Portable suction device

Abstract

One embodiment of a portable suction device as described herein is called a suction combat ready advanced multifunctional machine (SCRAMM). A SCRAMM is a portable suction device designed and developed to be used as both in-field hospital suction device and combat ready suction device. The device can be used in a horizontal or vertical position, i.e., the device is position independent.

Description

PORTABLE SUCTION DEVICEPRIORITY PARAGRAPH

[0001] This application is an international application claiming priority to U.S. Provisional Patent Application 63 / 657,646 filed June 07, 2024, which is incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY FUNDED RESEARCH

[0002] None.BACKGROUND

[0003] Airway injuries, which may result from blunt force and penetrating injuries to the neck and chest, can be life threatening conditions, particularly on a battlefield. The presence of concomitant severe injuries and non-specific symptoms and signs for this type of injury may delay diagnosis and lead to early fatal outcome due to asphyxiation from airway obstruction or death from tension pneumothorax, or late sequela such as airway stenosis and recurrent pulmonary infections.

[0004] Airway management is essential in trauma care and has been designated as a top priority in the “Guidelines for Medical Personnel” by the Committee on Tactical Combat Casualty Care (CoTCCC) (J. Spec. Oper. Med, 2017). Airway obstruction and compromise is the second leading cause of preventable battlefield death, which can be attributed to the unavailability of sufficiently powerful portable suction systems, among other factors (Lairet et al., Journal of Trauma and Acute Care Surgery, 2012, 73(2):S38-S42; Bedolla et al., Journal of special operations medicine, 2023:B4KU-GB0V; Burgess et al., Prehospital and disaster medicine, 2022, 37(6):723-726; Raczek et al., Medical Journal, US Army Medical Center of Excellence (MEDCoE), 2021). Therefore, prompt diagnosis is mandatory for the survival of these patients. However, treatment of these patients is similarly challenging, it includes securing a patient airway that will allow adequate ventilation and then repairing the injury with a smaller impact on the respiratory function and the quality of life of the patient. Recent analyses demonstrate that airway management life-saving interventions are overlooked over 50% of thetime on the battlefield(Lairet et al., Journal of Trauma and Acute Care Surgery 2012, 73(2):S38-S42; Bedolla et al., Journal of special operations medicine, 2023:B4KU-GB0V; Berard et al., Medical Journal, US Army Medical Center of Excellence (MEDCoE), 2021; US Patent App. 17 / 769,181; Copeland et al., Military medicine, 2022, 187(7-8):e862-e876). Having the right equipment is key to solving this problem.

[0005] During airway management, suctioning appears as a life-saving intervention implemented for rapidly and effectively clearing obstructions using a suction device, potentially followed by the placement of an airway securement device if necessary (Berard et al., Medical Journal, US Army Medical Center of Excellence (MEDCoE), 2021; Defense, U.D.o. Tactical, Casualty Care Guidelines, 2024; US Patent App. 17 / 286,404). Suction is integral to at least three of the ten core essential medical capabilities around which PFC is built: Ventilate and Oxygenate, Airway Management, and Ongoing Nursing Procedures (April et al., The Medical journal (Fort Sam Houston, Tex), 2023 (Per 23-1 / 2 / 3): 18-27; De Lorenzo et al., Texas University Medical School at San Antonio: San Antonio, TX, USA, 2017).

[0006] In situations where suction devices are either deficient (when lacking sufficient power) to clear airway obstructions or simply unavailable, the patient may suffer from a failure of an airway which can lead to critical hypoxia and aspiration pneumonia. Most advanced airway techniques that require placing a tube in the trachea, can be difficult or impossible to accomplish without suction. Even cricothyrotomy, often touted as an alternative, requires suctioning since it is a surgical procedure (Berard et al., Medical Journal, US Army Medical Center of Excellence (MEDCoE), 2021; Berard et al., Journal of the Mechanical Behavior of Biomedical Materials,2021, 114: 104211; Johnson et al., Prehospital and Disaster Medicine, 2022, 37(3):390-396).

[0007] In view of suction requirements for unimodal combat indications portable suction devices are emerging as essential instruments in combat medic’s airway management kits owing to their capability to rapidly clear airway obstructions such as blood, vomit, and tooth fragments from penetrating trauma, as well as mud, dirt, and gravel from environmental contamination, among other life-threatening obstructions (Johnson et al., Prehospital and Disaster Medicine,2022, 37(3):390-396; Vandenberg and Vinson, The American Journal of Emergency Medicine, 1999, 17(6):611-613; Jain et al., Prehospital and Disaster Medicine, 2020, 35(6):676-682). Suction devices, beyond their primary role, are instrumental in a range of other essential medicalprocedures that underscore their versatility and importance in patient care, being widely used in oral / nasal tracheal suction for intubated patients, surgical suction, gastrointestinal abdominal drainage, wound drainage, pleural mediastinal drainage, nasal gastric drainage, subglottic secretion removal, among other medical procedures (Raczek et al., Medical Journal, US Army Medical Center of Excellence (MEDCoE), 2021; De Lorenzo et al., Texas University Medical School at San Antonio: San Antonio, TX, USA, 2017).

[0008] Field hospitals, ground and air evacuation vehicles, and individual combat medics are expected to be equipped with suction devices. However, despite their life-saving capabilities, a significant number of combat medics and civilian first responders opt not to carry them, often due to their considerable weight and cumbersome nature (Army, U., Tactical Combat Casualty Care: Lessons and Best Practices. 2012: Ravenio Books; De Lorenzo and Porter, Tactical emergency care: Military and operational out-of-hospital medicine, Vol. 10. 1999: Prentice Hall; Schauer et al., Journal of Special Operations Medicine, 2020, 20(l):61-64). This issue is compounded by the fact that lighter, manually operated alternatives often fail to deliver the required suction power, leaving medics hesitant to include them in their kits as well (Schauer et al., Journal of Special Operations Medicine, 2020, 20(l):61-64). Market analysis and interviews have underscored the urgent need for suction devices that strike a balance between portability and effectiveness because the products available on the market are too heavy and / or provide insufficient suction.

[0009] Besides initial airway management, suction devices may be needed in other instances as well, such as for tracheal suction for intubated patients, gastric suctioning for patients with nasogastric or orogastric tubes, or build-up of fluids in the pleural cavities of the chest. Notably, the 2023 Department of Defense (DoD) Combat Casualty Care (CCC) Capability Gap document identifies developing new tools and devices for maintaining the airway as one of the key areas needing additional research and development. The following paragraphs describe multimodal indications for suction beyond oropharyngeal suctioning for the airway.

[0010] There are several injury types described by Vandenberg and Vinson where oropharyngeal suction is inadequate) / / re American Journal of Emergency Medicine, 1999, 17(6):611-613). These can range from airway obstruction to burn injuries. Airway obstruction occurs when build-up of bodily fluids (vomit, blood, saliva, bile, etc.) and debris (broken teeth,fracture bones, etc.) accumulate at the oropharynx and / or nasopharynx, blocking airway passages and preventing ventilation. Hodgetts et al. describes suction’s use for burn injuries, which can cause swelling of airways due to inflammation from bums or inhalation of a large amount of smoke or gas (Hodgetts et al., JR Army Med Corps, 2006, 152(4)).

[0011] In terms of field procedures to staunch external hemorrhage, it is occasionally necessary to evacuate blood from an actively bleeding wound via suction to visualize the precise source of hemorrhage. Noncompressible truncal hemorrhage (NCTH) and junctional bleeding represent as much as 2 / 3 of potentially preventable battlefield deaths (Eastridge et al., Journal of Trauma and Acute Care Surgery, 2012, 73(6): S431-S437; Van Oostendorp et al., Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, 2016, 24: 1 -13).

[0012] Intraoperative suction in mobile or field surgical units generally involves conventional suction provided by luggable battery powered or, in the case of field hospitals, cartmounted electrically-powered portable suction machines (Davey, Ward's Anaesthetic Equipment E-Book, 2012:421; U.S.AMM., Vol. UA 2267, 2007). Forward surgical units perform damage control surgery ranging from laparotomy for control of trauma induced internal bleeding and enteric spillage to rapid amputation of mangled limbs and fasciotomy (Department of the Army, Editor. 2020:Washington, D.C.).

[0013] Suction finds critical application in preoperative care or following major or minor surgeries including pleural or mediastinal drainage for placement of thoracostomy (chest tubes) for pneumothorax or pericardiocentesis, sump drainage placed in surgical wounds, wound vacuum assisted closure (VAC) to cover large orthopedic and soft tissue defects, and gastric and other forms of enteral suctioning.Pleural and mediastinal drainage requires very low pressures and so normally an additional pressure-limiting device is added in series. Examples include disposable 3-bottle water system (i.e., Pleur-evac,® Teleflex, Inc., Wayne, PA) or a dry suction control system (Lamb, B., et al., The Principles of Vacuum And Clinical Application in the Hospital Environment (ISO) .

[0014] A number of portable suction devices available in the market are either manually powered and less efficient, or battery powered and bulky / heavy for combat medics to carry in their kits. Examples of portable suction devices include the Laerdal Compact Suction Unit® 4 (LCSU® 4) by Laerdal Medical; the SSCOR Quickdraw® by SSCOR, Inc.; and the ClarioAirway Suction Pump by Medela AG. The LCSU® 4 includes a collection canister supported by a wire bracket. The collection canister can come in a 300 mL size or an 800 mL size container when extra suction volume is needed. The LCSU® 4 weighs between 3.3 to 4.3 pounds depending on the collection canister size and provides between 50 mmHg to 550 mmHg vacuum pressure for about 45 minutes when powered by batteries. The collection canister must also be correctly oriented to fit into the wire bracket. An air flow rate of 30 L / min can be obtained with the device. The overall dimensions of the LCSU® 4 are 18.5 cm x 26.2 cm x 8.12 cm with a 300 mL canister and 23.6 cm x 19 cm x 23.6 cm with an 800 mL canister. The SSCOR Quickdraw® Tactical requires 10 AAA sized batteries to power the device for 60 to 100 minutes. A maximum negative pressure of > 500 mmHg and a low negative pressure setting of 80 mmHg to 100 mmHg can be achieved with the device. The drainable collection canister can hold a maximum of 300 mL. The collection canister must also be correctly oriented. The SSCOR Quickdraw® Tactical weighs 2.6 pounds and has overall dimensions of 27 cm x 11 cm x 11 cm. The Clario Airway Suction Pump by Medela AG is intended for home health use and can operate for about 50 minutes when powered using the rechargeable battery. A low vacuum setting of 135 mmHg, a medium vacuum setting of 270 mmHg, and a maximum vacuum setting of 600 mmHg can be achieved with the device. The collection canister can hold a maximum of 550 mL and must also be correctly oriented during operation. A fluid flow rate of 15 L / min can be obtained with the device. The Clario Airway Suction Pump weighs about 2.0 kilograms and has overall dimensions of 22.3 cm x 25.5 cm x 9.5 cm.

