Improvised Devices Research Articles

Improvised intracranial pressure monitoring devices for traumatic brain injury management in a low-income environment: A single-centre randomised study demonstrating feasibility

BackgroundThe high cost and non-availability of standard ICP monitoring devices limit their use in low- and middle-income countries like Nigeria. This study aims to demonstrate the use of an improvised intraventricular ICP monitoring device as a feasible alternative. Research questionAre improvised ICP Monitoring devices feasible and effective in resource-constrained settings? Materials and methodsThe study was a prospective single-institution investigation involving 54 adult patients that presented with severe TBI (GCS of 3–8) within 72 ​h of injury and required operative intervention. All patients underwent craniotomy or primary decompressive craniectomy (DC) to evacuate traumatic mass lesions. 14-day in-hospital mortality was used as a primary endpoint of the study. 25 patients had ICP monitoring postoperatively using the improvised device. ResultsThe modified ICP device was replicated using a feeding tube and a manometer with 0.9% saline as a coupling agent. Based on hourly ICP recording (up to 72 ​h), patients were observed as having high ICP (>27 ​cm H2O) and normal ICP (27 ​cm H2O). In the ICP-monitored group, raised ICP was detected more than in the clinically assessed group (84% vs 12% p= <0.001). Discussion and conclusionThere was a 3-time higher mortality rate among the non-ICP monitored participants (31%) compared to the ICP-monitored participants (12%), although this did not reach statistical significance due to the small sample size. This preliminary study has shown that this modified ICP monitoring system is a relatively feasible alternative for diagnosing and treating elevated ICP in severe TBI in resource-constrained environments.

A proposed improvised pleural drainage system for veterinary use.

Active pleural suction devices may be required for continuous drainage of pleural fluid or air. Such devices may not always be available or economical to stock at all veterinary hospitals. Three designs of pleural drainage systems adapted from standard suction canisters are proposed. The designs were constructed from readily available materials from the veterinary hospital and consist of (1) a 1-bottle system intended for use with pneumothoraces, (2) a 2-bottle system, which can be used for draining air and fluid, and (3) an abbreviated 2-bottle system. The suction pressure was tested using a water manometer for each design. The suction pressure was consistently accurate with designs 1 and 2, with mild fluctuations, intermittently increasing suction pressure in design 1 due to bubbling through the air vent. Design 3 demonstrated a greater degree of pressure fluctuations, which was attributed to having the least water volume, reaching suction pressures up to 1cm H2 O above what was set. The improvised devices appear effective, allow accurate delivery of a set suction pressure, and can be rapidly constructed from inexpensive and readily available equipment.

Comparison Of Non-clinical Tourniquet Research for Appliance Superiority &amp; Tolerance (CONTRAST)

BACKGROUND: Tourniquets are effective tools to manage life-threatening extremity hemorrhage. Commercial devices are recommended over improvised ones; however, mass casualty incidents and austere environments may prevent access to commercial devices. The aim of this review is to systematically search and meta-analyze commercial and improvised tourniquets: arterial occlusion, application speed, and patient tolerance. METHODS: We searched MEDLINE, Embase, CINAHL, Cochrane Library, SPORTDiscus, and ProQuest Dissertations &amp; Theses Global using controlled terms; without date limits. Manikin, animal, and operative studies were excluded. Tourniquet devices were pooled by design and compared. Data regarding provider training and experience, recipient anthropometrics, application site, ease of application, speed, tolerance, and device efficacy were examined. RESULTS: 5169 studies were screened. The 36 included studies were prospective trials on healthy volunteers and published between 2000 and 2021. There were 8205 unique tourniquet applications to 1921 subjects using 23 unique commercial and improvised devices. Median sample size of included studies was 20 (IQR 26) participants, ranging from 1 to 773 participants; and 102 (IQR=152) applications ranging from 20 individual applications to 1546 unique applications. The most commonly assessed outcomes were: effectiveness (n=30), pain (n=18), speed of application (n=13), and amount of mechanical advantage (ex. Windlass turns) required (n=13). Male participants outnumbered females 1,414 to 169, mean age ranged from 21 to 45 years of age. Devices were pooled into 5 categories according to mechanical advantage mechanism: elastic, friction, mechanical, pneumatic, and windlass. Initial hemostasis was achieved in 95% of upper extremity placements (CI=0.89-0.98, p= 0.02), and 88% of mid-thigh applications (CI=0.78-0.94, p&gt;0.01), in both groups pneumatic and mechanical tourniquet devices had the highest rates of success, with friction and elastic devices having the lowest rates of success. Meta-analysis showed that mechanical and pneumatic advantage systems had superior rates of hemostasis, ease of use, and pain tolerance scores. Due to study heterogeneity, we could not determine which devices were the fastest to apply. The overall risk of bias assessment for included studies found the certainty of studies ranged from moderate to critical. CONCLUSION: In pre-clinical studies mechanical and pneumatic advantage systems appear to be the superior tourniquet design. Due to the low certainty of evidence and non-randomizable nature of traumatic injury, pre-clinical tourniquet devices will likely continue to be tested on well volunteers. Adoption of a minimum data set, agreed upon definitions for testable metrics, and a standardized experimental design could improve the comparability and quality of future tourniquet device studies.

