Kody Medicals Frequently Asked Questions

A hand-held Doppler is a compact ultrasound device that uses high-frequency sound waves to measure blood flow. Portable enough to fit in a pocket, it gives real-time audio or visual output at the bedside. These devices are used to detect blood flow in arteries and veins and can even pick up fetal heartbeats. Common uses include:
Assessing pulses and blood flow in the limbs (e.g. pedal and ankle pulses).
Monitoring fetal heart sounds in prenatal care.
Serving as a quick screening tool for circulatory problems like peripheral arterial disease (PAD).

Doppler ultrasound (also called vascular Doppler) is a non-invasive test that uses sound waves to measure the speed and direction of blood flow. During the exam, a probe placed on the skin above an artery senses the movement of blood cells, producing audible pulses and a waveform trace. Because it gives immediate results without radiation or needles, Doppler testing is standard for checking circulation in the feet and legs and for diagnosing conditions like peripheral artery disease.

Diabetic neuropathy is nerve damage caused by long-term diabetes, especially affecting the feet and legs. It typically begins with a loss of sensation (numbness) or painful tingling in the feet. If left unaddressed, diabetic neuropathy can cause neuropathic pain, diabetic foot ulcers, and lower limb amputations. Early detection through foot exams and nerve tests is important to prevent these complications.

The Vibration Perception Threshold test measures how much vibration a person needs to feel in order to detect it, reflecting the health of large nerve fibers. It is usually performed with a biothesiometer: a vibrating probe is placed on a patient’s toe or finger, and the vibration is gradually increased until the patient feels it. A higher VPT value (meaning the patient requires stronger vibration) indicates worse nerve function and is associated with a higher risk of foot ulcers in diabetics.

A biothesiometer is the device used to perform a VPT test. It consists of a handheld vibrating probe connected to a control unit. During testing, the probe is placed against the skin of a toe or finger, and its vibration intensity is increased until the patient feels it. This allows clinicians to quantify vibration sensitivity: a higher vibration threshold (VPT) means poorer nerve health.

The monofilament test checks sensory nerve function in the foot. In this test, a stiff 10-gram nylon filament is pressed against specific points on the sole of the foot. If the patient cannot feel the filament bending at one or more sites, that foot is considered at risk for injury or ulcers. It is a simple, low-tech screening tool commonly used in diabetes care to detect loss of protective sensation.

The ABI test compares blood pressure in the ankle to the pressure in the arm. It is calculated as the ratio of the ankle’s systolic blood pressure to the arm’s systolic pressure. A low ABI value suggests reduced blood flow to the legs, indicating possible arterial blockages or peripheral artery disease. ABI screening is a standard, non-invasive way to assess for circulatory problems in the lower limbs.

The TBI test is similar to ABI but uses the toe instead of the ankle. It measures the ratio of systolic blood pressure at the toe versus the arm. TBI is especially useful for people with diabetes or kidney disease, since toe arteries are less likely to be calcified than larger vessels. A low TBI indicates poor blood flow in the toes and may signal peripheral vascular disease.

Pulse Volume Recording measures changes in blood volume in a limb over the cardiac cycle. Cuffs and sensors placed around the limb detect volume pulses with each heartbeat, generating a waveform tracing. The shape of the PVR waveform reveals information about arterial health. Abnormal PVR patterns (such as flattened or delayed pulses) can indicate blockages or stenosis in the blood vessels, making it a useful test for peripheral vascular disease.