[0015] Market assessments and surveys conducted by the inventors have demonstrated that combat medics require a lightweight, compact, efficient, and reliable portable suction alternative for the battlefield because combat medics are required to carry everything on their backs. Similarly, civilian EMS providers need a lightweight, reliable, and effective means of clearing debris such as saliva and vomitus from the airway of critical patients. Thus, portability, effectiveness, and ruggedness are key attributes for an airway suction device. Currently, such a device does not exist. Current designs are over twenty years old and fall short on many aspects because they were developed using poor / outdated technology. The designs are typically heavy, bulky, provide inadequate suction, and have a short battery life. This results in unnecessary patient suffering and can lead to death from suffocation due to inadequate aspiration of debris or the inability to gain control of the patient’s airway in a timely manner.

[0016] In view of the foregoing, it is apparent that there exists a need for a device and method to clear airways of patients that overcomes, mitigates, or solves the above problems in the art.SUMMARY

[0017] Solutions to various problems with portable suction devices are provided with the improvements to such devices described herein.

[0018] One embodiment is directed to a portable suction device comprising (i) a vacuum device having an internal flow loop; (ii) at least two suction lines (2, 3, 4, or more suction lines) operably coupled to the vacuum device body, a first high power suction line configured to provide suction at 0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, to 550 mmHg, and a second and optionally a third low power suction line configured to provide suction at 0, 25, 50, 75, 100, 125, to 150 mmHg; (iii) a vacuum cannister, (iv) a user interface operably coupled to the vacuum device body, wherein the internal flow loop is configured to independently regulate suction pressure of the three suction lines. In certain aspects the first high power suction line has an internal diameter of 4.5 to 5.5 mm. In certain aspects the second and / or third low power suction line has an internal diameter of 3.5 to 4.5 mm. The first high power suction line, the second low power suction line, and the third low power suction line are coupled to the vacuum cannister and / or the vacuum device by adapters. In certain embodiments the internal flow loop comprises an exhaust valve configured to dynamically manage air release for real time pressure regulation, a pump, a pressure sensor, a manifold, and a pressure outlet. The device can further include a light-weight battery.

[0019] Other embodiments of the invention are discussed throughout this application. Any embodiment discussed with respect to one aspect of the invention applies to other aspects of the invention as well and vice versa. Each embodiment described herein is understood to be embodiments of the invention that are applicable to all aspects of the invention. It is contemplated that any embodiment discussed herein can be implemented with respect to any method or composition of the invention, and vice versa. Furthermore, compositions and kits of the invention can be used to achieve methods of the invention.

[0020] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and / or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

[0021] Throughout this application, the term “about” is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value.

[0022] The use of the term “or” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.”

[0023] As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0024] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains”, “containing,” “characterized by” or any other variation thereof, are intended to encompass a non-exclusive inclusion, subject to any limitation explicitly indicated otherwise, of the recited components. For example, a chemical composition and / or method that “comprises” a list of elements (e.g., components or features or steps) is not necessarily limited to only those elements (or components or features or steps), but may include other elements (or components or features or steps) not expressly listed or inherent to the chemical composition and / or method.

[0025] As used herein, the transitional phrases “consists of’ and “consisting of’ exclude any element, step, or component not specified. For example, “consists of’ or “consisting of’ used in a claim would limit the claim to the components, materials or steps specifically recited in the claim except for impurities ordinarily associated therewith (i.e., impurities within a given component). When the phrase “consists of’ or “consisting of’ appears in a clause of the body of a claim, rather than immediately following the preamble, the phrase “consists of’ or “consisting of’ limits only the elements (or components or steps) set forth in that clause; other elements (or components) are not excluded from the claim as a whole.

[0026] As used herein, the transitional phrases “consists essentially of’ and “consisting essentially of’ are used to define a composition and / or method that includes materials, steps, features, components, or elements, in addition to those literally disclosed, provided that these additional materials, steps, features, components, or elements do not materially affect the basic and novel characteristic(s) of the claimed invention. The term “consisting essentially of’ occupies a middle ground between “comprising” and “consisting of’.

[0027] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.DESCRIPTION OF THE DRAWINGS

[0028] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of the specification embodiments presented herein.

[0029] FIG. 1A illustrates a back perspective view of one example of a portable suction device that is in a horizontal position.

[0030] FIG. IB illustrates a front perspective view of one example of a portable suction device that is in a horizontal position.

[0031] FIG. 1C illustrates a front view of one example of a portable suction device that is in a vertical position with one example of dimensions for a particular non-limiting embodiment.

[0032] FIG. ID illustrates a side view of one example of a portable suction device that is in a vertical position showing an optional handle and / or rack attachment.

[0033] FIG. IE illustrates a side view of one example of a portable suction device that is in a vertical position listing various elements of a non-limiting embodiment.

[0034] FIG. IF illustrates a back view of one example of a portable suction device that is in a vertical position listing various elements of a non-limiting embodiment.

[0035] FIG. 1 G illustrates a top view of one example of a portable suction device that is in a vertical position listing various elements of a non-limiting embodiment.

[0036] FIG. 1H illustrates a back perspective view of one example of a portable suction device that is in a vertical position listing various elements of a non-limiting embodiment.

[0037] FIG. II illustrates a front perspective view of one example of a portable suction device that is in a vertical position listing various elements of a non-limiting embodiment.

[0038] FIG. 2 illustrates an exploded view of one example of a portable suction device that is in a vertical position listing various elements of a non-limiting embodiment.

[0039] FIG. 3A-3D Testing orientation of the suction devices.

[0040] FIG. 4A-4B Noise test setup to evaluate the maximum noise level emitted by the three suction devices under different line configurations.

[0041] FIG. 5 Setup for the 1 -meter drop test evaluating SCRAMM’s durability and compliance with ISO 10079-1 standards.

[0042] FIG. 6 Structural rib design to improve impact resistance.

[0043] FIG. 7A-7C Results of the liquid flow rate tests for each solution. A-C: results of flow rate tests for the SCRAMM High- Suction line compared to Zoll 330 and Impact Ultra-lite 326M, across three different liquid simulants: (A) water, (B) blood analog, and (C) vomit simulant. Error bars represent 95% confidence interval, and asterisks represent statistical significance (* p < 0.05).

[0044] FIG. 8 SCRAMM Low-suction lines flow rate characterization.

[0045] FIG. 9 Orientation independency water flow rate test results.

[0046] FIG. 10 Time taken to reach maximum vacuum pressure.

[0047] FIG. 11 Noise levels of different suction devices.

[0048] FIG. 12 Obstruction resistance test results across the three suction devices.

[0049] FIG. 13 SCRAMM’s water flow rate performance pre and post Im drop test.

[0050] FIG. 14 System Useability Scale (SUS) analysis.

[0051] FIG. 15 Proposed performance-to-weight standard for suction devices, comparing the SCRAMM, Zoll 330, and Impact 326M. Color dots represent mean liquid flow rates for viscous solutions, with error bars indicating 95% confidence intervals. The green shaded region denotes the proposed optimal standard, where devices meet both user-preferred weight limits and the required industry flow rate of 1.2 L / min for viscous solutions. The blue region highlights devices that, while lighter, fail to meet the required industry flow rate. The dotted lines intersecting at the ’X’ symbol represent the maximum weight allowed by the end users (vertical) and the minimum flow rate allowed for end users (horizontal), while the dashed lines intersecting at the * symbol represent the maximum weight allowed by industry standards (vertical) and the minimum suction of viscous solutions allowed by industry standards (horizontal).DESCRIPTION

[0052] The following discussion is directed to various embodiments of the invention. The term “invention” is not intended to refer to any particular embodiment or otherwise limit the scope of the disclosure. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be an example of that embodiment and not intended to imply that the scope of the disclosure, including the claims, is limited to that embodiment.

[0053] Airway compromise accounts for over 10% of preventable combat deaths , and airway management is a top priority for military medical personnel. Portable suction devices are essential for clearing lethal obstructions such as blood, vomit, and debris. The Suction Combat Ready Advanced Multifunctional Machine (SCRAMM) directly addresses this critical need, effectively closing the gap in current portable suction technology for both military and civilian emergency care.

[0054] The SCRAMM features three independent suction lines, allowing it to cater to various medical needs, from airway clearance to surgical procedures. This development was driven by a user-centered design philosophy, incorporating direct feedback from field users,including combat medics. Design iterations produced a prototype that exceeds field standards and is 1.5 kg lighter than existing models, boosting portability without losing functionality. Testing confirmed SCRAMM meets all performance criteria - flow rate, vacuum pressure, noise levels, and operational consistency - compared to Zoll 330 and Impact 326M. Adhering to ISO 10079-1 guidelines, end-user feedback highlighted its practical design and effective multifunctional suction lines.

[0055] Results indicate that SCRAMM is technically feasible for broad application in both military and civilian emergency care settings. The design and testing phases have substantiated capability to improve operational outcomes in prehospital care, ensuring that SCRAMM can be effectively integrated into the existing medical response framework. Table 1 summarizes important features of one example of the SCRAMM device.Table 1: SCRAMM's achieved values based on design requirements and ISO 10079-1 standards in comparison to the market leaders Zoll 330 and Impact 326M.

[0056] SCRAMM sets a new standard in emergency medical equipment, specially engineered to fulfill the requirements of both military and civilian medical environments. SCRAMM offers several innovative features: (1) It is the first device to provide three independent suction lines operating simultaneously, accommodating diverse medical needs during multiple casualty situations or in busy field hospitals. This capability is supported by an advanced control system that allows for immediate activation of high-power suction or adjustments for less intensive needs, ensuring versatility across various medical scenarios. (2) SCRAMM introduces practical enhancements such as differentiated tubing diameters to minimize operational errors and a versatile canister connection that accommodates vertical and horizontal setups, adapting to different emergency environments. (3) The design incorporates a high-efficiency electrical system with extended battery life, which is fundamental for areaswithout reliable power sources. (4) Developed with direct input from combat medics and emergency personnel, SCRAMM not only meets but exceeds user needs with its functionality and operational flexibility. (5) SCRAMM achieves a significant weight reduction compared to current models, enhancing its portability and ease of use in demanding situations. Its lightweight, durable design and intuitive interface substantially improve the standards of portable suction devices, positioning SCRAMM as an essential tool for advancing patient care in prehospital and combat environments.

