Melissa Naiman

Evaluation of advanced cooling therapy’s esophageal cooling device for core temperature control

ABSTRACT Managing core temperature is critical to patient outcomes in a wide range of clinical scenarios. Previous devices designed to perform temperature management required a trade-off between invasiveness and temperature modulation efficiency. The Esophageal Cooling Device, made by Advanced Cooling Therapy (Chicago, IL), was developed to optimize warming and cooling efficiency through an easy and low risk procedure that leverages heat transfer through convection and conduction. Clinical data from cardiac arrest, fever, and critical burn patients indicate that the Esophageal Cooling Device performs very well both in terms of temperature modulation (cooling rates of approximately 1.3°C/hour, warming of up to 0.5°C/hour) and maintaining temperature stability (variation around goal temperature ± 0.3°C). Physicians have reported that device performance is comparable to the performance of intravascular temperature management techniques and superior to the performance of surface devices, while avoiding the downsides associated with both.

Temperature modulation with an esophageal heat transfer device- a pediatric swine model study

BackgroundAn increasing number of conditions appear to benefit from control and modulation of temperature, but available techniques to control temperature often have limitations, particularly in smaller patients with high surface to mass ratios. We aimed to evaluate a new method of temperature modulation with an esophageal heat transfer device in a pediatric swine model, hypothesizing that clinically significant modulation in temperature (both increases and decreases of more than 1°C) would be possible.MethodsThree female Yorkshire swine averaging 23 kg were anesthetized with inhalational isoflurane prior to placement of the esophageal device, which was powered by a commercially available heat exchanger. Swine temperature was measured rectally and cooling and warming were performed by selecting the appropriate external heat exchanger mode. Temperature was recorded over time in order to calculate rates of temperature change. Histopathology of esophageal tissue was performed after study completion.ResultsAverage swine baseline temperature was 38.3°C. Swine #1 exhibited a cooling rate of 3.5°C/hr; however, passive cooling may have contributed to this rate. External warming blankets maintained thermal equilibrium in swine #2 and #3, demonstrating maximum temperature decrease of 1.7°C/hr. Warming rates averaged 0.29°C/hr. Histopathologic analysis of esophageal tissue showed no adverse effects.ConclusionsAn esophageal heat transfer device successfully modulated the temperature in a pediatric swine model. This approach to temperature modulation may offer a useful new modality to control temperature in conditions warranting temperature management (such as maintenance of normothermia, induction of hypothermia, fever control, or malignant hyperthermia).

Handheld directed energy sensor for environmental monitoring and clinician safety

INTRODUCTION Directed energy (DE) research and development is generating more powerful portable devices designed to support operational, environmental, clinical, point detection, and remote-sensing applications. These same DE devices present potential for injury, thereby impacting medical operations. The environmental surveillance and clinical communities require handheld sensor platforms that afford preemptive detection and monitoring of potentially hazardous exposures to DE and other electromagnetic (EM) frequencies. METHODS A personal digital assistant (PDA) was interfaced with a wavelength sensor board via a multifunction data acquisition card to passively detect wavelengths in the 480-950 nm range. A 9V DC battery coupled to a voltage up-converter with a manual ON/OFF switch powered the sensor board. The sensor board was integrated with a standard operating system-based PDA. Graphical programming software integrated the data acquisition card with the PDA. RESULTS The DE wavelength sensor/PDA platform detected and relayed laser radiation information from 480 to 950 nm ranges, with graphical data output to the PDA screen. DISCUSSION This project demonstrated the technical ability to detect anthropogenic DE frequency signatures using a handheld, battery-driven DE sensor platform. Laboratory and field assessment studies are underway to validate operational applications. This DE-sensing prototype is designed explicitly for DE medical measurement and signatures intelligence (MED MASINT) to meet the protection needs of environmental and clinical operators.

Overestimated electrical exposure risk associated with hands-on defibrillation?

We congratulate Lemkin et al. on their recent well-done study easuring a plausible worst-case energy-transfer scenario that escuers might encounter while performing routine resuscitative easures.1 However, we are concerned that the conclusions may verstate the risks, and potentially cause rescuers even greater ear of inadvertent shock, resulting in yet longer pauses in CPR. he authors’ estimation of electrical hazard for contact used the ssumption that contact would be between two anatomic sites with ome finite distance between them, and mention that a shock hazrd exists even if the only points of contact are both hands on top f the chest; however, in standard CPR, the hands are placed at he same location on the chest.2,3 Consequently, the value of the ariable Vrescuer in most, if not all, scenarios, is likely to be 0, and he derived rescuer-received dose (RRD) would likewise be 0 in the ast majority of cases. The alternative case of contact by additional ther body parts may offer a mechanism for greater RRD, but given he fact that little evidence exists that any rescuer or bystander has ver been seriously harmed by receiving an inadvertent shock,4 it ppears that this is an unlikely (multi-fault mechanism) scenario. e therefore advise caution before generating unnecessary fear or esitancy in rescuers attempting to provide optimal care for their atients.

