Patients with chronic or acute respiratory and lung conditions can benefit from oxygen therapy. Oxygen therapy is the delivery of supplemental oxygen to a patient for medical treatment. In the past, patients on oxygen therapy would need to use oxygen tanks – canisters filled with a set volume of oxygen, which would have to be refilled or replaced once the oxygen was used up.
Today, patients can use oxygen (O2) concentrators, which continuously filter nitrogen out of the ambient air in order to supply an oxygen-rich gas stream to the user. Oxygen concentrators are considered a safer, more convenient, and more cost-effective alternative to tanks of oxygen or pressurized cylinders and are used both in hospitals and in patients’ homes.
Portable oxygen concentrators are a relatively recent development in oxygen delivery, originally introduced in the early 2000s. These devices have gained popularity with technological advances that have made them smaller, lighter, and better performing. The availability of healthcare reimbursements and the ability to bring them onto airplanes have also increased the use of portable O2 concentrators.
Oxygen Delivery Methods
Oxygen concentrators use two main oxygen delivery methods – pulse dose (PD) oxygen delivery and continuous flow (CF) oxygen delivery. Most O2 concentrators operate using a single delivery method (either PD or CF), however there are concentrator models in the market that are capable of functioning in both modes.
Continuous Flow Delivery
Continuous flow oxygen concentrators deliver oxygen at a constant rate regardless of the patient’s breathing. Most at home or stationary concentrators use continuous flow delivery. CF oxygen concentrators are often great solutions for patients with sleep apnea or other conditions in which oxygen is required at night. Providing continuous flow requires a larger molecular sieve and pump/motor assembly plus additional electronics which can increase the device’s size and weight.
Continuous flows are measured as the flow rate in liters per minute (L/min) and devices typically offer multiple flow settings for patients to choose from. Flow rates can vary from 1 to 10 Standard L/min although approximately 70% of patients are prescribed 2 Standard L/min or less of oxygen.
TSI low flow meter model 5200-2: ideal for testing and calibrating oxygen concentrators with continuous flows
- Measures oxygen or mixed air/O2 gas flows with 2% of reading accuracy
- Provides bi-directional flow measurement that ranges from +/- 30 L/min
- Makes flow measurements in standard or volumetric flow conditions
- Added totalizer measurement can aggregate flow rate to provide total inhaled volume
Pulse Dose Delivery
Pulse dose oxygen concentrators deliver oxygen based on the user’s breathing/inhalation pattern. Pulse dose concentrators use an oxygen conserver and other technology to customize the oxygen delivery to the user’s breath rate. This makes the oxygen delivery system more efficient which can result in smaller-size equipment with increased battery run time. Pulse dose O2 concentrators are typically recommended for low oxygen patients who require ≤ 2 Standard L/min of oxygen.
Pulse doses (PD) are measured in milliliters (mL) and they can vary in size and rate. PD O2 concentrators typically provide multiple pulse dose settings for patients to choose from.
TSI low flow meter model 5210-2: ideal for testing and calibrating O2 concentrators with a pulse dose delivery system
- Provides bi-directional flow measurements at +/-30 L/min
- Makes precise volume measurements of pulse doses varying in size or frequency
- Measures the flow rate or volume of oxygen or air/oxygen mixes with 2% of reading accuracy
- Delivers measurement readings in milliliters (mL), liters (L), or cubic feet (ft3)
Combined Delivery, Pulse Dose and Continuous Flow
Combining pulse dose and continuous flow oxygen delivery allows the oxygen concentrator to meet a wider range of patient needs. These dual-supply concentrators can provide a larger volume of oxygen than smaller pulse units, however they need a more robust battery and they are heavier than pulse dose oxygen concentrators.
TSI low flow meter model 5210-2: ideal for testing oxygen concentrators that can produce both pulse dose and continuous flow oxygen delivery
- Provides volume measurements of pulse doses varying in size or frequency
- Measures the flow rate and volume of oxygen or air/oxygen mixes
- Delivers flow rate and volume measurements in milliliters (mL), liters (L), or cubic feet (ft3)
- Logs raw measurement data at 1 ms resolution and easily export as .csv files
Research and Development
TSI low flow meter model 5230-2: a great tool for oxygen therapy research and development (R&D) applications
- Makes precise volume and flow rate measurements with a +/- 1.7% of reading accuracy
- Measures the temperature, pressure, and humidity of the gas flows
- Compensates flow measurements to ensure accuracy in varying operating conditions
- Uses both standard and volumetric units for flow measurements, with customizable gas temperature and pressure standard conditions
- Logs all measurement data time at 1 ms resolution synchronized with easy export as .csv files
Oxygen Concentrator Testing Applications
TSI flow meters are excellent for testing stationary or portable oxygen concentrators for the following Home Medical Equipment (HME) applications:
- Research and Development (R&D)
- Manufacturing and Quality Control
- Service and Calibration
- Verification of device performance between patients
Measuring the Oxygen Concentration of the Gas
Please note TSI’s flow meters do not measure the concentration or ratio of the air/O2 mix. If you need to detect the air/oxygen mix while making your measurements, use the model 4070 Certifier Flow Analyzer with the 4073 Oxygen Measurement Kit. This will allow you to detect the concentration of oxygen from 21% to 100% while simultaneously measuring the volume and rate of the gas flow.