0.

Results

The prototype suction device demonstrated significantly shorter suction times and greater aspirated volumes across all fluid types (all p < 0.001), with efficiency gains ranging from 20% to 35%. User satisfaction and ergonomic ratings were also significantly higher with the prototype device (p < 0.001).

Conclusion

The prototype suction device demonstrated superior mechanical performance and improved operator usability under simulated prehospital conditions. Its ergonomic design, integrated lighting, and disposable components collectively contributed to enhanced overall functionality. Further clinical studies are required to determine its impact in real-world prehospital settings.

Key Messages

What is Already Known on This Topic

Existing portable manual suction devices used in prehospital emergency care often have limited suction power, poor ergonomics, inadequate lighting, and hygiene problems due to reusable collection chambers, which can delay airway clearance and increase the risk of contamination.

What This Study Adds

This study provides the first systematic evaluation of a portable manual suction device incorporating ergonomic handles, integrated LED lighting, and disposable collection bags. The upgraded model demonstrated 20–35% improvements in suction performance and significantly higher user satisfaction.

How This Study Might Affect Research, Practice, or Policy

The findings highlight the need to redesign prehospital airway equipment. This upgraded device may enhance emergency airway management efficiency and safety and can inform EMS procurement policies and future development of portable suction technologies.

Introduction

Prehospital emergency care represents a critical point in modern healthcare, where timely interventions can determine both survival and long-term outcomes.^1,2 Emergency Medical Services (EMS) personnel frequently operate in unpredictable, high-pressure environments—ranging from accident sites and rural areas to mass-casualty or combat scenarios—where conventional hospital resources are unavailable.^3,4 In these contexts, airway management is one of the most urgent and technically demanding tasks, and failure to maintain a patent airway remains a major cause of preventable death. ⁵ Studies have shown that approximately 10% of preventable deaths are directly attributable to inadequate airway clearance, underscoring the need for effective and reliable prehospital suction devices.^6,7

At present, no standardized or evidence-based design framework guides the development of prehospital suction devices.^7-14 Existing studies primarily focus on suction pressure specifications or device comparisons, but they do not evaluate whether current devices adequately meet field requirements such as ergonomic usability, visibility in low-light environments, hygiene management, and functional reliability under environmental stressors.^6-19 This gap highlights the need for studies that integrate technical performance metrics and human-factors engineering within a single evaluation framework.^9-14

Manual suction devices, although conceptually simple, play an important role in emergency airway management by enabling the rapid removal of blood, vomitus, and other secretions.^8,9 However, existing portable devices often fall short in real-world use, as documented in recent evaluations of prehospital suction systems.^9-11,18

Moreover, poor lighting, cramped spaces, and environmental instability exacerbate the difficulty of airway clearance in the field.^20,21 This gap underscores the importance of evidence-based equipment design in prehospital airway management. Despite these challenges, no prior study was found to assess the combined effects of ergonomic redesign, an integrated LED, and disposable fluid management systems in prehospital suction devices, as confirmed by recent reviews on portable suction technologies.^12-14 Therefore, the literature still lacks a clear evaluation of how current suction devices fail to meet essential prehospital needs in terms of suction power, contamination control, and usability under field constraints, leaving a critical gap in both technical performance and real-world operational suitability.^{6-16,18,22-24}

A major unmet need is the absence of devices that explicitly incorporate human-factors principles—such as ergonomics, visibility, operator workload, and infection-control pathways—into the technical design of prehospital suction systems. The integration of design elements—such as ergonomic handles, larger or disposable collection chambers, and LED lighting—has been proposed to enhance usability and safety.^{10,17,18,25,26} Such improvements not only facilitate faster and more effective suction but also reduce operator fatigue and infection risk, particularly in low-resource settings where EMS Taken together, these technical and practical considerations underscore the need for innovative prehospital suction devices that simultaneously optimize suction performance, ergonomics, and hygiene, reflecting the real-world operational realities faced by EMS personnel.^27,28

A growing body of evidence supports the incorporation of ergonomic and hygiene-oriented features in prehospital suction devices. Ergonomic handles have been shown to reduce operator fatigue, improve grip stability, and enhance precision in high-stress, motion-limited environments such as roadside or mass-casualty settings.^10,18,25 Integrated LED lighting has been recommended in several airway management studies as it significantly improves visibility in low-light conditions, reduces procedural errors, and facilitates faster secretion identification during suctioning.^{3,10,12-14,21,25} Additionally, disposable collection bags are supported by current infection-control studies showing high contamination rates in reusable canisters.^22-24,29 Therefore, these three features were deliberately incorporated to address the operational, ergonomic, and safety limitations consistently reported in the EMS literature. Additionally, real pre-hospital environments often involve extreme temperature fluctuations and high or variable humidity, which can alter fluid viscosity, reduce mechanical efficiency in manual pumps, and affect visibility or condensation on optical components. These environmental stressors represent important operational factors that informed the need for a more robust, field-suitable suction design.^{3,4,6-15,18,20,21,26}