Intubation outcomes using the aerosol box during the COVID-19 pandemic: A prospective, observational study.

Background and Aims:The aerosol box (AB), an improvised device used during the coronavirus disease (COVID)-19 pandemic, has attracted both interest and controversy. Several simulated studies have examined its protective efficacy as well as intubation efficiency. The aim of this study was to evaluate the practical conduct of intubation using the AB in patients undergoing elective, oncological surgery during the pandemic.Methods:This prospective, observational study included adult patients undergoing oncological surgery. Thirteen anaesthesiologists performed 132 intubations using one of three ABs designated as AB 1, AB 2 and AB 3. The primary outcome was the difference in the time to intubation (TTI) between patients with Mallampati score MP I-II (Group 1) and MP III-IV (Group 2). Secondary outcomes included first-pass success rate, fall in peripheral oxygen saturation to < 95%, total number of attempts and failure to intubate using the AB.Results:The mean TTI was not significantly different in Group 1 and Group 2 (71.02 (61.66) s vs. 101.35 (121.94) s respectively, P = 0.119). Desaturation during intubation was seen in 20 patients (15.1%). First pass success rate was achieved in 109 patients (82.6%). Twenty-one patients (15.9%) needed more than one attempt to intubate and the box had to be removed in 8 patients (6.1%) for facilitating intubation. The Mallampati score did not significantly influence either desaturation or first pass success rate.Conclusion:There was a non-significant increasing TTI trend in patients with a higher MP score with the use of an aerosol box. However, this did not translate to a clinically significant difference in the overall intubation outcomes.

Use of Fluorescence Foldscope as an Effective Tool for Detection of Biofilm Formation in Pseudomonas aeruginosa

AbstractPurpose:Pseudomonas aeruginosa is an opportunistic pathogen with biofilm-forming ability, by the virtue of which they can evade the immune response and antimicrobial chemotherapy. Several methods have been designed for the detection of biofilms but require sophisticated instrumentation and expertise. The present study, therefore, used an improvised device, ‘fluorescence foldscope’ which is an origami-based fluorescence microscope as an easy and effective tool to detect biofilm formation. Methodology: Three representatives of P. aeruginosa of clinical origin were taken for the study along with two reference strains PA01 and ATCC27853. The strains were cultured in Luria Bertani (LB) broth with and without carbapenem (imipenem and meropenem) and cephalosporin (ceftazidime, cefotaxime and ceftriaxone) pressure, respectively. The cultures were diluted to 1:100 in LB; seeded with sterile glass slides at 90° angle and incubated for 5 consecutive days. The slides were observed with fluorescence foldscope. Results: Fluorescence emission was observed in two test isolates CD1 and CD2 at 48 and 72 h, respectively, whereas no fluorescence was observed in CD3. The fluorescence observed in the isolates was not affected by 2 μg/ml carbapenem pressure, while with 2 μg/ml ceftazidime stress, a change in fluorescence was observed in CD2 in comparison to the fluorescence observed under normal growth condition. Conclusion: Fluorescence foldscopy is an effective and reliable tool for the detection of biofilm formation in clinical isolates of P. aeruginosa under different laboratory conditions. Biofilm-forming P. aeruginosa worsens the medical condition and is difficult to eradicate. The present study came up with an effective and reliable tool for the detection of biofilm formation in clinical isolates of P. aeruginosa.

