Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
A CPR machine is a powered device that compresses the chest during cardiac arrest, as an add-on to manual CPR rather than a replacement for it. It is used by emergency medical services, hospitals and other clinical teams, and studied by students and buyers comparing categories. This page gives the US regulatory definition, the named devices in the evidence, and what the large randomized trials found.
What a CPR machine is
US regulation calls this device an external cardiac compressor. 21 CFR 870.5200 describes it as an externally applied prescription device used to compress the chest periodically in the region of the heart to provide blood flow during cardiac arrest. The regulation frames it as an add-on to manual CPR for situations where manual CPR cannot be done effectively, such as patient transport or prolonged resuscitation.
The same category appears under many names: automatic CPR machine, automated CPR device, mechanical chest compression device, and brand names such as AutoPulse and LUCAS. They all describe powered chest compression for an adult in cardiac arrest.
How it works or is built
The FDA’s special controls for the category describe what a device must demonstrate: reliable compression depth and rate for the intended duration of use, electrical safety and electromagnetic compatibility, software verification and hazard analysis, biocompatibility of patient-contacting parts, and human factors testing that includes deployment time. These requirements show how the category is built: a powered mechanism, control software, and parts that touch the patient.
The AutoPulse Resuscitation System Model 100, made by Zoll Circulation, Inc., is described in its AccessGUDID record as “an automated, portable, battery powered device” that compresses the chest of an adult human as an adjunct to manual CPR. In the LUCAS-2 arm of the PARAMEDIC trial, the device delivered compressions at a depth of 40 to 53 mm at 102 per minute, according to a critical appraisal of the trial.
Types and variants
The table lists the devices named in the cited records. Each row states only what the cited source says.
| Device | Maker named in the source | What the source says |
|---|---|---|
| AutoPulse Resuscitation System Model 100 | Zoll Circulation, Inc. | AccessGUDID: product code DRM “Compressor, Cardiac, External”; automated, portable, battery powered; compresses the chest of an adult as an adjunct to manual CPR; not single use. |
| LUCAS Chest Compression System | Not stated in the trial record | Tested in the LINC trial (JAMA 2014) with defibrillation during ongoing compressions, against guideline manual CPR, in 2,589 patients. |
| LUCAS-2 | Not stated in the appraisal | Tested in the PARAMEDIC trial (Lancet 2015) in 4,471 patients; the appraisal reports 40 to 53 mm depth at 102 compressions per minute. |
Automatic CPR machine, automated CPR device and mechanical chest compression device
These are the same product class. The regulation uses the term external cardiac compressor, and the FDA product code for the class is DRM.
AutoPulse and AutoPulse device
AutoPulse is the name of a Zoll Circulation product. Its AccessGUDID record lists it under product code DRM and states that the labeling does not contain MRI safety information.
Regulation and FDA class
21 CFR 870.5200 places the external cardiac compressor in Class II with special controls. The current regulation text is the reference for class. The special controls require labeling that covers:
- clinical training for users;
- an indication limited to adjunctive use;
- the patient population, including size and age limits;
- the deployment time shown in testing.
They also require nonclinical testing of compression depth and rate, electrical safety and electromagnetic compatibility testing, human factors testing, software validation and hazard analysis, and biocompatibility testing of patient-contacting parts.
How to choose
The regulation does not rank devices, and this page does not either. The only selection criteria it states are what a device’s labeling and testing must cover. A reviewer comparing the instructions for use of two devices can check each against that list:
| Check in the instructions for use | Source |
|---|---|
| Indication stated as an adjunct to manual CPR | 21 CFR 870.5200(a) and (b) |
| Patient population, including size and age limits | 21 CFR 870.5200(b) labeling special control |
| Deployment time shown in testing | 21 CFR 870.5200(b) labeling and human factors special controls |
| Clinical training described for users | 21 CFR 870.5200(b) labeling special control |
| MRI safety information, where relevant to the setting | AccessGUDID record for AutoPulse Model 100 (that record states its labeling has none) |
What the randomized trials found
Two large randomized trials of the LUCAS device compared it with manual CPR. Neither found a survival advantage.
| Trial | Device | Patients | Primary outcome | Result |
|---|---|---|---|---|
| LINC (Rubertsson et al., JAMA 2014;311(1):53-61) | LUCAS plus defibrillation during compressions vs manual CPR | 2,589 (1,300 vs 1,289) | 4-hour survival | 307 (23.6%) vs 305 (23.7%); risk difference -0.05% (95% CI -3.3% to 3.2%) |
| PARAMEDIC (Perkins et al., Lancet 2015), as appraised by Greer and Tully, J Intensive Care Soc 2015 | LUCAS-2 vs manual CPR | 4,471 in 418 ambulance clusters (1,652 vs 2,819) | 30-day survival | No improvement in 30-day survival with LUCAS-2 compared with manual CPR, per the appraisal |
The LINC authors concluded that mechanical CPR using the presented algorithm did not improve effectiveness compared with manual CPR. The PARAMEDIC appraisal states that the device did not improve survival to 30 days. These results match the regulatory framing as an adjunct for situations where manual CPR is impractical, not as a way to improve survival in general.
Safe use and handling basics
- The device is a prescription device; the labeling must cover clinical training, so use follows the manufacturer’s instructions for use and the user’s training.
- The indication is adjunctive use with manual CPR, for adults of the size and age range the labeling states.
- Deployment time is a tested characteristic that the labeling must report.
- Related reading: what a defibrillator is and how an AED trainer differs from a real AED.
Common mistakes
- Treating a CPR machine as a replacement for trained manual CPR, when the regulation defines it as an adjunct.
- Stating the class from memory; the current regulation lists Class II with special controls.
- Assuming a mechanical device improves survival; the LINC and PARAMEDIC results above show no improvement in their primary outcomes.
- Confusing a compressor with a feedback tool or practice aid; compare CPR feedback devices and the CPR board, which are different product classes.
FAQ
What is a CPR machine?
A CPR machine is an external cardiac compressor: a prescription device that compresses the chest periodically to provide blood flow during cardiac arrest, as an add-on to manual CPR (21 CFR 870.5200).
What is an automatic CPR machine or automated CPR device?
The terms describe the same class. The AutoPulse Model 100 record calls the device automated, portable and battery powered, compressing the chest of an adult as an adjunct to manual CPR.
What is AutoPulse?
AutoPulse is the Zoll Circulation resuscitation system listed in AccessGUDID under the FDA product code DRM, “Compressor, Cardiac, External”.
What is a mechanical chest compression device?
It is the plain-language name for the same class: a powered device that compresses the chest, regulated by the FDA as Class II with special controls.
Does a CPR machine improve survival?
In the LINC and PARAMEDIC trials of the LUCAS device, it did not improve the primary survival outcome compared with manual CPR. See the trial table above.
Sources
- 21 CFR 870.5200, External cardiac compressor, Legal Information Institute: https://www.law.cornell.edu/cfr/text/21/870.5200 (checked 2026-11-01).
- AccessGUDID, AutoPulse Resuscitation System Model 100: https://accessgudid.nlm.nih.gov/devices/00849111001120 (checked 2026-11-01).
- Rubertsson S, et al. LINC trial. JAMA 2014;311(1):53-61, doi 10.1001/jama.2013.282538: https://pubmed.ncbi.nlm.nih.gov/24240611/ (checked 2026-11-01).
- Greer and Tully. Critical appraisal of the PARAMEDIC trial. J Intensive Care Soc 2015;16(3):241-243: https://pmc.ncbi.nlm.nih.gov/articles/PMC5606449 (checked 2026-11-01).
