Multiple Medical Devices Research Articles

Modified electrode placements for measurement of hemodynamic parameters using impedance cardiography

Measuring and monitoring hemodynamic parameters has brought many benefits in supporting diagnosis and treatment for cardiovascular patients. There are many advantages to measuring hemodynamic parameters by non-invasive technique based on impedance cardiography (ICG) such as simplicity, real-time and low cost. However, the electrode positions of this method are very difficult to implement in cases where the patient has to use multiple medical devices at the same time, especially for patients on active treatment and resuscitation. This paper presents the results of the study proposing new three locations of ICG electrodes to overcome the above limitation. Accordingly, we measured and evaluated 10 volunteers on the Niccomo device. The results show that all three positions of proposed electrode can be used to replace standard electrode position. In particular, the 1st proposed position, can be used to measure all five hemodynamic parameters HR, SV, LVET, Zo, CO and ICG waveforms, expressed by the average correlation and the relative average difference of five parameters, = 0.9641 and = 3.31%. The 2nd proposed position can be used to measure four parameters HR, SV, LVET, CO and ICG waveforms shown by = 0.9091 and = 8.67%. The 3rd proposed position can be used to measure three parameters HR, Zo and LVET, expressed by = 0.8485 and = 9.26%.

Likelihood Ratio Test Method for Multiple Medical Devices Comparison Using Multiple-Site Data with Continuous Outcomes.

With a record number of medical devices approved or cleared, it is important to understand the performance of devices once they are on the market. Using data from multiple medical devices and multiple sites, the problem of interest in this article is to detect if a device is a signal; that is, if a device performs significantly different from other devices of the same class, when the outcome of interest is a continuous variable. We develop a normal likelihood ratio test (LRT) method, henceforth referred to as normal-LRT, by incorporating sample size information into the methodological framework, to detect device signals using multi-site and multi-device data. It is shown via extensive simulation that the proposed method controls the type-I error and false discovery rate (FDR), while having good power and sensitivity. This method is applied to a hypothetical case study, in which 6 medical devices of the same class are compared. The normal-LRT method can be considered as a tool for device signal detection using data from multi-site and multi-device when the outcome of interest is a continuous measurement.

Developing an Evaluation Framework for Selecting Optimal Medical Devices

The objective of this study is to summarize the current general evaluation process that stakeholders use to evaluate single or multiple medical devices to select the optimal medical device. This study constructed a novel evaluation framework to select the optimal medical device by overcoming the limitations of assessments that were previously confined to the medical device cycle and the purpose of the specific assessment. It also presents a general framework for incorporating usability evaluations into the frame to reflect the objectives and characteristics of key stakeholders in the medical device industry. In addition, the results of medical device evaluation are further analyzed using the analytical hierarchy process (AHP).

Collodion Remover Can Degrade Plastic-Containing Medical Devices Commonly Used in the Intensive Care Unit

ABSTRACTCollodion remover, a solvent blend used to remove collodion glue after long-term video EEG monitoring, was implicated as a potential causative factor in patient safety events at our institution during which damage to plastic components of medical devices was noted in the intensive care unit. We sought to determine experimentally whether collodion remover could lead to degradation of multiple plastic-containing medical devices commonly used in the intensive care unit to determine whether workflow changes were needed during electrode removal. We exposed devices to collodion remover for brief, intermediate, and prolonged durations. We report that collodion remover is capable of degrading the hard plastic components of multiple medical devices after prolonged exposure; however, intermediate duration exposure was also capable of producing damage to clave connectors used with intravenous and central lines, which could plausibly lead to adverse events given the widespread use of these devices. These data suggest a pathway-based approach to collodion remover use might be beneficial in minimizing the potential impact of this solvent on plastic-containing medical devices.