Given the clinical urgency of airway management, the environmental challenges of fieldwork, and the functional limitations of existing suction devices, this study aimed to design and evaluate a portable manual suction device suitable for real-world prehospital emergency conditions within an operational EMS setting. The prototype manual suction device incorporates ergonomic handles, integrated LED lighting, and disposable collection bags, providing a comprehensive response to the gaps identified in prior research and field observations.^{3,4,6-16,18,20,21,30,31} Notably, this appears to be the first study to evaluate the combined effects of these three design features on device performance and user satisfaction in prehospital emergency care. In this study, suction performance was operationally defined based on suction time, aspirated volume, and efficiency percentage to allow objective comparison. To support a transparent, bias-reduced evaluation, these suction performance metrics were defined as primary outcomes before data collection, and user satisfaction and usability measures were defined as secondary outcomes. Accordingly, this study directly addresses these gaps by combining technical enhancements (vacuum performance, flow optimization, integrated lighting, disposable fluid-contact components) with human-factors considerations (ergonomic handling, fatigue reduction, stability under gloved conditions), providing the first integrated evaluation of both domains within a prehospital suction device.

Methods

Study Design

This study was a two-phase, simulation-based developmental study, consisting of (1) device development and prototype refinement and (2) simulation-based performance evaluation in a controlled laboratory environment with emergency medical personnel, not in field or outdoor conditions. All environmental variables—including lighting, noise, temperature, and humidity—were intentionally standardized to minimize measurement variability. The design followed established prehospital equipment development frameworks^20,26 and was reported according to CONSORT guidelines. ¹¹ The diagram summarizes participant flow in Figure 1.

Figure 1.

Flow diagram of participant recruitment, eligibility assessment, random allocation, simulation testing, and inclusion in the final analysis

Phase 1: Device Development and Prototype Refinement

A needs assessment (Feb–Jul 2024) identified key limitations of existing portable suction devices—including inadequate suction power, poor ergonomics, non-disposable canisters, and insufficient lighting—which guided upgrades in ergonomic handles, integrated LED illumination, and disposable collection bags.^11,16,18

The term prototype device in this study refers to an experimental manual suction device developed during Phase 1 based on user-identified design requirements. The device is a research prototype created solely for performance evaluation in a simulation environment and is not a commercially marketed product. Although Curran et al (1991) is an older study, it remains one of the few foundational standardized suction-performance comparisons available; therefore, more recent benchmarks^9,11,18 were also incorporated to ensure contemporary relevance.

The LED system was engineered to meet prehospital airway visualization requirements. It provides 55–70 lumens (≈80–110 lux at 10–12 cm), operates at 0.9–1.1 W, and uses a rechargeable micro-cell delivering 90–110 minutes of continuous light. The neutral-white output (5000–5500 K) and 90° beam angle improve visibility of secretions and blood, while the <18 g assembly is vibration-resistant and low-heat, suitable for field conditions.

The upgraded prototype—with enhanced suction capacity, ergonomic handles, LED lighting, and disposable fluid-contact components—was developed using machined parts and PETG-based 3D printed structures.^17,26 Only non-fluid-contact elements were printed to avoid sterilization challenges. Benchmarking was conducted using manufacturer specifications and prior studies ¹⁰ (Table 1). Vacuum pressure was calibrated with analog gauges, and devices outside a ±5% tolerance were re-primed.

Table 1.

Comparison of Technical Specifications of Commercial Portable Suction Devices and the Upgraded Prototype

Device name	Type	Vacuum pressure (mmHg)	Flow rate (L/min)	Weight (kg)	Power source	Additional features	Notes/Clinical relevance
Laerdal V-Vac	Manual	-150 to -200	20–25	0.45	Manual (hand)	Adjustable stroke; rugged	Lightweight; no external power required
Res-Q-Vac (Curaplex)	Manual	-150 to -300	20–30	0.50	Manual	Disposable canister; pediatric adapter	Widely used in EMS; simple operation
SSCOR Quickdraw	Battery	Up to -550	50–60	1.6	Rechargeable battery	Compact high-flow suction	Strong flow for field trauma
SSCOR 2200 Portable Unit	AC/Battery	Up to -525	30–40	4.0	AC + battery	Variable control; hospital-grade suction	High performance but heavy
Medela Basic Suction Pump	AC/Battery	Up to -600	∼60	3.0	AC + battery	Continuous clinical suction	Not ideal for prehospital portability
WEINMANN ACCUVAC Pro	Battery	0 to -550	∼30	4.3	Rechargeable battery	Rugged casing; indicator LEDs	Reliable but heavy for EMS
Oxylitre PD1200	AC/DC	Up to -550	25–30	2.2	AC/DC	Ambulance-compatible	Mid-range performance
Upgraded Prototype (This Study)	Manual + mechanical assist	-250 to -320	32–35	0.68	Manual + assisted pump	Integrated LED; disposable bags; ergonomic handle	Balanced portability + improved hygiene

Note: Table 1 presents a general comparison of commercially available portable suction devices to provide market context. However, for the experimental comparison in this study, only one device—the Laerdal V-Vac—was used as the standard comparator against the upgraded prototype.

For clarity, the core technical specifications of the prototype are summarized as follows:

• • Suction pressure: –250 to –320 mmHg (calibrated with analog vacuum gauge)

• • Flow rate under load: 32–35 L/min (measured during 200 mL suction trials)

• • Internal mechanism: manual piston-based pump with assisted mechanical return spring

• • Reservoir capacity: 600 mL disposable collection bag

• • LED illumination: 55–70 lumens, 5000–5500 K, 90° beam angle

• • Battery: micro-cell rechargeable module providing 90–110 min continuous operation

• • Materials: PETG housing (non-fluid-contact), medical-grade tubing and disposable liners.

