Device versions

Four generations in about twenty years. The mechanics of pushing on a chest have hardly changed; what changed is how the device is powered, how much it tells you, and how much you can adjust.

Side by side

	LUCAS 1	LUCAS 2	LUCAS 3	LUCAS 3, v3.1
Introduced	2003	2009	2016	2018
Power	Compressed air or oxygen	Rechargeable battery	Rechargeable battery	Rechargeable battery
Rate	About 100 per minute	102 per minute, fixed	102 per minute, fixed	102, 111 or 120 per minute
Depth	About 5 cm	53 mm, fixed	53 mm, fixed	45 to 53 mm, configurable
Decompression	Active: pulls the chest up past neutral	Suction cup returns chest to neutral	Suction cup returns chest to neutral	Suction cup returns chest to neutral
Data	None	None	Event log, read out by cable or Bluetooth	Wi-Fi and Bluetooth reports, LIFENET platform
Alerts and timers	None	Battery and fault lights	Battery and fault lights	Configurable ventilation and pause alerts
Weight with power source	About 6.5 kg plus gas supply	About 7.8 kg	About 7.8 kg	About 7.8 kg

LUCAS 1: the gas-driven original

The first generation was pneumatic. A hose from an oxygen or compressed-air cylinder drove the piston, which meant the device could only run as long as the gas lasted and had to be used near a supply. The original design also pulled the chest upward after each compression, a technique called active compression-decompression that was fashionable in the late 1990s. Steen’s 2002 paper describes the machine as light at 6.5 kg and quick to apply.[1]

LUCAS 2: battery power

What changed

Launched in June 2009, LUCAS 2 replaced the gas supply with an electric motor and a rechargeable battery.[2] This is the version that most of the clinical research was done on: both LINC and PARAMEDIC used LUCAS 2.[3][4] Rate and depth were fixed at 102 per minute and 53 mm, matching guideline targets of the time.

LUCAS 3: easier to maintain, starts to talk

Released in 2016, the third generation kept the same compression parameters but reworked the housing for easier cleaning and servicing, and added a log of each use that could be read out afterwards.[5] For a service that wants to know how long the device ran, how often it paused and whether the battery held up, this was the first version that could answer.

LUCAS 3, version 3.1: configurable and connected

Version 3.1, available from mid-2018, is the current model. A medical director can set the rate to 102, 111 or 120 per minute and the depth anywhere from 45 to 53 mm, to match local protocols. The device can send a post-event report over Wi-Fi or Bluetooth, and alerts can be configured, for example a reminder to ventilate or a timed pause.[5] Existing LUCAS 3 units could be upgraded with new firmware.

What has stayed the same

The back plate, two legs and a piston with a suction cup have been the layout since the first prototype. So has the basic promise: press to guideline depth, at guideline rate, without getting tired. Every generation has fitted roughly the same range of adult chests and none has been approved for children. If you have seen one LUCAS, you would recognise the next.