Elsie Effah Kaufmann | University of Ghana (original) (raw)

Papers by Elsie Effah Kaufmann

Experimental Biology and Medicine

Cellulose fiber–reinforced composite scaffolds have recently become an interesting target for bio... more Cellulose fiber–reinforced composite scaffolds have recently become an interesting target for biomedical and tissue engineering (TE) applications. Cassava bagasse, a fibrous solid residue obtained after the extraction of cassava starch and soluble sugars, has been explored as a potential source of cellulose and has been successfully used to enhance the mechanical properties of gelatin scaffolds for TE purposes. This study assessed the cytocompatibility of the cassava microfiber–gelatin composite scaffold using human embryonic kidney cells (HEK 293) and a breast cancer cell line (MDA MB 231) under ISO 10993-5 standards. The viability of cells within the composite scaffold was analyzed through MTT assay. The growth of HEK 293, as well as the cell morphology, was not affected by the presence of cellulose within the composite, whereas the growth of breast cancer cells appeared to be inhibited with noticeable changes in cell morphology. These findings suggest that the presence of the cas...

PLOS ONE

Purpose In vivo dosimetry is a quality assurance tool that provides post-treatment measurement of... more Purpose In vivo dosimetry is a quality assurance tool that provides post-treatment measurement of the absorbed dose as delivered to the patient. This dosimetry compares the prescribed and measured dose delivered to the target volume. In this study, a tissue-equivalent water phantom provided the simulation of the human environment. The skin and entrance doses were measured using GafChromic EBT2 film for a Theratron® Equinox Cobalt-60 teletherapy machine. Methods We examined the behaviors of unencapsulated films and custom-made film encapsulation. Films were cut to 1 cm × 1 cm, calibrated, and used to assess skin dose depositions and entrance dose. We examined the response of the film for variations in field size, source to skin distance (SSD), gantry angle and wedge angle. Results The estimated uncertainty in EBT2 film for absorbed dose measurement in phantom was ±1.72%. Comparison of the measurements of the two film configurations for the various irradiation parameters were field si...

International Journal of Gynecology & Obstetrics, 2019

Objective: To design and fabricate a subcutaneous contraceptive implant insertion simulator, and ... more Objective: To design and fabricate a subcutaneous contraceptive implant insertion simulator, and to characterize the performance of nursing students trained with and without the simulator. Method: A cross-sectional study was conducted on nursing students in Ghana who had no previous training in the insertion of contraceptive implants. They were given standardized training in insertion of implants from 25 April to 26 April, 2016, and then were randomly assigned to an intervention or control group. The control group watched insertions of live implants while the intervention group practiced using the simulator. Local materials were used to fabricate the simulator. The performance of both groups was assessed after the training. Results: The participants consisted of 50 nursing students. Those in the intervention group were more likely to: insert the implant accurately (95.2% vs 78.4%, P<0.001); take less time to complete an insertion (mean of 33.6 seconds vs 42.2 seconds, P<0.001); and commit fewer errors (1.9 vs 2.5, P=0.005) compared to the control group. In addition, participants rated the simulator high on 11/11 of the product requirements with the teaching (93.2%), learning (91.4%), and skill acquisition (88.6%) requirements being the highest rated. Conclusion: A low-cost, locally fabricated simulator is an effective tool for augmenting the current training protocol by improving insertion skills of contraceptive implants.

Journal of Biomedical Materials Research, 1995

The passivating surface oxide on titanium is one of the elements considered in the explanation of... more The passivating surface oxide on titanium is one of the elements considered in the explanation of the favorable biologic response of this metal in implant applications. In the present study, transmission electron microscopy was used to identify the crystal structure and morphology of the oxide film on commercially pure titanium specimens before and after immersion in simulated physiologic fluids. The results show that the oxide layer is composed mainly of anatase and rutile, both of which are tetragonal in structure. Although the simulated physiologic fluids did not induce an observable change in the crystal structure for the immersion times investigated, the results indicate an immersion-induced change in microstructure from a fine-grained to a coarser-grained structure. The grain growth observed could be attributed to the growth of the native oxide crystals; however, it most likely results from the formation of a new oxide layer. The results also support oxide thickening as one of the processes associated with passive dissolution of titanium.

Plenary Paper Session I: Water

... 153 DESIGN OF A SIZE-ADJUSTABLE SURGICAL SHOE: PROMOTING OPTIMAL ASEPSIS COMFORTABLY Jason At... more ... 153 DESIGN OF A SIZE-ADJUSTABLE SURGICAL SHOE: PROMOTING OPTIMAL ASEPSIS COMFORTABLY Jason Atike 1 and Elsie Effah Kaufmann 2 ... Introduction Until the introduction of the principles of aseptic technique in the late 1800s pioneered by Joseph Lister,[1, 2 ...

Stethoscopes are used to listen to acoustic signals from the internal organs of the human body. A... more Stethoscopes are used to listen to acoustic signals from the internal organs of the human body. Although stethoscopes play a very important role in the diagnosis process, the chest piece and the connecting cable are known to facilitate transmission of pathogens from patient to patient and from patient to the user. Replacing the connecting cable with a wireless system may help reduce the potential risk and further allow broadcasting of the signals to multi-users for examination. This work reports on the design of a two-piece Bluetooth-based wireless system that eliminates the connecting cables in electronic stethoscopes. The design consists of a Bluetooth based integrated chest-piece module for captured acoustic sound transmission and a microcontroller-based (MSP430) head-piece receiver module for decoding the data for the three operational modes of the stethoscope. The design was first tested using a chirp signal source with frequency of 10 Hz – 5 kHz. Results obtained for the three...

Biomedical Engineering: Applications, Basis and Communications, 2016

A need assessment exercise at various resource-limited hospitals in Ghana revealed that a convent... more A need assessment exercise at various resource-limited hospitals in Ghana revealed that a conventional method of monitoring uterine contractions is employed. This method is time consuming and ineffective with a likelihood of misrepresenting data on uterine contractions. There is therefore a need for a system that can potentially overcome the identified challenges. In this paper, the authors present the proof of concept for development of an automated uterine contraction monitoring system designed for use in resource-limited settings. Following the engineering design process, data were gathered to draft product specifications. Various concepts were evaluated and a mathematical model of chosen concept was built and simulated. A functional prototype was constructed to test the system’s ability to measure the frequency and average duration of muscle contractions over a specified interval. The results indicate the capability of the chosen concept to meet design specifications. The design...

Artificial bone graft materials formed from wollastonite have been extensively used in bone repai... more Artificial bone graft materials formed from wollastonite have been extensively used in bone repair because of their high degree of bioactivity and biocompatibility, thereby justifying the development of a protocol for large-scale production. This work reports a novel route for preparing wollastonite via the sol-gel process using bentonite clay as a cheap silica source. The obtained wollastonite was characterized for morphology, elemental composition, phase composition and bioactivity using scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction and Fourier transform infrared spectroscopy. Results obtained revealed that wollastonite phase was successfully formed in the material and it showed ability to induce formation of apatite within 0.5 day in biological fluid, an indicator for bone-bonding capability. Overall, the wollastonite prepared from the bentonite clay exhibited properties comparable to that synthesized from commercially obtained sodium metasilicate. Hence, our synthetic route may be useful for commercial-scale preparation of wollastonite.

In this study we investigate the cytotoxicity of de-starched cassava fibre granules and fine powd... more In this study we investigate the cytotoxicity of de-starched cassava fibre granules and fine powder using human peripheral blood mononuclear cells (PBMC) and examine changes in the composition of Simulated Body Fluid (SBF) resulting from immersion of cassava fibre samples. The purpose of the study was to characterise cassava fibre for possible biomaterial applications. Preliminary results indicate insignificant cytotoxic effects on PBMCs with cassava sample concentrations of 0.1g/ml, 0.025g/ml and 0.00625g/ml. Additionally there was little or no significant change in Na, K, Mg, Cl, Ca, Mn, and Cu concentrations upon immersion in SBF as observed over a one week period at a temperature of 37°C. These initial results suggest cassava fibre may be considered for biomaterial applications following more extensive characterisation.

To solve congestion problems facing many hospitals in developing countries, baby cots are being e... more To solve congestion problems facing many hospitals in developing countries, baby cots are being eliminated and mothers are made to sleep on the same bed with their new-born babies; a practice known as co-sleeping. The work presented here seeks to reduce risks of Sudden Infant Death Syndrome (SIDS) and suffocation associated with co-sleeping by employing the formal engineering design process to develop a portable, safe and cost effective baby cot. The cot is attachable to the mother’s bed, has four movement restrictors to regulate the movement of the baby within a given range and a hard surface mattress to ensure the safety of the baby. There are ventilation ports provided to keep the temperature within the cot comfortable. The design can be modified to be used by older babies and may be mounted on a collapsible stand where space limitations are not critical.

This research investigates how prototype format, here defined as the physical nature of a prototy... more This research investigates how prototype format, here defined as the physical nature of a prototype, influences feedback from stakeholders in the process of designing a medical device. We presented medical practitioners with a variety of prototypes, including a sketch, a cardboard mock-up, a CAD model and a 3D printed model, of the same idea for an assistive, contraceptive implant insertion device and asked for their feedback. We found that the prototype format influenced the distribution within the answer categories. We also found that the type of question influenced the distribution within the answer categories.

Journal of Biomimetics, Biomaterials and Biomedical Engineering, 2017

This paper proposes and presents the proof of concept for an improvised device adapted from the c... more 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 dev...

Australasian. Journal of Engineering Education, 2015

Biomedical and clinical engineers are critical to lowand middle-income countries (LMICs) in order... more Biomedical and clinical engineers are critical to lowand middle-income countries (LMICs) in order to facilitate the local design, development and production of health technologies. Undergraduate biomedical engineering programmes are growing in LMICs, but few studies have sought to understand student perceptions of their discipline. Two open-ended survey instruments were used to measure perceptions of biomedical engineering students at a large Ghanaian university. Upper and lower classmen revealed similar conceptions of what it means to be a biomedical engineer, however, they perceived limited job opportunities (almost exclusively in the sales, maintenance or procurement of hospital equipment). Furthermore, upper classmen noted the desire to pursue further education to obtain better employment, whereas lower classmen did not consider it a likely path after graduation.