Device Cleaning Considerations

The device was designed to meet infection-control standards by separating fluid-contact and non-fluid-contact components. All fluid-contact parts (suction tubing and collection bags) are single-use disposables and are discarded as biohazardous waste. The handle and housing, which do not contact fluids, are cleaned using a standardized surface-disinfection protocol. These PETG and machined components are compatible with hospital-grade disinfectants, including 70% isopropyl alcohol and quaternary-ammonium wipes.^22-24,31 The exterior was intentionally designed with smooth contours to reduce bioburden retention and allow rapid, effective cleaning between missions.

Technical Specifications of Standard Devices

Specifications were cross-validated using recent market reviews of contemporary suction equipment, ¹¹ ensuring that comparisons reflected up-to-date performance ranges. In this study, only one commercially available manual suction device was designated as the standard device for direct comparison with the upgraded prototype. Among the devices listed in Table 1, the Laerdal V-Vac was selected as the standard comparator because (1) it is one of the most widely used manual suction devices in EMS systems, (2) its performance characteristics fall within the benchmark range reported in prior literature,^10,16,18 and (3) its lightweight, power-independent design makes it the closest functional match to the upgraded prototype. The remaining devices in table 1 are presented only to provide an overview of market specifications and were not used in the experimental comparison.

Simulation Model and Performance Testing

Simulations were conducted in a controlled laboratory setting. Three standardized fluids were used: dyed water (blood),^16,18 a 2% activated charcoal suspension (thin secretions),^10,16,19 and blended vegetable soup (thick secretions).^16,18 Viscosity targets were <10 cP, <50 cP, and 2500–3000 cP respectively, measured via a Brookfield DV2T viscometer at 22 ± 1 °C, with batches outside ±5% discarded. These targets are consistent with prior suction simulation research using water-based models for non-coagulated blood, charcoal suspensions for thin secretions, and blended food-based mixtures for vomitus and thick secretions.^10,16,18,19 The selected viscosity ranges reflect reported clinical viscosities for blood, mucus, and gastric contents, supporting the clinical relevance of the simulation fluids. Fluid order was randomized.^16,18 A computer-generated permutation sequence (3! = 6 possible fluid orders) was used, and participants were assigned randomly to one of these sequences.

Although dyed water does not replicate the non-Newtonian, shear-thinning and clotting properties of actual blood, it remains a standard choice in suction benchmarking because it provides consistent viscosity (<10 cP), reproducibility, and controlled device-to-device comparison. The intention was to model fresh, non-coagulated blood rather than clotted hemorrhage.

Environmental and Calibration Controls

All simulations were performed in controlled indoor conditions (350–450 lux; <40 dB). Measurement instruments were calibrated before testing, including a Class A cylinder (±1 mL), a digital stopwatch (±0.1 s), a vacuum gauge (±2%), and an electronic scale (0.1 g), with calibration checks repeated every 10 participants. Viscosity variability across batches remained <3%.^10,16,19

Although these controlled conditions reduced measurement variability, real pre-hospital environments may involve temperature and humidity extremes that affect device performance. Elevated temperatures can lower fluid viscosity and increase flow rates, whereas low temperatures may stiffen tubing, reduce hand-pump efficiency, or slow fluid transit. These factors were intentionally held constant to enable standardized prototype assessment.

Operational Definition of Suction Performance

Performance outcomes included (1) suction time to aspirate 200 mL, (2) aspirated volume within predefined time windows, and (3) efficiency improvement percentage. Importantly, the “golden time” thresholds used in Table 4 were not predefined performance criteria and were not used for primary between-device comparison. These times were derived post-hoc from the mean suction times observed to create a standardized, fixed time window for evaluating how much fluid each device could evacuate under identical time constraints. The primary comparative analysis between the upgraded and standard devices relied solely on direct suction-time measurements (Table 3), which avoids bias in favor of either device.

Table 4.

Comparison of Suctioned Volume of Three Types of Fluids

Fluid type	Prototype manual suction device (mL)	Standard device (mL)	P-value*	Golden time (sec)	Effect size (r)
Blood simulator (pure water)	198.7 ± 5.4	160.3 ± 15.2	Z=14.21, p<0.001	8	0.92
Thick secretion simulator (vegetable soup)	192.4 ± 7.3	142.5 ± 18.7	Z=16.85, p<0.001	12	0.90
Thin secretion simulator (activated charcoal solution)	199.2 ± 4.8	170.8 ± 12.9	Z=13.94, p<0.001	9	0.94

*Mann–Whitney U test.

Table 3.

Comparison of Time Required to Suction 200 mL of Fluid

Fluid type	Prototype manual suction device (sec)	95% CI (upgraded)	Standard device (sec)	95% CI (standard)	P-value*	Effect size (r)
Blood simulator (pure water)	8.3 ± 3.5	7.51–9.09	10.6 ± 5.8	9.29–11.91	Z=17.62, p<0.001	0.91
Thick secretion simulator (vegetable soup)	12.9 ± 4.2	11.95–13.85	15.4 ± 6.7	13.88–16.92	Z=18.37, p<0.001	0.89
Thin secretion simulator (activated charcoal solution)	9.5 ± 3.1	8.80–10.20	11.8 ± 4.9	10.69–12.91	Z=16.08, p<0.001	0.93

*Mann–Whitney U test.

