A new, lightweight fetal telemetry system - Hp 50 T - Product Information

Hewlett-Packard Journal, Dec, 1995 by Andreas Boos, Michele Houghton Jagger, Gunter W. Paret, Jurgen W. Hausmann

The HP Series 50 T fetal telemetry system combines both external and internal monitoring of the fetus in a small, lightweight transmitter that is easy and comfortable for the patient to carry. It is useful for monitoring in labor, monitoring of high-risk patients, monitoring in transit, antepartum nonstress testing, and monitoring in the bath.

Electronic fetal monitoring records fetal heart rate, uterine activity, and fetal movements onto a trace, allowing obstetrical clinicians to better assess fetal well-being and the adequacy of fetal oxygenation.

In today's high-tech hospital environment it is easy to overlook the fact that the majority of pregnant women who are admitted to the hospital to give birth are not sick, but are experiencing a natural event, the delivery of their babies. With this in mind, many hospitals worldwide are anxious to create a more friendly environment in their labor and delivery departments by reducing the amount of technology at the patient's bedside. This reduction in technology can present a problem. Although patients want a more natural environment, the nursing staff still wants to be able to oversee fetal well-being during labor and delivery. There has to be a balance between these two goals, and monitoring of the fetus via telemetry offers a solution.

Telemetry monitoring of the fetus involves connecting a patient to a radio frequency transmitter, which she is able to carry (Fig. 1). This transmits the fetal information via UHF radio frequencies to a receiver connected to a fetal monitor. The monitor records the information as if the patient were connected directly to it. The fetal monitor and receiver can be placed in a central location for the nursing staff to view the fetal information, and need not be in the patient's room, thereby reducing the perception of technology at her bedside.

Fetal monitoring with telemetry has been available for the past ten years. Until now, these telemetry systems only allowed either external monitoring of the fetus such as ultrasound detection of the fetal heart rate, or internal methods such as direct monitoring of the fetal heart rate by means of a scalp electrode. Very few systems offered both of these methods, and those that did were large and heavy for the patient to carry, and had a very low battery life.

The Hewlett-Packard Series 50 T fetal telemetry system (HP M1310A) is a new lightweight, space-saving telemetry system. It combines both external and internal monitoring of the fetus in a small, lightweight transmitter that is easy and comfortable for the patient to carry. Because the patient is not connected directly to the fetal monitor, a number of additional clinical applications can be addressed, including monitoring in labor, monitoring of high-risk patients, monitoring in transit, antepartum nonstress testing, and monitoring in the bath.

Monitoring in Labor. The technology used in the HP Series 50 T ensures that the product can be used in the very earliest stages of labor, before the membranes have ruptured, right up to and during the second stage of labor when the baby is being delivered. This means that the patient is free to move around from the onset of labor, while a reliable, continuous fetal trace is available for overseeing fetal well-being Allowing the patient to walk around can be beneficial for the patient, especially when the delivery is long, and can even help reduce the pain of her contractions.

Monitoring of High-Risk Patients. When a high-risk patient has been admitted to the hospital for observation before the birth of her baby, it is often desirable to provide continuous monitoring of the baby to ensure its well-being. However, this is not normally practical because it would mean connecting the patient to a fetal monitor and confining her to bed for long periods of time. Using the HP Series 50 T fetal telemetry system, the patient is free to walk around, and the nursing staff has a constant overview of fetal well-being. Monitoring in Transit. Besides being compatible with all HP fetal monitors produced since 1982, the HP Series 50 T fetal telemetry system can use the standard transducers of the HP Series 50 family of fetal monitors. This is useful, for example, if an emergency occurs and the patient needs to be transported to the operating room for a Caesarean section. In certain countries it is a legal requirement to provide continuous monitoring of the fetus from the time the patient leaves her room to the delivery of the baby. By disconnecting the transducers from the fetal monitor and connecting them to the transmitter of the HP Series 50 T, continuous, uninterrupted monitoring of the fetus is ensured.

Antepartum Nonstress Testing. Nonstress testing is performed during the patient's regular visit to the clinic or hospital during her pregnancy. By allowing the patient to ambulate and record the fetal heart rate via ultrasound, nonstress testing can be performed without having to confine the patient to bed, thereby allowing her freedom of movement and the ability to socialize with the other patients.