About the equipment
Fetal and vascular Doppler technology is based on the Doppler shift principle first discovered by Christian Doppler, an Austrian physicist, in 1842. The principle is similar to hearing a train bell approaching, and then moving away from you, and how the audible pitch of that train bell changes from high to low. Basically, what happens is that the pitch or frequency is compressed (high pitch) or expanded (low pitch). Dopplers work on the principle of listening to the reflections of small, high frequency sound waves called ultrasound. The ultrasound sound waves are generated by the vibrations of microscope piezoelectric crystals. The ultrasound waves are sent into the body and then reflected back to the Doppler from moving objects, such as a fetal heart or blood flowing through an artery or a vein. These signals are then converted by the Doppler’s electronics into a sound that the physician can hear, or they are displayed as a number on the Doppler itself.
Fetal Dopplers are very common in the OB setting (office, labor & delivery, etc.). Practitioners typically begin to use them around the 12th week of gestation to listen to fetal heart tones, and continue to use them throughout the pregnancy.
Vascular Dopplers typically are used by cardiologists, vascular specialists and primary care physicians, as well as other doctors concerned with blood flow in the arteries, veins and, especially, the extremities. Vascular Doppler technology is also used to perform an ABI (Ankle Brachial Index) exam to help diagnose peripheral arterial disease (PAD).
Probing sales questions
- Are you getting reliable service out of your fetal/vascular Doppler?
- Would you be interested in a fetal Doppler that can use both a 3 and a 2 MegaHertz transducer in the same Doppler?
- Would you be interested in learning more about a reimbursable product that can help diagnose peripheral arterial disease?
- Are you aware that peripheral arterial disease affects approximately 8.5 million Americans?
- Do you currently provide ankle brachial index testing at your practice?
Customer objections
- I can buy a Doppler at a better price.
Reps should respond: Make sure you’re comparing apples to apples, as many Dopplers don’t have displays to show fetal heart rate, don’t have interchangeable transducers/cables, or have batteries that last up to 1,250 minutes of use time. Also, many Dopplers available on the market are cheaply made and difficult to use due to inferior design and technology.
- ABI testing is too difficult and time consuming to do.
Reps should respond: Leading ABI companies have built in automated functions and technology to help streamline the examination workflow. A trained clinician can complete a fully reimbursable exam in less than 15 minutes.
New products
Wallach/Summit offers a complete array of Doppler ultrasound transducers, including a unique and useful 5Mhz transvaginal version. This transducer is especially helpful in finding early fetal heart tones in difficult situations, such as when a patient is particularly obese or if a uterus is retroverted. All transducers are replaceable, which helps minimize/eliminate down time and repair costs and can save money when more than one transducer is required.
Preventive maintenance tips
It’s always a good idea to completely clean a Doppler transducer of the ultrasound gel that is used. Other than that, Wallach/Summit Dopplers are maintenance free and USA manufactured to the highest standards of medical product manufacturing.
Editor’s note: Repertoire would like to thank Wallach for its assistance with this piece.