Phase 2: Simulation-Based Performance Evaluation

Participants and Eligibility

The target population included prehospital emergency personnel with airway management experience. ¹⁰ Participants represented a range of professional roles commonly found in the Iranian EMS system, including EMTs (emergency medical technicians), emergency technicians (kardan level), bachelor-level paramedics, master-level providers, and a small number of personnel categorized as ‘other.’ These role categories were collected and reported to capture potential differences in training backgrounds that could influence suction performance or user satisfaction. Eligibility required ≥1 year of EMS experience and consent to participate in the study. Exclusion criteria included a lack of prior airway management experience or use of manual suction devices as reported by the personnel participating in the present study, previous involvement in prototype development, and inability to complete the simulation.

Sampling and Sample Size

Convenience sampling was used because EMS personnel operate under variable and unpredictable shift schedules, making probabilistic sampling infeasible within the time frame of prototype evaluation. This approach is commonly used in prehospital simulation studies, where access to on-duty staff is restricted. Nevertheless, to mitigate potential bias, the sampling frame included all eligible EMS staff across multiple stations, and random allocation was used after recruitment to preserve internal validity.

Sample size estimation was based on suction performance, defined as the time required to aspirate 200 mL of simulated fluid. Previous evaluations reported mean suction times of 10–18 s with standard deviations of 4.5–6.2 s for similar volumes.^10,16,19 These data supported selecting a moderate expected effect size (Cohen’s d = 0.50). Using α = 0.05 and power = 0.80, the calculated minimum sample size for two independent groups was 128 participants. To account for possible dropouts or incomplete simulations, a final planned enrollment of 150 participants (75 per group) was determined. Effect-size estimates from earlier comparisons of standard and upgraded devices (d = 0.45–0.60;^10,16,19) further supported the selection of d = 0.50.

Group Allocation and Study Procedure

Participants were randomized via computer-generated randomization sequence was prepared by an independent researcher, and allocation concealment was implemented using sequentially numbered, opaque, sealed envelopes. These envelopes were opened only after participant enrollment, ensuring that investigators responsible for recruitment were unaware of the upcoming assignment. A parallel-group design avoided learning effects.^10,16 Fluid order was randomized to prevent sequencing bias. All participants received standardized 15-minute orientation on device operation before testing. For performance testing, participants in the standard-device arm used the Laerdal V-Vac (listed in Table 1), which served as the single reference device for baseline comparison. No other devices from Table 1 were included in the experimental phase; the table provides market context only. The upgraded device used in the intervention arm was the prototype described in Phase 1.

Blinding

A single-blind design was used. Devices were covered with unlabeled sleeves to mask appearance. Participants were unaware of device classification during satisfaction assessment. Outcome assessors (timing, volume measurement, data entry) were blinded. Satisfaction questionnaires were completed individually immediately post-simulation.

To minimize recognition of device type during satisfaction evaluation, both devices were inserted into identical opaque sleeves that fully covered the handle, exterior casing, and LED module. The LED feature of the prototype was disabled during satisfaction rating to prevent visual identification, and participants handled the devices only during the suction procedure, not during the evaluation period. Participants were instructed that the study compared ‘two operational configurations’ without specifying which was new. These steps reduced perceptual and novelty bias.

User Satisfaction and Ergonomic Evaluation

User satisfaction was assessed using a 10-item questionnaire adapted from the validated USE (Usefulness, Satisfaction, and Ease of Use) Questionnaire (Lund, 2001),^10,18 based on a 5-point Likert scale (total score 10–50) evaluating grip ease, LED usefulness, and disposable bag convenience. Content validity was confirmed by three emergency medicine experts, and a pilot test with 20 EMS personnel demonstrated good internal consistency (Cronbach’s α = 0.86) and strong 7-day test–retest reliability (r = 0.91). These validity and reliability figures originate from our own pilot work, not prior publications. Three items measured ergonomics specifically (grip comfort, stability with gloved/wet hands, fatigue reduction).^10,18,25 The complete instrument is provided in Supplementary File S2.

A composite Usability–Ergonomics Index (UEI) was calculated from the three ergonomics items (range 3–15), with normalization to a 0–100 scale for easier interpretation. Between-device comparisons used the Mann–Whitney U test, consistent with the non-parametric analysis approach.

To minimize novelty bias, participants were not informed of which device was the prototype, LED illumination was disabled during satisfaction scoring, and both devices were placed inside opaque sleeves to reduce visual recognition. While full blinding is difficult in device trials, these steps substantially reduced recognition bias.

Primary and Secondary Outcome Measures

Prior to data collection, the study outcomes were prospectively defined to minimize selective reporting bias and to ensure transparent interpretation. The primary outcome was overall suction performance, operationalized through three objective metrics: (1) time required to suction 200 mL of fluid, (2) aspirated volume within predefined time thresholds, and (3) calculated suction efficiency percentage. Secondary outcomes included user satisfaction scores based on the validated 10-item questionnaire, and device usability indicators related to ergonomics, LED illumination utility, and ease of handling under simulated prehospital conditions. These predefined outcomes guided data collection procedures, statistical analysis, and reporting of results.

