Publications
253 results found
Grover G, Perera AH, Hamady M, et al., 2018, Cerebral embolic protection in thoracic endovascular aortic repair, JOURNAL OF VASCULAR SURGERY, Vol: 68, Pages: 1656-1666, ISSN: 0741-5214
- Author Web Link
- Cite
- Citations: 28
ffrench-Constant S, Weerakoon N, Amin R, et al., 2018, Dual-balloon assisted super-selective embolisation of high flow arterial venous fistula within a transplant kidney, CVIR Endovascular, Vol: 1, ISSN: 2520-8934
BackgroundIn this case report, we describe a novel application of the technique of ‘dual-balloon assisted’ cannulation and embolisation of a high flow arterial venous fistula (AVF) in transplant kidney, where attempts at standard and previously described embolisation techniques were proving difficult to achieve.Case presentationSeventy year old gentleman with renal transplant presenting with high output cardiac failure and deteriorating renal function. Angiography demonstrated high flow traumatic AV fistula within transplanted kidney, secondary to multiple biopsies. Attempts at guidewire and guiding sheath placement and stability for occlusion plug deployment were failing due to combination of very high back-flow pressures within the AVF and challenging vascular anatomy; with an aneurysmal, tortuous iliac artery as well as intra renal transplanted vessels. A combination of angioplasty and remodeling aortic balloons in the transplant artery and the host external iliac vein respectively, facilitated stabilization of guiding sheath and hence controlled delivery of an occlusion plug from the venous side of the fistula. The fistula was successfully embolised, leading to complete resolution of patient symptoms and improvement of renal function beyond his previous baseline.ConclusionsPercutaneous embolisation is an established technique to treat iatrogenic AVF in transplant kidneys. High flow pressure through an AVF, as demonstrated in this case, can cause difficulty and raise safety issues in accessing and embolising the AVF using previously described techniques. This case report describes an effective and novel application of the technique of using a second balloon in the host common iliac vein to; lower flow pressure, stabilise the guidewires during plug deployment and prevent displacement of wires and/or plug into the common iliac vein.
Grover G, Perera A, Hamady M, et al., 2018, SIGNIFICANCE OF TRANSCRANIAL DOPPLER DETECTED PERI-PROCEDURAL SOLID AND GASEOUS EMBOLISATION ON CEREBRAL INJURY: A SYSTEMATIC REVIEW, Publisher: SAGE PUBLICATIONS LTD, Pages: 26-26, ISSN: 1747-4930
Kok HK, Rodt T, Fanelli F, et al., 2018, Clinical and endovascular practice in interventional radiology: a contemporary European analysis, CVIR ENDOVASCULAR, Vol: 1
- Author Web Link
- Cite
- Citations: 5
Rolls AE, Bicknell CD, Cheshire NJ, et al., 2018, Recent developments in vascular robotics, Journal of Cardiovascular Surgery, Vol: 59, Pages: 307-309, ISSN: 1827-191X
Li MM, Hamady MS, Bicknell CD, et al., 2018, Flexible robotic catheters in the visceral segment of the aorta: advantages and limitations, JOURNAL OF CARDIOVASCULAR SURGERY, Vol: 59, Pages: 317-321, ISSN: 0021-9509
Rudarakanchana N, Hamady M, Harris S, et al., 2018, Early outcomes of patients transferred with ruptured suprarenal aneurysm or dissection, ANNALS OF THE ROYAL COLLEGE OF SURGEONS OF ENGLAND, Vol: 100, Pages: 316-321, ISSN: 0035-8843
Perera AH, Rudarakanchana N, Monzon L, et al., 2018, Cerebral embolization, silent cerebral infarction and neurocognitive decline after thoracic endovascular aortic repair, British Journal of Surgery, Vol: 105, Pages: 366-378, ISSN: 1365-2168
BACKGROUND: Silent cerebral infarction is brain injury detected incidentally on imaging; it can be associated with cognitive decline and future stroke. This study investigated cerebral embolization, silent cerebral infarction and neurocognitive decline following thoracic endovascular aortic repair (TEVAR). METHODS: Patients undergoing elective or emergency TEVAR at Imperial College Healthcare NHS Trust and Guy's and St Thomas' NHS Foundation Trust between January 2012 and April 2015 were recruited. Aortic atheroma graded from 1 (normal) to 5 (mobile atheroma) was evaluated by preoperative CT. Patients underwent intraoperative transcranial Doppler imaging (TCD), preoperative and postoperative cerebral MRI, and neurocognitive assessment. RESULTS: Fifty-two patients underwent TEVAR. Higher rates of TCD-detected