1. Technical Field
The present invention relates to apparatuses and methods for monitoring physiological conditions of a patient.
2. Description of the Related Art
In various medical environments, technology for monitoring physiological conditions like pulse rate and blood pressure are inadequate. For example, many such devices are cumbersome and lack portability. For example, in neonatal environments, medical personnel may wish to monitor the pulse located in the child's umbilical cord. This need occurs during delivery and resuscitation of newborn infants. To monitor the pulse, a technician often uses the fingers on his left hand to locate the pulse. Then, with his right hand, the technician taps out loud in synchrony with the pulse. Doing so conveys the pulse rate to the rest of the medical team. This procedure underutilizes the skills of the technician, is costly, inaccurate and also leads to a more crowded surgical environment.
As another example of shortcomings in present physiological monitors, continuous long-term blood pressure monitoring is traditionally very burdensome and inefficient. Sphygmomanometers are only used for intermittent monitoring. For example, to monitor blood pressure with a typical sphygmomanometer, the inflatable cuff is wrapped around the patient's arm and in then inflated to achieve a high pressure. The cuff is then slowly deflated to determine the patient's systolic and diastolic blood pressure. Due to the need for continuous inflation and deflation of the cuff, and the inconvenience associated with such actions, sphygmomanometers are best-suited for short-term monitoring.
Fluid-filled transducers can also be used for monitoring pressure in the short-term. These transducers are, however, costly and invasive to the patient. For example, a portion of the transducer can be placed directly in the blood stream of the patient. Such invasiveness can lead to infection. In addition, invasive procedures are uncomfortable for patients and require a skilled medical practitioner to perform them. Thus, invasive procedures are inadequate for patients that wish to monitor their blood pressure at home without professional assistance. Furthermore, the invasive nature of transducers can lead to bleeding, infection and clotting of the artery which can, in turn, lead to life-threatening complications. Medications must consequently be used to decrease blood clotting. These medications, however, carry significant potential side effects and can aggravate bleeding.
Therefore, an improved apparatus and method for continuously monitoring physiological conditions (e.g., pulse rate, blood pressure) is needed. Such an apparatus and method should be reliable, easily transportable, inexpensive, minimally invasive to the patient, accurate and not overly burdensome for medical personnel or patients.