Optium

MediSense^®

Optiumä β- Ketone Electrodes

Important: To ensure accurate results, you must read the MediSense Optium User's Guide before testing.

For use outside the body (in vitro diagnostic use) with the MediSense^® Optiumä Blood Glucose and Ketone Sensor for quantitatively measuring ketone (Beta-Hydroxybutyrate) in fresh capillary whole blood (i.e., from the finger). Healthcare professionals may also use venous whole blood samples, provided the samples are used within 30 minutes of collection.

Storage and Use

• Store the electrodes at temperatures between 4º and 30ºC (39º and 86ºF). Keep away from direct sunlight and heat.
• Do not use the electrodes beyond the expiry date printed on the foil packet and outer box.
• Use each electrode immediately after opening the foil packet.
• Do not use wet, bent, scratched or damaged electrodes.
• Use each electrode only once and then discard.

Precautions

• Always calibrate (code) the MediSense Optium Sensor with each new box of electrodes.
• Use only the calibrator supplied with the electrodes. Keep the calibrator until all the electrodes in the box have been used.
• Use only MediSense Optium b -Ketone Electrodes with the MediSense Optium Sensor.

Samples Collection and Preparation

Before obtaining a blood samples, use warm soapy water to wash your hands and dry completely. Warm water helps to increase the blood flow to your fingertips. If you have difficulty in obtaining a blood sample, hanging your arm down before lancing your finger may also help increase the blood flow. Avoid excessive squeezing of the puncture site. Use the capillary blood sample immediately. Sample volume: 5.0 microlitres.

Healthcare professionals: Venous whole blood samples are to be collected into sodium or lithium heparin tubes or EDTA tubes (do not use tubes containing fluoride or oxalate) and used within 30 minutes.

Quick Reference Procedure

Please read the MediSense Optium User's Guide for detailed testing and calibration (coding) procedures.

Materials provided:

MediSense Optium b -Ketone Electrodes and calibrator.

Materials required but not provided:

MediSense Optium Sensor and User's Guide, lancing device and lancets.

Calibration

1. With the contact bars facing up, insert the contact bars of the calibrator into the sensor. The sensor turns on automatically.
2. Ketone, Code = and the calibration code appear in the display window.
3. Check that this code matches the code on the calibrator. Calibration is complete.

Blood Test

1. With the three contact bars facing up, insert the contact bars of the electrode into the sensor. The sensor turns on automatically.

2. When Apply Blood appears in the display window, obtain a drop of blood. Touch the drop of blood to the target area. When the sample is detected, the test countdown begins automatically. Remove your finger when the display shows "---". Ketone and your blood ketone result will appear in 30 seconds.

Note: If the test fails to start, a second drop of blood may be applied within 30 seconds of the first blood drop. If the test fails to start after the second drop is applied or more than 30 seconds have passed, discard the electrode and repeat the test.

Test Messages

• If HI appears in the display window, the sensor has determined that your blood ketone result is higher than 6.0 mmol/l. Repeat the test with a new electrode. If HI appears again, follow your healthcare professional's instructions.

Expected Results

The b -Ketone test measures Beta-Hydroxybutyrate (b-OHB), the most important of the three ketone bodies in the blood¹. Normally, levels of b -OHB are expected to be less than 0.6 mmol/l².b -OHB levels may increase if a person fasts, exercises vigorously or has diabetes and becomes ill^1,3.

If your b-Ketone test result is between 0.6 and 1.5 mmol/l and your blood glucose is 16.7 mmol/l (300 mg/dl) or greater, this may indicate development of a problem that could require medical assistance. Follow your healthcare professional's instructions.

If your b -Ketone test result is greater than 1.5 mmol/l and your blood glucose result is 16.7 mmol/l (300 mg/dl) or greater, call your healthcare professional promptly for advice and assistance. You may be at risk of developing diabetic ketoacidosis (DKA)^2-6.

Limitations of Procedure

• This system is not designed for use with serum, plasma or neonatal whole blood samples.
• Use between 18º and 30ºC (64º and 86ºF) and 10% and 90% relative humidity for best results.
• Clinical testing demonstrates that altitudes upto 2,195 meters (7,200 feet) above sea level do not affect results.
• No Significant effect was found for haematocrits between 30% and 60%. Haematocrits below 30% may yield higher results and haematocrits higher than 60% may yield lower results.
• The following substances have no significant effect on b -Ketone results:

• Captopril up to 90 mg/ml (414 m mol/l) [therapeutic level: 2 m g/ml⁷ (9 m mol/l)]

• L-DOPA up to 30 mgml (152 m mol/l) [therapeutic level: 0.2-2.8 mg/ml⁸ (1-14 m mol/l)]

• Dopamine up to 10 m g/ml (65 m mol/l) [therapeutic level: 0.1 mg/ml⁹ (0.7 m mol/l)]

• Gentisic acid up to 80 mg/ml (519 m mol/l)
  [therapeutic level: 35-50 mg/ml¹⁰ (227-325 m mol/l)]

Test Principle

When the blood sample is applied to the electrode, the b -OHB in the blood reacts with the chemicals on the electrode, producing a small electrical current. This current is measured and then a result displayed by the MediSense Optium Sensor. The size of the current depends on the amount of b -OHB in the blood sample.

Composition

The reagent area of each electrode contains:

Hydroxybutyrate Dehydrogenase

(Pseudomonas sp.) > 0.06 IU

Other non-reactive ingredients > 90 mg

Performance Characteristics

Assay Range: 0.0-6.0 mmol/l

Test Time: 30 seconds

PRECISION

Precision testing shows that electrode-to-electrode results typically vary by no more than 3.2% to 10.5% from the average value. The following with-in-run precision data were obtained in a laboratory study using the MediSense Optium System to analyze venous whole blood samples (n = 20 per level).

	Low	Mid	High
Mean (mmol/l)	0.43	1.08	3.55
SD (mmol)	0.04	0.06	0.11
CV, %	10.5	5.9	3.2

ACCURACY

Accuracy testing shows that results compare well with a laboratory reference method and that results are comparable between trained operators and lay users. The accuracy of the MediSense Optium System was assessed at three clinics and four hospitals by comparing whole blood b -OHB results with those obtained using a reference laboratory instrument.

Sample Analyzed by Laboratory Instrument
Sample range (mmol/l)	0.0-5.6
No. of samples	120
Slope	0.981
Intercept, mmol/l	0.02
r	0.965

1 2 3 4