Hand-carried, portable ultrasound machines share many intended uses: facilitating initial patient examinations, managing critical situations, and performing a variety of guidance procedures. Some are designed with increased functionality to enable more complicated studies in specific applications. They often serve a triage role to help determine which patients are the most appropriate candidates for further medical imaging studies.

None is designed to supplant the full range of sonographic capabilities performed on the traditional large, cart-based systems. But the primary benefit of hand-carried systems is their portability and decreased space requirements for those times when a 250–400-pound standard system just isn’t practical. The tight quarters for managing a cardiac arrest in an ICU make portable ultrasound equipment quite attractive. Additionally, these systems often appear less intimidating to patients.

Bruce J. Kimura, MD, FACC, director of noninvasive cardiology at Scripps-Mercy Hospital (San Diego) and associate clinical professor (nonsalaried) at the University of California, San Diego, uses his OptiGo portable device from Philips Medical Systems (Andover, Mass) to augment his physical examination during routine office visits, especially for first-time patient appointments. He uses the OptiGo to determine whether he needs to send a patient for a more elaborate test outside his office.

“These devices are the first technologic breakthrough to assist physical examination at the bedside,” says Kimura. Although there have been many advances in laboratory tests and imaging techniques such as MRI or MRA, portable ultrasound systems are unique because they empower the physician to diagnose a variety of disorders that matter during an initial patient encounter.

As to the comparison of these portable devices to their full-sized cousins, Kimura explains that they are not intended to replace a complete and comprehensive imaging study but rather to enhance the use of a stethoscope to look for specific conditions and to triage patients.

“The comparison has to be with current bedside physical examination techniques, not with how this device compares with a high-end ultrasound machine,” he says.

Jeffrey Peiffer, manager of sales and marketing handheld, GE Medical Systems Ultrasound (Waukesha, Wis) explains, “With hand-carried devices, we see an accelerated penetration into some of the health care imaging markets where it is needed for managing the patient and the procedure, whether diagnostic or therapeutic.”

He lists a number of specific circumstances such as all types of guidance procedures, breast biopsies, accomplishing vein therapy, in interventional laboratories to guide a catheter, and in critical care settings and the operating room; where a large system may require too much space, yet ultrasound imaging is valuable, these portable devices offer significant advantage.

Systems: Simple to Complex
SonoSite Inc (Bothell, Wash), with a corporate emphasis on manufacturing ultrasound systems that weigh fewer than 10 pounds, offers a suite of products all driven by ASIC (Application Specific Integrated Circuit) chip technology that combines millions of transistors on a single chip.

Their iLook 25 that uses a 22-mm linear transducer is an application-specific tool according to SonoSite’s director for the visual procedures division, Nelson Patterson. Introduced last year, this machine is designed to examine superficial structures such as carotid arteries or for placement of central venous lines.

Christina Carletta, RN, clinic nurse for Option Care of Nevada (Las Vegas), uses the iLook 25 to insert PICC (Peripherally Inserted Central Catheter) lines for patients who are on long-term intravenous antibiotics or for those people who have poor venous access for one reason or another.

Their nurses became PICC certified using the iLook 25. Carletta says once they learned how to differentiate between veins and arteries, the device enhanced their performance.

“The SonoSite saves us an immense amount of time in trying to locate veins,” Carletta says. “It also relieves the patient’s state of mind, especially for someone who has had difficulty with nurses being able to find their veins.” Patterson explains that even though this product has been on the market for only a little over a year, they have patients who are requesting its use.

The Terason ultrasound system runs on Windows OS, either XP or 2000, and thus can be used with a desktop, notebook or tablet PC.

Besides two different iLook offerings, SonoSite introduced their Titan series in April. Dan Walton, SonoSite’s vice president and general manager, describes Titan as a more comprehensive system. It combines pulse wave Doppler and tissue harmonic imaging (THI), and has six transducers currently, with more to come. This year, they anticipate introducing duplex imaging for vascular applications as well as split-screen and velocity color capabilities.

Walton emphasizes that their goal with the Titan is not to compete with high-end systems. “We want to provide a system in radiology that can be used in portable applications, point of care, or as a second, third, or fourth piece of equipment that can expand the sphere of influence for the radiologist throughout the hospital.”

