Pressure applicator devices particularly useful for non-invasive detection of medical conditions

Abstract

A probe for application to a body part particularly a finger of a patient to detect a change in the physical condition of the patient includes a housing defining a compartment closed at one end and open at the opposite end for receiving the distal end of the patient's finger and means consituted of a medium wholly self-contained within the probe for applying a static pressure field substantially uniformly around the distal end of the patient's finger, of a predetermined magnitude sufficient to substantially prevent distention of the venous vasculature, uncontrolled venous backflow, and retrognade shockwave propagation into the distal end, and to partially unload the wall tension of, but not to occlude, the arteries in the distal end when at heart level or below. A sensor senses changes in the distal end of the patient's finger related to changes in arterial blood volume therein.

What is claimed is:  
     
         1 . A device for application to a body part of a patient to detect a change in the physical condition of the patient; said device comprising a probe including: 
 a housing defining a compartment closed at one end and open at the opposite end for receiving the distal end of the patient's body part including its terminal-most extremity;    pressurizing means for applying a static pressure field substantially uniformly around the distal end of the patient's body part, when received in said compartment, including its terminal-most extremity, which static pressure field is of a predetermined magnitude sufficient to substantially prevent distention of the venous vasculature, uncontrolled venous backflow, and retrognade shockwave propogation into said distal end, and to partially unload the wall tension of, but not to occlude, the arteries in said distal end when at heart level or below;    and a sensor for sensing changes in said distal end of the patient's body part related to changes in volume thereof due to changes in instantaneous blood volume related to arterial blood volume therein;    characterized in that said pressurizing means for applying said static pressure substantially uniformly around the distal end of the patient's body part, including its terminal-most extremity, is constituted of a medium wholly self-contained within said probe.    
     
     
         2 . The device according to  claim 1 , wherein said pressurizing means includes an inner resilient membrane within said housing and defining therewith an inner chamber to be filled with a fluid for applying said static pressure via said membrane substantially uniformly around the distal end of the patient's body part including its terminal-most extremity.  
     
     
         3 . The device according to  claim 2 , wherein said pressurizing means further includes an outer resilient membrane attached to said housing externally thereof and defining therewith an outer chamber communicating with said inner chamber via openings in said housing for enlarging the effective volume of said inner chamber such as to cause said inner membrane to apply substantially the same static pressure around the distal end of the patient's body part despite changes in volume thereof.  
     
     
         4 . A device to be applied around a body part of a patient, comprising a probe including: 
 a housing for application to the body part; and    pressurizing means for applying a static pressure field substantially uniformly around the body part; said pressurizing means including: 
 an inner resilient membrane within said housing and defining therewith an inner chamber to be filled with a fluid for applying said static pressure via said membrane substantially uniformly around the distal end of the patient's digit including its distal tip;  
 and an outer resilient membrane attached to said housing externally thereof and defining therewith an outer chamber communicating with said inner chamber via openings in said housing for enlarging the effective volume of said inner chamber such as to cause said inner membrane to apply substantially the same static pressure around the body part despite changes in volume thereof.  
   
     
     
         5 . The device according to  claim 3 , wherein said housing includes a port having a one-way valve for filling said inner chamber to the desired predetermined pressure.  
     
     
         6 . The device according to  claim 3 , wherein said outer resilient membrane is of annular configuration and is applied around an annular portion of the housing formed with said openings providing communication between said inner and outer chambers.  
     
     
         7 . The device according to  claim 3 , wherein said outer resilient membrane is of tubular configuration and is attached around the outer tip of the housing, which tip is formed with said openings providing communication between said inner and outer chambers.  
     
     
         8 . The device according to  claim 7 , wherein said housing includes an annular ring spaced from the outer resilient membrane attached to the housing for receiving the open end of a syringe to be used for enlarging said outer chamber by shifting the fluid from said inner chamber to said outer chamber to facilitate insertion of the patient's body part into said compartment.  
     
     
         9 . The device according to  claim 7 , wherein said outer resilient membrane includes a finger piece graspable by a user for enlarging said outer chamber by shifting the fluid from said inner chamber to said outer chamber to facilitate insertion of the patient's body part into said compartment.  
     