Statistical Analysis

All analyses were performed using SPSS v24.0. Continuous variables are reported as mean ± SD with 95% CIs, and categorical variables as frequencies and percentages. Normality of suction time and aspirated volume was assessed using the Shapiro–Wilk test and Q–Q plots, which indicated non-normal distributions; therefore, non-parametric tests were used. Comparisons between the standard and prototype devices were conducted using the Mann–Whitney U test, and Chi-square tests were applied for categorical variables after verifying assumptions.

Effect size r was calculated for each Mann–Whitney U test using the standard formula r = Z/√N, where Z is the standardized test statistic and N the total sample size. This non-parametric effect size reflects the magnitude of the association between device type and performance and is recommended for two-group non-parametric comparisons.

No multiple-comparison correction was applied because suction time, aspirated volume, and efficiency represent related components of a single performance construct. Independence of observations was ensured through random participant assignment and by analyzing each mean performance across repeated trials.

A predefined sensitivity analysis evaluated whether EMS experience (<10 vs. ≥10 years) modified performance outcomes. Subgroup comparisons used the same non-parametric methods, and interaction patterns were examined descriptively to assess whether experience influenced the magnitude or direction of device-related differences.

Results

As shown in Table 2, most participants were aged 32–40 years (42%), with a mean age of 32.43 years (range: 24–47). The majority had less than 10 years of work experience (65.3%), with a mean experience of 9.93 years. Most participants were based in urban stations (74.7%) and held a bachelor’s degree (77.3%). No significant differences were observed between the upgraded and standard device groups in age, work experience, workplace location, or professional role (p = 0.858), indicating strong baseline comparability. The distribution of professional roles—including paramedic/EMT, technician, bachelor-level paramedic, and master-level personnel—was similar across groups. Sensitivity and subgroup analyses showed no experience-related variability.

Table 2.

Demographic Characteristics of Participants (N=150)

Variable	Prototype manual suction device (N=75)	Standard device (N=75)	P-value*
Age (years)	24–32: 18 (24%)	24–32: 17 (22%)	0.893
	32–40: 30 (40%)	32–40: 32 (42%)
	>40: 27 (36%)	>40: 26 (34%)
Work experience (years)	<10: 48 (64%)	<10: 50 (66%)	0.795
	10–20: 10 (13%)	10–20: 11 (14%)
	20–30: 13 (17%)	20–30: 11 (14%)
	>30: 4 (5%)	>30: 3 (4%)
Workplace	Urban: 62 (82.67%)	Urban: 65 (86.67%)	0.752
	Roadside: 13 (17.33%)	Roadside: 15 (13.33%)
Education level	Paramedic: 1 (1%)	Paramedic: 3 (4%)	0.858
	Technician: 9 (12%)	Technician: 11 (14%)
	Bachelor: 59 (78%)	Bachelor: 57 (76%)
	Master: 4 (5%)	Master: 3 (4%)
	Others: 2 (2%)	Others: 1 (1%)
Professional Role	Paramedic: 1 (1%)	Paramedic: 3 (4%)	0.858
	Technician: 9 (12%)	Technician: 11 (14%)
	Bachelor: 59 (78%)	Bachelor: 57 (76%)
	Master: 4 (5%)	Master: 3 (4%)
	Others: 2 (2%)	Others: 1 (1%)

*Chi-square test.

In both experience subgroups (<10 vs. ≥10 years), the prototype manual suction device consistently demonstrated significantly shorter suction times and higher aspirated volumes across all fluid types (all p < 0.001). No interaction between device type and operator experience was observed, confirming that performance improvements were independent of user experience. (Table 2).

Figure 2 illustrates the upgraded manual suction device, highlighting the integrated LED illumination system and disposable collection bag. These design enhancements were developed to improve visibility during airway management in low-light pre-hospital environments and to reduce contamination risk through single-use collection components. The LED module provides 80–110 lux of neutral-white illumination at the typical working distance, enhancing visibility during suctioning under low-light prehospital conditions. (Figure 2).

Figure 2.

Overview of the upgraded portable manual suction device only, with labeled structural and functional components: A: LED battery compartment; B: Ergonomic handle; C: Disposable collection bag; D: LED illumination lamp; E: Side view of the prototype manual suction device; F: Front view of the prototype manual suction device

To obtain the results presented in Table 3, suction time measurements for each type of fluid were repeated three times per device under identical experimental conditions. Confidence intervals (95% CI) were also calculated for all suction time measurements. A volume of 200 mL was considered for each test. For statistical analysis, the mean of the three repeated measurements was used as a single observation for each device and fluid type, in order to reduce random error and improve reliability. Given the non-normal distribution of the data, comparisons between devices were performed using the Mann–Whitney U test, and effect sizes were calculated using r.

The results indicate that the prototype manual suction device not only suctioned a larger volume of fluid but also accomplished this task in a significantly shorter time. Specifically, the prototype manual suction device suctioned 200 mL of all tested fluids in a significantly shorter time compared to the standard device (p < 0.001), with very large effect sizes (r = 0.89–0.93), demonstrating a substantial and clinically meaningful improvement in suction efficiency (Table 3).