Non-invasive Detection of Unique Molecular Signatures in Laser-Induced Retinal Injuries

Unintentional laser exposure is an increasing concern in many operational environments. Determining whether a laser exposure event caused a retinal injury currently requires medical expertise and specialized equipment that are not always readily available. The purpose of this study is to test the feasibility of using dynamic light scattering (DLS) to non-invasively detect laser retinal injuries through interrogation of the vitreous humor (VH). Three grades of retinal laser lesions were studied: mild (minimally visible lesions), moderate (Grade II), and severe (Grade III). A pre-post-treatment design was used to collect DLS measurements in vivo at various time points, using a customized instrument. VH samples were analyzed by liquid chromatography/tandem mass spectrometry (LC-MS/MS) and relative protein abundances were determined by spectral counting. DLS signal analysis revealed significant changes in particle diameter and intensity in laser-treated groups as compared with control. Differences in protein profile in the VH of the laser-treated eyes were noted when compared with control. These results suggest that laser injury to the retina induces upregulation of proteins that diffuse into the VH from the damaged tissue, which can be detected non-invasively using DLS.

Retrospective Analysis of Esophageal Heat Transfer for Active Temperature Management in Post-cardiac Arrest, Refractory Fever, and Burn Patients

Abstract Core temperature management is an important aspect of critical care; preventing unintentional hypothermia, reducing fever, and inducing therapeutic hypothermia when appropriate are each tied to positive health outcomes. The purpose of this study is to evaluate the performance of a new temperature management device that uses the esophageal environment to conduct heat transfer. De-identified patient data were aggregated from three clinical sites where an esophageal heat transfer device (EHTD) was used to provide temperature management. The device was evaluated against temperature management guidelines and best practice recommendations, including performance during induction, maintenance, and cessation of therapy. Across all active cooling protocols, the average time-to-target was 2.37 h and the average maintenance phase was 22.4 h. Patients spent 94.9% of the maintenance phase within ±1.0°C and 67.2% within ±0.5°C (574 and 407 measurements, respectively, out of 605 total). For warming protocols, all of the patient temperature readings remained above 36°C throughout the surgical procedure (average 4.66 h). The esophageal heat transfer device met performance expectations across a range of temperature management applications in intensive care and burn units. Patients met and maintained temperature goals without any reported adverse events.

Non-invasive detection of laser-induced retinal injury through the vitreous using dynamic light scattering(Conference Presentation)

Laser radiation entering the eye has the potential of damaging the retina. As an inflammatory response, the proteins can rush to the lesion site created by laser exposure. We explore the hypothesis if these proteins can be detected non-invasively. In this preliminary study, we developed a new brief-case size dynamic light scattering instrument to detect these proteins in-vivo in the rabbit vitreous. The results were validated with bio-chemical analysis.

Cursor on Target: Research for a Sensor Network

Summary Terrorism, epidemics, natural, and man-made disasters have increased over the last decade, prompting ongoing evaluation and incremental rebuilding of the American public health system (Chan, Killeen, Griswold, & Lenert, 2004a; Yu, Brock, Mecozzi, Tran, & Kost, 2010). In February 2002, the Center for Disease Control (CDC) identified six focus areas to generate response capacities to bioterrorism and public emergencies. According to one focus area, information sharing and alert notifications between systems and public health agencies must be continuous and automatic (Popovich, Henderson, & Stinn, 2002) Advancements in technology set the stage for this uninterrupted data-sharing requirement to be met; for example, “smart devices” can digitally record and transmit information and text messages from remote disaster sites using wireless ad hoc networks. In this context, medical systems and personnel can provide enhanced patient support from the extraction point to the hospital, even when normal landline infrastructure has been damaged. However, care may be restricted due to the limited recognition of proprietary information and the distance between the transmitter and collector system. This article suggests that overcoming these limitations necessitates the adoption of interoperability by basic operations and illustrates how an Internet Protocol called Cursor-on-Target can facilitate communication between open source and propriety systems.