Centre for Anaesthesia Critical Care & Pain Medicine


Machine Setup (Sonosite S Nerve)


1. Turn machine on using Power Switch (1)

2.  How to change presets

There is a preset indicator in the top right of the screen, with S nerve will display NRV (nerve block preset) or VAS (vascular access preset). These are factory software settings that optimise the machine for different types of scanning procedures. Available presets will change based on probe selection and machine type.

There are two ways to change the preset.

Method 1. Press the "patient" button, (top left control key, 2) bringing up a screen to enter demographics (at this point you can add patient identifiers so that you can archive your images to the appropriate patient. Select "exam type" using trackpad (4), then select nerve (NRV) with touch pad key (5). Press "done to return to the scanning screen.

Method 2. The "Options" button (bottom right control key, 2) and then "Exam" also takes you to the presets menu.

The new preset is indicated on top right of screen

3. How to change probes

Probes are changed manually on the S-Nerve, as it is not compatible with the triple transducer connect. The operation does not require the machine to be powered off. Simply elevate the handle on the transducer plug, twist until it clicks and pull gently. The replacement transducer can be inserted using the reverse manouvre. The preset, depth, and other settings displayed in the right side margin of the screen will change to the default settings for the new probe.

The new probe is indicated on top right of screen display eg. L25, HFL, C60

4. Change frequency

Transducer frequency on the S Nerve is shown next to the control keys on the left side in the form of 3 presets resolution (RES), general (GEN) and penetration (PEN) settings. RES is the highest frequency setting, giving the best resolution but at the cost of limited penetration. PEN is the lowest frequency setting giving the best penetration at the cost of limited resolution. GEN is an intermediate frequency between the two. Change the frequency by pushing the "RES","GEN","PEN" key at the left side of the screen. Parameters changed include focal zones, aperture size, frequency (center and bandwidth), and waveform, which are not otherwise selectable by the user.

5. Change depth

Depth is indicated by the cm markings on the right hand side of the screen.

Depth is controlled using the control knob marked "Depth" in the bottom left of the screen. Focus position is automated by the S Nerve to the centre of the depth set, so ensure that a suitable depth is selected such that the target structure is positioned in the centre of the depth markings.

6. Change gain

Turning the control knob marked Gain (bottom left side of screen) increases or decreases gain (boosts the output of all transducers). This is analogous to the volume knob on an amplifier.

Pushing the knob toggles between "overall gain", "near gain", and "far gain".

Near gain is usually used to reduce disparities between a dark far field (lower half of the screen) and a light near field. The converse is true for far gain. 

Pressing auto gain (control key on left) will set the gain at that which the machine considers optimal. 

Gain makes the image brighter but will decrease resolution, as the pixels are boosted towards the white end of the gray scale, they will merge anatomical features. Optimal gain will give a visible picture, where the most gray scale contrast is visible between anatomical features. Consider turning the room lights down to reduce the need for added gain. For vessel imaging where the best resolution is not always required, you can boost gain without sacrificing image usability.