PubMed Health⌕ Search

Biomedical subjects

D M Clarkson

Publications and source records attributed to D M Clarkson.

11 recordsLinked to original sources
PubMed1993

New ultraviolet monitoring technology.

There is a growing awareness of the hazards of ultraviolet (UV) radiation to the health of the community and to our environment's integrity. There is a need for monitoring this hazard. Until recently, UV radiation sensors tended to be relatively expensive. However, as a result of the introduction of mass-produced GaAs photodiodes in the late 1980s, UV radiation now can be measured more accurately, cost-effectively and conveniently. A new, low-cost sensor is available with a wavelength tailored to the skin's erythmal response without additional complex circuitry or filter elements; it can be used in a variety of settings.

Hawaii↗
PubMed1992

Lasers in dentistry.

Lasers, which are constantly evolving, can be customized to meet dental requirements and could become a very useful tool for dental practitioners. The article provides an introduction to the instruments, which includes a description of how they work and discusses their applications in dentistry.

Dental Caries↗
PubMed1988

Flexible software for the processing of obstetric ultrasound scan and related information.

Software has been developed whose main function is to relate obstetric ultrasound scan data to patient details at delivery. Up to four separate scan measurements can be recorded for each ultrasound investigation. Data on up to six such scanning sessions can be stored in a separate computer record for each patient. Up to four gestational tables can be configured by the user and stored on disc for each scan measurement. Flexible selection of computer records is possible on a broad range of criteria. Summary information such as Apgar score and birth weight distribution and the deviation from predicted delivery dates in half week intervals and also discrete days for each relevant set of maturity estimations can be generated. The software, written in Microsoft BASIC (GWBASIC and quickBASIC) can be run on a broad range of 16 bit microcomputers.

Delivery, Obstetric↗
PubMed1982

Microcomputer system in an accident unit.

A microcomputer-based records system has been developed for use in the accident unit of a district general hospital. Patient details are entered directly at the reception desk and the computer generates a casualty card that is updated after the patient has been seen by the doctor, who determines the diagnosis to be recorded and specifies the injury coding. Information is stored on floppy discs, each holding the details of 3400 patients. The computer is used to produce a daily log-book of attendances, including revisits. The stored data may be examined and analysed for both administrative and medical purposes. The work load can be rapidly analysed according to various options that include the nature, type, and site of injuries. The system was introduced in December 1980. Location within the unit allows control over its operation, and many of the limitations of a manual system have been overcome.

Computers↗
PubMed1982

A microcomputer system for the collection and analysis of antibiotic sensitivity test data.

A microcomputer system for the routine collection and analysis of microbiological data is described. A digitising tablet is used as a method of data input. A series of analysis programmes was developed to allow investigation of the distribution of organisms in relation to the type of specimen in which they occur, the origin of the specimen and also to examine their associated sensitivity patterns. In this instance a Commodore PET was used, though other microcomputers could be similarly employed with equal facility.

Anti-Bacterial Agents↗
PubMed1980

Failure of propranolol and metoprolol to alter ventilatory responses to carbon dioxide and exercise.

Neither propranolol (80 mg) nor metoprolol (100 mg) give orally to eight normal subjects altered mean ventilatory responses to carbon dioxide or to moderate graded exercise. Incremental doses of the drugs to totals of 320 mg propranolol and 400 mg metoprolol also did not effect these ventilatory responses. Both drugs markedly decreased the heart rate response to exercise. Neither propranolol nor metoprolol are likely to cause CO2 retention by an effect on the ventilatory responses to inhaled carbon dioxide or to exercise.

Adult↗
PubMed1978

Effects of ultrasonication of the rabbit lens in situ as evaluated by analysis of crystallin composition.

Ultrasonication and aspiration is a recently developed method of lens extraction. We have attempted todetermine whether extraction by this procedure is total or partial and, if so, whether certain regions or components are preferentially removed, and also whether the contents of the lens are physico-chemically modified by the process of extraction. The water-soluble and urea-soluble protein fractions from the ultrasonicated lenses and the contra-lateral intact lenses of six rabbits were analysed by isoelectric focusing. Differences are found in the crystallin content which indicate that extraction is frequently non-representative and that beta- and gamma- crystallins are modified by the process.

Animals↗
PubMed1976

Lens extraction with ultrasound. Experiments in rabbits.

The extraction of the rabbit lens is described using a 25 G irrigating needle and a 22 G aspirating needle; at the latter's bevelled tip lens fragmentation occurs due to the longitudinal ultrasonic vibrations generated there--an 'acoustic horn' causes the tip to vibrate with large amplitudes. The use of small needles allows considerable manoeuvrability in the anterior chamber and usually eliminates the need for corneal suturing. Push-pull coupled syringes equate the volume of irrigation with that of aspiration. This procedure makes possible lens extraction through an aperture in the anterior capsule of the rabbit's lens and a similar machine is being constructed for trial on human cataract.

Animals↗
PubMed1975

Ultrasonic cataract extraction with acoustic horn.

An ultrasonic lens-disintegrations system is added to the aspiration side of an irrigation-aspiration system. It incorporates an acoustic horn of which one part is a stainless steel cone 4 cm long with a 1 cm diameter base. From the apex of the cone projects the other part, viz. a 22 gauge needle, which is inserted into the anterior chamber at the limbus temporally (left eye) and which carries aspirated lens fragments with saline out into a duct drilled 2 cm into the cone along its axis. At that point the duct turns at right-angles to leave the cone; a polythene tube connects the duct with the aspiration syringe. A vibration generator (sandwich transducer) initiates ultrasonic vibrations which the needle-cone combination magnifies about 100-fold at the tip of the needle. Saline input to and output from the anterior chamber are maintained exactly equal (and simultaneous) by means of a 'push-pull' system of twin reciprocating hand-driven 30 ml. syringes (Fig. 7). Saline input is through a 25 gauge needle at the limbus at 6 o'clock (left eye).

Amplifiers, Electronic↗