[0057] One embodiment of a portable suction device is a portable suction device designed and developed to be used as both in-field hospital suction device and combat ready suction device. The device can be used in a horizontal or vertical position, i.e., the device is position independent. FIG. 1A and IB show a front and back perspective view (respectively) of an embodiment of the device with the body 100 in a horizonal position. Referring to FIG. 1A to FIG. II The device having body 100 and cannister 101 that can be coupled by suction tubing 102 via adapters 103. Body 100 can include user interface 107, control panel 108, and various adapters 109. Cannister 101 has a cannister lid 101a and a cannister body 101b. The body 100 can include a handle 110 and / or a SMEAD rack attachment. Strap attachments 105 can be present on body 100. The cannister 101 can be detachable and attachable either parallel to the long axis of the body (body is in a vertical position such as FIG. 1C and FIG. ID) or perpendicular to the long axis of the body (body is in a horizonal position such as FIG. 1A and FIG. IB). Cannister 101 can be secured by straps, clips, or other such methods to the body 100 and positioned in one of two cannister nooks 104a or 104b for receiving the cannister body 101b. FIG. IH-and FIG. II enumerates several elements of the device and an example of the assembly of these elements into a body, cannister, and connecting tubing. The figure shows the cannister resting on a cannister holder or recess. The cannister being secured to body by holding rings or straps 106. The cannister lid being connected to the pressure lines by suction line or tubing. The face of the body having a user interface and regulator functions such as pressure modifiers, continuous and intermittent suction controllers, as well as general controls. The body can include a handle and various strap attachments.

[0058] FIG. 2 shows an exploded view of one example of the device showing various internal components of the device. Body case 100 can include tube adaptors 223 to connect suction tubing to pressure pumps 221 or 222 housed in body 100. In certain instance body 100can house at least one high pressure pump 222 and at least one and preferably two low pressure pumps 221. Various controllers and circuit boards 220 can be housed in body 100 and operably coupled to interfaces, switches controllers 108 and pumps 221 or 222 of the device. Battery 225 can be housed within body 100 and held in place by a battery enclosure 226. The body can have intake 227 that allows air to move through the pumps. The intake can have a filter 224 that removes microbes such as viruses from being expelled or inhaled by the device while in operation.

[0059] A Triple Suction Lines embodiment can have 3 suction lines which can be used to perform suction simultaneously. This is highly useful in crowded field hospitals, on one or more patients with multiple traumas that require different suction procedures, or during air evac of multiple casualties. The primary line provides high powered suction of 0 mmHg up to 550 mmHg, which is useful for rapid airway clearance, Oropharyngeal airway management, surgical suction and other indications requiring high performance. Two secondary lines that provide lower powered suction of 0 mmHg up to 150 mmHg, which are useful for many other indications where high-powered suction can damage tissue, such as infant and adult oral-nasal tracheal suction, dental suction, gastrointestinal abdominal drainage, nasal - gastric drainage, Wangensteen (duodenal) drainage, pleural or mediastinal drainage, suctioning wounds, and chest tube suctioning.

[0060] Fail Safe Suction Tubing. The suction lines, also referred to as vacuum lines, connecting to the cannister have a reduced diameter (5.5 mm internal diameter for high suction line and 4.5 mm for low suction lines) compared to the standard tubing (8 to 9 mm ID) in the market. This design ensures users can easily distinguish between the vacuum line and the patient line and it eliminates the possibility of the user being able to attach a commercially available suction tip directly to the suction device without passing through the canister. Additionally, the suction line tubes are equipped with various adapters to accommodate commercially available canisters.

[0061] Simultaneous Triple Pump Regulation. An internal flow loop can dynamically regulate suction pressure from three pumps (1 high-pressure, and 2 low-pressure) independently in real-time.

[0062] Novel Internal Flow Loop. The flow loop system optimizes vacuum pressure at the outlet through a sophisticated internal loop. It consists of an exhaust valve, pump, pressure sensor, manifold, and a pressure outlet. The exhaust valve, a key component, dynamically manages air release, ensuring real-time pressure regulation. Operating at its maximum capacity, the pump generates the necessary pressure, monitored by the pressure sensor for instant feedback. Users can input their desired pressure using the potentiometer and knob. The microcontroller, governed by a dedicated code, orchestrates the exhaust valve's maneuvering to meet the user-defined pressure setting. Facilitating seamless integration, the manifold connects the pump, exhaust valve, pressure sensor, and pressure outlet.

[0063] The exhaust valve controls air release, regulating vacuum pressure. A Pump operates at maximum capacity to generate pressure. A pressure sensor measures pump-generated pressure for real-time feedback. A potentiometer and knob allows user input for desired pressure setting, microcontroller and code governs exhaust valve maneuvering based on user-defined pressure. Manifold integrates pump, exhaust valve, pressure sensor and pressure outlet for efficient flow.

[0064] Versatile On-Board Electrical System. The on-board electrical system features a PCB Board, screen, switches, and knobs that collectively form the user interface. The suction functionality can be operated in either intermittent or continuous mode. The control system ensures precise feedback through a graphical user interface, preventing overheating and battery overload. Users can exercise control over alarms, pause operations, and adjust screen brightness.

[0065] The onboard electrical system has two modes, Basic and Advanced. Basic mode is a default mode. When first turned on, the SCRAMM starts in Basic Mode. This opens the high suction line at full power (vacuum pressure of 550 mmHg) immediately on activation, speeding intervention when a critical need is occurring such as an obstructed airway. The system will be performing continuous suction. The other two low suction lines remain off. Continuous and intermittent Mode is enabled by a toggle switch to activate either of these modes. Each suction line has its continuous and intermittent options, providing flexibility to operate all three lines simultaneously or a single line for standalone functions. Advanced mode is accessed through fine-tuning control of the primary line or activating the secondary lines. This allows specific control of the suction pressure. An alternative concept for an advanced mode includes incorporating preset modes for specific applications:

[0066] Mode 1 : “OP” suction line 1 with continuous vacuum pressure of 500 mmHg for surgical suction.

[0067] Mode 2: “Trach” suction line 1 with continuous vacuum pressure of 100 mmHg for nasal, and infant oral-nasal tracheal suction.

[0068] Mode 3: “GI” suction line 1 with intermittent vacuum pressure of 100 mmHg for gastrointestinal suction.

[0069] Mode 4: “Vac” suction line 1 with intermittent vacuum pressure of 95 mmHg for wound suction.

[0070] Mode 5: “CT” suction line 1 with continuous vacuum pressure of 15 mmHg for chest suction.

[0071] Light Weight Battery. The novelty lies in using a commercially available light weight battery to power the SCRAMM without compromising the power output. Despite utilizing a commercially available lightweight battery, SCRAMM stands out by delivering an equivalent power output as existing devices that often rely on bulkier power sources. The onboard electrical system has the capacity to monitor and display remaining battery life and battery charge, providing alerts for low battery, system errors, and critical conditions such as overheating of battery. A thermostat is connected to battery which helps in monitoring the temperature of battery. The battery can be recharged using either AC 110V or DC 12V power source. Moreover, SCRAMM has exceptional adaptability, as it can not only be recharged when connected to AC 110V or DC 12V but can also operate seamlessly with either power source. This emphasizes their remarkable capability to function effortlessly with both AC and DC, providing users with unparalleled flexibility.

[0072] Physical Specification. The device can be fabricated by 3D printing or machining the components. The SCRAMM device can withstand a drop of Im with 3D printed material and will be stronger and more robust if machined using composite material, Delrin, or Aluminum.

[0073] Adaptable Canister Connection. SCRAMM comes with the unique capability to accommodate canisters in both vertical and horizontal orientations. Users have the flexibility to attach the canister horizontally when operating the device in a horizontal position, or vertically when the device is in a vertical position. This versatile feature enhances usability andadaptability, making it a valuable tool for a wide range of applications. Currently SCRAMM is the only device with this capability.I. Examples

[0001] The following examples as well as the figures are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples or figures represent techniques discovered by the inventors to function well in the practice of the invention and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

[0074] Experiments are aimed at the following technical objectives. 1. Design: Finalize requirements based on input from Air Force customers and end-users and complete the SCRAMM prototype design. This involves a collaborative process to ensure the device meets practical field requirements effectively. 2. Build: Construct and validate SCRAMM prototype through benchtop testing. This stage transitions design into physical prototype, assessing their performance to refine and confirm adherence to design specifications. 3. Preliminary Usability Testing: Facilitate hands-on evaluations by Air Force customers and end-users against leading market devices, ensuring SCRAMM prototype meets user satisfaction comprehensively.A. Methods

[0075] The methodology outlined a structured approach to achieve SCRAMM’s three Technical Objectives: Design, Build, and Preliminary Usability Testing, as illustrated in FIG. 3. This process began with initial end-user interviews and market analysis, progressed through design iterations fed by end-user feedback throughout the process, advanced into prototyping, and culminated in preliminary end-user validation.

[0076] The first of these objectives focuses on the design phase. This initial stage is vital for integrating direct feedback from users, which in turn influences successive iterations and enhancements aligned with the specific requirements of military and civilian medical personnel.

[0077] Technical Objective #1 -Design: The SCRAMM user-centered design methodology was shaped to facilitate a cyclical development process, incorporating relevant user feedback and iterative design modifications. This process was implemented to ensure alignment with the needs identified by military and civilian medical personnel.