ガス供給と電源容量の問題が解決されhigh flow nasal cannula呼吸補助下に施設間陸路搬送した1例(A case of interhospital ground transport with a high flow nasal cannula for respiratory support enabled by the resolution of gas and power supply capacity problems)

要旨High flow nasal cannula（HFNC）療法は様々な医療場面での使用が増加しているが，HFNCを用いた施設間搬送の報告は少ない。これまで当院では，HFNCシステムへの酸素・混合ガス供給とドクターカーの電源容量の問題によりHFNC呼吸補助下の施設間陸路搬送が実施できなかった。しかし，新たなHFNCシステムの導入と，ドクターカーの電源容量増加と補助電源の確保により，HFNCを用いた施設間搬送が可能となった。今回，我々はHFNC呼吸補助下に施設間陸路搬送した症例を経験したので報告する。症例は11か月の男児。Respiratory syncytial virus（RSV）細気管支炎による急性呼吸不全のため当院へ転院し，pediatric intensive care unit（PICU）でHFNC療法が導入された。その後症状が軽快しHFNC呼吸補助下に医療機関へ転院搬送となった。搬送中，呼吸状態の悪化や重篤な副作用を認めず，安全に搬送が行われた。搬送にHFNCを用いる場合，デバイスによっては呼吸器設定に限界があること，屋外使用時はデバイスへの外気温の影響を考慮すること，および複数の医療機器を同時に使用する場合の総電源容量と搬送車両の電源容量を把握するなど留意すべき点がある。今後，症例を蓄積し施設間搬送におけるHFNC療法の安全性と有効性を評価する必要がある。

Successful control of Elizabethkingia meningoseptica outbreak in a neuro-surgical intensive care unit of a tertiary care hospital in North India

Elizabethkingia meningoseptica has been found to be associated with a broad range of infectious etiologies, most notably outbreaks of neonatal meningitis. In adults, it can also cause pneumonia, endocarditis, bacteremia, meningitis and even skin and soft tissue infections, primarily in immunocompromised individuals. We report a cluster of 3 cases with E. meningoseptica infection in an adult neurology critical care unit of a 400-bedded tertiary care hospital situated in Gurugram (Delhi-National Capital Region), India. Two patients were diagnosed with ventilator-associated-pneumonia (VAP) and one was a patient in whom the organism was isolated from a cerebrospinal fluid (CSF) sample. Clinical details were studied and outbreak investigation was carried out. We found the following common risk factors for infection: Prolonged ICU stay, exposure to multiple antibiotics, presence of underlying co-morbidities and insertion of multiple invasive medical devices. E. meningoseptica was isolated from the catheter mount connected between endotracheal tube and ventilation circuit of one patient but clonality could not be studied. Strict infection control protocols and environmental cleaning procedures terminated the outbreak.

Ultrasound Responsive Macrophase-Segregated Microcomposite Films for in Vivo Biosensing

Ultrasound imaging is a safe, low-cost, and in situ method for detecting in vivo medical devices. A poly(methyl-2-cyanoacrylate) film containing 2 μm boron-doped, calcined, porous silica microshells was developed as an ultrasound imaging marker for multiple medical devices. A macrophase separation drove the gas-filled porous silica microshells to the top surface of the polymer film by controlled curing of the cyanoacrylate glue and the amount of microshell loading. A thin film of polymer blocked the wall pores of the microshells to seal air in their hollow core, which served as an ultrasound contrast agent. The ultrasound activity disappeared when curing conditions were modified to prevent the macrophase segregation. Phase segregated films were attached to multiple surgical tools and needles and gave strong color Doppler signals in vitro and in vivo with the use of a clinical ultrasound imaging instrument. Postprocessing of the simultaneous color Doppler and B-mode images can be used for autonomous identification of implanted surgical items by correlating the two images. The thin films were also hydrophobic, thereby extending the lifetime of ultrasound signals to hours of imaging in tissues by preventing liquid penetration. This technology can be used as a coating to guide the placement of implantable medical devices or used to image and help remove retained surgical items.

Cost effectiveness of medical devices to diagnose pre-eclampsia in low-resource settings

