Advancements in medical technology continue to reshape how care is delivered. The application of sensors in healthcare has expanded what medical devices can measure and report in real time.Catheters are a clear example. With integrated sensor technology, these devices can capture temperature and pressure data from within the body, giving clinicians clearer information during procedures and recovery.
Below, we look at how sensor technology is influencing the use and design of several common catheter types.
4 Catheter Types Using Sensor Technology
There are several types of catheters used in healthcare that incorporate sensor technology, each with its own unique applications and benefits. Let's take a closer look at four common types of catheters and the sensors they use to improve patient care.
- Cardiac catheter
- Urinary (Foley) catheter
- Esophageal catheter
- Intracranial catheter
1. Cardiac Catheter
Cardiac catheters are used in a number of critical – and sometimes, high-stakes – medical procedures, such as measuring pressures within the heart or performing angioplasty to open blocked arteries. These catheters often include temperature and pressure sensors that detect and measure cardiac output, blood pressure, oxygen saturation levels, and other vital signs, giving medical professionals a clearer view of a patient's condition.
Temperature
Measuring cardiac output with a catheter and temperature sensor helps assess how much blood the heart pumps per minute. This technique is often used in critical care for patients with heart failure, shock, or other cardiac conditions.
When a thermistor is integrated into a cardiac catheter, changes in blood temperature within the pulmonary artery can be used to estimate cardiac output.
Temperature-based cardiac output measurement typically involves:
- Altering blood temperature using one of two methods:
- Warming the blood with a heater around the catheter
- Injecting cool saline into the right atrium
- Tracking the temperature change through the pulmonary artery
- Measuring the blood temperature as it passes the catheter’s thermistor
These readings help clinicians estimate cardiac output and identify potential obstructions.
Pressure
Cardiac catheterization with fractional flow reserve (FFR) is used to evaluate blockages in the coronary arteries. It’s typically performed when symptoms such as chest pain or shortness of breath are present and non-invasive tests have not provided a clear diagnosis.
During the procedure, a thin, flexible catheter is guided through an artery to the heart. Contrast dye allows clinicians to visualize the coronary arteries using X-ray imaging.
When equipped with a pressure sensor, the catheter measures the pressure difference across a narrowed section of a coronary artery. These readings are used to calculate FFR, which compares blood flow through the narrowed area to the expected flow if the artery were fully open.
Historically, this measurement relied on pressure sensors housed in external capital equipment. Advances in sensor technology now allow pressure measurements to be captured directly at the source within the body.
2. Urinary (Foley) Catheter
While its primary purpose is to drain the bladder, a urinary – or Foley – catheter may serve a dual function in patient monitoring.
Given that the device is immersed in a patient's body (typically after surgery), when outfitted with a thermistor sensor, the catheter can help monitor core body temperature. Put simply, there's no better way to measure a patient's core body temperature than from the inside.
Especially after surgery, measuring a patient's core body temperature is critical. Spikes and dips in the vital sign can indicate:
- Infection
- Inflammation
- Other serious complications
Suffice it to say, having this information provides helpful insight into the overall condition of a patient and necessary guidance for their care during recovery.
3. Esophageal Catheter
An esophageal catheter is a medical device that can be used to measure temperature during certain medical procedures, including cardiac ablation.
Cardiac ablation is a minimally invasive procedure that uses radiofrequency energy to destroy abnormal heart tissue that is causing an irregular heart rhythm. During this procedure, it is important to monitor the temperature of the esophagus, as heating the tissue too much can cause life-threatening damage.
The esophageal catheter is inserted through the patient's mouth and guided down the esophagus to a point near the heart. The catheter contains temperature sensors – primarily, an NTC thermistor – that measures the temperature of the esophagus in real-time. These sensors can provide information about the temperature of the tissue, allowing the medical team to adjust the ablation procedure as needed to avoid causing harm.
Measuring temperature with an esophageal catheter during ablation has several advantages, as it:
- Provides a more accurate measurement of temperature than other methods, such as surface temperature measurements.
- Allows for continuous monitoring of temperature, which is important during a procedure where the temperature can change rapidly.
- Can help the medical team avoid complications by providing feedback about the temperature of the tissue in real-time.
4. Intracranial Catheter
Much like a cardiac catheter, an intracranial catheter with both temperature and pressure sensors gives medical caregivers more than one window into monitoring a patient’s condition.
Temperature
Intracranial catheters with temperature sensors can be used to monitor patients who have suffered a traumatic brain injury (TBI) or have undergone certain neurosurgical procedures.
These catheters are designed to measure the temperature inside the patient's brain, providing doctors with important information about the patient's condition.
During a neurosurgical procedure, an intracranial catheter is inserted into the patient's brain through a small hole in the skull. The catheter contains one or more temperature sensors that are placed in different locations within the brain. Changes in temperature may indicate a major problem, such as bleeding or swelling.
In patients with TBI, intracranial catheters with temperature sensors are used much the same way. Elevated brain temperature can indicate inflammation or infection, which can be serious complications of TBI.
By monitoring brain temperature, doctors can identify these complications early and take steps to treat them before they become more severe.
Pressure
The story with intracranial catheters with pressure sensors is similar.
Used on patients who have undergone neurosurgical procedures – such as a craniotomy or shunt placement – or those suffering a TBI, intracranial catheters with pressure sensors measure a key metric for patient care and their recovery.
Changes in intracranial pressure (ICP) can be caused by conditions such as brain swelling, bleeding, or the accumulation of cerebrospinal fluid. In some cases, elevated ICP can be a sign of an impending stroke.
By measuring ICP with an intracranial catheter, medical professionals are able to detect changes that might signal the need for immediate intervention.
What Does Catheter Design Require for Sensor Integration?
Regardless of their intended application, a catheter is much like any other medical device that takes measurements – it's only as good as the sensor technology behind it.
The design of a catheter for integrated sensor technology is crucial in ensuring accurate and reliable measurements. The catheter must be developed so it can minimize interference to its sensors from external factors, such as surrounding tissues and fluids.
The design of the catheter must also take into consideration the size and shape of the sensor, as well as the materials used in the catheter to ensure compatibility with the patient's body and reduce the risk of adverse reactions.
Overall, the design of a catheter for sensor technology is a complex process that requires careful consideration of multiple factors.
A well-designed catheter with advanced sensor technology can provide valuable insights into a patient's health and aid in the delivery of more personalized and effective healthcare.
The Application of Sensors in Healthcare Through Catheters
Catheters continue to support a wide range of clinical procedures, and sensor integration has expanded how these devices contribute to patient monitoring and care.
Through the application of sensors in healthcare, catheter-based devices can provide timely, accurate data directly from within the body. This added visibility supports informed clinical decisions and helps care teams respond more effectively across different treatment settings.
Looking To Learn More About Critical Care Sensors?
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This article was originally published in May of 2023 and was recently updated to reflect current industry trends.
