The sonographic and CT appearances of 9 large cavernous hemangiomas of the liver were studied. On sonography, 6 masses (67%) exhibit heterogenous echo pattern; where in 2 patients the echotexture was a mixture of hypoechoic and isoechoic areas and in 4 patients there are varying amounts of bright hyperreflective areas similar to the texture typical of small hemangiomas. The masses were predominantly hypoechoic in the remaining 3 patients (33%). Incremental bolus or bolus-infusion dynamic CT showed peripheral contrast enhancement of varying intensities and thickness in all patients. The lesions were incorrectly diagnosed as hepatomas in 4 patients, suspected as hemangiomas with a differential diagnosis of hepatomas in 4 patients and an early liver abscess in 1 patient. It is concluded that large cavernous hemangiomas of the liver do not exhibit the typical homogenous hyperreflective echotexture as exhibited by small lesions and they mimic primary and secondary hepatic neoplasms. However, the diagnosis of hemangioma should be entertained when such a mass contains bright hyperechoic areas within its heterogenous echo pattern and exhibit peripheral enhancement on contrast enhanced CT. In addition to correlation with appropriate clinical information, confirmation of diagnosis include delayed scanning during a routine incremental bolus dynamic CT, single-slice dynamic contrast enhanced CT, angiography or isotope scintigraphy and magnetic resonance imaging depending on the availability of facility.
The purpose of this study was to retrospectively detect Aspergillus antigens in sera obtained from immunocompromised host using an in-house modified double antibody sandwich ELISA.
In this paper, a variable threshold voice activity detector (VAD) is developed to control the operation of a two-sensor adaptive noise canceller (ANC). The VAD prohibits the reference input of the ANC from containing some strength of actual speech signal during adaptation periods. The novelty of this approach resides in using the residual output from the noise canceller to control the decisions made by the VAD. Thresholds of full-band energy and zero-crossing features are adjusted according to the residual output of the adaptive filter. Performance evaluation of the proposed approach is quoted in terms of signal to noise ratio improvements as well mean square error (MSE) convergence of the ANC. The new approach showed an improved noise cancellation performance when tested under several types of environmental noise. Furthermore, the computational power of the adaptive process is reduced since the output of the adaptive filter is efficiently calculated only during non-speech periods.
This paper reports the design of an electronic nose (E-nose) prototype for reliable measurement and correct classification of beverages. The prototype was developed and fabricated in the laboratory using commercially available metal oxide gas sensors and a temperature sensor. The repeatability, reproducibility and discriminative ability of the developed E-nose prototype were tested on odors emanating from different beverages such as blackcurrant juice, mango juice and orange juice, respectively. Repeated measurements of three beverages showed very high correlation (r > 0.97) between the same beverages to verify the repeatability. The prototype also produced highly correlated patterns (r > 0.97) in the measurement of beverages using different sensor batches to verify its reproducibility. The E-nose prototype also possessed good discriminative ability whereby it was able to produce different patterns for different beverages, different milk heat treatments (ultra high temperature, pasteurization) and fresh and spoiled milks. The discriminative ability of the E-nose was evaluated using Principal Component Analysis and a Multi Layer Perception Neural Network, with both methods showing good classification results.
This paper deals with the interface-relevant activity of a vehicle integrated intelligent safety system (ISS) that includes an airbag deployment decision system (ADDS) and a tire pressure monitoring system (TPMS). A program is developed in LabWindows/CVI, using C for prototype implementation. The prototype is primarily concerned with the interconnection between hardware objects such as a load cell, web camera, accelerometer, TPM tire module and receiver module, DAQ card, CPU card and a touch screen. Several safety subsystems, including image processing, weight sensing and crash detection systems, are integrated, and their outputs are combined to yield intelligent decisions regarding airbag deployment. The integrated safety system also monitors tire pressure and temperature. Testing and experimentation with this ISS suggests that the system is unique, robust, intelligent, and appropriate for in-vehicle applications.
The intraoperative localisation of small intestinal bleeding lesions identified at pre-operative angiography has always been difficult, resulting in extensive resections in doubtful cases. We report two patients in whom, at angiography, a small intestinal lesion was noted to be the cause of gastrointestinal haemorrhage. They then underwent superselective mesenteric arterial cannulation at a second angiographic procedure and were operated upon with the angiographic catheter left within the branch responsible for the bleeding. This superselective catheter placement facilitates precise localisation of the bleeding site intraoperatively, enabling limited segmental resection of bowel. Both patients have had no recurrent bleeding episodes.
