Semi-Automated Urine Strip Reader

What is the Semi-Automated Urine Strip Reader?

A semi-automated urine strip reader requires the operator to place each strip in the reading position, after which the instrument measures the pads, calculates results and prints or transmits them. It suits low-volume clinics and wards that read fewer than one hundred strips per day.

Overview

The instrument contains a light source, a photodiode array or camera and a fixed strip carrier with a position stop so that pads align with the optical channels. The operator starts the reading a set time after dipping the strip, and the instrument compares reflectance with stored calibration data for each pad, applies colour compensation and reports the result. Parameters are usually the standard ten, with results printed on an integrated thermal printer or sent to a laboratory information system. Throughput depends on handling time rather than on the instrument, typically 60 to 120 strips per hour in practiced hands. Calibration is performed with the manufacturer's reference strip, and the reading window must be cleaned daily because any deposit biases reflectance values.

How does it work?

Each pad on a reagent strip contains reagents that change colour in proportion to the analyte concentration: glucose pads use a peroxidase-chromogen system, protein pads rely on the protein error of a pH indicator, blood pads detect the pseudoperoxidase activity of haemoglobin, leukocyte esterase cleaves an ester to release a diazonium-reactive compound, and nitrite is detected by diazotisation. The reader presses the strip against a light source and measures the light reflected from each pad with photodiodes or a camera at defined wavelengths, usually between 525 and 660 nanometres. A compensation pad or channel corrects for the intrinsic colour of the urine, and some instruments also compensate for ascorbic acid interference. The instrument converts reflectance into a category such as negative, trace, 1+, 2+, 3+ or a numeric value for pH and specific gravity.

What are the key features?

• Fixed strip carrier with alignment stop for pad positioning
• Photodiode or camera reading with colour compensation
• Standard ten-parameter report with integrated printer
• Stored calibration per strip type
• Barcode or operator identification in some models
• Result transmission to a laboratory information system

What are the technical specifications?

A typical semi-automated urine strip reader configuration offers measured parameters of Glucose, protein, blood, LE, nitrite, ketones, bilirubin, urobilinogen, pH, SG, wavelengths of 525, 560, 610 and 660 nm, throughput of 60–120 strips/h with manual handling, reading time of About 5 s per strip after dip, printer of Integrated thermal printer and data storage of 2,000 patient results. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Semi-Automated Urine Strip Reader is used in clinic urine screening, ward-based urinalysis, antenatal clinic testing and occupational health screening. Across the wider Urine Strip Readers class, laboratories also deploy it for routine urine chemistry screening in clinics, antenatal and pre-employment health checks and diabetes and renal clinic monitoring.

Which standards and certifications apply?

Relevant standards and methods include ISO 15189, CLSI GP16, CLSI EP05, CLSI POCT04, ISO 18113-1, IEC 61010-1 and IEC 61010-2-101. Certification candidates for this model are CE, ISO 13485 manufacturing and NMPA class II registration; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Read strips within the time stated in the instructions, because pad colour continues to develop and delays change results near category boundaries. Protect strips from moisture, heat and light, do not touch the pads and use them before expiry, since degraded strips give falsely negative results. Verify performance at installation with the manufacturer's calibration strip or reference panel, and run quality control material or a known urine sample each working day. Clean the reading window and strip carrier according to the manual, and check that the compensation channel is functioning, because a dirty window biases all reflectance readings. Treat urine as potentially infectious and decontaminate the strip carrier regularly.

How do I select the right Semi-Automated Urine Strip Reader?

Specify this variant when volume is low and manual strip placement is acceptable. In the RFQ confirm the strip types supported, whether colour and ascorbate compensation are included, the printer and interface options, and the interval recommended for calibration verification with a reference strip.

How does it compare with other Urine Strip Readers variants?

Decide first how many strips are read each day, because that determines whether a simple bench reader, an instrument with automatic strip feeding or a portable device is appropriate. Then check which parameters the reader measures and whether the report format matches what clinicians expect, especially if semiquantitative scales differ from other laboratories. Confirm the wavelengths and compensation features, since colour and ascorbate interference are the main sources of error, and check whether barcode or operator identification is supported for traceability. For portable and near-patient use, consider battery life, strip storage conditions and whether the device can transmit results. Confirm that the reagent strips specified for the reader are available locally and have an adequate shelf life.