JUSTIFICACIÓ DE PREUS

Participants gave positive feedback about their ability to interact with the anatomy and physiology on the mannequin, specifically related to peeling back layers of the anatomy to see underlying structures—“Wow, no way! That’s wild. That’s surprising, and almost shocking, to just have that

happen the first time that opens up and watching it drag around and reveal.” Participants were

excited about BodyExplorer’s automatic reactions to their interactions with the mannequin, especially when the physiology automatically updated in response to administration of simulated medications—“Wow, just double-checking, is there nobody behind the controls, this is all

automated? That’s pretty amazing!” In comparison to other software applications for anatomy and

physiology, participants were positive about BodyExplorer’s integration of anatomy and physiology into one application—“A lot of programs that are out there now, you can solely explore

the anatomy, or you can go and do classic physiology experiments online, but to be able to see it right here as you are watching the heart beat is pretty cool.”

Participants exhibited some difficulties and frustrations with the interface. The main difficulty with the interface was using the input device to manipulate anatomy windows. All participants commented on difficulty with the input device during testing sessions. Primary reasons for the difficulties derived from poor tracking of the input device (corresponding to poor control of the cursor on the mannequin) and difficulty using the button on the input device (either pressing the incorrect button or inadequate feedback that the button was pressed).. Participants commented that the input device was straightforward to use, it just didn’t appear to behave properly all of the time—“It seems pretty straightforward, but it takes a little bit of getting used to…The window

resizing. It is intuitive, but it is cumbersome in the way that it is implemented…I just had to get time to get used to it.” Quantitative analysis on input device usability will be presented in Section

5.5.

Participants also suggested adding more content to the scenarios. While participants were positive about having the ability to peel back layers of anatomy, they wanted to be able to see more organs and internal structures, specifically cutaway views inside organs such as the heart, lungs, and gastrointestinal (GI) system—“It would be really easy to visualize how the blood is flowing in

the heart, and it’s usually counterintuitive to how you learn it from textbooks because of the way that the anatomy is.” Multiple participants wanted the ability to see other patient vital signs, in

addition to the ECG, such as oxygen saturation, blood pressures, and lung gas exchange—“Being

a clinician, it would be good to have the vital signs.” In addition to the normal anatomy and

explore pathological conditions by visualizing anatomical differences, seeing variations of patient vital signs, and hearing the associated differences in auscultation during a patient assessment.

With respect to RSI in Task 2, participants appreciated being shown on the auxiliary display how hard they were pressing during application of cricoid pressure. A graduate student commented on not knowing how hard to press—“We are told to apply 30 to 40 Newtons, but I

never really knew what [applying] 30 to 40 Newtons felt like.” Participants also suggested adding

the recommended pressure range to the display of applied pressure so that they could be reminded to hold pressure in the correct range.

5.2.3 Discussion

The observed difficulties and frustrations while participants used the input device were not unsurmountable problems to address during the next design iteration. The two primary reasons postulated for difficulty while using the input device derived from poor tracking of the device, corresponding to cursor positioning on the mannequin’s surface, and missed button presses on the device—either the user pressed the wrong button or the system did not properly receive the “button press” signal from the device. When the method for tracking the input device cannot locate the device, the cursor position defaults to a screen position of (0,0), or the mannequin’s right lower quadrant when projected onto the mannequin. Modifying the software to default to the last known cursor position could fix some of the glitches observed with the interface. However, this modification does not ultimately fix the root cause of the issue—the camera loses sight of the input device’s IR-LED. Modifications to the input device design needed to be performed during the next iteration of testing to reduce the possibility of the camera losing sight of the input device’s IR-

The observation that users had difficulty with the button in the input device suggests that the button should be larger and more distinct from other buttons on the device. The active button was adjacent to an inactive button on the input device, and thus, the user would sometimes confuse the two. Furthermore, the tactile response of the button was subtle and did not provide enough tactile feedback to the user when the button was pressed. Future designs of the input device need to ensure that the button is distinct from others and provides enough tactile feedback when pressed. Future content development should support additional visualizations of anatomy and physiology. Both normal and pathological conditions should be able to be visualized and compared. In addition to heart rate and ECG, other patient vitals should be incorporated and synchronized with the visuals of anatomy and physiology.

5.3 USABILITY TESTING SESSION 2: INPUT DEVICE MODIFICATIONS AND