Faced with replacing a Doppler? There are so many options that it often is difficult to decide on what is right for you.
Let me walk you through the process so you can make an informed decision before buying.
The starting point is to identify your requirements clearly. For example, will you be assessing fetal heartbeats and what gestation periods or will you be assessing vascular blood flow. Many dopplers have the ability to do both applications (with the correct probes) but there are some that are better suited for special requirements such as intra operative use, High risk assessments and limited access sites such as ABI (ANKLE BRACHIAL INDEX) testing for peripheral arterial diseases.
1. How to choose the base units of the Doppler
There are two main sizes to choose from; pocket size and desktop. The Desktop model has proved to be a solution for hospitals and clinics that experience theft, damage and misplacement. The size of it creates a security against walking out the door in a pocket, bouncing of a door way in a pocket or simply disappearing in a drawer. The benefit of the pocket size is obviously the fact of portability. It is generally the preference for point of care applications however; the desktop models generally produce louder and clearer sound. Which best describe your requirement?
In addition to the Doppler size, there are other options to choose from. For example:
Do you require a digital display? The digital display is intended to confirm the manually counted numbers. All Dopplers base the numbers on pulses and cannot identify the difference between maternal blood flow and the fetal heart. It is therefore critical in the training of intermittent occultation that it is understood that the digital display is simply a confirmation of numbers and not a replacement for the care givers count.
Do you want it to be rechargeable? A Doppler will typically get between 300-500 assessments from a single set of alkaline batteries. Our recommendation is to use the alkaline battery type so that recharging isn’t an additional task that needs to be thought about by the staff. This would change if you decide to go with a Doppler that has a docking station and the charging base becomes a home for the Doppler. There are only a couple options on the market that offer this but it will also assist with theft, damage and misplacement.
You should now have a pretty good idea what you would prefer in the base unit so we will now talk about probes. There is one main point that I would like to stress initially. Vascular and obstetrical probes work on different ultrasound formats and it is highly improbable that you will be able to effectively assess the opposite sounds with accuracy to which the probe is designed.
2. How to choose the right probe
Probe technology has changed slightly but all the same principles still apply. With hand held dopplers, all probes less than a 3MHz will be used for obstetrical applications and everything above a 4MHz will be used for vascular applications.
A simple rule of thumb is: The higher the number, the more peripheral the detection will be.
Here is a brief description of the typical probes.
2MHz – This is a later term obstetrical probe and will attain deeper penetration. This is often the choice for anything after 21 weeks gestation. It is also often available in a waterproof version for tub labor or assessments in the shower.
3MHz – This is the early term obstetrical probe. It is more peripheral than the 2MHz and often used in the office assessments. Some have found that this probe is well suited during delivery once the child has dropped into position for birthing.
4MHz – This is a very deep penetration vascular probe that is best suited to areas requiring assessment of deep arterial sounds such as aortic, femoral and other major vascular assessments.
5MHz – This probe is commonly paired with the 8MHz probe as a good selection for total vascular assessments. This probe will be great for assessing with bariatrics or in some cases, the sclerosis patients. It is a mid-level assessment and a good multi-purpose probe to have.
8MHz – This is the most popular probe for peripheral detection such and ABI (Ankle, Brachial Index) assessments. Those looking for pedal pulses, brachial pulses and digital pulses will prefer the 8MHz. Some Dopplers will offer this in a Sterilizable model. These are often used intra-operatively.
Now you can package you main unit with the probes you require and confidently purchase a doppler that is best suited for you. You can view the many options on our website by clicking below.