BackgroundMaternal mortality remains a major health challenge facing developing countries, with pre-eclampsia accounting for up to 17% of maternal deaths. Diagnosis requires skilled health providers and devices that are appropriate for low-resource settings. This study presents the first cost-effectiveness analysis of multiple medical devices used to diagnose pre-eclampsia in low- and middle-income countries (LMICs). MethodsBlood pressure and proteinuria measurement devices, identified from compendia for LMICs, were included. We developed a decision tree framework to assess the cost-effectiveness of each device using parameter values that reflect the general standard of care based on a survey of relevant literature and expert opinion. We examined the sensitivity of our results using one-way and second-order probabilistic multivariate analyses. ResultsBecause the disability-adjusted life years (DALYs) averted for each device were very similar, the results were influenced by the per-use cost ranking. The most cost-effective device combination was a semi-automatic blood pressure measurement device and visually read urine strip test with the lowest combined per-use cost of $0.2004 and an incremental cost effectiveness ratio of $93.6 per DALY gained relative to a baseline with no access to diagnostic devices. When access to treatment is limited, it is more cost-effective to improve access to treatment than to increase testing rates or diagnostic device sensitivity. ConclusionsOur findings were not sensitive to changes in device sensitivity, however they were sensitive to changes in the testing rate and treatment rate. Furthermore, our results suggest that simple devices are more cost-effective than complex devices. The results underscore the desirability of two design features for LMICs: ease of use and accuracy without calibration. Our findings have important implications for policy makers, health economists, health care providers and engineers.

Extracorporeal Membrane Oxygenator Withdraw Protocol: Avoiding Chaos (SA522)

•Present the results of ECMO patient tracers and an institutional needs assessment, which was used to create a withdraw policy.•Show audience members a video of ECMO withdraw in the SIM lab to display the results of our streamlined process.•Share the ECMO policy and educational handouts to help institutions create their own policies and education modules. The use of extracorporeal membrane oxygenators (ECMO) is increasing in the United States. It has been used consistently in the pediatric patient populations for decades. In recent years, VenoVenous ECMO has become standard of care for refractory adult respiratory distress syndrome at quaternary care centers. In addition, VenoArterial ECMO is being used for viral cardiomyopathy, failed cardiotomies, and as a temporary bridge to transplant. With survival on VV ECMO at 60% and VA ECMO at 40%, there are growing numbers of Americans dying after ECMO withdraw. The process of ECMO withdraw is complex. Tracer patients at our health system have as many as 15 family members and 25 clinicians involved in the discontinuation. Technology withdraw often involved multiple medical devices and multiple teams of providers, leading to poor communication and increased distress. Death is unique and sudden following discontinuation, which adds additional moral distress for family members and members of the care team. Our institution conducted a needs assessment across multiple departments and constructed an ECMO withdraw protocol with an accompanying ECMO education program. Our goal for the initiative was to improve clinical efficiency, improve staff knowledge about ECMO withdraw to change attitudes and values, and ensure patient comfort at end of life.

Factors Associated With Occipital Pressure Ulcers in Hospitalized Infants and Children.

The occiput is a common location for development of pressure ulcers in hospitalized infants and young children. However, risk factors associated with occurrence of the ulcers have not been fully described. To identify factors associated with development of occipital pressure ulcers in acutely ill infants and children. Charts of all patients with occipital pressure ulcers reported in a computerized safety event reporting system since its implementation in 2005 and of any patients with such ulcers recalled by members of the skin care special interest group were reviewed retrospectively. During a 4-year period, 60 cases of occipital pressure ulcers were identified: 40% stage I, 12% stage II, 30% unstageable, and 18% deep tissue Injury. The median age of the sample was 12 months. Among the patients, 86% were in the intensive care unit with cardiovascular or pulmonary problems. A total of 68% had comorbid conditions. Most of the patients were less than 1 year old; were critically ill, requiring high-risk therapies; and had multiple medical devices in place. Patients with the ulcers were commonly treated with mechanical ventilation (83%) and sedation (74%) and were described as agitated (42%). Many of these patients were receiving vasoactive medications (50%) and had vascular access devices in the neck that restricted head movement (45%). When documented, the median Braden Q score was 16. Infants and children at risk for occipital pressure ulcers can be prospectively identified, allowing implementation of nursing interventions to prevent these ulcers.

Understanding barriers and facilitators to the use of Clinical Information Systems for intensive care units and Anesthesia Record Keeping: A rapid ethnography