For Table 4, the suction tests were similarly repeated three times per fluid type and per device, and the mean suctioned volume was used for statistical comparison. The suction duration for each fluid was set according to the results in Table 3. To avoid bias, golden times were not used as a basis for between-device comparison. Instead, after completing the primary suction-time analysis (Table 3), these times were repurposed only as fixed time windows to examine the volume each device could evacuate under identical temporal constraints.

The results indicate that the prototype manual suction device performed better for all three fluid types, nearly evacuating the entire 200 mL standard volume within the defined golden times. In contrast, the standard device showed significantly lower suctioned volumes, particularly for thick secretions, suctioning approximately 25–30% less than the prototype manual suction device. These differences were statistically significant (p < 0.001) and associated with very large effect sizes (r = 0.90–0.94), underscoring the superior functional performance of the prototype manual suction device under time-critical conditions (Table 4).

As shown in Table 5, overall user satisfaction was significantly higher for the prototype manual suction device than for the standard device (45.53 ± 4.53 vs. 17.94 ± 2.11; p < 0.001; r = 0.88). Item-level satisfaction scores with corresponding effect sizes are presented in Supplementary Table S1. Across the three ergonomics-related items, most participants reported meaningful improvements with the upgraded design: 84% rated the handle ergonomics as “good” or “excellent,” 81% noted better device stability during rapid suction and 78% reported reduced hand or forearm fatigue. These findings align with the markedly higher overall satisfaction scores for the prototype manual suction device (Table 5), indicating a consistent positive ergonomic effect.

Table 5.

Comparison of Total User Satisfaction Scores and Usability–Ergonomics Index (UEI) Between the Standard and Upgraded Portable Manual Suction Devices (Mean ± SD)

Variable	Device	Mean ± SD	P-value*	Effect size (r)
User Satisfaction Scores	Prototype manual suction device	45.53 ± 4.53	p<0.001	0.88
	Standard Device	17.94 ± 2.11
Usability–Ergonomics Index (UEI)	Prototype manual suction device	13.4 ± 1.2	p<0.001	0.82
	Standard Device	6.1 ± 1.5

*Mann–Whitney U test (overall score).

To quantify these perceptions, the Usability–Ergonomics Index (UEI) was calculated from the three ergonomics items. The prototype manual suction device demonstrated a significantly higher UEI score compared with the standard device (p < 0.001), indicating better handling, more stable grip, and reduced operator fatigue. Normalizing the UEI to a 0–100 scale further emphasized the substantial improvement in usability associated with the prototype device.

Discussion

Airway management is a critical component of prehospital care, where rapid and reliable suctioning directly impacts patient outcomes. ⁷ Manual suction devices, although widely used, commonly demonstrate performance limitations as shown in modern evaluations.^6,9,18 Our results indicate that a design informed by EMS feedback can enhance device effectiveness and user satisfaction. Despite relying on self-reported ratings, internal consistency and test–retest reliability supported the stability of responses.

Suction performance—assessed by suction time, aspirated volume, and efficiency—improved across all measured domains. Simulated fluids reflected typical airway contaminants (non-coagulated blood, mucus, vomitus) consistent with validated models in previous research. However, dyed water does not replicate the shear-thinning, non-Newtonian behavior or clot-forming properties of real blood, which may influence flow resistance and suction dynamics. Consequently, blood-related findings represent performance in non-coagulated fluid only and may not fully model partially clotted hemorrhage.^16,19

Standardized calibration supported internal validity, and prospectively defined outcomes minimized selective-reporting bias. Because the ‘golden times’ used in Table 4 were derived from observed mean suction times rather than predefined targets, they were not used as comparative endpoints. Instead, they served only as standardized time windows to explore relative evacuation capacity. The primary comparison between devices was based exclusively on direct suction-time measurements (Table 3), which minimizes bias and ensures an objective performance assessment. Furthermore, because simulation-based testing reduces operator variability and environmental disturbances, the resulting comparisons may amplify statistical effect sizes relative to real-world field conditions.

Baseline comparability was further supported by the similar distribution of professional roles (EMT, technician, bachelor-level paramedic, master-level providers) across the two study groups, reducing the likelihood that training background or role-related skill differences influenced performance or satisfaction outcomes.

Compared with previously reported portable suction devices, the upgraded prototype performed favorably. Earlier evaluations of manual suction systems reported flow rates typically ranging from 20 to 30 L/min and vacuum pressures around −150 to −300 mmHg for commonly used EMS devices such as the V Vac and Res Q Vac.^16,18 In contrast, the upgraded prototype demonstrated a flow rate of approximately 32–35 L/min and vacuum pressure of −250 to −320 mmHg, placing it among the highest-performing manual suction devices while maintaining lightweight portability. Similar device characterization studies have shown that higher flow rates are associated with shorter airway clearance times in simulated contamination models.^10,19

In addition to these performance parallels, it is important to critically consider where our findings diverge from previous studies. Unlike earlier evaluations conducted under field-replicated or dynamic contamination conditions,^16,18,19 our simulation environment minimized movement, ambient noise, and lighting variability. These contextual differences likely contributed to narrower confidence intervals and may partly explain why the prototype showed larger performance contrasts than those reported in field-based studies. Moreover, several prior investigations emphasized the operational trade-offs of manual suction devices—particularly fatigue, reduced stability with wet gloves, and visibility limitations in dark scenes.^9,10,25 The substantial ergonomic and illumination improvements observed in our prototype align with these documented shortcomings, yet the magnitude of improvement should be interpreted in light of the study’s controlled conditions.