MySono 201 is the portable ultrasound system offered by Medison America Inc (Cypress, Calif). Director of Education Dennis Wisher describes it as using digital beam-forming technology to enhance the quality of the image. It offers a full-sized keyboard and the ability to write text and perform measurements as it completes either a two-dimensional examination in gray scale and basic M-mode (motion mode) for heart measurements or THI and linear ray technology for superficial high-resolution scanning, such as thyroid or breast examinations. Some physicians, he says, are using it for targeted musculoskeletal examinations for patients with sports injuries.

Besides MySono 201, Medison offers the SONOACE PICO that is capable of performing spectral, wave Doppler, and freehand three-dimensional studies. While available for functions similar to those of MySono, this system can be used for vascular patients as well. PICO has been used for a common application of looking at the veins in the leg to rule out a DVT (deep vein thrombosis) or to treat that problem.

Terason (Burlington, Mass) has adopted an entirely different technology approach—utilizing the power and capability of the PC with its specialized software/hardware.

“We’ve fit a high-performance system into a small package that leverages the power of the PC in terms of its processing speed, display technology, and innate ability to connect to the Internet and share data,” explains Terason’s senior vice president of sales and marketing, Kerr Spencer. “For the customer, having a PC with an open architecture where you can do other things with the PC and just have the Terason application sitting on Windows has a huge benefit.” Many of their international customers have found this system helpful in performing telemedicine functions.

Terason is an application that runs on Windows OS, either XP or 2000, so it can be used with a desktop, notebook, or tablet PC. In addition to imaging capabilities, the user can employ a database of images produced by another vendor to compare the real-time imaging study with known diagnostic images of abnormal findings.

Clifford J. Fields, DO, director of emergency medicine ultrasound at St. Anne’s Hospital (Fall River, Mass), has been using a Terason system for the past 2 years. He and his colleagues selected this system because they found the image quality to be equivalent to larger systems and users were comfortable working with a Windows-based computer. He describes it as an intuitive program with software that is very easy to upgrade as advances are added.

“We use it to look for pericardial effusion, dampened, and to direct us during resuscitation,” says Fields. They also use the system for guidance in placing central lines, to diagnose and drain pleural effusion, to identify free intra-abdominal fluid resulting from trauma, to locate foreign bodies, to perform carotid artery assessment, and to accomplish peripheral vein cannulation to avoid the need for a central line. He explains that most patients are comfortable with the system because basically they see a laptop computer that is familiar rather than a large machine that they may never have seen before.

Companies that produce primarily smaller systems begin with a portability concept in their design approach. Other manufacturers have used technology developed on their larger platforms and reduced the size to the point of portability.

Miniaturizing Proven Technology
GE, Philips, and Siemens Medical Solutions (Mountain View, Calif) have leveraged technology designed for their full-sized systems to produce complex ultrasound imaging devices the size of a briefcase.

“Our vision for OptiGo is to take proven technology that has made contributions in medicine for years and miniaturize it so that it becomes a tool for physicians at the bedside to enhance their physical exam and diagnostic capabilities,” says Toni Burkett, Philips’ product manager for specialty ultrasound. “It’s designed to answer specific clinical questions immediately.” The system is not intended to replace the full formal exam performed on a full-sized.

SonoSite's iLook 15 (left) and iLook 25 (right) are based on ASIC chip technology, combining millions of transistors on a single chip.

OptiGo offers two-dimensional and traditional color flow Doppler, is durable and easy to use, and boots up in less than 3 seconds according to Burkett. It is capable of performing traditional color Doppler for cardiac examinations.

Burkett describes one class of patients who may benefit from a quick ultrasound exam with the OptiGo as those who arrive in the emergency department in full cardiac arrest and with no pulse, but EKG monitor leads reveal electrical activity (PEA, or pulse less electrical activity). Physicians need to determine immediately whether there is organized cardiac motion, and an ultrasound exam can demonstrate that situation.

“There have been a couple of studies that have shown that if there is no organized cardiac activity by ultrasound, the prospects of reviving the patient are very grim,” Burkett states.

