Navigation Links
New guidance system could improve minimally invasive surgery

Johns Hopkins researchers have devised a computerized process that could make minimally invasive surgery more accurate and streamlined using equipment already common in the operating room.

In a report published recently in the journal Physics in Medicine and Biology, the researchers say initial testing of the algorithm shows that their image-based guidance system is potentially superior to conventional tracking systems that have been the mainstay of surgical navigation over the last decade.

"Imaging in the operating room opens new possibilities for patient safety and high-precision surgical guidance," says Jeffrey Siewerdsen, Ph.D., a professor of biomedical engineering in the Johns Hopkins University School of Medicine. "In this work, we devised an imaging method that could overcome traditional barriers in precision and workflow. Rather than adding complicated tracking systems and special markers to the already busy surgical scene, we realized a method in which the imaging system is the tracker and the patient is the marker."

Siewerdsen explains that current state-of-the-art surgical navigation involves an often cumbersome process in which someone usually a surgical technician, resident or fellow manually matches points on the patient's body to those in a preoperative CT image. This process, called registration, enables a computer to orient the image of the patient within the geometry of the operating room. "The registration process can be error-prone, require multiple manual attempts to achieve high accuracy and tends to degrade over the course of the operation," Siewerdsen says.

Siewerdsen's team used a mobile C-arm, already a piece of equipment used in many surgeries, to develop an alternative. They suspected that a fast, accurate registration algorithm could be devised to match two-dimensional X-ray images to the three-dimensional preoperative CT scan in a way that would be automatic and remain up to date throughout the operation.

Starting with a mathematical algorithm they had previously developed to help surgeons locate specific vertebrae during spine surgery, the team adapted the method to the task of surgical navigation. When they tested the method on cadavers, they found a level of accuracy better than 2 millimeters and consistently better than a conventional surgical tracker, which has 2 to 4 millimeters of accuracy in surgical settings.

"The breakthrough came when we discovered how much geometric information could be extracted from just one or two X-ray images of the patient," says Ali Uneri, a graduate student in the Department of Computer Science in the Johns Hopkins University Whiting School of Engineering. "From just a single frame, we achieved better than 3 millimeters of accuracy, and with two frames acquired with a small angular separation, we could provide surgical navigation more accurately than a conventional tracker."

The team investigated how small the angle between the two images could be without compromising accuracy and found that as little as 15 degrees was sufficient to provide better than 2 millimeters of accuracy.

An additional advantage of the system, Uneri says, is that the two X-ray images can be acquired at extremely low dose of radiation far below what is needed for a visually clear image, but enough for the algorithm to extract accurate geometric information.

The team is translating the method to a system suitable for clinical studies. While the system could potentially be used in a wide range of procedures, Siewerdsen expects it to be most useful in minimally invasive surgeries, such as spinal and intracranial neurosurgery.

A. Jay Khanna, M.D., an associate professor of orthopaedic surgery and biomedical engineering at the Johns Hopkins University School of Medicine, evaluated the system in its first application to spine surgery. "Accurate surgical navigation is essential to high-quality minimally invasive surgery," he says. "But conventional navigation systems can present a major cost barrier and a bottleneck to workflow. This system could provide accurate navigation with simple systems that are already in the OR and with a sophisticated registration algorithm under the hood."

Ziya Gokaslan, M.D., a professor of neurosurgery at the Johns Hopkins University School of Medicine, is leading the translational research team. "We are already seeing how intraoperative imaging can be used to enhance workflow and improve patient safety," he says. "Extending those methods to the task of surgical navigation is very promising, and it could open the availability of high-precision guidance to a broader spectrum of surgeries than previously available."


Contact: Catherine Kolf
Johns Hopkins Medicine

Related biology news :

1. Lyme retreatment guidance may be flawed
2. NJIT students win seed capital and expert guidance to launch business ventures
3. European Guidance for the diagnosis & management of osteoporosis in postmenopausal women
4. Anglo-French partnership develops guidance on future management of English Channel
5. IU biologists offer clearer picture of how protein machine systems tweak gene expression
6. Unexpected crustacean diversity discovered in northern freshwater ecosystems
7. Hot meets cold at new deep-sea ecosystem: Hydrothermal seep
8. Glacier-fed river systems threatened by climate change
9. Melting glaciers, enough sand to bury London, and ancient ecosystem engineering
10. Immune system implicated in prematurity complication
11. Key to immune system disease could lie inside the cheek
Post Your Comments:
Related Image:
New guidance system could improve minimally invasive surgery
(Date:10/26/2015)... PALO ALTO, Calif. and LAS ... – Nok Nok Labs , an innovator in ... FIDO Alliance , today announced the launch of its ... the first unified platform enabling organizations to use standards-based ... authentication. The Nok Nok S3 Authentication Suite is ideal ...
(Date:10/23/2015)... Oct. 23, 2015 Research and Markets ( ... "Global Voice Recognition Biometrics Market 2015-2019" report to ... --> The global voice recognition biometrics market to ... --> --> The ... prepared based on an in-depth market analysis with inputs ...
(Date:10/22/2015)...  Aware, Inc. (NASDAQ: AWRE ), a leading supplier of ... quarter ended September 30, 2015.  --> ... $4.0 million, a decrease of 33% compared to $6.0 million in ... of 2015 was $2.2 million, or $0.10 per diluted share, which ... same period a year ago.  --> ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... Nov. 24, 2015 /PRNewswire/ - Aeterna Zentaris Inc. ... that the remaining 11,000 post-share consolidation (or 1,100,000 ... (the "Series B Warrants") subject to the previously ... November 23, 2015, which will result in the ... effect to the issuance of such shares, there ...
(Date:11/24/2015)... ... November 24, 2015 , ... In harsh ... Insertion points for in-line sensors can represent a weak spot where leaking process ... series of retractable sensor housings , which are designed to tolerate extreme process ...
(Date:11/24/2015)... ... November 24, 2015 , ... Creation Technologies would like to ... Deloitte's 2015 Technology Fast 500 list of the fastest growing companies in North ... II medical device that speeds up orthodontic tooth movement by as much as ...
(Date:11/24/2015)... Capricor Therapeutics, Inc. (NASDAQ: ... development and commercialization of first-in-class therapeutics, today announced that ... scheduled to present at the 2015 Piper Jaffray Healthcare ... at The Lotte New York Palace Hotel in ... . --> . ...
Breaking Biology Technology: