Medical Physics
Medical Physics at Dorset County Hospital started in 1982 when Dr Joe Aindow was appointed. In 1985 Peter Robins joined the department followed, in 1989, by Jonathan Fowler who filled a newly created technician post.
1996 saw Mike Lunt join the department while Joe took a sabbatical year as a Director of a ultrasound technology company. Mike remained with us on a part-time basis providing weekly Doppler scanning sessions and, more recently, as a research scientist until his retirement in April 2007.
In November 2000 Coral Stockley was appointed as a Trainee Technician. After qualifying in 2002, Coral took up the post of MEM Software technician.
James Goracy joined the department in September 2003 as the latest Trainee/Student Technician. He will be attending, on a block release basis, Peoples College / De Montfort University, Nottingham, for the academic component of his training.
Consortium
Since 1991 the Medical Physics Department has been a member of a Consortium of similar departments, in line with the guidance given by the Department of Health for the organisation of such scientific services in HN(90)18. Other members of the local Consortium include the Medical Physics Departments at the Royal United Hospital (Bath), Great Western Hospital (Swindon) and Odstock Hospital (Salisbury), Royal National Hospital for Rheumatic Diseases (Bath) and the Bath Institute of Medical Engineering.
The Consortium is accredited for the training of Medical Physicists and member departments benefit from access to specialist skills or equipment not available in their own establishment. Following recent organisational changes, the Consortium continues but on an informal basis.
Clinical services
Doppler Ultrasound Vascular Assessment
The Medical Physics Department provides an ultrasound Doppler scanning service for the assessment of peripheral arterial and venous disease. The equipment used is an ATL HDI 5000 ultrasound scanner. The service operates Monday and Tuesday mornings and all day Wednesday.
GFR (Glomerular Filtration Rate) Testing
Renal clearance can occur by glomerular filtration or tubular secretion. Glomerular filtration rate (GFR) is relatively constant under standard conditions and is independent of urine flow. Values for normal GFRs are 120±25mls/min/1.73m2.
The patient is given an intravenous injection of 99mTc DTPA in the Nuclear Medicine Department. Sequential blood samples are taken two, three and four hours post injection (in-patients can have the samples taken on the ward). The patient’s height and weight is recorded and is used to estimate their body surface area.
The blood samples are centrifuged to separate the plasma. Plasma from each sample is taken and placed into tubes for radioassay.
Each sample is then counted and the decrease in activity of the plasma, as a function of post injection time lapse, is used to calculate the GFR. The GFR value is then normalised to a patient of body surface area of 1.73m2.
Outpatient Nebuliser Loan Service
Medical Physics has been responsible for this service since June 2003, having taken over from the Respiratory Medicine Department. Equipment is loaned to patients referred to us by either the hospital wards or Respiratory Medicine.
We have two main types of nebuliser pump. These are Profile Portaneb and the Medikare.
We also have a few smaller portable nebulisers (Profile Freeway - various models) for short term loan so that patients can take a nebuliser on holiday with them. It comes complete with carry case, multi voltage mains adapter and car power lead.
If you require the use of one of these nebulisers please contact us in plenty of time before you leave on holiday. These work in the same way as normal nebulisers and use the same kits and preparations, so don't forget to take them with you.
If you are flying, it is best to get a covering letter from the doctor who is treating you. If you are finding this difficult we may be able to provide one.
Radioiodine therapy
The Medical Physics Department (in conjunction with Nuclear Medicine) offer a therapy service for the treatment of thyrotoxicosis by radioiodine.
Patient treatments usually comprise of a single outpatient treatment of between 400 – 600 MBq of the radioisotope iodine 131. The administration of radioiodine is a simple procedure in which a small gelatine capsule containing I131 is swallowed by the patient. For safety reasons this is carried out in the Clinical Room of the Nuclear Medicine Department, DCH and the patients are issued which an instruction card detailing precautions to be taken on returning home etc. These precautions typically remain in force for one to three weeks depending upon the administered dose.
Schillings testing
The Medical Physics Department provides a Schilling test service for the measurement of vitamin B12 absorption.
The test involves an intramuscular injection of vitamin B12 together with an oral dose of vitamin B12 labeled with the radioisotope cobalt-57. The radiation dose to the patient is very small (approximately 0.1 mSv), somewhat similar to a low dose X-ray examination.
Radiation safety
The Medical Physics Department advises the hospital on all issues of radiation safety. These areas currently include:
- Ionising radiation - X-rays and radioactive materials
- Non-ionising radiation - Lasers, ultraviolet, ultrasound, audible sound and magnetic fields
These energy forms are widely used in medicine, either diagnostically or therapeutically. In all cases there are nationally accepted guidelines in place to ensure their safe use and, especially in the case of ionising radiation, complex and detailed legal requirements have to be met. A comprehensive library of safety standards is held by the department, together with relevant legal documentation.
A full range of instrumentation is available to the Medical Physics Department to allow the detection and measurement of all the above energies. These instruments are calibrated, through traceable means, to UK National standards.
Medical gases
Medical Physics is responsible for the upkeep of all the oxygen, suction and 'Entonox' equipment.
