Turbulence of Ambulance

Test	Seat-pad vibration total values [m/s2]
	Unweighted			Weighted
	Mean	SD	SD/Mean	Mean	SD	SD/Mean
Hand transport	1.46	0.29	0.20	1.06	0.25	0.24
Ambulance off-road	1.87	0.18	0.10	1.21	0.12	0.10
Ambulance urban	1.03	0.15	0.15	0.64	0.08	0.13
Helicopter cruise	1.02	0.05	0.05	0.27	0.02	0.07

Acceleration measured on the stretcher at feet, center of gravity and head position. Head is toward the front of the vehicle. ——Δ—— unweighted acceleration values, ---•--- Weighted acceleration values.

From data analysis it is evident that exposure of the patient’ feet to vertical vibrations is higher than the exposure suffered by the head. Since feet are above the rear vehicle axis and the head is near the ambulance center of mass, these differences are probably related to vehicle pitch.

Referenced from Whole body vibration in mountain-rescue operations, E. Alberti^a, D. Chiappa^b, G. Moschioni^a, B. Saggin^a,  , M. Tarabini^a

Controllers

Option 1

CONTROLLER

NI cRIO-9014

·  400 MHz processor, 2 GB nonvolatile storage, 128 MB DRAM memory

·  10/100BASE-T Ethernet port with embedded Web and file servers with remote-panel user interface

·  Full-speed USB host port for connection to USB flash and memory devices

·  RS232 serial port for connection to peripherals; dual 9 to 35 VDC supply inputs

NI cRIO-9022

·  533 MHz processor, 2 GB nonvolatile storage, 256 MB DDR2 memory

·  Dual Ethernet ports with embedded Web and file servers for remote user interfacing

·  Hi-Speed USB host port for connection to USB flash and memory devices

·  RS232 serial port for connection to peripherals; dual 9 to 35 VDC supply inputs

NI cRIO-9114

·  8-slot reconfigurable embedded chassis that accepts any CompactRIO I/O module

·  Xilinx Virtex-5 reconfigurable I/O (RIO) FPGA core for ultimate processing power

·  Ability to automatically synthesize custom control and signal processing circuitry using LabVIEW

PORTS

NI 9205

·  32 single-ended or 16 differential analog inputs

·  16-bit resolution; 250 kS/s aggregate sampling rate

·  ±200 mV, ±1, ±5, and ±10 V programmable input ranges

NI 9264

·  25 kS/s/ch simultaneous output

·  Hot-swappable operation

·  Spring terminal or D-SUB connectivity options

·  250 Vrms isolation (spring terminal version)

·  60 VDC isolation (D-SUB version

NI 9401

·  8-channel, 100 ns ultrahigh-speed digital I/O

·  5 V/TTL, sinking/sourcing digital I/O

·  Bidirectional, configurable by nibble (4 bits)

NI 9435

·  ±5 to 250 VDC, 10 to 250 VAC, universal sink/source digital input

·  4-channel, 3 ms digital input

Option 2

CDS-3310 Galil with own command language -- WSDK servo design software

·  Axis motion controller with on-board PWM drive for brush or brushless servo motor; 18-72V input, 7A cont. drive

·  Ethernet 10/100 Base-T and (1) 19.2kb RS232 port; USB option

·  Accepts encoder feedback up to 12 MHz

·  PID compensation with velocity and accceleration feedforward, integration limits, notch filter and low-pass filter

·  Modes of motion: jogging, point-to-point positioning, contouring, electronic gearing and ECAM

·  Dual encoder, home input and forward and reverse limits

·  8 TTL uncommitted inputs and 10 TTL outputs

·  2 uncommitted analog inputs (0-5V) and 1 analog output (+/-10V)

·  Add 8 analog inputs and 40 digital I/O with optional DB-28040

DMC-21x3 Ethernet motion controllers

·  Accepts up to 12 MHz encoder frequencies for servos. Outputs up to 3 MHz for steppers

·  PID compensation with velocity and acceleration feedforward, integration limits, notch filter and low-pass filter

·  8 TTL uncommitted inputs and 8 outputs for 1- to 4-axis, 16 in/16 out for 5- to 8-axis models

·  Add 8 analog inputs and 40 digital I/O with DB-28040 -- 40 digital inputs and outputs, and eight 12-bit (16-bit optional) analog inputs (default I/O is 3.3 V. For 5 V I/O).