ObjectiveThis study evaluated the current use of commercial-off-the-shelf Clinical Information Systems (CIS) for intensive care units (ICUs) and Anesthesia Record Keeping (ARK) for operating rooms and post-anesthesia care recovery settings at three Veterans Affairs Medical Centers (VAMCs). Clinicians and administrative staff use these applications at bedside workstations, in operating rooms, at nursing stations, in physician's rooms, and in other various settings. The intention of a CIS or an ARK system is to facilitate creation of electronic records of data, assessments, and procedures from multiple medical devices. The US Department of Veterans Affairs (VA) Office of the Chief of Nursing Informatics sought to understand usage barriers and facilitators to optimize these systems in the future. Therefore, a human factors study was carried out to observe the CIS and ARK systems in use at three VAMCs in order to identify best practices and suggested improvements to currently implemented CIS and ARK systems. MethodsWe conducted a rapid ethnographic study of clinical end-users interacting with the CIS and ARK systems in the critical care and anesthesia care areas in each of three geographically distributed VAMCs. Two observers recorded interactions and/or interview responses from 88 CIS and ARK end-users. We coded and sorted into logical categories field notes from 69 shadowed participants. The team transcribed and combined data from key informant interviews with 19 additional participants with the observation data. We then integrated findings across observations into meaningful patterns and abstracted the data into themes, which translated directly to barriers to effective adoption and optimization of the CIS and ARK systems. ResultsEffective optimization of the CIS and ARK systems was impeded by: (1) integration issues with other software systems; (2) poor usability; (3) software challenges; (4) hardware challenges; (5) training concerns; (6) unclear roles and lack of coordination among stakeholders; and (7) insufficient technical support. Many of these barriers are multi-faceted and have associated sub-barriers, which are described in detail along with relevant quotes from participants. In addition, regionalized purchases of different CIS and ARK systems, as opposed to enterprise level purchases, contributed to some of the identified barriers. Facilitators to system use included (1) automation and (2) a dedicated facility-level CIS-ARK Coordinator. ConclusionsWe identified barriers that explain some of the challenges with the optimization of the CIS and ARK commercial systems across the Veterans Health Administration (VHA). To help address these barriers, and evolve them into facilitators, we categorized report findings as (1) interface and system-level changes that vendors or VA healthcare systems can implement; (2) implementation factors under VA control and not under VA control; and (3) factors that may be used to inform future application purchases. We outline several recommendations for improved adoption of CIS and ARK systems and further recommend that human factors engineering and usability requirements become an integral part of VA health information technology (HIT) application procurement, customization, and implementation in order to help eliminate or mitigate some of the barriers of use identified in this study. Human factors engineering methods can be utilized to apply a user-centered approach to application requirements specification, application evaluation, system integration, and application implementation.

Modeling Lengthy Work-ups in Gastrointestinal Bleeding

Multiple procedures and medical devices are being used in a complex interplay to diagnose and treat gastrointestinal bleeding. The aim of the study was to develop a mathematical model that helps in estimating the average number of procedures to be expected in the general management of gastrointestinal bleeding. The modeling process serves as an example of how mathematical analysis in general can be used to answer unresolved clinical questions, lead to a better understanding of the underlying influences in a disease process, and provide a starting point for future clinical trials. The analysis uses a Markov chain to model the transition probabilities among consecutive interventions used to find and treat a bleeding site. The results show that starting a work-up of gastrointestinal bleeding with an esophagogastroduodenoscopy will lead on average to 2.69 procedures per patient. Of these expected procedures, 1.46 will be esophagogastroduodenoscopies, 0.69 colonoscopies, 0.25 video capsule endoscopies, 0.14 double-balloon enteroscopies, and 0.14 procedures from interventional radiology. Management chains initiated with a colonoscopy result in similar outcomes. Among 10,000 simulated individual patients, the number of procedures varies between 1 and 16 consecutive procedures, with 95% of all patients undergoing 6 procedures or less. The outcomes of the model suggest that the published success rates of endoscopic and radiographic procedures are overly optimistic. The results also point to the need to generate clinical data through future studies that more reliably account for treatment failures and the interchange among various complementary diagnostic modalities.