Although the effect sizes observed in this study (r = 0.89–0.94) are uncommon in medical device evaluations, several factors may explain their magnitude. First, the prototype demonstrated higher baseline mechanical performance—particularly vacuum pressure and flow rate—which is known to correlate strongly with reduced suction times in simulation models. Second, the controlled laboratory environment minimized external variability, thereby increasing statistical contrast between devices. Third, previous studies on portable suction systems reported similarly large performance gaps when comparing optimized or upgraded suction mechanisms with conventional manual units.^10,16,18,19 Therefore, while the effect sizes reflect true mechanical differences, their magnitude is partly influenced by reduced environmental variability and the limited variance of standardized simulations.

The suction times observed in this study (8.3–12.9 s for 200 mL depending on viscosity) are also comparable to or faster than values reported in previous simulation studies of portable emergency suction devices, where evacuation of similar fluid volumes typically required 10–18 seconds depending on device type and viscosity conditions.^16,19 These comparisons suggest that the improved suction efficiency observed in the present study is consistent with the mechanical specifications of the prototype and aligns with previously documented performance ranges for optimized suction systems.

Beyond these performance considerations, several methodological characteristics warrant critical reflection. First, the controlled laboratory environment—while necessary for standardized comparison—does not replicate the dynamic, unpredictable, and often chaotic conditions found in actual prehospital practice. Second, although the study included a diverse EMS workforce, each participant tested only a single device configuration, which may limit insight into intra-individual performance variability. Third, the use of simplified, viscosity-calibrated fluids enhances reproducibility but cannot fully model the heterogeneous rheological behavior of real airway contaminants. These factors collectively suggest that the observed performance gaps, while robust, may differ in magnitude under real-world operational conditions.

Environmental conditions such as temperature and humidity may influence real-world suction performance by affecting fluid viscosity, tubing flexibility, LED clarity, or grip friction. Because this study was conducted in a controlled environment, these factors were not assessed and should be explored in future evaluations.

The prototype manual suction device reduced suction times and increased aspirated volumes across all simulated fluids, which is highly relevant for time-critical prehospital care.^16,19 However, because no patient-centered outcomes—such as oxygenation, aspiration prevention, or complication rates—were measured, the improvements should be interpreted as enhanced mechanical performance rather than as proven clinical benefit.

More rapid suctioning may facilitate earlier initiation of airway interventions.^3,5 Although causal effects cannot be inferred from this non-experimental study, the findings align with prior evidence indicating that device design substantially influences prehospital suction effectiveness.^8,18 Subgroup analyses showed consistent superiority of the prototype manual suction device across experience levels, supporting the robustness of the results.

Integration of LED illumination improved visibility in constrained or low-light contexts,^2,30 aligning with evidence that lighting enhances procedural accuracy and reduces complications.^10,25 Disposable collection bags reduced contamination risk,^22-24,29 consistent with reports that reusable canisters often carry microbial pathogens. However, the current study did not measure microbial contamination or bioburden reduction; therefore, infection-control interpretations are based on prior literature rather than direct microbiological testing.

3D-printed structural components were intentionally limited to non-fluid-contact surfaces to avoid sterilization challenges. PETG showed compatibility with routine surface disinfection, though future large-scale manufacturing will require injection-molded medical-grade polymers for durability and regulatory compliance.

Maintaining the reusable housing is crucial for infection control. Simplified geometry helped reduce cleaning time, and future industrial versions may support automated reprocessing methods (e.g., ISO 17664-compliant protocols).

The expanded technical comparison (Table 1) places the prototype manual suction device among high-performing manual suction units such as the V-Vac, Res-Q-Vac, and Curaplex, while offering advantages in illumination and disposability. These features position the device between lightweight manual pumps and bulkier powered devices. Additional comparisons suggest performance approaching that of some powered systems while retaining manual simplicity, addressing known trade-offs in EMS suction technology. ¹⁸

Ergonomic enhancements—including weight reduction and optimized handle geometry—reduced operator fatigue and improved maneuverability. A composite Usability–Ergonomics Index supported these findings. Human-factors research underscores the importance of ergonomics in high-stress EMS environments.^11,29 Further analysis showed that improved comfort and grip stability contributed to faster performance, consistent with prior studies.^10,18,25

These improvements align with global priorities for evidence-based EMS device innovation^4,27,32 and address key prehospital challenges in low- and middle-income settings.^28,31 The ergonomic, illumination, and hygiene features collectively support both operational efficiency and user safety.

The prototype’s design rationale is supported by previous evidence indicating that ergonomic optimization, illumination, and improved hygiene pathways enhance airway management.^{3,10,12-14,21-25} Converging results across performance, satisfaction, and safety domains highlight the relevance of these design choices in prehospital settings. Overall, the findings illustrate that thoughtful, user-informed refinements to manual suction devices can meaningfully improve prehospital airway management.^1,33 The results reinforce the value of integrating ergonomics, illumination, and disposability into medical device design.

