Basic Ultrasound Specification

An extract from "The future use of new imaging technologies in developing countries" (WHO, 1985, Technical Report Series).

Section 2.3

Minimum Specification for the general-purpose ultrasound scanner.

Transducer

Standard Unit: 3.5Mhz centre frequency
Optional unit: 5.0MHz centre frequency
Ficed in-slice focussing on both units desirable but not essential.
Sector angel: 40 degrees (sector scanner) or better.
Array length: 5-8cm (linear array scanner).

Controls

To be simple and clearly arranged.
Gain control is required.
Time gain compensation to be by choice of preset and variable conditions.

Frame rate

5-10Hz (sector scanner), 15-30Hz (linear array scanner).

Frame freeze and display

512 x 512 x 4bits (to provide 16 grey levels).

Omnidirectional calipers

One pair to be provided, with facility for quantitative readout and recording.

Patient identification

Facilities to be provided for manually entering and recording data (patient identification, date, etc) on the image screen.

Permanent recording

Provision must be made for the economical preparation of good-quality permanent image records.

Construction

The unit should be portable (not more than 8kg), drip-proof and dust-proof. Proper and continuous operation should be psooible under the following conditions:
Temp: 0 degrees to 40 degrees C.
Humidity: up to 95%
Storage should be possible under the following conditions:
Temp: -30 degrees to +50 degrees C
Humidity: up to 100%
The unit should be rugged and capable of withstanding the vibration likely to occur during rough, cross country transport. Special care should be taken to avoid failure of the transducer, its cable, and its connector under the above conditions. The mechanical design of the transducer should include:
(a) Maximum protection against damage by dropping
(b) Tolerance of the sue of a variety of coupling media - particularly local vegetable oils.

Electrical and mechanical safety

The equipment should conform to the standards set by the International Electrotechnical Commission (Medical Electrical Equipment) [published 1977, No. 601-1]
Where interventional use is intended, particular care must be taken to ensure that the relevant standards of equipment earthing (grounding) and leakage of current are met.

Power supply

The equipment must be capable of working from any of the following types of supply:
Direct Current (DC): standard batteries, preferably rechargeable.
Alternating Current (AC): 50 and 60 Hz, 100,110,117,125 Volts, and 200,220, and 240V.
Surge protection to be provided.
Extract ends
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