Single gas-containing pyogenic liver abscesses in 11 patients were studied by ultrasound and computed tomography (CT). On ultrasound, all abscesses were predominantly echogenic compared to the normal liver parenchyma. The gas collections appeared as hyperreflective areas arranged in clusters associated with acoustic shadowing and ring-down artifacts. Ten abscesses (90%) had ill-defined margins on ultrasound, causing underestimation of their sizes in these patients. All abscesses were shown to be multiloculated and had clearly defined borders on CT, not appreciated or mistaken for multiplicity of abscesses on ultrasound. Ultrasound may be inadequate in the evaluation of gas-containing liver abscesses, as they have complex echotexture in addition to ring-down artifacts, acoustic shadows and poorly-defined margins; leading to underestimation of abscess size, difficulty in identifying loculations and erroneous interpretation of multiplicity of abscess cavities.
The pattern of analgesic use, abuse and incidence of analgesic-associated nephropathy in 79 patients with chronic headache was studied. Sixty-eight of these patients had migraine. Most patients had consumed a combination of analgesics (81%) while 19% had taken single analgesics for their headache. Nonsteroidal anti-inflammatory drugs were the most commonly used analgesics (96.2%) followed by paracetamol (70.9%) and aspirin, phenacetin and caffeine compounds (5.1%). Mefenamic acid was the commonest nonsteroidal anti-inflammatory drug consumed (97.4%). Analgesic abuse which was defined as a minimum total of 1 kg of analgesics such as paracetamol or aspirin, phenacetin and caffeine compounds or 400 capsules/tablets of nonsteroidal anti-inflammatory drugs was noted in 65 patients. Nonsteroidal anti-inflammatory drugs were the most commonly abused analgesics (89.2%) followed by paracetamol (38.5%). Forty-five of the 65 analgesic abusers had an intravenous urogram or ultrasound performed and renal papillary necrosis was documented in one patient. Three (4.6%) of the analgesic abusers had mildly raised serum creatinine levels. Mild proteinuria of less than 1 gm/litre was present in 27.7% of abusers. In conclusion, although analgesic use and abuse is common in patients with chronic headache, the short term incidence of analgesic-associated nephropathy (2.2%) and renal impairment (4.6%) was low. Prolonged observations will be necessary to ascertain the safety of these drugs for long term use.
Spinal vascular malformation is an uncommon but potentially treatable cause of myelopathy. We describe two cases of angiographically proven spinal vascular malformation in Malaysia. The first case is a 47-year-old man who had a progressive myelopathy and the second a 60-year-old man with intermittent attacks of transient paraparesis leading to paraplegia. As the clinical presentation of spinal vascular malformation is variable, it should be considered as a cause of patients with myelopathy.
A case of symptomatic polycystic liver disease treated by fenestration and segmental liver resection is reported. The intraoperative use of ultrasound to define the plane of liver resection is emphasised. No significant post-operative complication was encountered. The clinical presentation, management and treatment are discussed.
The risk of renal papillary necrosis and renal dysfunction due to the chronic use of nonsteroidal anti-inflammatory drugs (NSAIDs) is unknown. In a prospective study of 259 heavy analgesic users seen in a general medical hospital over an 11-year-period beginning in January 1982, 69 new cases of analgesic nephropathy with renal papillary necrosis were confirmed by intravenous urogram (26.6%), ultrasonography (30.4%), and/or computed tomography (43%). Twenty-nine of these patients (42%) had consumed excessive quantities of NSAIDs alone; an additional nine patients (13%) had consumed NSAIDs predominantly in combinations with paracetamol, aspirin, phenacetin, caffeine, and/or traditional herbal medications. Of those patients who consumed NSAIDs alone, 17 had consumed only a single type of NSAID and the remaining 12 had consumed multiple types of NSAIDs. The amount of NSAIDs administered ranged from 1,000 to 26,600 capsules or tablets over a 2- to 25-year period. Renal impairment (serum creatinine, 126 to 778 mumol/L) was noted in 26 of these 38 patients (64.8%). The reasons given for consuming NSAIDs include gouty arthritis (18 patients), osteoarthritis (seven patients), rheumatoid arthritis (six patients), chronic headache (three patients), gouty arthritis plus chronic headache (three patients), and chronic backache (one patient). All patients were prescribed these drugs and were followed medically. The occurrence of analgesic nephropathy was predominantly in males (male to female ratio, 1.9:1). Most of the patients did not have the characteristic psychological profile attributed previously to analgesic abuse nephropathy. Associated addictive habits, such as the use of psychotropic drugs and sleeping tablets, purgative abuse, and alcoholism, were absent.(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenal tumours are either functioning or non-functioning. Non-functioning adrenal tumours are generally asymptomatic and usually of enormous proportions at the time of presentation. A case is presented here of a patient with a huge right adrenal haemangioma which was successfully treated surgically. This unusual tumour was 25 cm in diameter, was well encapsulated and weighed 4 kg. The literature pertaining to this interesting case is reviewed.