The study’s methodological framework—combining iterative prototyping, human-factors testing, and standardized fluid simulations—offers a useful model for next-generation medical technologies, with relevance to drug delivery, bio sensing, and handheld diagnostics.^34-36 The contaminant simulation protocols may also inform testing of environmental monitoring and pollutant-capture systems, particularly in demanding field conditions. From an engineering perspective, the design and evaluation pipeline provides insights applicable to compact robotics, portable mechanical systems, and human–machine interfaces.^37-42

Although simulation enables controlled comparison, real prehospital environments involve additional complexities such as patient movement, environmental instability, and high-stress decision-making; therefore, real-world validation is required. Therefore, until clinical studies are conducted, the implications of the observed performance gains for patient safety and clinical outcomes should be interpreted cautiously.

Finally, manufacturing scalability and cost considerations remain unassessed. The early-stage prototype uses machined parts and PETG 3D-printed components; industrial production will require injection-molded polymers and cost-effectiveness evaluation. The LED module and disposable bags add recurring costs that should be evaluated for resource-limited EMS systems.

Limitations

This study has several limitations. Although primary outcomes were predefined to reduce selective reporting bias, the protocol was not preregistered; future preregistration is recommended to improve methodological transparency. The subgroup analysis by experience level showed consistent patterns, but the study was not powered for interaction testing, indicating the need for larger stratified samples. Environmental factors—including temperature, humidity, and outdoor exposure—were kept constant, although these conditions may influence device performance, fluid behavior, grip ergonomics, and LED visibility in real prehospital settings; field-based evaluation remains necessary.^10,16,19 Additionally, the use of convenience sampling may have introduced selection bias, as participation depended on staff availability rather than probabilistic recruitment. Although demographic comparability between groups and random allocation helped reduce this risk, future studies will require representative sampling across broader EMS populations.

This study did not isolate the individual contributions of specific design features, such as LED illumination, ergonomic handle geometry, or the disposable collection system. As a result, the observed performance advantage cannot be attributed to any single component, and the findings should be interpreted as the combined effect of the integrated prototype rather than of individual elements.

Another limitation arises from the use of dyed water as the blood simulant. Although widely used for benchmarking suction performance, dyed water does not replicate the viscosity profile, shear-thinning behavior, or clotting properties of real blood. As a result, the study may underestimate the challenges associated with suctioning partially clotted or highly viscous blood. Future studies should incorporate advanced blood analogs or animal-model fluids to better represent real airway contamination.

The cross-sectional, simulation-based design limits causal inference and does not fully represent real prehospital conditions such as environmental hazards, variable lighting, constrained spaces, and time pressure. Moreover, because no clinical airway cases were included, the findings reflect device behavior in simulation only and cannot be used to infer real-world clinical effectiveness. Additionally, although the disposable collection system was designed to reduce contamination risk, microbial contamination, surface bioburden, or pathogen reduction were not assessed in this study, and infection-control implications should be interpreted cautiously until validated through microbiological testing.

Thus, performance improvements should be generalized cautiously. Although simulation is appropriate for early-stage prototype assessment, further validation through high-fidelity simulations, ambulance-based testing, and prospective clinical studies is required.

Convenience sampling may have introduced selection bias, and although the satisfaction questionnaire underwent pilot testing and expert review, broader psychometric validation is still needed. Because each participant tested only one device, inter-individual variability in subjective ratings cannot be excluded, though randomization and demographic balance helped mitigate this concern.

No patient-centered clinical outcomes (e.g., hypoxia, aspiration, complication rates, mortality) were assessed; therefore, observed improvements should be interpreted as technical and operational rather than proven clinical benefit. Prospective clinical studies are required to determine whether enhanced suction performance translates into measurable patient outcomes. Long-term durability and repeated sterilization of 3D-printed components were not evaluated, and neither manufacturing scalability nor cost analysis was performed; future work should address these elements to support real-world implementation.

Conclusions

This simulation-based developmental study shows that a portable manual suction device can substantially improve suction efficiency and user satisfaction. Design features—including ergonomic handles, integrated LED illumination, and disposable collection systems—address key shortcomings of traditional devices and offer a transferable framework for advancing related medical and engineering technologies. Future research should include prospective clinical evaluations measuring patient-centered outcomes (e.g., airway safety, complication rates, oxygenation status) to determine whether performance gains translate into clinical benefit in real prehospital environments. Simulation-based evaluation remains an essential first step in device development, enabling controlled assessment prior to clinical trials.

Although this study demonstrates meaningful improvements in suction efficiency and user satisfaction, these findings are based solely on controlled simulation data. As such, they reflect mechanical and operational performance under standardized laboratory conditions rather than proven clinical benefit. Confirmation of practical advantages—such as reductions in airway obstruction, aspiration risk, or hypoxia—will require high-fidelity simulation, field-based EMS testing, and prospective clinical evaluations in real prehospital environments.

ORCID iD

Mohammad Sadegh Aboutalebi https://orcid.org/0000-0002-6301-4755

Ethical Considerations

This study was approved by the Ethics Committee of Isfahan University of Medical Sciences (Ethics code: IR.MUI.NUREMA.REC.1403.100; approval date: 2024/09/07) and was conducted as part of an approved academic thesis (Thesis code: 3403337). Available online at: ethics.research.ac.ir/ProposalCertificateEn.php?id=495304&Print=true&NoPrintHeader=true&NoPrintFooter=true&NoPrintPageBorder=true&LetterPrint=true.

Consent to Participate

Written informed consent was obtained from all participants prior to their participation in the study.

Data Availability Statement

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.*