embolization were observed with greater aortic atheroma (median 207 for grade 4-5 versus 100 for grade 1-3; P = 0·042), more proximal landing zones (median 450 for zone 0-1 versus 72 for zone 3-4; P = 0·001), and during stent-graft deployment and contrast injection (P = 0·001). In univariable analysis, left subclavian artery bypass (β coefficient 0·423, s.e. 132·62, P = 0·005), proximal landing zone 0-1 (β coefficient 0·504, s.e. 170·57, P = 0·001) and arch hybrid procedure (β coefficient 0·514, s.e. 182·96, P < 0·001) were predictors of cerebral emboli. Cerebral infarction was detected in 25 of 31 patients (81 per cent) who underwent MRI: 21 (68 per cent) silent and four (13 per cent) clinical strokes. Neurocognitive decline was seen in six of seven domains assessed in 15 patients with silent cerebral infarction, with age a significant predictor of decline. CONCLUSION: This study demonstrates a high rate of cerebral embolization and neurocognitive decline affecting patients foll
Rueda MA, Riga C, Hamady MS, 2018, Flexible robotics in pelvic disease: what pathologies? Does the catheter increase applicability of embolic therapy?, J Cardiovasc Surg (Torino)
Interventional Radiology procedures, equipment and techniques as well as image guidance have developed dramatically over the last few decades. The evidence for minimally invasive interventions in vascular and oncology fields is rapidly growing and several procedures are considered the first line management. However, radiation exposure, image guidance and innovative solutions to known anatomical challenges are still lagging behind. Robotic technology and its role in surgery have been developing at a steady speed. Endovascular robotics are following suit with a different set of problems and targets. This article discusses the advances and limitations in one aspects of endovascular robotic, namely pelvic pathology that includes aneurysms, fibroids, benign prostatic hypertrophy and vascular malformation.
Lim CS, Dhutia A, Riga C, et al., 2018, Two-vessel branched stent graft for severely angulated aortic arch aneurysm in a Jehovah's Witness, Vascular and Endovascular Surgery, Vol: 52, Pages: 154-158, ISSN: 1538-5744
Aneurysmal disease involving the origins of supra aortic vessels often requires complex open and/or endovascular repair that is not only associated with significant risk of mortality and morbidity but also often with perioperative blood loss requiring transfusion. We report a successful repair of a large thoracic aortic aneurysm (TAA) involving the aortic arch with a custom-made Bolton Relay 2-vessel branched thoracic aortic endograft in a 42-year-old Jehovah’s Witness who would otherwise be very unlikely to survive an open repair. Branched thoracic aortic endografting offers a potentially safe, minimally invasive, and effective alternative for TAA disease involving the supra-aortic arteries, especially in patients who are at high risk of open surgery.
Kok HK, Rodt T, Fanelli F, et al., 2018, Clinical and endovascular practice in interventional radiology: a contemporary European analysis (vol 1, 8, 2018), CVIR ENDOVASCULAR, Vol: 1
Hamady MS, Sharma P, Patel R, et al., 2017, Hybrid endovascular repair of aneurysmal right-sided aortic arch and Kommerell’s diverticulum using a two-vessel branched stent graft; Case report and review of literature, SAGE Open Medical Case Reports, Vol: 5, ISSN: 2050-313X
Right-sided aortic arches are rare, affecting approximately 0.1% of the population. They are a result of abnormal developmentof the primitive aortic arches and may present later in life with later life with aneurysmal expansion of the aberrant leftsubclavian artery ‘Kommerell’s diverticulum’. These can be challenging to treat effectively. We report a rare case presentingwith mild dysphagia and right-sided aneurysmal aortic arch with aneurysmal aberrant left-sided. The patient underwenthybrid endovascular repair incorporating bilateral carotid–subclavian bypasses and dual-arch-branch endograft placement tothe left and right common carotid arteries. Although endovascular approaches have been described, there are no reports ofbranched endografts in this scenario. Right-sided aneurysmal aortic arch and the aneurysmal aberrant left subclavian arteryare rare and represent a significant therapeutic challenge. Endovascular repair in conjunction with extra-anatomical bypassutilising a custom-made branched thoracic endograft is feasible.
