Journal of Medical Engineering and Technology最新文献

The mechanical properties of the myocardium in the left ventricle and right atrium were estimated by simultaneously measuring the local impedance (LI) and contact force (CF) using an ablation catheter. Radiofrequency catheter ablation (RFCA) is a well-established arrhythmia treatment. Monitoring the RF power, CF and properties of myocardium during RFCA are necessary to estimate the effect of ablation. Indices, such as CF, lesion size index and ablation index, do not include the myocardium mechanical properties. Therefore, there is the risk of side effects, such as cardiac tamponade, by excessive catheter indentation into vulnerable areas. We propose the simultaneous measurement of LI and CF for estimating the myocardial mechanical properties to reduce the side effects. In this study, an in vitro experimental system was constructed to measure LI and CF via the catheter. The relationship between the porcine myocardial tissue thickness and CF-LI curve was investigated using the left ventricle and right atrium. Power function coefficients approximating the CF-LI curve increased with thicker left ventricle. The thickness of the myocardium can be estimated by simultaneously measuring LI and CF. Intraoperative measurement of the myocardial mechanical properties can be used to determine the ablation conditions at each site.

To allow an amputee resume healthy walking, a well-designed lower limb prosthesis is required. However, in many developing countries, the cost of high-tech and often imported prosthesis is out of the financial reach of many amputees. The objective of this study was to design and implement a mechanical, body-powered transfemoral prosthetic device to help transfemoral amputees regain functional ambulation. The materials used include socket adapter, acetone hardener, plaster of Paris bandages, perlite lining, and polyester resin. Using anthropometric measurements of a volunteer amputee, a user-friendly and ergonomic transfemoral prosthetic device was designed using AutoCAD rendering and fabricated using engineering methods such as casting and welding. The prosthetic limb consists of a polypropylene socket, a galvanised iron knee joint with a hinge and spring suspension system, and a perlite foot. An evaluation of the prosthetic limb after fabrication showed that it restores the ambulatory function of the amputee.

The recent global coronal virus pandemic raised increased awareness towards ideal hand hygiene procedures as promoted by World Health Organisation (WHO) and other related health care associations. Compliance to the prescribed procedure has been rather difficult as people gradually get accustomed to this effective hand wash habit, especially with regards the 20 s hand rub process. Traditional hand wash faucets with manual controls are prone to exposing users to recontamination or transmission of infectious deceases. Also, water wastage of 51.32% was observed from empirical studies. The designed automated standalone hand wash unit (ASHU) seeks to solve the contamination problem by running a contactless tap operation, while guiding users through the ideal hand wash procedure with the aid of visual and audio annunciators. Being a standalone unit, solar energy in used to power of the low power design system for uninterrupted outdoor operation, even in unelectrified rural regions. With the suitable level sensors and IoT infrastructure put in place, the unit maintenance operators are able to monitor the fluid levels in with the aid of a custom-built mobile app. Subsequently, the ASHU yields a water wastage potential of only a maximum of 13.31% and a user satisfaction guarantee for 93% of the refill cycle.

The present work deals with the design of a cylinder-piston arrangement to deliver the required tidal volume (TV) of air to the patient through the respiratory tract especially in the setting of severe acute respiratory syndrome corona virus 2 (SARS CoV-2) or corona virus disease (COVID-19). The design ensures that only the desired volume of air is delivered in each breath and a negative pressure is retained at the delivery point in a separate cylinder. The frequency of piston motion is the same as that of the average human respiratory rate (RR). The effect of negative pressure on time of evacuation under the present condition has been verified. The present design provides a compact ventilator unit with a surface area of 0.8 × 0.4 m² with a minimal power requirement of 116.48 W. An RR of 16 is obtained with a volume flow rate in lit/s by using a twin cylinder arrangement with bore diameter 0.1 m and length 0.4 m. The ratio of inspiration time to expiration time is designed to be 1:2 by controlling the stroke frequency as 16 and piston speed 0.32 m/s. The present design provides promising quantitative information on the design of an automated continuous mechanical ventilator (CMV), which is different from bag mask valve (BMV) operated ventilators, and on preventing and minimising barotrauma.

The COVID-19 pandemic has seen the advent of novel medical devices and practices. Demand for quality healthcare services rose exponentially which eventually led to accessibility becoming a major issue of concern. In addition to this, in-person consultations and various other conventional treatment methods were proven to be problematic. Limitations of traditional health care systems such as in-person consultations were highlighted, and conventional treatment methods have proven to be problematic. As an alternative approach, telehealth services are now gaining recognition due to their high efficiency, ease of use, and state-of-the-art technology. In this article, trends of telemedicine and its evolving popularity across the medical community due to the pandemic and beyond are studied and highlighted. An online survey form was circulated to 42 medical practitioners and interns to analyse the growing interest in telemedicine. The questionnaire covered the physicians' perspectives, preferences, experiences, and other important aspects of home-based teleconsultation. Based on the responses collected from doctors and medical interns, 14.2% disapproved, whereas 38.1% favoured and 47.6% showed a neutral response to the teleconsultation. More than 50% of the respondents claim the process to be time-consuming and 42% of them perceived it to be the other way round. 4.8% of the doctors preferred it to be only through computers whereas 45.2% per cent preferred consultation through smartphones and 50% of them preferred it be both ways. More than half (59.5%) of the doctors preferred the pandemic scenario and the remaining for its continued usage post-pandemic. Although India has the world's second-largest online market, a major population in India is digitally illiterate according to the Digital Foundation of India. Thus, it is important to devise telehealth technology that is simplest to use to reach also the economically backward patient communities.

Monitoring blood glucose levels is a vital indicator of diabetes mellitus management. The mainstream techniques of glucometers are invasive, painful, expensive, intermittent, and time-consuming. The ever-increasing number of global diabetic patients urges the development of alternative non-invasive glucose monitoring techniques. Recent advances in electrochemical biosensors, biomaterials, wearable sensors, biomedical signal processing, and microfabrication technologies have led to significant research and ideas in elevating the patient's life quality. This review provides up-to-date information about the available technologies and compares the advantages and limitations of invasive and non-invasive monitoring techniques. The scope of measuring glucose concentration in other bio-fluids such as interstitial fluid (ISF), tears, saliva, and sweat are also discussed. The high accuracy level of invasive methods in measuring blood glucose concentrations gives them superiority over other methods due to lower average absolute error between the detected glucose concentration and reference values. Whereas minimally invasive, and non-invasive techniques have the advantages of continuous and pain-free monitoring. Various blood glucose monitoring techniques have been evaluated based on their correlation to blood, patient-friendly, time efficiency, cost efficiency, and accuracy. Finally, this review also compares the currently available glucose monitoring devices in the market.

Thermal threshold testing is important for evaluating the thermal function of small-fibre nerve types C and A-delta. This study investigated the reliability and validity of a novel nerve testing device (NNTD) in evaluating thermal detection and thermal pain thresholds. Test-retest reliability of the NNTD and its concurrent validity compared to the current technology (Medoc TSA-2, Advanced Thermosensory Stimulator, Israel) were investigated among 10 healthy participants. Each participant was tested for the warm detection threshold (WDT), cold detection threshold (CDT), hot pain threshold (HPT) and cold pain threshold (CPT) on the medial forearm with NNTD for two trials and the Medoc TSA-2 for one trial over two consecutive days. Intraclass Correlation Coefficient values, Standard Error of Measurement and Bland Altman plots were calculated for test-retest reliability. One-way ANOVA and Bland Altman plots were calculated for validity. The test-retest reliability of the NNTD was good for CPT (ICC = 0.88), moderate for WDT (ICC = 0.545) and HPT (ICC = 0.710). The NNTD was valid for both trials of HPT and CPT and one trial for WDT compared to the Medoc TSA-2. In conclusion, the NNTD showed good to moderate reliability and was found to be valid compared to the Medoc TSA-2.

In view of the gaps between the current clinical thermometer standards and the commercially available products, in particular the introduction of forehead radiation thermometers into the market, ISO initiated a review on standard for clinical thermometers. The original clinical thermometer standard includes requirements for evaluating tympanic (ear) thermometers using identified reference blackbody sources. However, one of the challenges in reviewing the standard is to understand if the reference blackbody sources identified for ear thermometers are still usable for evaluating the laboratory accuracy of forehead thermometers. In order to answer this challenge, four brand new forehead thermometers from two different manufacturers are evaluated at NMC. Two reference blackbody sources, one JIS standard source with very small opening and one NMC source with larger opening, are used for the evaluation. In order to use JIS standard source, two types of adaptors, one supplied by one of the manufactures, one 3D printed, are evaluated. The measurement results together with their measurement uncertainties are presented and analysed. Suitable adaptors are identified and recommended.

An exploratory study was performed to determine the distribution of surgical smoke particulate matter (SSPM) and evacuation times within an AirSeal^® System and a traditional insufflation access system in various simulated surgical scenarios. Identified trends showed statistical significance when setting the AirSeal^® System to Low smoke evacuation that it reduces the percentage of particulate matter at the Access Port opening. Additionally, it was observed that when utilising a laparoscopic tool a similar trend in particle distributions were seen between either insufflation and access system at the opening of the Access Port and trocar. Evacuation times for SSPM removal within the AirSeal^® System showed an overall average to ≥95% reduction of 5.64 min within the surgical cavity, 3.69 min at the Access Port opening, and 3.61 min within the smoke evacuation line. The overall average for the traditional insufflation and access system was 9.38 min within the surgical cavity and 6.06 min at the trocar opening. Results showed that when using the traditional system compared to the AirSeal^® System, it resulted in a percent change increase in evacuation times of 66.31% within the surgical cavity and 64.23% at the trocar opening.