Damage Control Vascular Surgery

Exsanguination is one of the most fearsome sequelae of trauma and is responsible for a large portion of both civilian and military mortality. The concept of damage control surgery is a critical development in the field of trauma largely driven by the growing understanding that coagulopathy and physiologic derangements are the primary cause of death in critically ill trauma patients. Damage control vascular surgery focuses on the rapid temporization of vascular injuries. Balloon occlusion can be utilized for rapid hemorrhage control (REBOA, foley catheter, retrohepatic caval balloon, etc.). In the setting of damage control, most veins can and should be ligated. Consideration of shunting should be made regarding the suprarenal inferior vena cava, the portal vein, and the superior mesenteric vein. The named arteries should be shunted and repaired when possible; however, redundant arterial beds can be safely ligated. Vessels of all sizes can be safely shunted with commercially available or improvised devices. Systemic heparinization is not necessary to maintain patency. More recently, the concept of using endovascular stents as long-term shunts has gained attention. These can be deployed traditionally under angiographic guidance or using the novel direct site endovascular repair (DSER) technique. The rapidly evolving field of endovascular trauma management has afforded a host of new management strategies for the physiologically deranged critically ill trauma patient.

Comparison of the Pharmacokinetic Properties of Naloxone Following the Use of FDA-Approved Intranasal and Intramuscular Devices Versus a Common Improvised Nasal Naloxone Device.

For more than a decade, first responders and the general public have been able to treat suspected opioid overdoses using an improvised nasal naloxone device (INND) constructed from a prefilled syringe containing 2mg of naloxone (1mg/mL) attached to a mucosal atomization device. In recent years, the U.S. Food and Drug Administration (FDA)-approved Ezvio, an autoinjector that delivers 2mg by intramuscular injection and Narcan nasal spray (2- and 4-mg strengths; 0.1mL/dose) for the emergency treatment of a known or suspected opioid overdose. The present study was conducted to compare the pharmacokinetics of naloxone using the FDA-approved devices (each administered once) and either 1 or 2 administrations using the INND. When naloxone was administered twice using the improvised device, the doses were separated by 2minutes. The highest maximum plasma concentration was achieved using the 4-mg FDA-approved spray. The highest exposures at 5minutes postdose, based on AUC values, were after administration with the autoinjector and the 4-mg FDA-approved spray; at 10, 15, and 20minutes postdose, the latter yielded the greatest exposure. Even after 2 administrations, the INND failed to achieve naloxone plasma levels comparable to the FDA-approved devices at any time. The ease of use and higher plasma concentrations achieved using the 4-mg FDA-approved spray, compared with the INND, should be considered when deciding which naloxone device to use.

Critical analysis of guidelines for providing sedation to patients undergoing gastrointestinal endoscopy procedures

In spite of growing numbers of gastrointestinal endoscopic procedures performed under deep sedation, guidelines are lacking. Hypoxemia and aspiration continue to be the main source of morbidity. Anesthesia providers have tried to address these concerns by modifying their technique and employing newer or improvised devices. In addition, preprocedural evaluation poses many challenges. In many centers, workload pressures determine the time available to perform such an evaluation. A comprehensive history and examination similar to a major surgical procedure is often not possible. As a result, a focused history and examination is essential. This should be followed by an appropriate explanation of risks before obtaining consent. A plan should be in place to manage complications such as aspiration. This paper provides a succinct review of the above aspects.

Обчислення похибок саморобних фізичних приладів з цифровими і аналоговими датчиками

The article deals with the problem of calculation of errors of improvised devices and installations for physical training experiment in the construction of which digital and analog sensors are used, which are intended for measuring various physical quantities. The general requirements for educational devices are considered: scientific and pedagogical, technical, ergonomic, aesthetic, economic. In the article special attention is paid to the technical requirements of improvised devices and installations. It is noted that it is necessary to ensure their reliability and durability, perfection and simplicity of construction, high metrological indicators. The basic stages of calculation of errors of measurement of physical quantities, features of measurements with use of digital measuring devices are given. The measurement process using digital measuring instruments and automatic measurement methods remove the measurement from subjective errors and have a number of other advantages. It is convenient to make computers and sensors in combination with hardware platforms Arduino, STM32, Raspberry, etc. for the output of home-made appliances. Analog sensors are connected to the analog inputs of the hardware and software platforms that perform analog-to-digital conversion. Digital sensors are easier to use and capable of providing high metrological performance in the design of self-made physical devices. Most sensors have errors in the instructions. The cases of calculation of errors, when the home-made installation uses optical steam as the main measuring tool, are considered. Optical pairs are used in many homemade physics installations - studies of body motion on an inclined plane, studies of rotational motion using Oberbeck pendulum, studies of mathematical pendulum, etc. Examples and schemes of installations and description of experiments with methods of calculation of measurement errors using optical pairs are given. As a result, it is noted that homemade devices using digital sensors, hardware platforms Arduino, STM32, Raspberry and others meet the general requirements for training devices, in particular, have high metrological indicators, are easy to manufacture and require little financial cost.