Rolls AE, Riga CV, Rahim S, et al., 2017, Video motion analysis in live coronary angiography differentiates levels of experience and provides a novel method of skill assessment, Eurointervention, Vol: 13, Pages: E1460-E1467, ISSN: 1774-024X
Aims: Video motion analysis (VMA) uses fluoroscopic sequences to derive catheter and guidewire movement, and is able to calculate 2D catheter-tip path length (PL) on the basis of frame-by-frame pixel coordinates. The objective of this study was to validate VMA in coronary angiography as a method of skill assessment.Methods and results: Forty-seven coronary interventions performed by 10 low- (<1,000 cases; group A), five medium- (1,000-4,000; group B) and six high- (>4,000; group C) experience-volume cardiologists were prospectively recorded and analysed using VMA software. Total PL was calculated and procedure, fluoroscopy times, and radiation dose were recorded. Comparisons of PL were made between groups of experience. Groups A, B and C performed 24, 14 and 6 paired (right and left coronary) cannulations, respectively. Calculation of PL was possible in all recorded cases and significantly correlated with procedure (p=<0.001, rho=0.827) and fluoroscopy times (p=<0.001, rho=0.888). Median total path length (combined right and left coronaries) was significantly shorter in group C which used 3,836 pixels of movement (IQR: 3,003-4,484) vs. 10,556 (7,242-31,408) in group A (p=<0.001) and 8,725 (5,187-15,150) in group B (p=0.013).Conclusions: VMA in coronary angiography is feasible and PL is able to differentiate levels of experience.
Clark S, Westley S, Coupland A, et al., 2017, Buttock wounds: beware what lies beneath, BMJ Case Reports, Vol: 2017, ISSN: 1757-790X
A 25-year-old man presented to a major trauma centre with multiple stab wounds, most significantly to the right buttock. Triple-phase CT revealed no acute bleeding and his wounds were closed. In the month following injury, he re-presented seven times to the emergency department (ED) complaining of bleeding and wound breakdown. After his seventh ED attendance, he was examined under general anaesthesia. Intraoperatively, profuse arterial bleeding was encountered and the local major haemorrhage protocol was activated. The on-call consultant vascular surgeon attended and definitive control was achieved. A large haematoma had acted to tamponade ongoing arterial bleeding and an underlying pseudoaneurysm: a finding not reported, but present, on the initial CT angiogram. Following 24 hours in the intensive care unit, he was transferred to the surgical ward and discharged 4 days later. Regular review in the outpatient department over the following 9 weeks monitored successful wound healing.
Alsafi Z, Hameed Y, Amin P, et al., 2017, Assessing the effects of manual dexterity and playing computer games on cathetere-wire manipulation for inexperienced operators, CLINICAL RADIOLOGY, Vol: 72, ISSN: 0009-9260
- Author Web Link
- Cite
- Citations: 3
Alsafi Z, Bhrugubanda V, Ramachandran S, et al., 2017, Is it Time for a Specific Undergraduate Interventional Radiology Curriculum?, CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY, Vol: 40, Pages: 1062-1069, ISSN: 0174-1551
- Author Web Link
- Cite
- Citations: 8
Perera AH, Riga CV, Monzon L, et al., 2017, Response to commentary on "Robotic Arch Catheter Placement Reduces Cerebral Embolisation During Thoracic Endovascular Aortic Repair (TEVAR)", European Journal of Vascular and Endovascular Surgery, Vol: 54, Pages: 126-127, ISSN: 1078-5884
Nasr LA, Faraj WG, Al-Kutoubi A, et al., 2017, Median Arcuate Ligament Syndrome: A Single-Center Experience with 23 Patients., Cardiovasc Intervent Radiol, Vol: 40, Pages: 664-670
BACKGROUND: Median arcuate ligament syndrome (MALS) is a rare entity that occurs when the median arcuate ligament of the diaphragm is low-lying, causing a compression to the underlying celiac trunk. We reviewed the vascular changes associated with MALS in an effort to emphasize the seriousness of this disease and the complications that may result. METHODS: This is a retrospective descriptive analysis of 23 consecutive patients diagnosed with MALS between January 1, 2012 and December 31, 2015 at a tertiary medical center. Computed tomographic (CT) scans, medical records, and patient follow-up were reviewed. RESULTS: The number of patients included herein was 23. The median age was 56 years (17-83). Sixteen patients (69.6%) had a significant arterial collateral circulation. Eleven patients (47.8%) were found to have visceral artery aneurysms; 4 patients (36.4%) bled secondary to aneurysm rupture. All ruptured aneurysms were treated with endovascular approach. The severity of the hemodynamic changes appears to be greater with complete occlusion, CONCLUSIONS: MALS causes pathological hemodynamic changes within the abdominal vasculature. Follow-up is advised for patients who develop a collateral circulation. Resulting aneurysms should preferably be treated when the size ratio approaches three. Treatment of these aneurysms can be done via an endovascular approach coupled with possible celiac artery decompression to restore physiologic blood flow.
