Vital signs probe

• US 20050209516A1
• Filed: 03/22/2004
• Published: 09/22/2005
• Est. Priority Date: 03/22/2004
• Status: Abandoned Application

• Current Assignee: Jacob Fraden
• Original Assignee: Jacob Fraden
• Inventors: Fraden, Jacob
• Application Number:
  US10/806,766
• Publication Number:
  US 20050209516A1
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 2562/247 Hygienic covers, i.e. for covering the sensor or apparatus during use
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1491 Heated applicators
• CPC Class Codes: A61B 5/6817 Ear canal

Abstract

A combination of a patient core temperature sensor and the dual-wavelength optical sensors in an ear probe or a body surface probe improves performance and allows for accurate computation of various vital signs from the photo-plethysmographic signal, such as arterial blood oxygenation (pulse oximetry), blood pressure, and others. A core body temperature is measured by two sensors, where the first contact sensor positioned on a resilient ear plug and the second sensor is on the external portion of the probe. The ear plug changes it'"'"'s geometry after being inserted into an ear canal and compress both the first temperature sensor and the optical assembly against ear canal walls. The second temperature sensor provides a reference signal to a heater that is warmed up close to the body core temperature. The heater is connected to a common heat equalizer for the temperature sensor and the pulse oximeter. Temperature of the heat equalizer enhances the tissue perfusion to improve the optical sensors response. A pilot light is conducted to the ear canal via a contact illuminator, while a light transparent ear plug conducts the reflected lights back to the light detector.

Claims

1. A system for detecting photo-plethysmographic signals from a patient ear canal, comprising a sensor'"'"'s housing, a first light emitting source, a light detector and a housing extension, wherein distal side of said housing extension is inserted into the patient ear and proximal side of the extension is optically coupled to said light emitting sources and light detector.

2. A system for detecting photo-plethysmographic signals from a patient ear canal as defined in claim 1 further comprising a second light emitting source operating at a different wavelength from first light source and a processor for computer arterial blood oxygenation.

3. A system for detecting photo-plethysmographic signals from a patient ear canal as defined in claim 1 wherein said housing extension is fabricated of material that is substantially transparent for wavelength of light generated by said first light emitting source.

4. A method for monitoring patient'"'"'s arterial blood oxygenation and core temperature by an ear probe consisting of a housing, ear plug, two light emitting devices, one light detecting device, a heater and a temperature detector, comprising steps of

Attaching temperature sensor to a flexible ear plug;

Inserting the ear plug into the patient'"'"'s ear canal;

Alternatively transmitting to the ear canal two wavelengths of light from two light emitting devices and measuring the reflected light by a light detecting device;

Measuring temperature of said ear plug by said temperature sensor;

Measuring temperature of the ear probe by said temperature detector;

Generating heat by said heater to minimize temperature difference between said temperature sensor and said temperature detector;

Computing level of blood oxygenation from the signals detected by said light detecting device, and

Computing the patient core temperature from signals received from said temperature sensor and temperature detector.

5. A method for monitoring patient'"'"'s arterial blood oxygenation and core temperature by a body surface probe consisting of a housing, two light emitting devices, one light detecting device, a heater and a temperature detector, comprising steps of

Inserting the probe to the surface of a patient'"'"'s body;

Alternatively transmitting to the patient body two wavelengths of light from two light emitting devices and measuring the reflected light by a light detecting device;

Measuring surface temperature of the patient by said temperature sensor;

Measuring temperature of the probe by said temperature detector;

Generating heat by said heater to minimize temperature difference between said temperature sensor and said temperature detector;

Computing level of blood oxygenation from the signals detected by said light detecting device, and

Computing the patient core temperature from signals received from said temperature sensor and temperature detector.