Surgeons today receive entirely different types of technical support during operations compared to 10 or 20 years ago. For example, imaging techniques enable spatial orientation using 3D computer models. Based on the models, the operation is then planned – for example, the optimum point of entry, the best entry angle, and the optimum entry depth with an ablation needle that is intended to destroy a tumor. During the operation, the tip of the surgical needle is followed and is shown as a virtual needle in the computer model. This helps those operating to place the needle as intended by using the model on the screen.
New Acoustic Approach
“We have an entirely new approach – namely an acoustic one,” says Dr. Tim Ziemer. The music scholar works on the technical implementation of psychoacoustics in spatial audio systems at Bremen Spatial Cognition Center (BSCC) at the University of Bremen. Together with the cognitive scientist PD Dr. Holger Schultheis, the psychology doctoral student Tina Vajsbaher, and eleven master’s students, he is developing an Android and Windows game that is to run on other operating systems soon. The core of the project is formed by a foreign sound – the “psychoacoustic sonification.” The term refers to the displaying of data by means of sound.
The various characteristics of the sound relay a position in a 3D space to the players. During the course of the game, the players then learn to interpret the individual dimensions of the sound: How far to the left or to the right, to the top or bottom, to the front or back is the target? Additionally, players initially learn to combine two and then finally three dimensions so that they can navigate within the 3D space when blind.
Hearing Tones During an Operation
“Hopefully, the players just have a great deal of fun. They are entertained, are training their hearing, trying to reach expert status, and break the high score,” says Tim Ziemer. “The fact that they will maybe be able to save lives in the future due to their playing is an additional motivation.” One day, the acoustic orientation in space is to help surgeons with complex, spatial target finding during minimally invasive procedures, as visualization does.
The game with a total of five parts is to provide further information on how humans deal with psychoacoustic sonification: “On which level does an inexperienced player start and what do learning curves look like? How quickly does a user become how precise, how prone is the user to mixing up axes or directions, and what is the top performance level?”, explains Tim Ziemer. “How long can people listen to the sound? Do people make systematic mistakes when interpreting the sound which could be avoided by optimizing the sound design?”
Listening Is Less Tiring Than Seeing
The aim of the “game-supported research” is to add an “acoustic orientation guide” to the “optical orientation guide.” “Twice as good,” explains Holger Schultheis. “One day, we want to additionally offer psychoacoustic sonification for complicated surgeries.” The problem with imaging processes is that spatial orientation uses a great deal of brain resources. The computer monitor does not show the spatial constellation from the viewpoint of the surgeon. They must mentally scale, rotate, move, and especially interpret the depth dimension from the two dimension graphic on the monitor. “This requires a great deal of training and procedures can be tiring. The acoustic orientation guide lessens the strain on surgeons and can increase patient safety in this way,” according to Schultheis. “The support offered by our technique would also make more precise procedures possible and would allow for surgeries to be carried out on tumors that are dangerously close to large arteries, important nerves, or sensitive membranes.”
“The tones tell the surgeons in real time and from their perspective if the needle must be moved left/right, upwards/downwards, or forwards/backwards – and exactly how far,” explains Tim Ziemer. “This is possible at any time and if desired, down to a tenth of a millimeter. The psychoacoustic sonification is a world first, for which we have already received prizes.” The team has shown that after a 30-minute training session with the “acoustic orientation guide”, people can find a four-millimeter target in a 20 by 20 centimeter large space just as reliably as with visual aids.
Information from the Game Important for Further Development
“We can optimize the tones in surgeries thanks to the information that we are collecting with the game outside of surgeries. We are currently also preparing experiments in surgical surroundings,” states Holger Schultheis. “But only a few dozen participants are involved in experiments and they always only take between one and two hours. In order to be able to make statements regarding long-term training effects and a larger population, we need data from the game.”
Alongside surgery, further scenarios are thinkable for the implementation of psychoacoustic sonification – for example, the controlling of drones and underwater robots or the monitoring of patient data.
http://curat.informatik.uni-bremen.de/en/projectday.html - On this website, you can find more information, demo videos, and the game download link.
Dr. Tim Ziemer
University of Bremen
Bremen Spatial Cognition Center (BSCC)
Phone: +49 (0)421 218-64280
Email: ziemerprotect me ?!uni-bremenprotect me ?!.de
PD Dr. Holger Schultheis
University of Bremen
Bremen Spatial Cognition Center (BSCC) and Institute of Artificial Intelligence
Phone: +49 (0)421 218-64292
Email: schulthprotect me ?!informatik.uni-bremenprotect me ?!.de