Sterilisation, a key method for reducing the transfer of communicable diseases, is an exterminati... more Sterilisation, a key method for reducing the transfer of communicable diseases, is an extermination method for microorganisms from the surface of devices, culture media, fluids and reagents. In a developing country such as Ghana, electricity is often unavailable and supply when available is frequently unreliable. High cost of existing sterilisation systems, inefficient microbe elimination by improvised methods and material degradation were identified as major inadequacies associated with sterilisation systems, currently being employed. Using a formal engineering design process, a sterilisation system satisfying objectives of user safety, high operational efficiency, competitive cost, and an aesthetically pleasing appearance was developed for hospitals, clinics, traditional birth attendants and beauty parlours. The affordable steriliser resolves the aforementioned limitations by operating without the use of electricity and attains sterility without material degradation. The design ma...

International Journal of Engineering Education, 2018

We have developed an experiential learning global health design program that emphasizes direct in... more We have developed an experiential learning global health design program that emphasizes direct interactions withstakeholders and first-hand exposure to the contexts in which solutions will be implemented. Students in the program gainpractical hands-on experience identifying and defining unmet global health needs in low-resource settings and applyhuman-centered and co-creative design approaches. Device designs that incorporate rigorously collected and analyzedfirst-hand data from diverse users and stakeholders rather than anecdotal or poorly represented information are moreeffective at meeting true needs. To date, more than 100 undergraduate student participants have identified hundreds ofneeds in collaboration with sub-Saharan and Asian healthcare providers. Approximately 400 students from the U.S.,Ghana, Ethiopia, and Uganda have contributed to the generation of technology concept solutions to address these needs.Program outcomes include approximately 100 student design projects co...

Polymers

This work reports on the use of low-cost pineapple leaf fiber (PALF) as an alternative reinforcin... more This work reports on the use of low-cost pineapple leaf fiber (PALF) as an alternative reinforcing material to the established, commonly used material for prosthetic socket fabrication which is carbon-fiber-reinforced composite (CFRC) due to the high strength and stiffness of carbon fiber. However, the low range of loads exerted on a typical prosthetic socket (PS) in practice suggests that the use of CFRC may not be appropriate because of the high material stiffness which can be detrimental to socket-limb load transfer. Additionally, the high cost of carbon fiber avails opportunities to look for an alternative material as a reinforcement for composite PS development. PALF/Methyl Methacrylate-based (MMA) composites with 0°, 45° and 90° fiber orientations were made with 5–50 v/v fiber volume fractions. The PALF/MMA composites were subjected to a three-point flexural test to determine the effect of fiber volume fraction and fiber orientation on the flexural properties of the composite....

Glass Physics and Chemistry

Glass/polymer composites can mimic the natural structure of bone by possessing a fiber-matrix con... more Glass/polymer composites can mimic the natural structure of bone by possessing a fiber-matrix configuration which provides appropriate physical and biological properties. Wollastonite ceramics are known for their promising bioactivity and biocompatibility when applied in bone regeneration. Polyvinyl alcohol (PVA) has various attractive properties including biocompatibility and degradability which may be exploited as a polymer matrix in composites for biomedical applications. Therefore, a cost-effective method of preparing wollastonite/PVA composites is desirable by starting from bentonite clay as a silica source for the glass, instead of traditional alkoxysilanes. The composite prepared was characterized by mechanical testing, scanning electron microscopy, X-ray diffractometry and Fourier-transform infrared spectroscopy to evaluate its compressive strength, morphology, phase composition and bioactivity, respectively. Results obtained revealed for the composite a compressive strength of 0.3 MPa, the ability to induce apatite on its surface when immersed in a simulated body fluid for 7 days and desirable controlled degradation. Hence, this method can be up-scaled for preparation of wollastonite/PVA composite commercially for possible use in bone regeneration.

Blood warming is usually required to get the temperature of blood to 37 o C from storage temperat... more Blood warming is usually required to get the temperature of blood to 37 o C from storage temperatures of 1-6 o C to prevent hypothermia during transfusions. Needs assessment at various hospitals revealed that blood warming is a major challenge in Ghana. Local methods of warming blood include leaving blood bags on walls in the open at ambient temperature to warm, putting bags in warm water or leaving blood bags under running tap water. These methods are inefficient, unsafe and time consuming. Efficient blood warmers are available but they are very expensive and unaffordable for the resourcelimited hospitals surveyed. A cost effective, safe and efficient blood warming and thawing device was designed to address the above-mentioned problems in resource-limited settings. Materials and components were selected based on specifications obtained from potential users, functional analysis, existing products and standards. The components of the device are encased in a housing insulated with polymer foam to reduce heat loss to the environment. It is anticipated that this intervention will be invaluable in situations where quick blood transfusions are required to save lives.