[0078] End-user Interviews, Market Analysis, and Product Specifications: Initially, the team conducted a series of surveys and interviews through the NSF I-CORPS program to establish priorities in portable suction characteristics relevant to prehospital care. Interviews were conducted (102 in total) with AirForce customers and end-users, including combat medics, emergency medicine doctors, US Special Forces, paramedics, emergency medical technicians, supply chain personnel, manufacturing representatives, U.S. Food and Drug Administration (FDA) consultants, and police officers in Texas and the Washington D.C. area. Additionally, market leaders such as Zoll 330 Multifunction Aspirator and the Impact 326M were studied and compared. Based on the feedback collected and the market analysis, user requirements were listed as shown in Table 2, leading to the definition and categorization of product specifications and design requirements. These categories encompassed physical, performance, and functional specifications, as shown in Table 3. Moreover, the typical clinical specifications based on the suctions procedures and the vacuum level required are listed in Table 4. This Table 4 was developed as a guiding tool to assist in defining performance specifications.Table 2: User RequirementsUser Requirement DescriptionPortability Device should be portable, as both a compact design and low carry weightEfficiency Device should provide fast and effective suctionOperational Flexibility Device should provide suction in any orientationVolume Capacity Device should evacuate a volume of at least1 LObstruction Management Device should overcome large particulate obstructionPower Source Versatility Device should be battery and wall operated Infection Control Device should not transmit any kind of virus from patient to userSterilization Compatibility Device should be sterilizableTable 3: Product Specifications and Design Requirements Categorized Between Physical, Performance, and Functional Specifications.PHYSICAL SPECIFICATIONSSpecifications Design RequirementsOverall Dimensions without Canister (Length < 21 x 32 x 12 cm (8 x 12.5 x 4.5 in) x Width x Height)Volume < 450in3 Overall Weight without Batteries Device Weighty 4.5kg (lOlbs.) Canister Capacity > 1000 mlPERFORMANCE SPECIFICATIONSSpecifications Design RequirementLiquid Flow Rate > IL / min Orientation Independency Canister design to be orientation independentVacuum Pressure at Suction Tip Range: 10 - 550 mmHg Device Operation Time Minimum operational time of 8.5 hours under maximum load; targets 2 hours continuous operation with an additional 6 hours as a safety factor based on end-user feedback and competitor analysisDevice Operation Type Battery-operated with a voltage range of 12 - 24 VDCPower grid operation with a voltage range of 120 - 240 VACOperational Temperature Range Device shall operate within the temperature specification mentioned in military standards for medical devices (0 - 60 °C)Device Robustness Drop Test: Device must withstand a drop from1 m onto a hard surface (e.g., concrete)Vibration Test: Device must withstand vibration at a frequency of 1000 Hz for 20 minutes Maximum Noise Level for Overall Device < 69 dBSuction Tube Length 1 m Suction Tube Diameter Inner Diameter (ID) 12 mmViscosity Device must perform suction of liquids with viscosities up to 25 cPFUNCTIONAL SPECIFICATIONSSpecifications Design RequirementIndicator for suction Indicator light activates when suction is operationalViral filtration to protect caregivers Device must incorporate hydrophobic viral fdters to prevent aerosolized pathogen spreadSterilizability Device components shall be disposable and capable of being sterilizedLow battery indication Battery life shall be monitored via an external displayVariable pressures available at need Graphical user interface shall allow access to different suction pressures and operationalmodes as required (e.g., intermittent suction)Multiple Suction Capability Device must independently provide suction through 2 or more hoses at variable pressuresTable 4: Typical Clinical Specifications for Each Suction Procedure.

[0079] Device Design: Once user feedback was gathered and formulated into detailed design requirements, the design phase for the SCRAMM device began, marking the transition from conceptualization to detailed design development. The design of the novel suction device SCRAMM was based on a user-centered design methodology. Each version was 3D modeled in SOLIDWORKS® (Dassault Systemes), ensuring detailed CAD, precision in design and engineering. Following the design phase, the models were rendered in KeyShot® (Luxion ApS), providing high-quality visual representations key for reviewing aesthetic and functional aspects. This enabled the team to integrate feedback effectively at every stage, refining the device through nine major versions based on significant modifications influenced by user preferences, such as moving away from conventional shapes toward a book-style form factor.

[0080] Electrical Design: Incorporating feedback from US AirForce end-users and engineering team insights, the control unit’s system requirements were detailed, as outlined inTable 5. Developed concurrently with design iterations, this table serves as the foundation for describing the electrical features.Table 5: Control Unit System RequirementsRequirement DescriptionSuction pressure regulation Must regulate the suction pressure of the three pumps simultaneously: high-suction line 1 (0 - 550 mmHg), low-suction lines 2 & 3 (0 - 150 mmHg)Real-time pressure adjustment Must allow adjusting the pressure value for the three pumps in real timeOperational modes Must support basic mode (high-suction line 1 at 550 mmHg and both low-suction lines 2 & 3 at 0 mmHg) and advanced mode (control of all the pressures in the three lines and control between continuous and intermittent mode for all the lines separately)Battery life monitoring Must monitor battery life and display remaining battery life on the screenAlarm system Must include alarm system for error, malfunction, and maintenance notifications Overheating prevention Must prevent the system for overheating above the battery capacity (>60 C)Alarm muting Must silence all alarms when loud / silent button is pressed Pause / Resume functionality Must pause the operation of the system (in any mode) when the pause / resume button is pressed. Screen Brightness adjustment Must change the screen brightness when the light / dark button is pressed Green LED indicators Must turn on / off indicating LEDs for line operational status (on / off)Yellow LED indicator Must turn on / off indicating LED for the charging status Electromagnetic interference Requires minimal electromagnetic interference with other medical equipment and electronic systems

[0081] After synthesizing the intellectual insights garnered from end-user feedback and refining the electrical requirements, the design team proceeded to select the case material.

[0082] Case Material Selection: The material selection for the SCRAMM enclosure was determined by evaluating the durability of various Formlabs resins against a 1 -meter drop test, as outlined in the ISO 10079-1 guidelines. The choice was limited to Formlabs resins due to the rapid prototyping capabilities of available 3D printing technology, the accessibility of a Formlabs 3D printer in the team’s laboratory, and the detailed mechanical properties listed on the supplier’s website. For the next development phase, a broader range of materials, including different composites, will be considered to enhance the prototype’s performance.

[0083] To conduct this test, enclosures replicating SCRAMM’s most critical geometric design were 3D printed using Formlabs Tough 2000 and Formlabs Durable resins, selected for their mechanical properties and suitability for impact-resistant enclosures. Each prototype had an internal mass of 740 g attached to mimic the weight of the device’s future internal components. The test protocol involved dropping each resin sample followed by visual inspections to evaluate visible damage and assess the structural integrity post-impact.

[0084] Graphical User Interface (GUI) Design: The device’s GUI was designed and prototyped using Figma (Figma, Inc.). Alarm signals were selected based on competitor analysis, end-user feedback, and compliance with ISO 10079-1 guidelines.

[0085] Technical Objective #2 - Build: Following the user-centered design methodology and based on the user requirements, the control system requirements, and the material selection from Technical Objective #1, the SCRAMM prototype was developed and verified via comprehensive benchtop testing. This phase involved building the prototype, assembling the parts, assessing the prototype’s performance against the design requirements, and comparing it with the top market competitors, the Zoll 330 and the Impact 326M.

[0086] Prototyping: The SCRAMM prototype consisted of a variety of materials and commercially available components. The parts manufactured in-house, were produced using stereolithography (SEA) 3D printing technology on a Formlabs Form 3L printer (Formlabs, Somerville, MA).

[0087] Testing: The testing protocols for SCRAMM, alongside Zoll 330 and Impact 326M and in adherence to the ISO 10079-1 guidelines. Each device was subjected to evaluation through a series of 10 distinct tests, each consisting of five individual trials (n=5). The number of trials was determined through a power analysis, guided by ISO 10079-1 norms, which allow for a 5% margin of error on a flow rate of 1.5 L / min. This analysis was conducted, assuming a 95% confidence level with a Z-value of 1.96, based on a previously established standard deviation of 0.08 L / min for pump testing. These tests included measuring the flow rate of water, blood analog, and vomit simulant, reflecting the devices’ performance in realistic medical scenarios, as well as flow rate tests in lateral, horizontal and inverted device orientations to simulate various operational conditions. Further measurements of vacuum pressure, noise level, particle lift capability and obstruction resistance contributed for verifying each device compliance with thespecified requirements. Specifically targeting SCRAMM’s durability, the device underwent a 1 - meter drop test, followed by a liquid flow rate test with water to identify any potential functional impairments resulting from the drop.

[0088] Liquid Flow Rate Test (water, blood analog, and vomit simulant): To assess the performance of suction devices used by US Military Forces, specifically, the Zoll 330 and the Impact 326M, in comparison with SCRAMM, liquid evacuation flow rates (L / min) were assessed using Eq. (1), where Q represents the liquid evacuation flowrate, AV is the change in liquid, and At is the elapsed measured time (minutes). This involved calculating the liquid volume (V) using the density formula shown in Eq. (2), where p represents the density, m is the mass of the liquid and V is the volume of the liquid.m (2)P =V

[0089] All liquid flow rate tests included four measured variables-liquid density, suction duration, initial and final reservoir weight, and set vacuum pressure-and three calculated variables: volume of liquid evacuated, liquid flow rate, and maximum vacuum pressure during suction.

[0090] Three types of liquids were utilized: water, blood analog, and vomit simulant, with each device undergoing five trials. The composition for the blood analog and vomit simulant was prepared according to ISO 10079-1, 2015, Section A.15 guidelines. The blood analog consisted of a mix of 276 mL of Glycerol and 1224 m of distilled water, while the vomit simulant was comprised of 10 g of Xanthan Gum, 1000 mL of distilled water, and 100 g of 1 mm diameter glass beads. The density of each liquid was determined by measuring 1 L of the prepared solution in a graduated cylinder, and weighing it on a calibrated scale, with this process repeated five times to obtain an average density of each fluid for flow rate calculations.

[0091] The testing setup evaluated the liquid flow rate for each device using each solution. Each trial began with the reservoir pre-filled with 1 L of the test solution, providing a consistent volume across all tests. In addition, the load cell (model LC62SP-6KG, Omega Engineering Inc) was calibrated before and after each test using a calibrated 500g weight. The suction device wasconnected through each device’s recommended vacuum tubing to a 1.2 L canister. The canister was linked to the reservoir via standardized 10mm ID, 1 m length tubing, simulating real -world scenarios with commonly used tubing diameters. Integrated within this tubing an Omega Pressure Transducer (model: PX309-015V5V, Omega Engineering Inc) was affixed at a T- junction, to monitor vacuum pressure during device operation.

[0092] Once the suction device was activated at 550 mmHg, the liquid was drawn from the reservoir into the canister. Throughout this process, the load cell situated beneath the reservoir accurately measured the mass changes corresponding to the evacuated liquid. The data from the load cell and pressure transducer were relayed to a data acquisition system (The National Instruments Data Acquisition System (NIDAQ)) (I). MATLAB software (The MathWorks, Inc), collected and processed the data in real time and measured the suction time elapsed. A signal conditioner was integrated to ensure clean and reliable signals for analysis. The setup was powered by three separate power sources of 28 VDC (J), 15 VDC (K), and 24 VDC (L), to energize the pressure transducer, load cell and signal conditioner respectively.

[0093] In addition to the initial tests conducted at a vacuum setting of 550 mmHg for evaluating high-suction performance, the SCRAMM device was further assessed for its low- suction capabilities. Specifically, the same testing procedure was replicated for SCRAMM’ s two low-suction lines, each set at a reduced vacuum pressure of 150 mmHg. This test aimed to measure the device’s efficacy and flow rate under lower pressure conditions, closely mirroring clinical scenarios where less powerful suction is required. Five trials were conducted for each of the low-suction lines.

[0094] Orientation Water Flow Rate Test (vertical, lateral, horizontal, and inverted): To evaluate the device’s performance across different orientations, the SCRAMM, along with Zoll 330 and Impact 326M, was subjected to operation in four distinct orientations: vertical, lateral, horizontal, and inverted. The objective was to measure the liquid flow rate in each orientation to assess any impact on the device’s performance due to positional changes.

[0095] As shown in FIG. 3A, Vertical Position: The device was oriented on a vertical standard position with the information of the screen reading conventionally. (FIG. 3B) Lateral Position: The device was positioned on its left side, simulating scenarios where space constraints might require non-standard device placement. (FIG. 3C) Horizontal Position: The device waslaid on its back, testing its performance in scenarios akin to transport or constrained operational spaces. (FIG. 3D) Inverted Position: The device was flipped such that its base faced upwards, challenging its design to perform under potentially adverse conditions.

[0096] The methodology for liquid flow rate testing was applied to each device across all orientations. Five trials were conducted for each device in each specified orientation to ensure reliability and consistency of data. For SCRAMM, this testing was extended to include all three suction lines, offering a comprehensive view of its functional adaptability to orientation changes.

[0097] A two-sample paired t-test was employed to statistically evaluate the potential differences in mean water flow rate attributed to changes in the device’s orientation. The aim was to determine whether orientation significantly influenced the performance of each individual suction line, comparing the flow rates of lateral, horizontal, and inverted orientations against the standard vertical position. The null hypothesis postulated that there would be no significant difference in flow rates between the altered orientations and the vertical baseline for each of the suction lines.

[0098] Vacuum Pressure Test: In the vacuum pressure test, the efficacy of the SCRAMM, Zoll 330, and Impact 326M devices was evaluated based on the time required for each to achieve a specified vacuum pressure. Set to operate at their maximum capacities, the devices were tasked with creating vacuum conditions within a 2-liter canister, with the process carefully monitored and timed in accordance with ISO 10079-1 guidelines.