Oxygen
The Trust is equipped with, in the most part, two makes of oxygen flowmeters. A full stock of spare parts is held for both makes by the department as well as several spare units, which are available on an exchange basis. Follow this link for the BOC Medical Gases website.
Medical vacuum/suction
Spare suction controllers are also kept in stock and are available on an exchange basis. A rolling replacement program is in place. Stocks of spare parts are held for most of the models.
'Entonox'
Otherwise known as 'gas & air' is a 50/50 mix of oxygen and nitrous oxide (laughing gas or N2O)The Trust is equipped with, in the most part, two makes of demand valves. A stock of spares is available. 'Entonox' is the product name given to this gas mix by BOC Gases (Medical)©.
Equipment management
Dorset County Hospital has an inventory of medical equipment that comprises of in excess of 5,000 items. These range from relatively small devices such as electronically controlled infusion pumps to sophisticated imaging equipment such as the CT and MRI scanners.
Many of these devices require regular servicing and scheduling of quality assurance procedures to ensure optimised performance. There are also safety issues such as Hazard Notices (issued from time to time by the Medical Devices Agency) and financial issues such as the need for periodic replacement to be dealt with.
To meet these needs the hospital purchased a specialist commercial software package in 2001, known as 'Sophie 9000' and is available to a selected group of intranet users within the Trust. These users each have a separate but direct interest in medical equipment management.
The database of equipment is also available on a small number of PDAs, equipped with barcode scanners, so that equipment can be identified, jobs written up and records modified or added whilst away from the department. On returning, the PDA is dropped into its docking station and the main database is updated with the new information.
Every piece of equipment that is listed on Sophie is labelled with a numbered barcode.
Medical device design
From time to time Medical Physics is requested to undertake the development of medical devices on a one off basis, whether it be adaptation of an existing device or designing one from scratch.
We are able to offer a wide range of design skills in electronics and mechanical engineering producing equipment compliant with the latest medical safety guidelines.
Research and development
Since the foundation of the department in 1982, the Medical Physics team have collaborated with our medical colleagues on a wide variety of research projects. The topics have varied in discipline from surgery to psychology but with a specialist interest in diagnostic ultrasound. The initial outcome of the research work is generally presentation at conference or by publication in refereed journals. Wherever possible the department prefers to follow projects through to commercial production with consequent widespread patient benefit.
The main research project at the moment relates to the acoustic detection of stenosed arteries. Sample publications produced by the department since its foundation include:
- J.D. Aindow, J. Lesny, P.A. Robins, D.S. Deogan. Fine needle biopsies – Enhanced visualisation using tip mounted miniature polymer transducers.4th International congress on Interventional Ultrasound, Copenhagen, Denmark, 19th-22nd August 1986
- P.A. Robins, P.C. Barrington, and J.D. Aindow. Electroconvulsive Therapy - what are the relevant physical parameters for its optimum administration? The Hospital Physicists Association and The Institute of Physical Sciences in Medicine 44th Annual Conference, September 1987
- J.D. Aindow, P.A. Robins, K. Nicolaides, M. Peters, and J. Lesny. Ultrasonically guided needle procedures utilising tip mounted acoustic sensors for image enhancement - a discussion of scientific aspects and preliminary clinical trials. First International Symposium on Interventional and Intraoperative Sonography, Zagreb, Yugoslavia, 24-26th May 1989
- P.A. Robins, J.D. Aindow, and J.V.P. Fowler. Experimental aspects of high frequency ultrasound measurements. Physics and Technology of Medical Ultrasound, University of York, 15-16th April 1991
- P.A. Robins, G. Petley, J.D. Aindow and J. Bottle. Ultrasonic bone assessment: is wavefront aberration the principal limitation of current technology? The 23rd Annual Meeting of the British Medical Ultrasound society, Bournemouth, 10-12th December 1991
- G. Petley, P.A. Robins and J.D. Aindow. Broadband ultrasonic attenuation: are current measurement techniques inherently inaccurate? British Journal of Radiology 1995;68;1212-1214
- J.D. Aindow, M.A. Bangash, P.A. Robins and R.C. Chivers. A high specification hydrophone for the determination of ultrasonic source behaviour. Proceedings of the Institute of Acoustics 1995;17;Part 6
- J. Lesny, P.A. Robins and J.D. Aindow. Guided “freehand” technique. 81st Scientific Assembly and Annual Meeting of the Radiological Society of North America, 1995
- J.V.P. Fowler, P.A. Robins, J.D. Aindow. Anechoic rooms for audiometric calibrations – an experimental evaluation of a low cost design for a new District General Hospital. 4th Annual Scientific Meeting of The Institute of Physics and Engineering in Medicine, Brighton, 15-17th September 1998
- M.J. Lunt, F.A. Duck. Ultrasonic power balances--effect of a coupling window on the power measured from physiotherapy ultrasound units. Ultrasound in Medicine and Biology. 2001 Aug;27(8):1127-32
- M.J. Lunt, J.D. Aindow and P.A. Robins. Acoustic emission from stenosed blood vessels”. 8th Annual Scientific Meeting of The Institute of Physics and Engineering in Medicine, Durham, 10-12th September 2002