Grover G, Perera A, Rudarakanchana N, et al., 2017, Neuroprotection in TEVAR: cerebral embolic protection to safeguard the brain, a pilot study, Annual Meeting of the Society-of-Academic-and-Research-Surgery (SARS), Publisher: WILEY, Pages: 23-23, ISSN: 0007-1323
Vandini A, Glocker B, Hamady M, et al., 2017, Robust guidewire tracking under large deformations combining segment-like features (SEGlets), Medical Image Analysis, Vol: 38, Pages: 150-164, ISSN: 1361-8415
Robust tracking of interventional tools, such as guidewires and catheters, in X-ray fluoroscopic video sequences has a wide range of clinical applications for endovascular procedures. Thus far, the tracking is usually achieved by finding the optimal displacement of the control points of a spline, which models the guidewire, between consecutive frames. The displacement of the control points is typically driven by a data term and smoothed by a regularization term. In the presence of large deformation and changes in length of the tool, the current tracking methods may fail to recover the guidewire motion. This can occur because of the limitation of the data and regularization terms, and the absence of an explicit solution for coping with elongations of the guidewire. The purpose of this paper is to present an algorithm that can robustly track guidewires under these challenging conditions. The algorithm is based on two main contributions: (a) new robust features termed SEGlets for segment-like features are introduced to overcome the limitations of the current data terms; (b) a tracking formulation based on the generation of tracking hypotheses by organizing the SEGlets in plausible guidewire shapes. The proposed method allows high flexibility of the guidewire between consecutive frames in contrast to the spline model, which can suffer from the limitations of the regularization terms. Furthermore, the technique models elongations of the guidewire which makes it possible for robust tracking under motion. A tool model which is recursively updated by employing a Kalman filter, is also proposed for modelling the regularization term. A detailed evaluation and a comparative study with three state-of-the-art guidewire tracking methods have been performed to demonstrate the potential clinical value of the technique. The proposed method achieves an overall guidewire tracking precision of 2.40 pixels, tip precision of 25.55 pixels, false tracking rate of 5.73%, missi
Perera AH, Riga CV, Monzon L, et al., 2017, Robotic Arch Catheter Placement Reduces Cerebral Embolization During Thoracic Endovascular Aortic Repair (TEVAR), EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY, Vol: 53, Pages: 362-369, ISSN: 1078-5884
Desender L, Van Herzeele I, Lachat M, et al., 2017, A multicentre trial of patient specific rehearsal prior to EVAR: impact on procedural planning and team performance, European Journal of Vascular and Endovascular Surgery, Vol: 53, Pages: 354-361, ISSN: 1532-2165
OBJECTIVE: Patient specific rehearsal (PsR) prior to endovascular aneurysm repair (EVAR) enables the endovascular team to practice and evaluate the procedure prior to treating the real patient. This multicentre trial aimed to evaluate the utility of PsR prior to EVAR as a pre-operative planning and briefing tool. MATERIAL AND METHODS: Patients with an aneurysm suitable for EVAR were randomised to pre-operative or post-operative PsR. Before and after the PsR, the lead implanter completed a questionnaire to identify any deviation from the initial treatment plan. All team members completed a questionnaire evaluating realism, technical issues, and human factor aspects pertinent to