FORENSIC ASSESSMENT OF HOMEMADE AIRSOFT GRENADES

The paper presents the results of forensic analysis of improvised dummy grenades modeled after the airsoft hand grenade RGS-4 for use in tactical simulation wargames like «Airsoft». Initial testing by experts affiliated with a different system of forensic science institutes led to the conclusion that these devices are capable of producing explosions and causing fragmentation damage. The purpose of this study conducted by two forensic science centers of the Ministry of Justice of the Russian Federation was to correct the classification of improvised devices as explosive devices. Results indicate that these devices that consist of a cardboard (paper) or rubber-like casing filled with dried peas, with a «Korsar-4» firecracker in the middle, have the formal characteristics of an explosive device but cannot be regarded as such (as per Article 222 of the Criminal Code of the Russian Federation), since they are in effect typical imitation pyrotechnic devices similar to dummy hand grenades RGS-4 and display no significant damaging properties.

An emergency response decision matrix against terrorist attacks with improvised device in chemical clusters

Chemical industrial areas may constitute potential targets for deliberate actions by terrorists. Terrorists having sufficient knowledge of chemical process operations or plant layout may take advantage of improvised explosive devices (IEDs) to cause major events such as fire, explosion and toxic gas dispersion with cross-border consequences in chemical clusters. Thus, an efficient cluster-wise emergency plan to enhance the promptness and efficacy of responding to such attacks is crucial. In this study, the effects of blast wave caused by IEDs are assessed and its potentiality in triggering domino scenarios are analysed. A decision tree is developed to determine the emergency level of each company within the cluster based on the attack outcomes. Furthermore, an alert notification system is set based on a decision matrix. Finally, the identified emergency levels and the alert levels are presented in form of a multi-plant decision matrix. The application of the developed methodology is demonstrated in a case study.

Uterine Tamponade Device to Control Atonic Primary Postpartum Haemorrhage in Resource-Poor Settings

This paper proposes and presents the proof of concept for an improvised device adapted from the condom tamponade used for controlling atonic primary postpartum haemorrhage in resource-poor settings. The device has been designed to address the setbacks of the conventional condom tamponade. The setbacks of the condom tamponade were assessed. Using the systematic engineering design process, a device was designed to address the setbacks of the condom tamponade. The device comprises an inflation/deflation system, blood drainage system and clamping system. Results from testing show that for an inexperienced user, the device has quicker inflation (3.36 ± 1.70 minutes/ 500 ml) and faster set-up time (3.60 ± 1.50 minutes), as compared to the conventional condom tamponade. The clamping system of the device also ensures effective control of fluid dynamics and prevents backflow. The device, however, was not tested on human subjects to prove its efficacy for actual treatment of patients. The device also can be easily and quickly set-up and operated by frontline healthcare providers with limited expertise, in resource-poor settings. It has further been designed for safety (use of biocompatible materials and elimination of sharp edges for the parts expected to have direct contact with the uterus).

Single-frequency subsurface remote sensing via a non-cooperative source

ABSTRACTThe problem of detecting buried scatterers from their scattered field collected under a remote arrangement (i.e. with the sensors deployed at some stand-off distance from the air/soil interface) is considered. A new imaging method that does not require the knowledge of the incident field, information about the transmitting antenna position or timing is proposed. More in detail, the detection problem is cast as the reconstruction of the support of the equivalent surface currents (located at the air/soil interface), which the scattered field can be ascribed to. To this end, a single-view/multistatic configuration, which also reduces the radar system’s cost and complexity, can be employed. It is remarked that the proposed method does not allow to retrieve the scatterers’ depth. Therefore, it is conceived for all those situations where depth is of minor importance or when it is a priori known that the scatterers reside just beneath to the air/soil interface. This is the case, for example, in mine or unexploded improvised device detection where the primary aim is to detect the buried ordnances and locate them transversally. In these cases, the need for a frequency band can be relaxed as well, so that reconstructions can be achieved also in the single-frequency limit case. The latter is clearly a further advantage in that it simplifies the imaging system. The proposed method is checked against half-space synthetic data. The paper also includes some experimental results with data collected under free-space controlled laboratory conditions that can be considered as a proof of concept.

