Noninvasive blood pressure measuring system

A noninvasive blood pressure monitoring apparatus comprising:

• an inflatable cuff for encircling a portion of the human body;
• means for inflating the inflatable cuff to a pressure sufficient to occlude arterial flow;
• pressure relief valve means for deflating the cuff by increments;
• pressure sensor means for sensing the pressure within the cuff;
• means for controlling the time duration of each opening of the pressure relief valve means as a function of an incremental decrease in pressure resulting from a preceding opening of the pressure relief valve means;
• sound monitoring means for monitoring sounds of arterial flow past the cuff and producing electrical signals in response to the sounds;
• Korotkoff sound processor means for receiving the electrical signals and providing a systolic event signal indicative of occurrence of a systolic event and a diastolic event signal indicative of occurrence of a diastolic event;
• pulse signal producing means for receiving the electrical signals and providing a pulse signal indicative of occurrence of each arterial flow pulse;
• means for providing a signal indicative of the systolic pressure as a function of a first sensed pressure associated with the occurrence of the systolic event signal;
• means for providing a signal indicative of the diastolic pressure as a function of a second sensed pressure associated with occurrence of the diastolic event;
• means for opening the pressure relief valve means at predetermined time intervals prior to production of a pulse signal, and for opening the pressure relief valve means in response to the pulse signals after a pulse signal has been produced;
• means for providing a disable signal to the sound monitoring means to prevent production of electrical signals during a predetermined time period;
• and
• wherein means for opening the pressure relief valve means opens the pressure relief valve means only during the predetermined time period.

A noninvasive blood pressure and pulse rate measuring apparatus comprising:

• an inflatable cuff for encircling a portion of the human body;
• means for inflating the cuff to a pressure sufficient to occlude arterial flow;
• pressure relief valve means for deflating the cuff by increments over a period of time sufficient to permit systolic and diastolic events to occur;
• sound monitoring means for monitoring sounds of arterial flow past the cuff and producing electrical signals in response to the sounds;
• means for providing a disable signal to the sound monitoring means to prevent production of electrical signals during a predetermined time period, and for causing the pressure relief valve means to open only during the predetermined period;
• means for providing a systolic event signal indicative of occurrence of the systolic event;
• means for supplying a diastolic event signal indicative of occurrence of the diastolic event;
• means for providing a pulse signal indicative of occurrence of each arterial flow pulse;
• means for determining the time elapsed between occurrence of the systolic event and diastolic event signals;
• means for counting the number of pulse signals provided between the occurrence of the systolic event signal and the occurrence of the diastolic event signal;
• means for sensing the pressure in the inflatable cuff;
• means for providing a signal indicative of the systolic pressure as a function of a first sensed pressure and the occurrence of the systolic event signal;
• and
• means for providing a signal indicative of pulse rate based upon the number of pulse signals counted and the time elapsed between occurrence of the systolic event and diastolic event signals.

A noninvasive blood pressure monitoring apparatus comprising:

• an inflatable cuff for encircling a portion of the human body;
• means for inflating the inflatable cuff to a pressure sufficient to occlude arterial flow;
• pressure relief valve means for deflating the cuff by increments;
• pressure sensor means for sensing the pressure within the cuff;
• sound monitoring means for monitoring sounds of arterial flow past the cuff and producing electrical signals in response to the sounds;
• Korotkoff sound processor means for receiving the electrical signals and providing a systolic event signal indicative of occurrence of a systolic event and a diastolic event signal indicative of occurrence of a diastolic event;
• pulse signal producing means for receiving the electrical signals and providing a pulse interrupt signal indicative of occurrence of each arterial flow pulse;
• digital computer means for receiving the systolic, diastolic and pulse interrupt signals and pressure readings from the pressure sensor means and calculating systolic pressure and diastolic pressure, the digital computer means controlling the pressure relief valve means to cause the pressure relief valve means to open at predetermined time intervals during a first time period prior to receiving a pulse interrupt signal, and for causing the pressure relief valve means to open in response to each pulse interrupt signal during a second time period after a pulse interrupt signal has been received, wherein the digital computer means provides a disable signal to the sound monitoring means to prevent production of electrical signals during a predetermined time period, and causes the pressure relief valve means to open only during the predetermined period.