[0099] The testing setup involved connecting the suction device’s vacuum port to a 2-liter canister’s vacuum port using the manufacturer-supplied suction tubing. To simulate patient conditions, a 10 mm ID and 1-meter-long tube linked the canister’s patient port to a pressure transducer, model PX309-015V5V from Omega Engineering Inc. This transducer effectively sealed the patient line, facilitating vacuum build-up within the canister.[000100] A power source, set to 28 VDC, energized the pressure transducer, while the ensuing pressure variations were captured and computed by a combination of NI DAQ and MATLAB. The resultant data provided a measure of the duration each device took to reach the predetermined vacuum pressure.[000101] Each trial began with the device set to its highest vacuum setting - 550 mmHg for SCRAMM’s high suction line, Zoll 330, and Impact 326M, while 150 mmHg for SCRAMM’s low suction lines. Upon confirming secure tubing connections, the MATLAB analog reader- initiated pressure data collection from the transducer. Simultaneously, the device’s suction function was activated for a continuous two-minute interval, providing a uniform basis for comparison across all tests. After the operation ceased, data analysis proceeded to ascertain the time each device needed to attain the set vacuum level, with this procedure replicated over five individual trials for each device.[000102] Noise Test: The assessment of noise levels for each suction device while operating at maximum capacity was conducted in a controlled environment to ensure accuracy. Following the procedures outlined in ISO 10079-1, the suction devices - SCRAMM (high and low suction lines), Zoll 330, and Impact 326M - were evaluated for their auditory output.[000103] The devices were configured to their maximum vacuum pressure settings prior to testing, with SCRAMM’s high suction line and the competing devices (Zoll 330 and Impact 326M) operating at 550 mmHg, and the low suction lines of SCRAMM at 150 mmHg. The measurements took place in an anechoic chamber, a specialized room designed to suppress echoes and external noise, thus focusing solely on the noise produced by the devices themselves. A calibrated digital sound level meter with RS232 (model: 407750 Extech Instruments) was positioned 1 meter from the suction device to accurately capture the emitted sound.[000104] To establish a baseline, the ambient noise level was recorded over a ten-second period before the devices were activated. The testing proceeded in two distinct modes as shown in FIG. 4 to simulate different operational conditions: FIG. 4 (a) shows an occluded line mode, where the suction line was blocked, and FIG. 4 (b) shows a free air flow mode, allowing for unimpeded air movement. In both scenarios, the peak noise levels were recorded during a ten-second operation of the suctioning process. This data was carefully logged and analyzed using Microsoft Excel, with each device and line being subjected to a total of five independent trials.[000105] Particle Lift Test: The particle lift test aimed to evaluate whether the suction pressure generated by each device was capable of lifting or evacuating solid particles from a liquid medium. This simulation mirrors real-life emergency scenarios where medics may encounter various debris, such as bone fragments, broken teeth, and stones mixed with vomit duringsuction procedures. To conduct this test, three sets of metal spheres, each differing in size and weight, were submerged in 1 L of water to simulate these solid obstructions. The characteristics of the metal spheres used are as follows:Table 6: Metal Sphere Characteristics Metal Sphere Set Metal Sphere Metal SphereDiameter (mm) Weight (g)A 6 0.86B 8 2.04C 14 11.02[000106] Five trials were carried out for each suction device across all three sets of spheres. The device’s vacuum line was attached to a 1.2 L canister, which was, in turn, connected via a standardized tube to the liquid container holding the spheres. By engaging the suction device at its highest setting, the test measured the devices’ efficiency in lifting these particles, quantified by the number of spheres removed from the water after each trial.[000107] Obstruction Resistance Test: The obstruction resistance test was conducted exclusively on the high suction lines of the three suction devices: SCRAMM, Zoll 330, and the Impact 326M, to determine their reliability during continuous operation. A thick, viscous test solution was prepared by diluting cream of mushroom soup (Hill Country Fare condensed soup) with distilled water at a ratio of 3:1. This mixture contained large solid pieces, measuring up to 14 mm at the longest axis, designed to potentially obstruct the suction tubing. For this test, a suction catheter was not employed to increase the likelihood of tubing obstruction.[000108] Each device’s performance was measured based on the frequency of obstructions and the uninterrupted operational time during the evacuation of 250 ml of the solution. The obstruction frequency was defined as the number of times the fluid flow ceased completely while suctioning the specified volume. Uninterrupted run time was gauged from the start of the device to the point of the first obstruction. Each device underwent five individual trials.[000109] Drop Test (1 m): To evaluate the impact of mechanical stress on the performance of the SCRAMM device, a drop test was implemented following the ISO 10079-1. The device underwent three consecutive 1 -meter drops onto a hard surface in a vertical orientation, starting from a stationary position, as illustrated in FIG. 5. This test aimed to investigate the potential effects of mechanical stress on the suction capabilities of the device’s three independent lines:the high-suction line, low-suction line 1 , and low-suction line 2. Flow rate measurements before and after the drop provided comparative data for each line under two distinct conditions. The liquid flow rate test was conducted with water. The hypothesis tested was whether the drop had an impact on flow rate, with the null hypothesis stating that there is no significant difference in the flow rates pre-drop compared to post-drop. The statistical approach involved using a two- sample paired t-test to compare the mean flow rates between these two conditions for each suction line.[000110] Technical Objective #3 - Preliminary Usability Testing: Upon successful completion of the in-house benchtop testing and building from the developments achieved in Technical Objectives #1 and #2, the SCRAMM prototype advanced to the end-user validation phase. This phase was instrumental in affirming the prototype’s practical effectiveness and usability, ensuring its alignment with the DoD’s stringent requirements and the actual needs of real endusers in operational settings. The methodology for conducting end-user tests to validate SCRAMM prototype incorporated both qualitative and quantitative research techniques. To systematically organize and analyze the data collected from initial user feedback, the affinity mapping methodology was employed. An affinity map is a visual tool that groups large amounts of data into thematic clusters, which was used here, to categorize information based on Heuristic Principles tailored to the project, as well as critical tasks identified by both the design team and subject matter experts. The construction of the affinity map was a collaborative process, which then informed the development of the end-user testing method.[000111] Sample population: The military medical personnel for this study were chosen based on their previous experience with suction devices, affiliation with the US Military, and local availability at the Department of Emergency Medicine at The University of Texas Health Science Center at San Antonio. In keeping with the use of SCRAMM for multiple clinical indications, all end users were either active duty or reservist physicians with the US Air Force or Army. Selecting this population allowed end users to evaluate and comment on indications most often used in hospitals (and by extension, enroute care or PFC) such as nasogastric suctioning, pleural and chest tube suctioning, and wound VAC.[000112] Testing: The study took place at the Simulation Laboratory from the Department of Emergency Medicine at The University of Texas Health Science Center at San Antonio. The testenvironment was controlled with minimal environmental distractions. The test sessions were divided into four groups - two groups of four and two groups of one - based on participant availability for pre-selected dates and times. Before starting each test, the team, suction devices, purpose of the test and session format were introduced. Each participant was randomly assigned to one station equipped with a suction device - either SCRAMM, Zoll 330 and Impact 326M - an airway mannequin, and a team member. End users were instructed to independently initiate the device, adjust it for high-vacuum suction, and perform a water suction procedure from the mannequin’s mouth, requesting assistance only if needed after multiple attempts. Participants were instructed to rotate among the stations to perform the suction procedure using all three devices. Upon completing all the suction procedures, medics were given the opportunity to compare the devices’ weights and perform any additional suction-related actions they wished to explore. The session concluded with participants completing a printed Posttest questionnaire, with sessions lasting between 15 to 25 minutes.[000113] Posttest Questionnaires: The Posttest questionnaire consisted of two parts designed to elicit detailed feedback on SCRAMM’ s usability and comparative user experience.[000114] Part 1 - Structured Questions: A structured Posttest questionnaire was designed based on the Heuristic Principles, and the critical tasks identified. The objective of the questionnaire was to address specific usability concerns, capture user likes and dislikes, and solicit novel suggestions for device enhancement, thereby ensuring comprehensive and valuable end-user feedback. The questionnaire comprised two Likert scale questions assessing the perceived weight of SCRAMM and the usefulness of its screen information. Additionally, two yes / no questions were posed to determine SCRAMM’ s integration into field equipment and its portability across large field hospitals. Open-ended questions further solicited feedback on the default mode operation, suggestions for modifications, and a comparative analysis against Zoll 330 and Impact 326M.[000115] Part 2 - System Usability Scale (SUS): To evaluate SCRAMM’s usability from the perspective of end-users, the study implemented the System Usability Scale (SUS) questionnaire. This ten-item instrument utilizes a 5 -point Likert scale to capture a wide spectrum of user interactions with the system. First introduced in 1986, SUS is lauded for its high adaptability and validity in a variety of contexts. Literature attests to its robust reliability, with a Cronbach’salpha coefficient commonly reported at 0.85, underscoring its trustworthiness as a measure of usability.[000116] Data Analysis: Quantitative data from Part 1 was organized and documented using Microsoft Excel. Qualitative feedback was categorized into positive or negative and subsequently visualized using word clouds to facilitate the interpretation and representation of recurring themes and feedback prominence.[000117] For Part 2, SUS responses were similarly processed in Excel. Score for each SUS question was calculated with even-numbered questions’ scores being the scale position subtracted from five, and odd-numbered questions’ scores being the scale position minus one. The aggregate of these scores, multiplied by 2.5, converted the original range to a 0-100 scale, representing the relative usability of the system. The overall SUS score was derived by averaging individual scores, formulated as Eq. (3).Where Q represents the question number and N is the number of respondents.[000118] The visual representation of the System Usability Scale data was facilitated using the System Usability Scale Analysis Toolkit provided by Mixality (Emden, Germany). The outputs were cross-verified and corroborated with the computational results derived from the Eq. (3).B. Results[000119] The results achieved across SCRAMM’s three technical objectives: Design, Build, and Test with end-users are outlined herein. The results encapsulate the transition from theoretical design and user feedback integration to practical application and real-world user validation.[000120] Technical Objective #1 - Design: Informed by feedback gathered from interviews and outlined in Table 2 and Table 3, the design phase of the device was initiated. This comprehensive process began with 3D modeling to establish a detailed representation of the device. Subsequently, the design of the electrical system and the GUI were developed. The finalstage of this phase involved selecting the case material. Detailed descriptions of these substages are provided in the following sections.[000121] Device Design: The detailed 3D models, assemblies and realistic material and finish representation were made using SOLIDWORKS® (Dassault Systemes) and KeyShot® (Luxion ApS). Comments and suggestions received at each stage were instrumental in guiding the evolution of the SCRAMM device through nine versions. Among the feedback that shaped the development process were (1) The need for a departure from conventional shapes, leading to a significant geometry change in Version 2 for a modem look and adherence to design trends. (2) The requirement to integrate three canisters, addressed in Version 3 with a deployable canister holder, making the device more versatile without compromising design integrity. (3) Preferences for a book-style design, recessed buttons and sliders, and specific mounting capabilities, leading to Version 4’s drastic design overhaul to incorporate these features. (4) The demand for tactile “start” buttons for each suction line and the elimination of touchscreen functionality, prompting the design adjustments seen in Version 5. (5) Requests for an enhanced graphical user interface and three independent suction lines, culminating in the significant updates of Version 6. (6) The need for streamlined controls and an advanced mode for experienced users, addressed in Version 7 with the reorganization of suction line controls and the addition of a customizable advanced mode panel. (7) Suggestions for procedure-specific abbreviations on buttons, separate controls for screen brightness and alarm sound, and the introduction of LED indicators, leading to the targeted refinements of Version 8. (8) Finally, the simplification of the advanced mode to focus on essential functionalities, resulting in Version 9’s streamlined design featuring a three-position button for each suction line to easily switch between flow modes.[000122] After the iterative process, the ninth version of SCRAMM was developed up to a prototype-ready level. SCRAMM final design includes three independent suction lines. The primary high-suction line can deliver vacuum pressures up to 550 mmHg, ideal for rapid airway clearance, oropharyngeal airway management, and surgical suction. The two secondary low- suction lines, with a maximum vacuum pressure of 150 mmHg, are useful for procedures where high-powered suction could cause tissue damage, including oral-nasal tracheal suction, dental suction, gastrointestinal abdominal drainage, wound suction, and chest tube suction. Table 4 served as a guideline to assist in defining performance specifications, particularly identifying theclinical pressure settings for each suction line. However, some of these settings, specifically those with the ‘Fail Safe’ feature that ensures the device reverts to ambient atmospheric pressure in case of a failure, were not deemed a priority by the end-users and are planned to be added in a future phase of development. Three different colors (yellow, blue, and red) were implemented in the design to improve usability.[000123] Electrical Design: In addition to the device main functionality, the electrical design of SCRAMM encompassed a power on / off switch, a pause / resume push button, two push buttons for selecting the screen brightness mode and the alarm volume, three 3 -position switches dedicated for flow selection, three potentiometers for vacuum regulation, three LED green indicators for vacuum operation, a yellow LED for battery charging status, and a 7.0” Nextion screen (model: NX8048T070, Nextion). This screen significantly enhances user interaction by providing dynamic data visualizations that facilitate the monitoring and adjusting of device settings, thereby simplifying the user interface and improving ease of use.