스마트폰의 CMOS 영상센서를 이용한 광용적맥파 측정방법 개발

맥파는 심전도와 같이 자율신경계를 통해 생리적 반응을 측정하는 신호이지만, 손가락에 센서 하나만 부착시키면 되기 때문에 상대적으로 신호의 측정이 간편하다는 장점을 가지고 있어 u-Healthcare 분야에서의 활용이 용이하다. 따라서 본 연구의 목적은 스마트폰 카메라의 CMOS 영상 센서를 활용하여 맥파를 비침습적으로 측정하는 방법 중의 하나인 광용적 맥파를 획득하고 이로부터 스트레스 여부를 판단하는 휴대형 시스템을 개발하여 u-Healthcare 분야에서의 활용 가능성을 확 인하는 것이다. 이를 위해 광용적맥파를 별도의 센서에 의한 측정이 아닌 스마트폰 카메라에서 획득되는 영상 데이터를 활용 하여 광용적맥파를 획득한 후 분석하였다. 또한 확보된 광용적맥파 영상신호 데이터를 이용하여 심박변이도와 스트레스 지 수를 별도의 호스트 장비 없이 스마트폰만을 이용해 사용자에게 제공 하였다. 또한 부가적으로 스마트폰에 부착가능한 별도 의 하드웨어 디바이스를 개발함으로써 획득된 데이터의 신뢰도 및 정확성을 향상시켰다. 실험결과를 통해 스마트폰의 카메 라 영상을 활용하여 광용적맥파 신호를 통한 심박수 측정과 스트레스의 정도를 분석하기 위한 스트레스 지수 추출이 가능함 을 확인할 수 있었다. 본 연구에서는 상용화된 제품 또는 정형화된 센서가 아닌 스마트폰의 카메라를 이용하기 때문에 상용 화된 외부 센서에 의한 광용적맥파 신호 보다는 해상도가 떨어지는 단점이 있음에도 불구하고 결과 데이터의 신뢰도 향상을 위한 별도의 추가외부 장치 개발 및 여러 가지 최적화 알고리즘을 통해 신뢰성 있는 데이터를 확보할 수 있어 u-Healthcare 장비로써의 활용 가능성을 확인할 수 있었다.

Prevention and Decontamination of Chemical, Biological, Radiological, and Nuclear Contaminants for the Emergency Medical Personnel during Ambulance Services

The first role and responsibility of emergency ambulance service is to provide a resource to save and serve the patient with the highest quality of care. Second, ambulance services are an option to temporarily provide treatment for an injured or exposed patient while removing decontamination. Lastly, rescue the exposed and or injured patient in the most suitable mode of transportation. These roles are all necessary to maintain a high level of confidence in ambulance practices while adhering to proper protocol transfer for a contaminated patient. Chemical, biological, radiological and nuclear defense (often abbreviated as CBRN defense or CBRND) is the term for protective measures taken in situations in which any of these four hazards are present. To account for improvised devices, the term CBRNe (e for explosives) is also used. CBRN defense consists of CBRN passive protection, contamination avoidance and CBRN mitigation [1]. Hanyang Med Rev 2015;35:146-151 http://dx.doi.org/10.7599/hmr.2015.35.3.146

Expériences et enjeux de la psychiatrie militaire en opération

For the French army, Afghanistan is a new challenge, especially for the French health service. That theatre is very different from other which the army knows better like Africa or Yugoslavia. The threat is constant, provided by fight, improvised explosive device, terrorism in the cities and rockets aiming the bases. Since 2009, a French military psychiatrist is based with the NATO Hospital at Kabul Airport. The mains problems are the consequences of three threats: fight with Talibans, risk of explosion on the road by improvised devices and attack by rockets on the camps. For each, the psychic reactions are different. Combats provide among the men postoperational stress and for some of them a risk of moral disengagement. But for the most part of them theses symptoms disappears quickly. The improvised explosives devices are the threat feared the most by troops, especially for the logistic convoy. The frequent symptoms are burn out, exhaustion and stress. Rockets like explosives devices are a blind threat and aren’t feared. But when some of them fall on a camp, the people presents sleep troubles, continual stress and PTSD. Alcohol or moral disengagement are not specific of Afghanistan but constitute other challenges. Each of the cases we described is an illustration of these observations of our experience during three months in Afghanistan.

