A Handheld Noninvasive Sensing Method for the Measurement of Compartment Pressures

2013 ◽  
Author(s):  
C. Flegel ◽  
K. Singal ◽  
R. Rajamani
Keyword(s):  
Compartment Syndrome ◽  
Fluid Pressure ◽  
Magnetic Field Measurement ◽  
In Vitro Test ◽  
Non Invasive ◽  
Fluid Compartment ◽  
Combat Casualty ◽  
The Individual ◽  
Compartment Pressures

Compartment syndrome is a major concern in cases of extremity trauma, which occur in over 70% of military combat casualty. Without treatment, compartment syndrome can lead to paralysis, loss of limb, or death. This paper focuses on the development of a handheld sensor that can be used for the non-invasive diagnosis of compartment syndrome. Analytical development of the sensing principle is first presented in which a relation is obtained between the pressure in a fluid compartment and the stiffness experienced by a handheld probe pushing on the compartment. Then a handheld sensor that can measure stiffness of an object without requiring the use of any inertial reference is presented. The handheld sensor consists of an array of three miniature force-sensing spring loaded pistons placed together on a probe. The center spring is chosen to be significantly stiffer than the side springs. The ratio of forces between the stiff and soft springs is proportional to the stiffness of the soft object against which the probe is pushed. Small mm-sized magnets on the pistons and magnetic field measurement chips are used to measure the forces in the individual pistons. Experimental results are presented using an in-vitro test rig that replicates a fluid pressure compartment. The sensor is shown to measure pressure accurately with a resolution of 0.1 psi over the range 0.75 psi to 2.5 psi.

Development and Experimental Validation of A Handheld Noninvasive Sensor for the Measurement of Compartment Pressures

2014 ◽  
Vol 8 (1) ◽  
Author(s):  
C. Flegel ◽  
K. Singal ◽  
R. Rajamani ◽  
R. Odland
Keyword(s):  
Compartment Syndrome ◽  
Fluid Pressure ◽  
Magnetic Field Measurement ◽  
Fluid Compartment ◽  
Combat Casualty ◽  
Analytical Development ◽  
Extremity Injuries ◽  
The Individual ◽  
Compartment Pressures

Compartment syndrome is a major concern in cases of extremity trauma, which occur in over 70% of military combat casualty. Without treatment, compartment syndrome can lead to paralysis, loss of limb, or death. This paper focuses on the development of a handheld sensor that can be used for the noninvasive diagnosis of compartment syndrome. Analytical development of the sensing principle is first presented in which a relation is obtained between the pressure in a fluid compartment and the stiffness experienced by a handheld probe pushing on the compartment. Then a handheld sensor that can measure stiffness of an object without requiring the use of any inertial reference is presented. The handheld sensor consists of an array of three miniature force-sensing spring loaded pistons placed together on a probe. The center spring is chosen to be significantly stiffer than the side springs. The ratio of forces between the stiff and soft springs is proportional to the stiffness of the soft object against which the probe is pushed. Small millimeter-sized magnets on the pistons and magnetic field measurement chips are used to measure the forces in the individual pistons. Experimental results are presented using both an in vitro pneumatic test rig and a compliant agarose gel chamber that replicates a fluid pressure compartment. The sensor is shown to measure pressure accurately with a resolution of 0.1 psi over the range 0.75–2.5 psi. The developed sensor has the potential to be useful for convenient handheld diagnosis of compartment syndrome in traumatic extremity injuries.

scholarly journals Tablet Scoring: Current Practice, Fundamentals, and Knowledge Gaps

2019 ◽  
Vol 9 (15) ◽  
pp. 3066 ◽  
Author(s):  
Emmanuel Reginald Jacques ◽  
Paschalis Alexandridis
Keyword(s):  
Prescription Drugs ◽  
In Vitro Test ◽  
Dose Administration ◽  
Solid Dosage ◽  
Non Invasive ◽  
Health Care Practitioners ◽  
Tablet Splitting ◽  
Vitro Test

Oral solid dosage formulations and/or tablets have remained the preferred route of administration by both patients and health care practitioners. Oral tablets are easy to administer, they are non-invasive and cause less risk adversity. Because of the lack of commercially available tablet dose options, tablets are being split or partitioned by users. Tablet scoring refers to the breakage of a tablet to attain a desired efficacy dose and is an emerging concept in the pharmaceutical industry. The primary reason for the tablet scoring practice is to adjust the dose: dose tapering or dose titrating. Other reasons for tablet partitioning are to facilitate dose administration, particularly among the pediatric and the geriatric patient population, and to mitigating the high cost of prescription drugs. The scope of this review is to: (1) evaluate the advantages and inconveniences associated with tablet scoring/portioning, and (2) identify factors in the formulation and the manufacturing of tablets that influence tablet splitting. Whereas tablet partitioning has been a common practice, there is a lack of understanding regarding the fundamentals underpinning the performance of tablets with respect to splitting. Several factors can influence tablet partitioning: tablet size, shape, and thickness. A requirement has recently been set by the European Pharmacopoeia and the U.S. Food and Drug Administration for the uniformity of mass of subdivided tablets. For breaking ease, an in-vivo reference test and a routinely applicable in-vitro test need to be established.