Robert J. Siegel, MD, FACC, director of the cardiac noninvasive laboratory at Cedars-Sinai Medical Center (Los Angeles) and professor of medicine at the University of California, Los Angeles, uses OptiGo for every new patient examination in his office or as a consultant in the hospital to assess cardiac, including heart valve, function. One patient, who presented with a murmur, was found with this device to have a cardiac tumor. Siegel surmises that observation of the tumor through this ultrasound examination abbreviated the admission and workup by days or weeks.

“OptiGo is extremely easy to use because the transducer has a nicely sized footprint, so you get surprisingly good images,” says Siegel. “In addition, the color flow Doppler on the OptiGo is superb and compares very favorably with the color flow Doppler of standard machines.”

Along with diagnostic activities, he says they also use it in their training of resident physicians. They have their postdoctoral fellows take the OptiGo to emergency patients or cardiac arrests to facilitate management. The portability of the system enhances its utility.

Kimura, who is a cardiologist at Scripps-Mercy Hospital in San Diego, says he has found the OptiGo to be very reliable, with no system failures to date, as well as easy to use. However, the primary value he sees to the addition of this type of sonographic information to a routine physical examination is that it helps refine a diagnosis and inform next steps.

For example, using a high-frequency transducer to detect minimal atherosclerosis in the carotid arteries would help to select the patients who need a complete evaluation and direction about cholesterol management. He believes that efficiency arises from an improved initial diagnosis, with appropriate triage afforded by the inclusion of ultrasound in the physical examination process.

LOGIQ Book is the portable ultrasound system launched last November by GE. The GEMS approach has been to develop technology and applications on their high-end system and then migrate those capabilities across the product line, including the LOGIQ Book.

“With hand-carried devices, we see an accelerated penetration into some of the health care imaging markets where it is needed for managing the patient and procedures, whether diagnostic or therapeutic,” says GE’s Peiffer. In critical care environments where the standard machine may require too much space, the LOGIQ Book on its stand requires the space of a standard IV pole and infusion pump.

Gerald Niedzwiecki, MD, interventional radiologist and president of Advanced Intervention (Clearwater, Fla), uses his LOGIQ Book for several applications, both in his office and at the hospital. Not only has he found it to be invaluable for venous assessment, PICC line placement, and radiofrequency closure procedures for treating greater saphenous vein reflux, but he appreciates the opportunity to leave the standard machine for other procedures for which it provides a more comprehensive examination when needed.

“The LOGIQ Book is most like a standard ultrasound machine in that it has overall gain adjustment, auto-optimization, preset settings for multiple different examinations, and a split screen that is extraordinary,” says Niedzwiecki.

Siemens’ Cannon explains that the Cypress system is a highly miniaturized, all-digital, phased-array echocardiography system that is intended to perform a complete cardiovascular ultrasound examination. Because it has extensive digital archival and networking capability, studies can be stored, transmitted to DICOM servers, transported across networks, and archived on PACS.

“Some of the large high-end machines do have capabilities we don’t have on this portable unit, but they are not necessarily ideal for mobile applications because they are heavy and tend to be located in a dedicated central lab,” says Cannon. The Cypress is intended for bedside use or in other portable applications.

“It has a full range of blood flow imaging detection, an extensive calculations package, and a patient report package,” says Cannon. Files can be transferred in multimedia format so that they can be reviewed on a PC with a standard media player.

Joshua Penn, MD, director of iCardio (Los Angeles), describes his business as a national provider of echocardiography and ultrasonic imaging services based almost exclusively on the Cypress platform. They provide these imaging studies in referring physician offices, clinics, military installations, and other sites.

“What sets the Cypress apart is the high level of integrated technology that is built into it,” says Penn. He considers the image quality to be equivalent to that of the full-sized systems and includes a number of probes for pediatric and adult patients, and capabilities for Doppler, Tissue Harmonic Imaging, and methods of processing digital images for storage and transfer.

Using this system, the iCardio team is able to image a patient in one day anywhere in the country or around the world, review the study, and return a report to the referring physician within 24 hours.

Conclusion
Portable ultrasound systems prove their importance to the health care industry every day across a wide array of patient care settings. Not intended to replace standard systems, they provide visual information that improves diagnosis and treatment. Clinicians who have employed them in their practice are uniformly enthusiastic about their utility and value.