Faulhaber MCLM 3006 c/s

Standard mode is a servomotor, but can be configured into speed sensor, hall effect sensor and encoder.

Analog position control, the maximum position can be approached with a voltage of 10 V.

Performing Ultrasound

The aim is to get the angle of incidence perpendicular, or close to perpendicular to the target site. By maneuver the probe, the direction of the beam changes, slightly different ultrasound images of the same structure is obtained. This also avoids anistropy allowing different tissues to be seen clearly for diagnosis. 

There is an orientation marker on the transducer that corresponds to the marker on the screen. For the sake of not creating confusions in the direction of probe manipulation for the sonographer in the trauma centre, correspondence should always be checked. 

Probe Manipulation: PART

Pressure:

Correct pressure could improve image quality whereas excessive pressure will cause underestimation of depth and discomfort of patient. Even pressure is applied to get the correct direction of scan, operator may apply uneven pressure on one side of the probe intentionally to move certain tissue.

Alignment(sliding):

Maneuver to the target of interest and optimise its display on the screen for diagnosis.

Rotation:

By rotating the probe, a true axial view of the target could be attained. It is also used to align the target into a more favorable trajectory. When applying rotation, caution is required as it could change the view into the undesired short-axis view.

Tilt:

The directions of tilt of the probe and ultrasound plan are opposite. Correct tilting could aid viewing of the long-axis of the target. If the probe is tilted out of the true axial view, false information of the target such as distorted shape and increased depth will be obtained.

Referenced form Ultrasound: Basic understanding and learning the language

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3063344/

FAST Examination

FAST is a focused, goal-directed ultrasound scan for the abdomen and pericardium in order to detect existence of blood in these cavities. It is part of the primary survey for patient with evidence of abdominal/truncal injury and suspicion of haemorrhage(profuse bleeding from ruptured blood vessels). Demonstration had show FAST has a sensitivity of haemorrhage of 86% to 99% and a specificity of 90% to 99%. FAST is recommended to be performed using a 3.5 or 5 MHz ultrasound sector transducer probe and gray scale ‘B mode’ ultrasound scanning. The total time taken for a scan would be around 5-8 minutes.

A FAST examination consists of 4 scans.

Perihepatic Scanning (RUQ)
The hepatorenal space (pouch of Rutherford-Morison) is the most dependent part of the upper peritoneal cavity and small amounts of intra-peritoneal fluid may collect in this region first. 80% of haemoparitonium  could be detected with heptorenal view alone. Planning beams in this plan demonstrate liver, kidney and diaphragm. Look for blood in the RUQ and fluid between liver and kidney.
The probe is placed in the right mid- to posterior axillary line at the level of the 11th and 12th ribs.
Perisplenic Scanning (LUQ)
The left upper quadrant examination visualises the spleen and perisplenic areas.Planning beams in this plane demonstrate spleen, kidney and diaphragm. Look for blood between spleen and kidney or diaphragm.The transducer is placed on the left posterior axillary line region between the 10th and 11th ribs.
Pelvic Scanning
The pelvic examination visualises the cul-de-sac: the Pouch of Douglas in females and the rectovesical pouch in the male. It is the most dependent portion of the lower abdomen and pelvis, hence where fluid will collect.
The transducer is placed midline just superior to the symphysis pubis, angled downwards. It is then rotated 90 degrees to move beam into sagittal plane.
Pericardial Scanning
The pericardial examination screens for fluid between the fibrous pericardium and the heart, and hence possible cardiac tamponade.
The transducer is placed just to the left of the xiphisternum and angled upwards under the costal margin.

Referenced from:

Focused Abdominal Sonography in Trauma (FAST)

Col R Chaudhry, VSM*, Lt Col A Galagali+, Maj RV Narayanan#

Ergonomics of US

Around ¾ of ambulance assistants are females, whose hands are smaller than those of males’. The average length of a female hand is 172mm (189mm), with a width of 74mm (84mm). For all assistants to grab the handle (possibly with the actuators) tightly during turbulence, the surface area of width and length of the handle should be limited below 342mm sqr.

The assistants are required to apply at least 3.8, 4.2, 6.4 Newtons of forces in the x,y and z direction during a FAST examination with somehow an awkward gesture. In long terms, this will fatigue mainly the shoulder joint of the assistant as well as the wrist. This effect can start appealing 5 years into the career.