scholarly journals In vitro efficacy of several disinfectants against Salmonella enterica serovar Enteritidis and Escherichia coli strains from poultry

2016 ◽  
Vol 46 (8) ◽  
pp. 1438-1442
Author(s):  
Sonia Martínez-Martínez ◽  
Sheila Yubero-Delgado ◽  
Elías-Fernando Rodríguez-Ferri ◽  
Rafael Frandoloso ◽  
Álvaro Álvarez-Estrada ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Environmental Control ◽  
Control Measures ◽  
In Vitro Test ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Vitro Test ◽  
The Individual ◽  
Ammonium Compounds

ABSTRACT The efficacy of 28 individual or blended disinfectants against avian Salmonella enterica serovar Enteritidis and Escherichia coli strains was determined. An in vitro test in the presence and absence of serum as source of organic material was conducted. Povidone-iodine (releasing 1% available iodine), 1% potassium permanganate, 70% ethanol, 2% chlorhexidine digluconate and three commercial formulations based on quaternary ammonium compounds + formaldehyde or cresol derivates were the most effective against all strains tested and reduced bacterial counts by more than 106 times (6-log10) regardless of the presence of organic matter. These commercial compounds as well as ethanol and chlorhexidine among the individual substances tested might be helpful in the adoption of environmental control measures against these two enterobacteria in poultry industry.

Non-invasive monitoring method for lower-leg compartment syndrome using a wireless sensor system and finite element analysis

2020 ◽  
pp. 095441192098124
Author(s):  
Fuh-Yu Chang ◽  
Ping-Tun Teng ◽  
Liang-Chun Chen
Keyword(s):  
Finite Element ◽  
Compartment Syndrome ◽  
Lower Leg ◽  
Sensor System ◽  
Compartment Pressure ◽  
Posterior Compartment ◽  
Element Analysis ◽  
Non Invasive ◽  
Detecting Method

In this study, a non-invasive pressure monitoring system that is portable and convenient was designed for detecting compartment syndrome. The system combines a wireless module and smartphone, which aids in the achievement of mHealth objectives, specifically, the continuous monitoring of the compartment pressure in patients. A compartment syndrome detecting method using a wireless sensor system and finite element analysis is developed and verified with an in vitro lower-leg model by rapid prototyping. The sensor system is designed to measure a five point pressure variation from the outside of the lower leg and transmit the data to a smartphone via Bluetooth. The analysis model based on the finite element method is employed to calculate the change of pressure and volume inside the four compartments of the lower leg. The in vitro experimental results show that the non-invasive detecting method can monitor the compartment pressure and provide a warning for the occurrence of compartment syndrome if the compartment pressure is higher than 30 mmHg. Furthermore, the theoretical simulation of the real lower leg shows similar trends to those of the in vitro experiments and can promptly detect the occurrence of compartment syndrome. Measured pressure values exceeding 6.3, 2.7, and 2.8 kPa for the three sensors contacting the outside centers of the superficial posterior, anterior, and lateral compartments, respectively, can indicate that each compartment contains a pressure higher than 30 mmHg. These results can provide a warning for the risk of compartment syndrome of each compartment. In addition, the measured values from the three sensors contacting the superficial posterior compartment at the outside center, close to the tibia, and close to the lateral compartment exceeding 1.8, 0.7, and 0.7 kPa, respectively, can indicate the risk of deep posterior compartment syndrome.

scholarly journals Real-time, non-invasive thrombus detection in an extracorporeal circuit using micro-optical thrombus sensors

2020 ◽  
pp. 039139882097865
Author(s):  
Nobutomo Morita ◽  
Daisuke Sakota ◽  
Akiko Oota-Ishigaki ◽  
Ryo Kosaka ◽  
Osamu Maruyama ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Sensors ◽  
Thrombus Formation ◽  
Flow Channel ◽  
Working Fluid ◽  
In Vitro Test ◽  
Extracorporeal Circuit ◽  
Non Invasive ◽  
Maximum Range