[000124] For the suction control, one high-pressure pump (e.g., model: NMP830.1.2KPDC-B4 HP, KNF Neuberger, Inc.) was implemented for the primary high-suction line with vacuum pressure ranging from 0 to 550 mmHg, and two low-pressure pumps (e.g., model: UNMS 020KPDC-B 6V, KNF Neuberger, Inc.) were selected to provide the two low-suction lines with vacuum pressure ranging from 0 to 150 mmHg. The pumps flows were controlled through one high flow proportional valve (model: VSO MAX HP, Parker) and two miniature proportional valves (model: VSO LowPro, Parker), respectively. Additionally, a custom Li-ion 18650 Battery (14.4V 10.05Ah), made of 12 pcs Panasonic NCR18650B Li-Ion cylindrical cells arranged in 2 rows of 6 configuration (4S3P) (Panasonic Corporation of North America, Newark, NY) was used.[000125] To manage the electrical features an electric main board was developed centralized around an Arduino Micro microcontroller (model: A000053, Arduino, Somerville, MA). This board also integrated a 16-BIT I / O Expander, and three Panasonic Gauge Pressure Sensor (Panasonic Corporation of North America, Newark, NY). Additionally, a power management board was developed and manufactured to allow battery control and power distribution within the device. The electrical control boards were outsourced to Wavetrix (Richardson, Texas), which facilitated rapid prototyping in collaboration with a manufacturing partner, NPITechnologies. NPT Technologies programs comply with IS0900T2015 and IPC-610, ANSI_JST-001, ensuring high-quality board assembly. This collaboration underscores the potential for future partnerships with Wavetrix and NPI Technologies, aligning with end-user standards and enhancing SCRAMM’s development.[000126] The integration of the Nextion NX8048T070 display into the electrical design enhances the usability of the SCRAMM device by providing real-time data visualizations essential for emergency medical care. The process involved developing custom graphical user interfaces using the Nextion Editor, tailored to the specific needs of the SCRAMM device, such as control menus, status indicators, pressure readings, sensor data, and battery level indications. The interface dynamically reflects changes and system statuses in real time, allowing for immediate visual feedback on the Nextion display as adjustments are made via the external buttons and knobs. The microcontroller unit was programmed to handle specific commands from the Nextion display, incorporating the development of interrupt service routines (ISR) to manage asynchronous events triggered by user interactions. This programming enables key functionalities such as starting and stopping suction, adjusting suction power, and modifying system configurations, thereby enhancing the operational efficiency and responsiveness of the SCRAMM device.[000127] Case Material Selection: In the material selection process for the SCRAMM enclosure, Formlabs Tough 2000 and Formlabs Durable resins were evaluated for their durability. Upon conducting 1 m drop tests, it was observed that the Tough 2000 resin sustained major cracks, indicating a lower threshold for impact resistance. Conversely, the Durable resin exhibited only minor cracks, showcasing superior durability and impact resistance.[000128] Further development led to the incorporation of structural ribs into the critical geometry of the SCRAMM enclosure, aimed at enhancing its resilience against crack propagation. Subsequent testing of a newly designed prototype, 3D printed in Durable resin, demonstrated significant improvements in its ability to withstand impact without cracking. Based on these results, the Durable resin was selected as the preferred material for prototyping the SCRAMM enclosure. This choice underscores the material’s suitability for ensuring the device’s durability and reliability in operational settings.[000129] Graphical User Interface (GUI) Design: The GUI of the suction device was designed to display important operational information in a concise and clear manner. The top panel of the interface is dedicated to status indicators, including screen brightness, alarm volume, port connection, and battery life - represented as a percentage. Below this, the interface is sectioned into three distinct areas for the independent suction lines. Each section uniformly displays the type of suction flow (either continuous or intermittent), the preset vacuum pressure, the actual vacuum pressure being applied, and a dynamic visual bar that reflects real-time fluctuations in the vacuum pressure. This design ensures that users have immediate access to all the necessary details for the effective management of the suction device.[000130] The device’s operational alarms are an integral feature, providing immediate alerts for malfunctions or other important operational issues. These alerts were systematically categorized based on urgency into three tiers of priority. Displayed at the bottom of the screen, a triangular warning symbol with exclamation marks conveys the level of attention needed: three exclamation points denote high-priority alerts, two signify medium priority, and a single exclamation point indicates a lower priority situation. This tiered system allows users to quickly ascertain the severity of any given alert and respond accordingly.[000131] Technical Objective #2 - Build: Building on the comprehensive design work completed in Technical Objective #1, the SCRAMM project transitioned into the build phase, where the theoretical design concepts were translated into a tangible prototype. This phase involved the practical assembly of the device, utilizing the selected materials, electrical components, and the user interface previously determined. During this stage the prototype’s functionality and performance were put to the test through rigorous benchtop testing, aiming to benchmark SCRAMM’ s capabilities against established market competitors.[000132] Prototyping: The SCRAMM prototype encompassed a blend of commercially available components and parts fabricated in-house. To rigorously test the electrical system and validate the software code, a dedicated system development platform was constructed. This platform served as a tool in the iterative design process, enabling the team to simulate the SCRAMM’ s circuitry and interactive elements in real-time.[000133] This custom-built testbed featured a comprehensive array of interfaces and modules, mirroring the actual control environment of the SCRAMM prototype. It included a power supplysection with inputs and indicators for charging status, an array of voltage options to mimic the device’s power conditions, and a simulation interface for the suction pumps and valves. The platform’s central component - a large screen - allowed for immediate feedback and interaction during the testing phase, while an array of switches and indicators provided direct control over the various functions such as suction intensity, flow rate, and system presets.[000134] Notably, the SCRAMM prototype achieved a significant reduction in weight, registering at 3.4 kg. This lightweight design represents a major advancement over existing models, aligning with the initial feedback from Air Force end-users who prioritized ease of maneuverability and portability for field operations.[000135] The internals of SCRAMM include a vacuum pressure controller, two electric boards, and distinct pumping mechanisms - two low-pressure pumps and one high-pressure pump - precisely installed within the front and back enclosures. Additionally, the battery and its compartment are designed for easy access, allowing for quick battery changes as necessary.[000136] The device’s enclosures were manufactured using Stereolithography (SLA) 3D printing technology, assembling several sections to form both the front and back housings. Each electrical component, from the controller board to the pressure sensors, was securely anchored within the housing using Phillips head screws. This design not only ensures the structural integrity appropriate for field conditions but also offers the convenience of complete assembly and disassembly using a single type of screwdriver, facilitating maintenance and repair.[000137] The enclosures, fabricated from Formlabs Durable resin selected for its superior impact resistance, hold all the functional elements in a compact form factor. The final design incorporates a detachable canister system, where each canister capable of holding 1 L, can be securely mounted onto the device using adjustable straps, providing flexibility during use.[000138] Upon completion of the assembly, a preliminary test was conducted with fluids of various colors to verify the operational efficiency of each suction line. This test served to confirm that the SCRAMM prototype functioned as expected across its multiple channels.[000139] Testing: After building the prototype, a series of in-house benchtop tests were conducted to evaluate the performance of the SCRAMM prototype against established market leaders. These tests focused on assessing key operational parameters, including liquid flow rate,device orientation, vacuum pressure, noise levels, particle lift capability, obstruction resistance, and the impact of physical stress tests.[000140] Liquid Flow Rate Test (water, blood analog, and vomit simulant): The SCRAMM high suction line successfully met the ISO 10079-1 standard of 1.2 L / min for oropharyngeal suction and the internal specification of 1 L / min, as suggested by feedback from AF users, as illustrated in FIG. 7. For the vomit simulant, SCRAMM’s flow rate exceeded the necessary ISO requirement by 23%, in contrast to the Zoll 330 and Impact 326M, which surpassed it by 145%. FIG. 15 shows the proposed performance-to-weight standard for suction devices, comparing the SCRAMM, Zoll 330, and Impact 326M.[000141] In the blood analog tests, SCRAMM demonstrated flow rates of 4.13 L / min, while the Zoll 330 and Impact 326M devices achieved higher flow rates of 6.39 L / min and 6.38 L / min respectively. Similarly, in water tests, SCRAMM achieved a flow rate of 4.07 L / min compared to the Zoll 33O’s 6.48 L / min and Impact 326M’s 6.40 L / min.[000142] The SCRAMM device also includes two low-suction lines, which were evaluated separately due to their specific clinical applications. As show in FIG. 8, the low-suction lines 1 and 2 achieved mean flow rates of 0.25 L / min, 1.21 L / min and 1.24 L / min for vomit simulant, blood analog, and water, respectively. Table 7 summarizes the test results.Table 7: Liquid flow rate test results.Devices Water Blood Analog Vomit SimulantMean SD Mean SD Mean SDSCRAM 4.07 0.03 4.13 0.10 1.48 0.04M High-SuctionLineZoll 330 6.48 0.16 6.39 0.05 2.93 0.06Impact 6.40 0.16 6.38 0.12 2.95 0.11326MSCRAM 1.31 0.01 1.26 0.01 0.24 0.01M Low-SuctionLine 1SCRAM 1.17 0.02 1.15 0.02 0.26 0.02M Low-SuctionLine 2[000143] Orientation Water Flow Rate Test (vertical, lateral, horizontal, and inverted): In the orientation water flow rate test, the SCRAMM device along with Zoll 330 and Impact 326M underwent thorough evaluation in various positions: vertical, lateral, horizontal, and inverted, to ascertain the influence of orientation on liquid flow rate performance. Table 8 and Figure 9 illustrate the mean flow rates achieved by each device in the differing orientations.[000144] As shown in Table 9, the SCRAMM device’s High-Suction Line maintained consistent performance across different orientations. Statistical analysis did not indicate significant differences in flow rate when altering the device from a vertical to lateral, horizontal, or inverted position (with p-values >0.05). This result signifies a failure to reject the null hypothesis, suggesting orientation does not significantly affect the device’s flow rate. This is also supported by the device’s design, which allows versatile canister mounting options for operational adaptability in diverse settings.Table 8: Water flow rate of each device in different orientations.Devices Lateral Position Horizontal Position Inverted PositionMean SD Mean SD Mean SD SCRAM 4.08 0.16 4.03 0.15 3.84 0.10 M High- Suction Line SCRAM 1.32 0.01 1.34 0.02 1.30 0.01 M Low- Suction Line 1 SCRAM 1.20 0.01 1.21 0.01 1.23 0.01 M Low- Suction Line 2 Zoll 330 6.43 0.09 6.40 0.07 6.51 0.03 Impact 6.62 0.15 6.63 0.18 6.54 0.16 326M[000145] Contrastingly, SCRAMM Low-Suction Line 1 exhibited statistically significant differences with p-values <0.05, in flow rates when positioned laterally and horizontally relative to the vertical orientation, necessitating the rejection of the null hypothesis for these orientations due to notable orientation sensitivity. Nonetheless, the inverted orientation did not reveal a significant variance (p-value >0.05), hence the null hypothesis is maintained for this position.Table 9: Statistical analysis of p-values from orientation independency water flow rate tests across devices.Orientation SCRAMM Zoll 330 Impact 326M SCRAMM SCRAMM Comparison High- Suction Low- Suction Low- SuctionLine Line 1 Line 2Vertical - 0.9795 0.5418 0.0520 0.0353 0.0134 Lateral Vertical - 0.9832 0.3477 0.0655 0.0042 0.0125 Horizontal Vertical - 0.9991 0.6877 0.2228 0.3466 0.0002 Inverted[000146] Similarly, SCRAMM Low-Suction Line 2’s performance was significantly affected by changes in orientation with p-values <0.05 across all tested positions, leading to the rejection of the null hypothesis. These findings indicate that orientation changes influence the device’s functionality for both low-suction lines.[000147] In comparison, both Zoll 330 and Impact 326M maintained stable flow rates regardless of orientation, with all p-values >0.05, which does not support rejecting the null hypothesis. This consistency underscores the ability of these devices to operate effectively without performance degradation when oriented laterally, horizontally, or inverted.[000148] Vacuum Pressure Test: As per FIG. 10, SCRAMM successfully met the design specifications for vacuum pressure, which is to reach a vacuum of 350 to 550 mmHg at the suction tip. SCRAMM takes an additional 0.47 minutes ~ 28 seconds to develop vacuum pressure into a 2 L canister when compared to Zoll 330, and Impact 326M. The two low-suction lines of SCRAMM also reached the maximum pressure of 150 mmHg. Table 10 summarizes the results.Table 10: Vacuum pressure test results summary.Devices Average time taken SD Set vacuum to reach set vacuum pressure (mmHg) pressure (sec)SCRAMM High- 0.63 0.06 550Suction LineZoll 330 0.15 0.01 550Impact 326M 0.15 0.02 550SCRAMM Low- 0.66 0.04 150Suction 1SCRAMM Low- 0.54 0.02 150Suction 2[000149] Analysis of vacuum pressure test: SCRAMM met the design specification for the vacuum pressure test. Competitors performed this test significantly faster than SCRAMM because they contain larger and heavier pumps. SCRAMM was purposely designed to be portable and lightweight.[000150] Importantly, the vacuum pressure test is a non-clinical and arguably non-relevant test for the performance of suction devices.[000151] Noise Test: According to FIG. 11, the SCRAMM device successfully met the design specification with a noise level of < 69 dB, proving to be 25% quieter than required. This analysis only considered the maximum noise levels produced by the devices; thus, noise from SCRAMM’ s low suction line was not separately measured, as it was quieter than its high suction line. The results are summarized in Table 11.Table 11 : Noise test results summary.Devices Peak noise level Peak noise level Peak noise level before testing for 10 when free flow for when occluded for seconds 10 seconds 10 secondsValue Mean SD Mean SD Mean SDSCRAMM 37.72 0.23 51.66 0.86 51.36 0.93Zoll 330 38.44 0.99 50.76 0.50 55.06 0.72Impact 38.14 0.27 68.70 0.60 68.60 0.73326M[000152] Particle Lift Test: The particle lift test was conducted to determine whether the suction pressure of the devices was sufficient to lift or evacuate solid particles submerged in liquid. In this evaluation, all three suction devices successfully evacuated 6 mm metal spheres, each weighing 0.86 grams, from a submerged state in water. The spheres were successfully transported into the canister using standard tubing with an inner diameter of 7.5 mm, demonstrating the devices’ capability to effectively handle particulate matter of minimal diameter.[000153] Challenges were encountered with 8 mm spheres, each weighing 2.04 grams. While these spheres were initially lifted from the water, they consistently became lodged at the tubing’s entry point. Manual intervention was required to dislodge the spheres, allowing suction to continue. This issue underscores a limitation in the tubing diameter relative to the sphere size.[000154] Further testing with 14 mm spheres, each weighing 11.02 grams, highlighted additional limitations. Although the devices could lift these larger spheres from the water, they were unable to maintain suction once the spheres were out of the liquid. The spheres were too large to be drawn into the tubing, illustrating the practical constraints of suctioning larger solid particles in air. This experiment underscores that while all devices are capable of removing heavier particles from a liquid, their effectiveness diminishes significantly with larger particles in the air.