PsR. Technical and human factor skills, and technical and clinical success rates were compared between the randomised groups. RESULTS: 100 patients were enrolled between September 2012 and June 2014. The plan to visualise proximal and distal landing zones was adapted in 27/50 (54%) and 38/50 (76%) cases, respectively. The choice of the main body, contralateral limb, or iliac extensions was adjusted in 8/50 (16%), 17/50 (34%), and 14/50 (28%) cases, respectively. At least one of the abovementioned parameters was changed in 44/50 (88%) cases. For 100 EVAR cases, 199 subjective questionnaires post-PsR were completed. PsR was considered to be useful for selecting the optimal C-arm angulation (median 4, IQR 4-5) and was recognised as a helpful tool for team preparation (median 4, IQR 4-4), to improve communication (median 4, IQR 3-4), and encourage confidence (median 4, IQR 3-4). Technical and human factor skills and technical and initial clinical success rates were similar between the randomisation groups. CONCLUSION: PsR prior to EVAR has a significant impact on the treatment plan and may be useful as a pre-operative planning and briefing tool. Subjective ratings indicate that this technology may facilitate planning of optimal C-arm angulation and improve non-technical skills. TRIAL REGISTRATION:
Ahmed S, Lewis J, Abidia A, et al., 2016, Thoracic outlet syndrome arising from an extrapleural lipoma, Journal of Vascular Surgery Cases and Innovative Techniques, Vol: 2, Pages: 149-151
Thoracic outlet syndrome refers to a multitude of signs and symptoms in the upper limb resulting from compression of the neurovascular bundle within the interscalene triangle. It is a complex clinical entity to diagnose on imaging, given its transient and postural nature, which is not often appreciable on nondynamic imaging. Here we describe an uncommon presentation of thoracic outlet syndrome resulting from an extrapleural lipoma and outline its multimodality-based investigation and management.
Grover G, Perera A, Rudarakanchana N, et al., 2016, Neuroprotection in thoracic aortic stent-grafting; use of a cerberal embolic protection device, 28th Annual Meeting of the Transcatheter Cardiovascular Therapeutics (TCT), Publisher: ELSEVIER SCIENCE INC, Pages: B326-B326, ISSN: 0735-1097
- Author Web Link
- Cite
- Citations: 1
Grover G, Perera A, Rudarakanchana N, et al., 2016, TCT-806 Neuroprotection in thoracic aortic stent-grafting; use of a cerberal embolic protection device., J Am Coll Cardiol, Vol: 68
Ribé L, Bicknell CD, Gibbs RG, et al., 2016, Long-term results of intra-arterial onyx injection for type II endoleaks following endovascular aneurysm repair., Vascular, Vol: 25, Pages: 266-271, ISSN: 1708-5381
PURPOSE: The aim of this paper is to report our experience of type II endoleak treatment after endovascular aneurysm repair with intra-arterial injection of the embolizing liquid material, Onyx liquid embolic system. METHODS: From 2005 to 2012, we performed a retrospective review of 600 patients, who underwent endovascular repair of an abdominal aortic aneurysm. During this period, 18 patients were treated with Onyx for type II endoleaks. PRINCIPAL FINDINGS: The source of the endoleak was the internal iliac artery in seven cases, inferior mesenteric artery in seven cases and lumbar arteries in four cases. Immediate technical success was achieved in all patients and no endoleak from the treated vessel recurred. During a mean follow-up of 19 months, no major morbidity or mortality occurred, and one-year survival was 100%. CONCLUSIONS: Treatment of type II endoleaks with Onyx is safe and effective over a significant time period.