Online mining abnormal period patterns from multiple medical sensor data streams

With the advanced technology of medical devices and sensors, an abundance of medical data streams are available. However, data analysis techniques are very limited, especially for processing massive multiple physiological streams that may only be understood by medical experts. The state-of-the-art techniques only allow multiple medical devices to independently monitor different physiological parameters for the patient's status, thus they signal too many false alarms, creating unnecessary noise, especially in the Intensive Care Unit (ICU). An effective solution which has been recently studied is to integrate information from multiple physiologic parameters to reduce alarms. But it is a challenge to detect abnormalities from high frequently changed physiological streams data, since abnormalities occur gradually due to the complex situation of patients. An analysis of ICU physiological data streams shows that many vital physiological parameters are changed periodically (such as heart rate, arterial pressure, and respiratory impedance) and thus abnormalities are generally abnormal period patterns. In this paper, we develop a Mining Abnormal Period Patterns from Multiple Physiological Streams (MAPPMPS) method to detect and rank abnormalities in medical sensor streams. The efficiency and effectiveness of the MAPPMPS method is demonstrated by a real-world massive database of multiple physiological streams sampled in ICU, comprising 250 patients' streams (each stream involving over 1.3 million data points) with a total size of 28 GB data.

The Braden Q+P: A Pediatric Perioperative Pressure Ulcer Risk Assessment and Intervention Tool

Pressure ulcers continue to be a personally and financially expensive complication of surgery and hospitalization. The effects of anesthesia, immobilization during surgery, and use of multiple medical devices all place the surgical patient at high risk for pressure-related skin injury. As part of a comprehensive pressure ulcer prevention initiative, nurses in the cardiac and main ORs at Children's Hospital Boston, Massachusetts, became concerned that current pressure ulcer risk assessment tools did not adequately capture the intense but short-term risk posed in the operating and procedural suites. A team, formed to investigate this matter, developed a tool to guide nursing assessment of patient risk and to plan nursing interventions to prevent pressure ulcers. Results after implementation of the Braden Q+P tool appear to show improvement in preventing pressure ulcers. Increased awareness of pressure ulcer prevention, a hospital focus on skin care, and nursing education about pressure ulcers supported this improvement.

Disruptive Innovation: The Future of Healthcare?

The traditional face-to-face doctor-patient relationship is the core of conventional medical practice. One key aspect of this changing relationship is the increasing dependency on asynchronous data collection in clinical consultations. Such electronic communications and data streams may be numeric, text-based, audio, digitized still pictures, video and radiologic, as well as emanating from multiple medical devices. While asynchronous medicine may be established in specialties like radiology and dermatology, there is little research regarding the use of asynchronous medicine in areas of medicine that traditionally rely on the physical doctor-patient interaction such as primary care, internal medicine, geriatrics, and psychiatry. The practice of psychiatry stands out as a discipline that is highly dependent on the quality of the physical meeting between the doctor and the patient, yet even in this specialty it is possible to utilize asynchronous medicine for some types of psychiatric consultations. Asynchronous medicine has the potential to be significantly disruptive to our current healthcare processes, as well as more clinically and economically efficient.

Maximizing a transport platform through computer technology.

One of the most recent innovations coalescing computer technology and medical care is the further development of integrated medical component technology coupled with a computer subsystem. One such example is the self-contained patient transport system known as the Life Support for Trauma and Transport (LSTAT(tm)). The LSTAT creates a new transport platform that integrates the most current medical monitoring and therapeutic capabilities with computer processing capacity, creating the first "smart litter". The LSTAT is built around a computer system that is network capable and acts as the data hub for multiple medical devices and utilities, including data, power, and oxygen systems. The system logs patient and device data in a simultaneous, time-synchronized, continuous format, allowing electronic transmission, storage, and electronic documentation. The third-generation LSTAT includes an oxygen system, ventilator, clinical point-of-care blood analyzer, suction, defibrillator, infusion pump, and physiologic monitor, as well as on-board power and oxygen systems. The developers of LSTAT and other developers have the ability to further expand integrative component technology by developing and integrating clinical decision support systems.

A follow-up study of electromagnetic interference of cellular phones on electronic medical equipment in the emergency department.

Considering the growing use of cellular phones and the fast appearance of new phone models, the electromagnetic interference of currently popular cellular phones on electronic medical equipment was tested. Three Personal Communication System cellular phones were put at different distances from multiple electronic medical devices, the interference effect was observed and the electromagnetic field strength measured with a spectrum analyser. Only two small pieces of equipment, the CO2 airway adapter and the haemoglucostix meter were affected and then only when the phone was in very close proximity. Compared to the results of our study in 1997 testing Global System for Mobile Communication phones, the Personal Communication System phones generated less electromagnetic interference. However a much larger scaled study and an accurate international electromagnetic interference standard are recommended before any change in the current restrictive hospital policy on mobile phone usage could be recommended.