Introduction: Real-time, non-invasive monitoring of thrombus formation in extracorporeal circuits has yet to be achieved. To address the challenges of conventional optical thrombus detection methods requiring large devices that limit detection capacity, we developed a micro-optical thrombus sensor. Methods: The proposed micro-optical thrombus sensor can detect the intensity of light scattered by blood at wavelengths of 660 and 855 nm. Two thrombus sensors were installed on in vitro circuit: one at the rotary blood pump and one at a flow channel. To evaluate the variation in the ratio of incident light intensity at each wavelength of the two sensors, Rfluct (for 660 nm) and Ifluct (for 855 nm) were defined. Using fresh porcine blood as a working fluid, we performed in vitro tests of haematocrit (Hct) and oxygen saturation (SaO2) variation and thrombus detection. Thrombus tests were terminated after Rfluct or Ifluct showed a larger change than the maximum range of those in the Hct and SaO2 variation test. Results: In all three thrombus detection tests, Ifluct showed a larger change than the maximum range of those in the Hct and SaO2 variation test. After the tests, thrombus formation was confirmed in the pump, and there was no thrombus in the flow channel. The results indicate that Ifluct is an effective parameter for identifying the presence of a thrombus. Conclusion: Thrombus detection in an extracorporeal circuit using the developed micro-optical sensors was successfully demonstrated in an in vitro test.

Putative anticarcinogenic actions of carotenoids: nutritional implications

1993 ◽  
Vol 71 (9) ◽  
pp. 732-745 ◽  
Author(s):  
Allan Davison ◽  
Eunice Rousseau ◽  
Bruce Dunn
Keyword(s):  
Epidemiological Studies ◽  
Optimal Choice ◽  
In Vitro Test ◽  
Cause And Effect ◽  
Intervention Trials ◽  
Dark Green ◽  
The Individual ◽  
Β Carotene

This review provides an update on nutritional aspects of carotenoids (as distinct from retinoids), with specific relevance to anticarcinogenesis. Critical gaps remain in our knowledge of the nutritional functions of carotenoids despite an overwhelming accumulation of research data in areas tangential to human nutrition. In addition to their roles as precursors of retinol and retinoids, carotenoids have distinct functions of their own in animals and humans. In vitro they are antioxidants with a broad range of potencies. In vivo, they protect porphyries against sunlight. The evidence for anticarcinogenic actions of β-carotene in certain specified test situations is persuasive. Nevertheless, despite a large number of studies demonstrating protection by carotenoids, the characteristics that render a given carotenoid effective and the relative efficacy of the individual carotenoids are not known. Moreover, dose–response and pharmacokinetic relationships remain virtually unexplored. Research to uncover mechanisms of protection by carotenoids is, for technical reasons, painfully slow. Epidemiological studies reveal associations but not cause and effect. To explore cause and effect, intervention trials are underway, hampered by the paucity of data regarding optimal choice of carotenoid, dosage, and regimen. The in vitro test systems that would provide this information are not available because the molecular sites relevant to the chemopreventive action of carotenoids are obscure. Each of these problems has a solution, but not a simple one. Until these are resolved, blanket recommendations regarding supplementation will remain problematic. To this point, health authorities have not recommended dietary supplementation with carotenoids. Instead, they recommend increased consumption of yellow and dark green carotenoid-rich vegetables. In the future, an individual at risk for a particular carcinogenic process may be recommended a supplement of the most appropriate anticarcinogen, specific to their individual endowment of genetic and environmental risk factors. This review emphasizes not only what is known but also what is not known. Consequently we identify priorities for research that, if undertaken, will allow such recommendations to be made or discounted with more confidence.Key words: β-carotene, carotenoids, free radicals, antioxidants, carcinogenesis, chemoprevention.

REDUCED FIBRINOLYTIC POTENTIAL IN PATIENTS WITH ARTERIAL OCCLUSIVE DISEASE (AOD) IN COMPARISON WITH NORMAL SUBJECTS

1987 ◽  
Author(s):  
D Hartl ◽  
E Tiso ◽  
K Anderle ◽  
A Philapitsch ◽  
G Anger
Keyword(s):  
Whole Blood ◽  
Test System ◽  
Individual Response ◽  
In Vitro Test ◽  
Dependent Manner ◽  
The Individual ◽  
Dose Dependent ◽  
Fibrinolytic Potential ◽  
Normal Controls