     
         10 . The device according to  claim 9 , wherein said finger piece includes a knob extending externally of the outer membrane for grasping by the user and fixed to a backing member engageable with the inner surface of the outer membrane.  
     
     
         11 . The device according to  claim 3 , wherein said housing is made of two sections hinged together to assume open and closed conditions, and including fastening elements for fastening the two sections in their closed condition.  
     
     
         12 . The device according to  claim 11 , wherein said fastening elements are “Velcro” (T.M.) hook and loop fastener strips carried by the two housing sections.  
     
     
         13 . The device according to  claim 11 , wherein said fastening elements are tongue and recess formations integrally formed in the two housing sections.  
     
     
         14 . The device according to  claim 11 , wherein said housing includes a tubular side wall closed at one end by an end wall and open at the opposite end, said tubular housing being split into two half-sections and hinged together at said end wall.  
     
     
         15 . The device according to  claim 11 , wherein said housing includes a tubular side wall closed at one end by an end wall and open at the opposite end, said housing being split into two half sections and hinged together along said tubular side wall.  
     
     
         16 . The device according to  claim 14 , wherein said hinge is an integral hinge integrally formed with said two half sections of the housing.  
     
     
         17 . The device according to  claim 14 , wherein said hinge is a strip of flexible strechable material attached to the two housing half-sections.  
     
     
         18 . The device according to  claim 14 , wherein: 
 said inner membrane includes a membrane strip joined to the side wall and end wall of each housing section;    and said outer membrane includes another membrane strip attached to the outer surface of each housing section.    
     
     
         19 . The device according to  claim 1 , wherein said pressurizing means includes an adhesive layer within said compartment to be contacted by the patient's body part received within the device.  
     
     
         20 . The device according to  claim 19 , wherein said adhesive layer is on an inner surface of a plastic strip having an other adhesive layer on its outer surface, said plastic strip further including a protective layer covering said adhesive layer on its inner surface and strippable therefrom to enable said inner surface to contact and firmly adhere to the patient's body part when received within the device.  
     
     
         21 . The device according to  claim 1 , further including an annular pressure cuff applied around the patient's body part contiguous to said housing on the heart side of the patient to extend the static pressure field past the sensor on the heart side of the patient.  
     
     
         22 . A device for application to a body part of a patient to detect a change in the physical condition of the patient; said device comprising: 
 a first housing defining a first compartment closed at one end and open at the opposite end for receiving the distal end of the patient's body part including its terminal-most extremity;    pressurizing means for applying a static pressure field substantially uniformly around the distal end of the patient's body part, when received in said compartment, including its terminal-most extremity, which static pressure field is of a predetermined magnitude sufficient to substantially prevent distention of the venous vasculature, uncontrolled venous backflow, and retrognade shockwave propogation into said distal end, and to partially unload the wall tension of, but not to occlude, the arteries in said distal end when at heart level or below;    a sensor for sensing changes in said distal end of the patient's body part related to changes in volume thereof due to changes in instantaneous blood volume related to arterial blood volume therein;    and a second housing separate and apart from said first housing and defining a second compartment having a fluid connection to said first compartment; said sensor being located within said second housing in operative position with respect to said second compartment.    
     
     
         23 . The device according to  claim 22 , wherein said second housing includes a presettable pressure source for presetting a predetermined pressure in the interior of said second housing.  
     
     
         24 . The device according to  claim 22 , wherein said second housing is vented to the atmosphere.  
     
     
         25 . The device according to  claim 1 , wherein said pressurizing means includes a body of resilient sponge material formed with a recess defining said compartment for receiving the patient's digit when inserted therein.  
     
     
         26 . The device according to  claim 25 , wherein: 
 said housing is made of two sections hinged together to assume open and closed conditions;    said body of resilient sponge material is also made of two sections, one carried on each section of the housing;    and said housing sections further include fastening elements for fastening the two housing sections in their closed condition.    
     