One of the babies in a pair of xiphaomphalopagus conjoined twins developed oliguria, transient rise in serum creatinine and persistent nephrogram on the sixth day of life following injection of radiocontrast medium for computerised axial tomography scanning of the urinary system. The other twin was spared but developed hypertension and "dialysed" the oliguric twin. The renal profiles of both neonates subsequently remained normal until they reached adequate weight for surgical separation at a later date.
The use of wireless communication using inductive links to transfer data and power to implantable microsystems to stimulate and monitor nerves and muscles is increasing. This paper deals with the development of the theoretical analysis and optimization of an inductive link based on coupling and on spiral circular coil geometry. The coil dimensions offer 22 mm of mutual distance in air. However, at 6 mm of distance, the coils offer a power transmission efficiency of 80% in the optimum case and 73% in the worst case via low input impedance, whereas, transmission efficiency is 45% and 32%, respectively, via high input impedance. The simulations were performed in air and with two types of simulated human biological tissues such as dry and wet-skin using a depth of 6 mm. The performance results expound that the combined magnitude of the electric field components surrounding the external coil is approximately 98% of that in air, and for an internal coil, it is approximately 50%, respectively. It can be seen that the gain surrounding coils is almost constant and confirms the omnidirectional pattern associated with such loop antennas which reduces the effect of non-alignment between the two coils. The results also show that the specific absorption rate (SAR) and power loss within the tissue are lower than that of the standard level. Thus, the tissue will not be damaged anymore.
The development of implanted devices is essential because of their direct effect on the lives and safety of humanity. This paper presents the current issues and challenges related to all methods used to harvest energy for implantable biomedical devices. The advantages, disadvantages, and future trends of each method are discussed. The concept of harvesting energy from environmental sources and human body motion for implantable devices has gained a new relevance. In this review, the harvesting kinetic, electromagnetic, thermal and infrared radiant energies are discussed. Current issues and challenges related to the typical applications of these methods for energy harvesting are illustrated. Suggestions and discussion of the progress of research on implantable devices are also provided. This review is expected to increase research efforts to develop the battery-less implantable devices with reduced over hole size, low power, high efficiency, high data rate, and improved reliability and feasibility. Based on current literature, we believe that the inductive coupling link is the suitable method to be used to power the battery-less devices. Therefore, in this study, the power efficiency of the inductive coupling method is validated by MATLAB based on suggested values. By further researching and improvements, in the future the implantable and portable medical devices are expected to be free of batteries.
Implanted medical devices are very important electronic devices because of their usefulness in monitoring and diagnosis, safety and comfort for patients. Since 1950s, remarkable efforts have been undertaken for the development of bio-medical implanted and wireless telemetry bio-devices. Issues such as design of suitable modulation methods, use of power and monitoring devices, transfer energy from external to internal parts with high efficiency and high data rates and low power consumption all play an important role in the development of implantable devices. This paper provides a comprehensive survey on various modulation and demodulation techniques such as amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK) of the existing wireless implanted devices. The details of specifications, including carrier frequency, CMOS size, data rate, power consumption and supply, chip area and application of the various modulation schemes of the implanted devices are investigated and summarized in the tables along with the corresponding key references. Current challenges and problems of the typical modulation applications of these technologies are illustrated with a brief suggestions and discussion for the progress of implanted device research in the future. It is observed that the prime requisites for the good quality of the implanted devices and their reliability are the energy transformation, data rate, CMOS size, power consumption and operation frequency. This review will hopefully lead to increasing efforts towards the development of low powered, high efficient, high data rate and reliable implanted devices.
