1. Equipment selection and calibration

(1) Select the appropriate Vein Finder type

Infrared type (such as ZD Medical Vein Finder Systemr) : Suitable for superficial veins (back of the hand, forearm, leg and so on).

Portable (such as wireless handheld type) : Suitable for emergency or mobile blood collection.

(2) Equipment calibration and environmental adjustment

Adjust the brightness/contrast: Ensure that the veins are clearly visible (avoid overexposure or underexposure).

Turn off strong light interference: It works better in a darker environment (such as by drawing the curtains).

Clean the skin: After wiping with an alcohol swab, wait for it to dry (wet skin scatters infrared light).



2. Patient assessment and preparation

(1) Select the best puncture site

Preferred areas: dorsal hand vein, anterior elbow vein (vital vein, head vein).

Avoid areas: joint bends, scar tissue, and edematous regions.

(2) Improve venous filling

Apply a tourniquet (with appropriate pressure, not too tight).

Have the patient clench or loosen their fist (to promote venous dilation).

Hot compress (optional) : Apply a heat pack or warm water bag for 2-3 minutes to dilate blood vessels.



3. Use Vein Finder correctly

(1) Equipment placement skills

Maintain an appropriate distance (usually 25-35cm, adjust according to the equipment instructions).

The Angle should be vertical or slightly inclined (to avoid interference from light reflection).

Stabilize the device (to avoid image blurring caused by hand tremors).

(2) Identify the optimal puncture point

Select straight, thick and unbranched venous segments (avoid curved or bifurcated parts).

Mark the vein course (use a sterile marker pen to indicate the puncture path).



4. Puncture techniques

(1) Needle insertion Angle

Conventional veins: 15°-30° (the Angle of superficial veins is smaller, while that of deep veins is slightly larger).

Obesity/deep veins: 30°-45° (with ultrasound guidance).

(2) Needle insertion technique

“First penetrate the skin, then enter the blood vessels” (avoid slanting and causing the veins to roll).

After blood return, lower the Angle (to avoid puncturing the posterior wall of the blood vessel).

(3) Adjustment for special groups

Patient type skills

For children/newborns, the smallest needle size (25G-27G) should be used, with priority given to the dorsal hand vein.

Elderly people (with fragile blood vessels) should reduce negative pressure suction and avoid excessive compression.

Obese patients use the ultrasound Vein Finder to select deeper veins.

For patients with dehydration or hypotension, apply hot compresses, tourniquets and make a fist. Use a smaller needle if necessary.



5. Handling after blood drawing

Quickly remove the tourniquet (to avoid interference with blood return).

Gently pull out the needle and press for 3 to 5 minutes (avoid bruising).