     
         27 . The device according to  claim 26 , wherein each of said sections of the body of resilient sponge material includes a layer of a gel material exposed for contact with the patient's body part when inserted into the housing and the housing sections are in their closed condition.  
     
     
         28 . The device according to  claim 1 , wherein a pressure sensing device is located within said housing to sense the pressure applied to the patient's body part by said pressurizing means.  
     
     
         29 . The device according to  claim 1 , wherein said sensor is an optical sensor and includes a light source carried within said housing on one side of the patient's body part when inserted therein, and a light detector carried within said housing on the opposite side of the patient's body part.  
     
     
         30 . The device according to  claim 1 , wherein said sensor is a Hall effect sensor and includes a permanent magnet carried within said housing on one side of the patient's body part when inserted therein, and a magnetic field detector carried within said housing on the opposite side of the patient's body part.  
     
     
         31 . The device according to  claim 1 , wherein said sensor includes the combination of an optical sensor device and a volumetric sensing device.  
     
     
         32 . The device according to  claim 1 , wherein said sensor is a pulse oximeter sensor for sensing the oxygen saturation of blood.  
     
     
         33 . The device according to  claim 1 , further including electrical conductors leading from said sensor to an electrical circuit carried by a band applied to another body part of the patient.  
     
     
         34 . The device according to  claim 33 , wherein said electrical circuit includes a storage device for storing the output of said sensor.  
     
     
         35 . A device to be applied to a body part of a patient, comprising: 
 a housing made of two sections hinged together to assume open and closed conditions;    a body of a resilient sponge material divided into two sections, each carried by one of said housing sections, and defining, in the closed condition of the two housing sections, a compartment for receiving the patient's body part;    and fastening elements for fastening the two housing sections in their closed condition.    
     
     
         36 . The device according to  claim 35 , wherein each of said sections of the body of resilient sponge material includes a layer of a gel material exposed for contact with the patient's body part when inserted into the housing and the housing sections are in their closed condition.  
     
     
         37 . The device according to  claim 35 , wherein said fastening elements are “Velcro” (T.M.) hook and loop fastener strips carried by the two housing sections.  
     
     
         38 . A device for application to a body part of a patient to detect a change in the physical condition of the patient, said device comprising: 
 a housing defining a compartment closed at one end and opend at the opposite end for receiving the distal end of the patient's body part;    a first membrane defining a first chamber containing a pressurized fluid to apply a static pressure field to the patient's body part when received within the housing;    a second membrane defining a second chamber communicating with said first chamber and of a volume such that the combined volumes of the two chambers maintain a relatively constant pressure despite changes in volume according to the Laplace Law;    and sensor elements in at least one of said chambers for sensing changes in said distal end of the patient's body part related to changes in volume therein.    
     
     
         39 . The device according to  claim 38 , wherein said second membrane encloses at least a portion of said housing to define said second chamber with the outer surface of the enclosed portion of the housing, said second chamber communicating with said first chamber via openings through said housing.  
     
     
         40 . The device according to  claim 39 , wherein said sensor elements are carried by said first membrane in said first chamber.  
     
     
         41 . The device according to  claim 39 , wherein said second membrane is of annular configuration and is applied around an annular portion of the housing formed with said openings providing communication between said inner and outer chambers.  
     
     
         42 . The device according to claim  391  wherein said second membrane is of tubular ocnfiguration and is attached around the outer tip of the housing, which tip is formed with said openings providing communication between said first and second chambers.  
     
     
         43 . The device according to  claim 38 , wherein said second chamber defined by said second membrane is located in a second housing and is connected to said first chamber by a fluid tube.  
     
     
         44 . The device according to  claim 43 , wherein said sensor is Located in said remote housing in operative position with respect to said second chamber.  
     
     
         45 . The device according to  claim 44 , wherein said second membrane is subject to the differential pressure with respect to the pressure in said second chamber and the ambient pressure in said second housing.  
     
     
         46 . The device according to  claim 45 , wherein said second housing includes a pressure presetting device for presetting the pressure within said second housing acting on said second membrane.  
     
     
         47 . The device according to  claim 46 , wherein said remote housing includes a pressure sensor for sensing the ambient pressure within said second housing.