Jindal R, Majed A, Hamady M, et al., 2016, Cystic adventitial disease of the iliofemoral artery: Case reports and a short review, VASCULAR, Vol: 14, Pages: 169-172, ISSN: 1708-5381
- Author Web Link
- Cite
- Citations: 3
Martin G, Riga C, Gibbs R, et al., 2016, Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair: A Benchmark for New Technologies, Journal of Endovascular Therapy, Vol: 23, Pages: 783-790, ISSN: 1545-1550
PURPOSE: To evaluate the short- and long-term outcomes of hybrid repair of the arch and proximal descending aorta in a single tertiary center for aortic disease. METHODS: A retrospective analysis was performed of 55 patients (median age 67 years; 36 men) who underwent hybrid repair of thoracic aortic pathology with involvement of the arch between January 2005 and May 2015 at a single tertiary center. The pathologies included 40 (73%) with aneurysmal disease, 10 (18%) acute type B aortic dissections, 2 with acute aortic syndrome, an acute type A dissection, and left and aberrant right subclavian artery aneurysms. Seven (13%) procedures were performed as an emergency. Demographics and procedure characteristics were collected for analysis of survival and reinterventions. RESULTS: Complete aortic debranching was performed in 14 (25%) to facilitate endograft placement in zone 0; debranching was partial in 20 (36%) patients for zone 1 deployments and 21 (38%) for zone 2. Primary technical success was achieved in 51 (93%) cases. One patient died in-hospital from aneurysm rupture following aortic debranching prior to stent-graft repair. In another, the stent-graft procedure proved infeasible and was abandoned. The other 2 technical failures were due to type Ia endoleaks. Five (9%) patients died in-hospital (4 of 48 elective and 1 of 7 emergency cases); 2 of these patients died within 30 days (4%). Eight (14%) patients had a stroke, 6 of 48 elective and 2 of the 7 emergency patients. Spinal cord ischemia was reported in 3 (6%) patients. Mean follow-up was 74.6 months. Overall cumulative survival was 70% at 1 year, 68% at 2 years, and 57% at 5 years. Reintervention to the proximal landing zone for type Ia endoleak was required in 6% of cases. The overall rate of aortic reintervention was 18% at 1 year, 21% at 2 years, and 36% at 5 years. Overall extra-anatomic graft patency was 99%. CONCLUSION: Hybrid repair of the aortic arch and proximal descending thoracic aorta is technic
Kandail HS, Hamady M, Xu XY, 2016, Hemodynamic Functions of Fenestrated Stent Graft under Resting, Hypertension, and Exercise Conditions., Frontiers in Surgery, Vol: 3, ISSN: 2296-875X
The aim of this study was to assess the hemodynamic performance of a patient-specific fenestrated stent graft (FSG) under different physiological conditions, including normal resting, hypertension, and hypertension with moderate lower limb exercise. A patient-specific FSG model was constructed from computed tomography images and was discretized into a fine unstructured mesh comprising tetrahedral and prism elements. Blood flow was simulated using Navier-Stokes equations, and physiologically realistic boundary conditions were utilized to yield clinically relevant results. For a given cycle-averaged inflow of 2.08 L/min at normal resting and hypertension conditions, approximately 25% of flow was channeled into each renal artery. When hypertension was combined with exercise, the cycle-averaged inflow increased to 6.39 L/min but only 6.29% of this was channeled into each renal artery, which led to a 438.46% increase in the iliac flow. For all the simulated scenarios and throughout the cardiac cycle, the instantaneous flow streamlines in the FSG were well organized without any notable flow recirculation. This well-organized flow led to low values of endothelial cell activation potential, which is a hemodynamic metric used to identify regions at risk of thrombosis. The displacement forces acting on the FSG varied with the physiological conditions, and the cycle-averaged displacement force at normal rest, hypertension, and hypertension with exercise was 6.46, 8.77, and 8.99 N, respectively. The numerical results from this study suggest that the analyzed FSG can maintain sufficient blood perfusion to the end organs at all the simulated conditions. Even though the FSG was found to have a low risk of thrombosis at rest and hypertension, this risk can be reduced even further with moderate lower limb exercise.
Hamady M, Lister GG, Zissis G, 2016, Calculations of visible radiation in electrodeless HID lamps, Lighting Research and Technology, Vol: 48, Pages: 502-515, ISSN: 1477-1535
This paper compares the measured photometric properties and power balance of a conventional electroded metal halide lamp containing mercury and thallium iodide with those obtained from a theoretical model for discharges sustained by a microwave electromagnetic field. In the calculations, the discharge is assumed to be in the TM010 mode, sustained by a microwave field of frequency 2.45 GHz. The numerical model used to obtain the power balance in the discharge is based on a solution to the Elenbaas-Heller equation for the gas temperature, and a simple 'skin depth' model to describe the penetration of the maintenance electric field in the discharge. A ray tracing method is employed to simulate the radiation transport, to compute the emitted radiation flux, luminous flux, luminous efficacy and the correlated colour temperature. The calculations of the total radiation flux from the discharge as a function of electric power is consistent with previously published calculations, showing that the fraction of electric power converted to radiation increases as electric power increases, provided all other lamp parameters are constant. However, our results indicate that this does not necessarily correspond to an increase in the fraction of electrical power converted to visible radiation.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.