When combining angioplasty and local lysis with urokinase (UK) in treatment of peripheral arterial occlusions we have observed marked differences in the individual patient's response irrespective of the age of the thrombus. The extensive arteriosclerotic changes revealed by angioghraphy in some of these patients suggest a reduced fibrinolytic potential depending on the underlying disease.In the standard in vitro test system we measured the UK-dependent thrombolysis in blood samples from 10 normal controls at UK concentrations of 150, 200, and 300 IU/ml of whole blood. In comparison we determined the whole blood thrombolysis time (WBTT) of 10 patients with A0D using UK concentrations of 150, 200, and 300 IU/ml of whole blood. The mean WBTT values for normal controls obtained at UK concentrations of 150 IU/ml, 200 IU/ml, and 300 IU/ml, respectively, amounted to S.5, 5.5, and 3.5 minutes, respectively, while in patients mean values of 20.7, 8.1, and 5.5 minutes, respectively, were found.Studies on plasma samples had shown that the lysis time could be shortened in a dose-dependent manner by addition of lys-plasminogen and to some extent also glu-plasminogen. Since lys-plasminogen gave clearly superior results we tried to improve the lytic potential in terms of a shortening of the WBTT by adding different doses of lys-plasminogen (0.14 - 0.56 CU/ml whole blood) to each patient sample. Although the individual response varied, the addition of lys-plasminogen to the patient samples resulted in a clear dose-dependent improvement of pathologically Pronged lysis times. We conclude from these in vitro findings that the failure of fibrinolytic therapy may in some cases be due to a reduced lytic potential, which may be enhanced Dy administration of lys-plasminogen, even when the plasminoqen level is normal.

Haemostatic Platelet Plug Formation in the Isolated Rabbit Mesenteric Preparation - An Analysis of Red Blood Cell Participation

1980 ◽  
Vol 44 (01) ◽  
pp. 006-008 ◽  
Author(s):  
D Bergqvist ◽  
K-E Arfors
Keyword(s):  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
In Vitro Test ◽  
Pharmacological Agents ◽  
Vitro Test ◽  
Releasing Effect ◽  
Plug Formation

SummaryIn a model using an isolated rabbit mesenteric preparation microvessels were transected and the time until haemostatic plugs formed was registered. Perfusion of platelet rich plasma gave no haemostasis whereas whole blood did. Addition of chlorpromazine or adenosine to the whole blood significantly prolonged the time for haemostasis, and addition of ADP to the platelet rich plasma significantly shortened it. It is concluded that red cells are necessary for a normal haemostasis in this model, probably by a combination of a haemodynamic and ADP releasing effect.The fundamental role of platelets in haemostatic plug formation is unquestionable but there are still problems concerning the stimulus for this process to start. Three platelet aggregating substances have been discussed – thrombin, adenosine diphosphate (ADP) and collagen. Evidence speaking in favour of thrombin is, however, very minimal, and the discussion has to be focused on collagen and ADP. In an in vitro system using polyethylene tubings we have shown that "haemostasis" can be obtained without the presence of collagen but against these results can be argued that it is only another in vitro test for platelet aggregation (1).To be able to induce haemostasis in this model, however, the presence of red blood cells is necessary. To further study this problem we have developed a model where haemostatic plug formation can be studied in the isolated rabbit mesentery and we have briefly reported on this (2).Thus, it is possible to perfuse the vessels with whole blood as well as with platelet rich plasma (PRP) and different pharmacological agents of importance.

Follicular fluid and assisted reproductive technology programs outcomes (literature review)

GYNECOLOGY ◽  
2020 ◽  
Vol 21 (6) ◽  
pp. 36-40
Author(s):  
Anna G. Burduli ◽  
Natalia A. Kitsilovskaya ◽  
Yuliya V. Sukhova ◽  
Irina A. Vedikhina ◽  
Tatiana Y. Ivanets ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Assisted Reproductive Technology ◽  
Follicular Fluid ◽  
Economic Cost ◽  
Reproductive Technology ◽  
Art Programs ◽  
Vitro Fertilization ◽  
Non Invasive ◽  
Established Fact

The review presents data on metabolites in the follicular fluid (FF) from the perspective of reproductive medicine and their use in order to predict outcomes of assisted reproductive technology (ART) programs. It considers various components of this biological medium (hormones, lipids, melatonin, etc.) with an assessment of their predictive value in prognosis of the effectiveness of in vitro fertilization (IVF) programs. The data on experimental directions in this field and the prospects for their use in clinical practice are presented. The article emphasizes that the growing clinical need and the unsolved problem of increasing the effectiveness of ART programs determine the need for further studies of the FF composition. Materials and methods. The review includes data related to this topic from foreign and Russian articles found in PubMed which were published in recent years. Results. Given the established fact of a direct effect of FF composition on growth and maturation of oocytes, and further, on the fertilization process, various FF metabolites are actively investigated as non-invasive markers of quality of oocytes/embryos. The article provides data on the experimental directions in this field and the prospects for their use in clinical practice. However, clinical studies of a relation between various FF metabolites levels and outcomes of IVF programs are contradictory. Conclusion. Owing large economic cost for treatment of infertility with IVF, there is need for expansion and intensification of studies to identify and use reliable predictors in prognosis of ART programs outcomes.

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