The Efficacy of Spontaneous and Controlled Ventilation With Various Cricothyrotomy Devices: A Quantitative In Vitro Assessment in a Model Lung

Guidelines for the management of a difficult airway recommend performing a cricothyrotomy in a "can't intubate/can't ventilate" situation. We investigated the tidal volumes delivered by controlled and spontaneous ventilation by seven commercially available cricothyrotomy sets (cuffed: Quicktrach II, Portex Cricothyroidotomy Kit, and Melker cuffed cannula and uncuffed: Airfree, 4.0-mm ID Quicktrach, 6.0-mm inner diameter Melker, and 13-gauge Ravussin cannula) and two improvised devices (14-gauge intravenous cannula and spike and drip chamber device). A LS800 model lung, set at different values for compliance and resistance and modified with different upper airway diameter, was ventilated via the respective cricothyrotomy device mechanically and using a self-inflating bag. With the 13-gauge Ravussin cannula and the 14-gauge intravenous cannula, a Manujet injector was used for jet ventilation. Spontaneous ventilation was simulated with a Michigan 560i lung. During controlled or manual ventilation, all cuffed cricothyrotomy devices yielded adequate tidal volumes. Uncuffed devices provided tidal volumes≥300 mL only with an upper airway diameter of ≤3 mm. With a Manujet injector, adequate tidal volumes required an upper airway diameter between 3 mm and 5 mm. A spike and drip chamber device does not provide suitable emergency airway access. Spontaneous ventilation at adequate inspiratory pressure levels required a device inner diameter of at least 4 mm. As expected, cuffed cricothyrotomy devices yield the best results during controlled, manual, and spontaneous ventilation. With uncuffed cricothyrotomy devices, ventilation becomes ineffective when the upper airway obstruction allows for an upper airway diameter>3 mm.

Soft tissue damage attributed to the use of tongue depressors as an improvised device to apply pressure to treat epistaxis

Soft tissue damage attributed to the use of tongue depressors as an improvised device to apply pressure to treat epistaxis

The “Elbow-Way” to Proper Handwashing: A Device Improvised for Health Facilities Where there is no Running Water

Lack of running pipe-borne water is common to developing countries and therefore, water used in hospitals and laboratories are collected in buckets or basins from wells or bore holes. This often leads to contamination of the water from contact with the hands when this is used for routine handwashing. By improvising a plastic intravenous infusion bottle as soap dispenser, a longitudinal water tank with tap to deliver water, a hose-pipe connected to a plastic bowl on a table and a box containing clean towels, a handwashing set was designed. By applying pressure with the elbow on soap dispenser to obtain liquid soap and turning the tap with the elbow, hands can be properly washed. Using the elbow to control all manouvres reduced the chance of water contamination as no contact was made with the hands. The use of home-made liquid antiseptic soap also made the set useful in preventing contamination, especially as the shelf life of the prepared soap was shown to be up to four weeks with no significant microbial growth. More than 70% of health professionals on a trial run were assertive of the usefulness of the handwashing device. Overall result showed that hands were properly washed and contamination was minimal using the improvised device when there is no running tap water. Key Words: Handwashing, Elbow-way, Water Contamination, Running water. Jnl of Nigerian Infection Control Association Vol.4(1) 2001: 16-20

A Recycled Aid for Microscopists

To the Editor.— Immersion oil for use with microscopes is messy when it gets on the outside of the container, which it seems to do sooner or later. Various improvised devices and containers have been used in the past to cope with this problem, such as imbedding the bottle of immersion oil in a small platform of wax. A neat and simple holder for a common type of immersion oil bottle (1 fl oz capacity) can be made from the plastic top of an aerosol spray container if the outer diameter of the inner cap measures about 32 mm (Figure). The inner diameter of the inner cap and the diameter of the bottle to be held in it vary from sample to sample, so some element of custom fitting is necessary. This arrangement is unlikely to tip over, and after a five-year trial, has not become messy.