Three children aged 3-11 years had ultrasonography of the urinary tract for the investigation of dysuria and haematuria. A bladder mass was seen in these 3 children. One child had computed tomography scan, cystoscopy and bladder biopsy because rhabdomyosarcoma was considered. The biopsy revealed an inflammatory process. The urine culture of the other 2 children revealed E. coli. On ultrasonography, the inflammatory mass may appear homogeneously hypoechoic or may contain moderate level echoes. The mucosal surface of the mass may be smooth or lobulated. It is important to consider an infective cause for a bladder mass in children because computed tomography, cystoscopy and biopsy may be avoided.
This is a case report of a pseudoaneurysm due to Salmonella aortitis in a 52 year old man. The condition is rare and represents one of the few cases reported in Malaysia. The diagnosis was made preoperatively by ultrasonography and computed tomography. This was confirmed at surgery where there was a 3 cm defect at the posterior wall of the aorta at L2/3 level. The aneurysmal sac extended to the retrocrural space at the 12th vertebra level cranially on the right side to the lower border of the 3rd lumbar vertebra caudally. It had a smooth fibrous wall and contained a mixture of organised haematoma and pus. At operation the aneurysm was excised, the affected region was carefully debrided and the aorta grafted with an in-situ in-lay graft. Antibiotic therapy was instituted until clinical response was evident, leukocytosis was reduced and blood culture was negative. However 4 months after surgery, the patient returned in irreversible shock and succumbed to disseminated intravascular coagulation secondary to massive upper gastrointestinal haemorrhage from an aortoduodenal fistula.
We determined the consumption of non-steroidal anti-inflammatory drugs (NSAIDs) and the prevalence of chronic renal impairment and renal papillary necrosis (RPN) in patients with various types of arthritis. Ninety-four patients with chronic arthritis who had consumed more than 1000 capsules and/or tablets of NSAIDs were studied. Renal profiles and radiological investigations such as intravenous urogram (IVU), ultrasonography (US) and computed tomography (CT) were performed to look for evidence of RPN. Twelve patients did not complete the study. Ten of the 82 patients who had completed the study (12.2%) had radiologic evidence of RPN. Five out of 53 patients (9.4%) with rheumatoid arthritis, three out of 11 patients (27.3%) with gouty arthritis and two out of seven patients (28.6%) with osteoarthritis had RPN. Renal impairment (serum creatinine levels of 125-451 mumol/l) was found in 20 patients (24.4%). The patients had consumed 1000-26,300 capsules and/or tablets over a period ranging from 1 yr to more than 30 yr. Patients with chronic arthritis who consume excessive amount of NSAIDs are at risk of developing RPN and chronic renal impairment.
Realtime ultrasonography with general purpose sector transducer was used to guide 87 percutaneous biopsies on 82 patients with lesions suspected to be mediastinal masses on plain chest radiographs. In seven patients who had dyspnea the biopsies were done in erect or semi-erect sitting positions. Definitive diagnosis was obtained from 66 lesions (80.5%) where 46 (70.0%) were mediastinal and the remaining 20 lesions (30.0%) arising from the lung. Of the 46 mediastinal lesions where specific diagnosis were made, 42 (91.0%) were anterior and four (0.9%) posterior mediastinal lesions. The majority of these anterior mediastinal masses were lymphomatous nodes followed by germ cell tumours whereas all four posterior mediastinal masses were neurogenic. Of the lung lesions, 19 were primary malignancies. The remaining lung lesion which was located posteriorly was cryptococcus infection. One patient developed massive hemothorax, but subsequently recovered. No significant complications were encountered in the remaining patients. Surgery was carried on 11 patients. There is correlation between definitive diagnosis from percutaneous biopsy and final diagnosis after surgery in 80% of patients. It is proposed that all percutaneous biopsies for thoracic masses which abut the chest wall and cause mediastinal widening on a plain chest radiograph be guided by ultrasound. It can be effectively accomplished with ease and safety even without the use of dedicated biopsy ultrasound probes or biopsy attachments, and on patients in erect or semi-erect positions.