Blood draws, also called venipunctures, are one of the most common medical procedures patients experience since blood samples are often required for testing as part of medical exams. Medical professionals have investigated the use of ultrasound imaging and robotic devices to improve blood collection techniques. Most recently, researchers conducted the first human clinical trial to evaluate a robotic device that collects blood samples for laboratory testing. The ultrasound image-guided robot finds the vein, punctures it with a needle, and then draws blood.Though the trial showed promising results, improvements to the device and more studies are needed before it could be used in clinical practice.
Writing in the journal Technology, researchers from Rutgers University, Robert Wood Johnson Foundation University Hospital, and Icahn School of Medicine at Mount Sinai say the robot could make blood draws safer for both patients and healthcare providers. The technology could potentially help make blood draws much quicker and easier, especially in people whose veins are difficult to access. These include veins that can't be seen or felt easily and those that are misshapen or roll out of position easily.
Venipunctures are also one of the leading causes of medical care-related injuries to both patients and healthcare providers. Blood draws can be challenging when a vein is difficult to access, often resulting in bruising, inflammation of the vein, and, in rare situations, infections or injuries to surrounding arm nerves. Furthermore, accidental needlestick injuries to healthcare workers occur frequently and can be serious. Healthcare-worker infections from needlesticks may occur at a rate of about 3 in 1,000 needlesticks and the most worrisome are exposures to hepatitis and HIV.
Although their study focused on routine blood draws, the researchers say the robot could be adapted for other uses, such as administering fluids or medications through a vein (IV therapy), dialysis, or arterial line placement. "The combination of robotic needle placement and ultrasound guidance provides a framework for future applications in medical robotics," the authors write.
Successful blood collections
The authors of the paper describe the first clinical trial of the robot involving 31 human participants, including six with veins that were considered difficult to access. The robot successfully drew blood into collection tubes with one or two needle insertion attempts, a rate of 97% in patients whose veins were considered normally accessible and 87% in patients overall. The researchers say their device's overall successful blood collection rate is comparable to that of manual blood draws, which is about 90%. However, the study was not intended to show a direct comparison between the robot venipunctures and manual venipunctures.
The device was unable to collect blood from three participants with difficult veins. The researchers say failures were likely due to veins rolling out of position as the needle attempted to puncture them. No subjects with normal or difficult veins suffered bruising, punctures to back walls of blood vessels, or other inadvertent injuries.
Not ready for prime time
Much more work would be needed before the robot could be used in a clinical setting. The researchers are planning to make improvements to the device and to conduct follow-up studies. Future research will involve a direct comparison of the success rates and the time needed to complete robot-performed blood draws versus manual venipuncture, with and without ultrasound guidance. Such research would also involve larger groups of patients, the authors say.
Commentators on previous blood-drawing robotic devices have noted that the robot cannot perform other tasks necessary to complete routine blood draws, such as applying and removing tourniquets, cleaning the skin with alcohol, applying pressure to puncture sites, labeling the blood tubes, and applying bandages. The current study does not mention these aspects of blood draws. Human medical professionals would still be needed to perform these tasks, as well as take care of other issues as they arise, like comforting patients who are anxious or feeling faint. Questions remain about how useful robotic devices would be for certain patients, such as children who may be particularly anxious during blood draws.