The Rad-57 Pulse CO-Oximeter from Halma - handheld monitor built for real-world first responders

Rad-57 Pulse CO-Oximeter from Halma delivers rapid point-of-care carbon monoxide checks with a rugged handheld form factor. Anyone holding Halma stock (OTC: HLMAF, ISIN GB0004052071) should know this product.

By Julian Reed, ad hoc news Lifestyle & Consumer Desk. Reviewed July 03, 2026, 12:13 AM ET. Details in the imprint.

Rad-57 Pulse CO-Oximeter from Halma is one of those devices you only really notice when the red backlight cuts through a smoky room and a paramedic snaps the sensor on a patient's finger. The small handheld monitor fits in one hand yet throws off a crisp numeric display. That mix of compact size, bright screen, and fingertip sensor is what many fire chiefs and ER doctors now trust for fast carbon monoxide checks in the field.

What the Rad-57 actually does

The Rad-57 Pulse CO-Oximeter is a portable monitor that measures noninvasive carboxyhemoglobin levels, pulse rate, and oxygen saturation using Masimo's signal processing technology. It combines standard pulse oximetry with SpCO, giving first responders a quick read on possible carbon monoxide poisoning without a blood draw. The device is part of Masimo's portfolio, and Masimo is one of Halma's safety-related subsidiaries focused on medical monitoring and sensor solutions.

On the front, the Rad-57 features a color-coded LED display that shows SpO2, SpCO, pulse rate, and optional methemoglobin readings, along with perfusion index and pleth waveform depending on configuration. The fingertip sensor connects via cable, so paramedics can clip it on and glance at the screen even in cramped ambulances or busy emergency departments. This handheld format is critical because carbon monoxide exposure often needs to be assessed on-site at homes, industrial facilities, or fire scenes rather than waiting for lab tests.

Design choices built for real scenes

Halma tends to acquire businesses that solve very specific safety problems, and Masimo's Rad-57 is a good example of that focus: a single-purpose, portable device designed for rough use by non-specialist operators. The housing is compact and slightly rubberized, with physical buttons rather than a touch interface, which matters when users are wearing gloves in cold or hazardous environments. The device can be carried using a strap or mounted in a docking station for charging and storage.

In use, the Rad-57 resembles classic hospital pulse oximeters, but the addition of carbon monoxide and methemoglobin markers dramatically changes its value for pre-hospital care. Fire departments in the US purchase these units to test both victims and firefighters after exposure to smoke, using the SpCO values to decide whether a patient needs urgent treatment or oxygen therapy. In press interviews, Masimo founder and CEO Joe Kiani has emphasized noninvasive monitoring like SpCO as a way to reduce delays and discomfort for patients who would otherwise need arterial blood sampling. That philosophy shows up in the Rad-57's everyday workflow, where the operator simply clamps the sensor to the index finger and waits for stable readings instead of drawing blood.

US availability, pricing, and users

The Rad-57 Pulse CO-Oximeter is marketed in the United States through Masimo's medical distribution channels and is typically sold to hospitals, emergency medical services, and fire departments, rather than individual consumers. Official list prices are not prominently published on Masimo or Halma's sites, but US medical equipment distributors quote Rad-57 packages in the low-thousands of dollars per unit depending on included sensors and options. This positions the device as a capital purchase for institutional buyers, not as a mass-market gadget.

For US buyers, the system usually includes the handheld monitor, a rechargeable battery pack or docking station, and one or more single-patient-use or reusable sensors designed to work with Masimo's signal algorithms. An advantage cited by distributor documentation is the ability to integrate Rad-57 readings into existing patient care protocols, because the device uses familiar SpO2 and pulse indicators plus numerical SpCO thresholds that clinicians can map onto established treatment guidelines. These deployment details matter for investors, because they help explain how Halma's health and safety businesses generate recurring revenue from both hardware and consumable sensors rather than from monitors alone.

Clinical use and limitations

Clinically, Rad-57 is intended to provide indicative carbon monoxide levels that can support early diagnosis of CO poisoning or guide decisions on oxygen therapy and hyperbaric treatment. It uses Masimo's Pulse CO-Oximetry algorithms, which differentiate normal hemoglobin from carboxyhemoglobin and methemoglobin based on light absorption at multiple wavelengths. Several emergency medicine studies have evaluated noninvasive SpCO devices similar to Rad-57 and noted that they can be useful for screening, though confirmatory blood gas analysis remains standard for precise quantification. That makes the device more of a triage and monitoring tool than a complete replacement for lab testing.

For firefighters and industrial safety teams, Rad-57 becomes a practical way to check crews after exposure to smoke or exhaust. Instead of guessing based on symptoms like headache or nausea alone, they can capture SpCO values and correlate them with exposure history. However, literature and Masimo documentation also remind users that readings can be affected by factors such as poor perfusion, patient movement, and certain dyes, so training is required. The balance between convenience and caveats is typical for noninvasive sensors, and Halma's subsidiary model reflects that, with training, documentation, and disposables forming part of the revenue mix.

Halma context and stock angle

Halma is a UK-based group focused on safety, environmental, and medical technologies, and Masimo's monitoring range falls inside the healthcare segment alongside other diagnostic and sensing businesses. The Rad-57 is not a consumer product most US readers will buy directly, but it plays into themes investors track closely: noninvasive monitoring, hospital capital equipment, and recurring sensor sales. Halma stock (OTC: HLMAF, ISIN GB0004052071) trades in US markets via an over-the-counter listing, which gives US investors exposure to this kind of medical technology portfolio even though the company is primarily London-listed.

Rad-57 Pulse CO-Oximeter – key facts

• Product: Rad-57 Pulse CO-Oximeter
• Manufacturer: Halma plc (through subsidiary Masimo Corp.)
• Category: Lifestyle & Consumer (professional medical monitoring device used in emergency and safety contexts)
• Launch: Rad-57 has been available for several years as part of Masimo's Pulse CO-Oximetry range, with ongoing updates and configurations for different markets.
• MSRP / Price: Typically quoted by US medical distributors in the low-thousands of USD per unit, depending on configuration and included sensors.
• Availability: Sold primarily to US hospitals, emergency medical services, and fire departments via Masimo's medical equipment distribution channels.
• Target audience: Emergency physicians, paramedics, firefighters, industrial safety officers, and clinical staff who need rapid, noninvasive assessment of carbon monoxide exposure.
• Standout / USP: Combines handheld pulse oximetry with noninvasive carboxyhemoglobin measurement (SpCO), enabling quick field screening for carbon monoxide poisoning without a blood draw.

This article was AI-assisted and editorially reviewed. Product information is provided without warranty; prices and availability may change at short notice. Not investment advice and not a buy or sell recommendation. Securities trading carries risks up to total loss.