[000155] Obstruction Resistance Test: The objective of the obstruction resistance test was to evaluate the duration of uninterrupted suction before encountering an obstruction. In this test, the SCRAMM device demonstrated a longer duration of uninterrupted suction compared to the Zoll 330 and Impact 326M, as shown in FIG. 12. However, the results exhibited a high standard deviation, indicating variability in the performance across different trials.[000156] Drop Test (1 m): During the 1-meter drop tests conducted on the SCRAMM device to evaluate its durability, various degrees of hardware damage were observed, impacting the device’s physical integrity but not its operational functionality. After the first drop, the rear casing’s top right corner chipped, leading to the internal disassembly of the main power switch. This damage temporarily impeded the device’s ability to power on. However, after reassembling the switch, the device’s functionality was restored, and a subsequent liquid flow rate test confirmed its operational efficacy.[000157] The second drop resulted in minor cracks on both the front and rear casings. The main power switch again suffered disassembly, and the small pumps became loose from their brackets. Despite these setbacks, once the power switch was reassembled and the pumps secured, the device resumed normal operation.[000158] After the third drop the existing cracks worsened, causing additional cosmetic damage. Notably, the main power switch remained intact, and no further dislocations of the small pumps occurred. An internal inspection post the third drop revealed that all key components — pumps, valves, manifolds, screen, PCBs, switches, tubing, and electrical connections — remained intact and functional, demonstrating the device’s resilience to physical shocks.[000159] Upon completion of the 1 -meter drop tests, the functionality of SCRAMM’s suction lines was evaluated through flow rate measurements before and after the drops. Statistical analysis using a two-sample t-test revealed no significant differences in mean flow rates between pre-drop and post-drop conditions across the suction lines. The p-value > 0.05 indicated no statistically significant impact of the drops on the device’s suction capability. This result leads to a failure to reject the null hypothesis, suggesting that the mechanical stress from dropping did not affect the flow rate performance of the high-suction line, low-suction line 1, or low-suction line 2. Specific flow rates pre and post-test are illustrated in FIG. 13.[000160] Technical Objective #3 - Preliminary Usability Testing: After completing the design and prototyping phases, and successfully characterizing the device against leading market competitors, the prototype underwent end-user validation tests. These tests were crucial to confirm that the device met the specific requirements of the military and the DoD.[000161] Eight subjects participated in the study, including four Doctors of Osteopathic Medicine (DO), with three ranking Capt. at the USAF and one ranking MAJ. at the USA, and four Medical Doctors (MD), with three ranking Capt. at the USAF and one ranking Maj. at the CTANG.[000162] The structured questionnaire facilitated systematic data collection, enabling an in- depth analysis of SCRAMM’s operational efficacy and user interface design from the perspective of military medical personnel.[000163] For the first part of the Posttest questionnaire, quantitatively, the device’s weight was perceived as “somewhat light” by 62.5% of participants (5 out of 8), suggesting an optimal compromise between durability and portability, a crucial factor for field deployment. Regarding the utility of on-screen information, 37.5% of respondents (3 out of 8) found it to be "Somewhat useful," indicating potential areas for enhancement in data presentation and accessibility. Importantly, SCRAMM’s integration into field equipment was endorsed by 87.5% of medics (7 out of 8), and its portability was unanimously recognized (8 out of 8), affirming its design’s alignment with the exigencies of field hospital use.[000164] Qualitative feedback illuminated areas for iterative design refinement. Positive remarks affirmed SCRAMM’s intuitive operation and effective default settings. However, suggestions for increased suction power and interface adjustments for gloved use highlighted theneed for targeted improvements to fully meet the specific requirements of combat medics. Comparative feedback positioned SCRAMM favorably against market competitors regarding weight and usability. Still, it also highlighted the imperative of strengthening its suction capability to ensure comprehensive operational superiority.[000165] The end-user tests revealed several key findings: (1) Suction Feedback Capability: Participants highlighted concerns regarding the suction feedback. Issues included the need for clearer feedback mechanisms. There was a desire for physical suction feedback, such as feeling pressure or hearing suction at the tip, to ensure effective operation. (2) Buttons / Dials Issues: Participants expressed the need for larger dials / buttons that facilitate the operation with gloves. (3) Device Performance: While SCRAMM was generally perceived as lightweight, portable, and functional, users suggested improvements in suction power and interface design to enhance task performance. The default mode was seen as adequate. (4) Night Vision Compatibility: Participants suggested implementing a compatible night vision coat for button and dials.[000166] The second part of the Posttest questionnaires was the SUS. Results are shown in FIG. 14. The SUS provided an "Excellent", Grade A usability score of 83.44 for SCRAMM, demonstrating its design and functional attributes through a recognized evaluative metric. This quantitative validation, compared with detailed user feedback, underscores the device’s considerable potential while delineating clear directives for future development.[000167] Discussion: SCRAMM emerges as a novel multifunction portable suction device within the medical-military suction market, designed and developed to serve in field hospitals and combat-ready scenarios. SCRAMM is the first device equipped with three suction lines that offer independent pressure adjustments, enabling simultaneous suction operations. This feature highlights its potential to be widely used in busy field hospitals settings, where the simultaneous treatment of multiple patients or a single patient with multiple traumas is common.[000168] The data presented in Table 12 underscore that SCRAMM adheres to all defined specifications, establishing it as a market-ready device with competitive features. Notably, SCRAMM has a distinct advantage over its competitors, Zoll 330 and Impact 326M, in terms of both weight and dimensions - factors that are especially important for the Air Force end-users and the Department of Defense’s stringent requirements. While the suction power of the competing devices is noted to be higher, SCRAMM offers a 40-50% weight reduction, a keyfactor in enhancing portability for field deployment and its ability to surpass the benchmarks set by current market offerings.Table 12: Comparison and meeting criteria of the product specifications for the suction device market leaders and SCRAMM.[000169] During the design phase for the Technical Objective #1, the evolution across nine iterative versions of SCRAMM lightens the responsiveness of the design team to end-user feedback, highlighting a progressive refinement of features without sacrificing the functionality. The device’s operational interface, with its practical alterations such as tactile switches over touchscreen inputs, resonates with the environmental conditions anticipated in the field, where users operate under pressure and often with gloved or wet hands. Moreover, the decision to use distinct color coding to distinguish between suction lines is evidence of the detailed attention given to enhancing user experience.[000170] The integration of high-fidelity renders at each iteration of the SCRAMM prototype was a strategic move that significantly enhanced the feedback loop with end-users. This visual clarity allowed users to critique and suggest alterations in a context that closely mirrored actual usage scenarios, thereby streamlining the design process, and avoiding potential rework that might arise from misinterpretation of conceptual designs. As a result, the realistic renders playedan important role in converging towards a final design that integrated both functional requirements and user preferences.[000171] The integration of a flow control system with independent exhaust valves and manifolds independent for each suction line, allowed the possibility of managing the pressure of the pumps in real time to adhere to the required vacuum pressure of each existing medical procedure. The strategic partnership with Wavetrix for the development of the electrical control boards illustrates the successful intersection of in-house medical expertise and external engineering prowess.[000172] During the material selection for the enclosure, the comparative evaluation between Formlabs Tough 2000 and Durable resins through rigorous drop tests demonstrated the superior performance of Durable resin in resisting impact-related damage. This was further validated through the strategic incorporation of structural ribs, which significantly enhanced the resilience of the enclosure design against potential cracks. These meticulous steps in material testing and selection not only ensured the structural integrity of SCRAMM but also aligned with the operational durability required by military medical personnel.[000173] Transitioning into the build phase as outlined in Technical Objective #2, the SCRAMM project moved from detailed design to the physical assembly of a working prototype. The utilization of a system development platform during the prototype stage was fundamental, ensuring seamless integration of software code and electronic components prior to full assembly. The adoption of SLA 3D printing technology facilitated the rapid production of a highly detailed prototype with precise tolerances, significantly expediting manufacturing times. Furthermore, the comprehensive BOM streamlined the assembly process by preemptively organizing all necessary materials and tools, thereby minimizing delays and reprocessing times. The preliminary coloredliquid testing further underscored the high suction line’s superior performance in liquid flow rate tests, which was demonstrated through the complete evacuation of liquid from the yellow canister while the process was still ongoing in the red and blue low suction lines.[000174] The benchtop testing results, however, indicated a lower liquid flow rate for the SCRAMM high-suction line compared to its competitors, Zoll 330 and Impact 326M. Despite this, SCRAMM’ s performance still met and exceeded the specified user requirement of 1 L / min and the ISO standard of 1.2 L / min, which is deemed sufficient for oropharyngeal suction. Thisoutcome suggests that flow rates exceeding 1 .2 L / min may offer unnecessary excess capacity. By optimizing rather than maximizing suction capabilities, it is feasible to incorporate smaller vacuum pumps into the design. This approach directly contributes to a more compact and lighter device, aligning with operational needs for portability and ease of use in field conditions. Reflecting this design philosophy, the SCRAMM prototype demonstrated a significant weight reduction, thereby offering a superior advantage in portability compared to market leaders.[000175] The high-suction lines of SCRAMM, Zoll 330, and Impact 326M consistently met performance specifications and demonstrated orientation-independent functionality, with no significant impact on flow rate when the devices were repositioned. Conversely, the low-suction lines of SCRAMM displayed variability in flow rate across different orientations, potentially attributed to the operating principles of the pumps and the influence of gravity on fluid dynamics, as evidenced by the increased flow rate in the inverted position. This observation identifies a possible area for enhancement in subsequent design iterations, emphasizing the need for orientation-agnostic performance in low-suction lines to match the reliability of the high- suction counterparts. However, the standard commercially available canisters used in these tests were not designed to support multi-orientation operation due to limitations in the filter’s permeability. To truly achieve a device capable of operating effectively in multiple orientations, it is imperative to pair it with a canister specifically engineered to handle such conditions. This would ensure that the suction capability is not compromised by the orientation of the device.[000176] In the noise level tests, all devices adhered to the maximum permissible noise levels stipulated in operational standards. Notably, the Impact 326M recorded the highest noise level among the tested devices, suggesting that its design was optimized just sufficiently to meet ISO standards for FDA approval. A comparative analysis between the older model, the Impact 326M, and its improved successor, the Zoll 330, revealed a significant noise reduction of 20%. This reduction underscores the manufacturer’s efforts to enhance device usability and patient comfort in newer models.[000177] The Particle Lift Test confirmed that all tested suction devices effectively evacuated large particles, crucial for airway clearance tasks such as removing teeth or bone fragments. However, the performance in particle evacuation is significantly dictated by the catheter tip and suction tube’s diameter, emphasizing the necessity for appropriate sizing in these components tomaximize clinical efficacy. Moreover, the experiment indicated that while all three devices could evacuate heavier solid particles from a liquid medium when the particle’s shape closely matched the internal diameter of the suction tube, their ability to lift heavier particles diminished once outside the liquid. Additionally, all the devices surpassed the Obstruction test effectively.[000178] The 1 -meter drop test, conducted exclusively on the SCRAMM device, resulted in cosmetic damage after three drops. These observations were attributed to the UV-cured resin used for the device’s 3D-printed enclosure, which likely became more brittle due to prolonged exposure to light prior to testing. This material was chosen for its prototyping efficiency but would necessitate replacement with a more mechanically stable material for future commercial production. Notably, despite the cosmetic damage, the functional integrity of the device remained unaffected. However, the main power switch did sustain internal disassembly, leading to operational disruption, underscoring the need for a redesign to enhance durability in future models.[000179] Finally, the end-user validation phase of SCRAMM, conducted under Technical Objective #3, was markedly enriched by the direct involvement of Air Force end-users, thereby enhancing the validity and relevance of the study results to real-world military requirements. The inclusion of the System Usability Scale (SUS), a reliable and recognized tool for assessing usability, was instrumental in quantitatively confirming the device’s user interface effectiveness. This allowed for a thorough gathering of valuable usability data, complementing the qualitative insights from the end-users.

Claims

CLAIMS1. A portable suction device comprising:(i) a vacuum cannister having an internal flow loop;(ii) at least three suction lines operably coupled to the vacuum cannister, a first high power suction line configured to provide suction at 200 to 550 mmHg, and a second and third low power suction line configured to provide suction at 50 to 150 mmHg;(iii) a user interface operably coupled to the vacuum cannister; wherein the internal flow loop is configured to independently regulate suction pressure of the three suction lines.

2. The device of claim 1, wherein the first high power suction line has an internal diameter of 4.5 to 5.5 mm.

3. The device of claim 1, wherein the second and third low power suction line has an internal diameter of 3.5 to 4.5 mm.

4. The device of claim 1, wherein the first high power suction line, the second low power suction line, and the third low power suction line are coupled to the vacuum cannister by adapters.

5. The device of claim 1, wherein the internal flow loop comprises: an exhaust valve configured to dynamically manage air release for real time pressure regulation, pump, pressure sensor, manifold, and a pressure outlet.

6. The device of claim 1, further comprising a light weight battery.

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