Although diagnostic ultrasound has a wide variety of uses important for maternal and fetal health, it is rarely available in low-resource settings. Full-size ultrasound machines are both prohibitively expensive and quite large, making them impossible to take them into community settings. In recent years, the development of portable, compact ultrasound technologies have allowed health workers in smaller clinics and community settings to use this valuable tool in maternal and fetal health. As with full-size ultrasound machines, portable ultrasound machines have broader applicability beyond maternal and fetal health as they can be used to diagnose a variety of medical conditions. Thus far, there are few published studies on the use of portable ultrasound in low-resource settings and so the public health benefit, while implied, cannot be quantified at this time.i Because ultrasound only offers the means to detect health concerns, it is only effective if additional resources exist to treat the conditions identified.
Caution must be taken with the expansion of ultrasound into community settings to ensure that the devices are not being used for sex selection and female feticide.ii Currently, some countries ban the use of portable ultrasound or outlaw its use outside of approved health facilities. Devices that include a locking mechanism or system password may help prevent them from unauthorized use or removal from a facility.i Many existing portable devices offer password protection that is only intended to guard patient data and the devices can still be used without logging into the machine. Further, the small size of handheld devices prevents the installation of a locking mechanism. Therefore, clinics should take care to secure the equipment when it is not in use.
Portable ultrasound devices range in price from about US$3,600 to US$20,000. In addition to the cost of the machine, there are a number of other costs associated with ultrasound. Although a few portable ultrasound devices do come with a transducer (probe) included, transducers must often be purchased separately. Because transducers are designed for specific clinical applications, there are a variety of transducers available for each machine and the user will need to have the appropriate transducer for the intended clinical application. A transducer intended for abdominal or obstetric applications may cost an additional US$1,500 to US$2,500. Further, ultrasound requires the use of specific kinds of conductive gel to conduct 3 sound waves between the transducer and the patient’s skin. Although the gel is not a significant operational cost, it must be available in order to prevent the use of locally available substances which can damage the transducer. Many battery-powered health technologies, including portable ultrasound, use lithium-ion (Li-ion) batteries. Li-ion batteries are the newest rechargeable battery technology on the market and changes and improvements have been occurring relatively quickly over the past 20 years. While considered to be the highest-quality rechargeable battery, they have a mid-range life cycle, are expensive to replace, and age more quickly at higher temperatures.iii,iv Further, frequent power outages can have a significant impact on the lifespan of portable ultrasound devices.v Training of staff to use ultrasound is also necessary. Doctors or midwives will require about two to three weeks of training to be able to conduct basic obstetric measurements using ultrasound.i
In a 2009 article, Harris and Marks defined important factors for portable ultrasound use in low-resource settings. These factors are outlined in the following summary of portable ultrasound technologies.i
This guide contains commercialized portable ultrasound devices available on the market today. The devices are organized by price.