Force monitoring shoe

• US 6,122,846 A
• Filed: 08/30/1999
• Issued: 09/26/2000
• Est. Priority Date: 08/30/1999
• Status: Expired due to Fees

• Current Assignee: Frank B. Gray
• Original Assignee: Frank B. Gray
• Inventors: Riffert, Raimer G., Gray, Frank B., Parris, John L., Gray, David H.
• Primary Examiner(s): Sewell, Paul T.
• Assistant Examiner(s): ARNOLD III, TROY G
• Application Number:
  US09/385,393
• Time in Patent Office: 393 Days
• Field of Search: 36/136, 36/132, 36/137, 36/139, 600/592, 73/172, 340/573
• US Class Current: 36/136
• CPC Class Codes: A43B 3/34 with electrical or electronic arrangements
• CPC Class Codes: A43D 1/025 comprising optical means, e.g. mirrors, photo-electric cells, for measuring or inspecting feet
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies

Abstract

An apparatus and method of operation for measuring forces applied to a wearer'"'"'s foot, the apparatus providing an indication to the wearer when forces on the foot exceed pre-selected upper limits or do not meet pre-selected lower limits. A body member is disclosed for attachment around the wearer'"'"'s foot, the body member having an exterior sole and an interior sole portion covered by a rigid foot plate. The foot plate includes an upper support surface for contact with the foot. The interior sole portion includes at least one cavity within, with a force sensing unit attachable partially within the cavity. At least one strain gage is positioned at a midpoint on the force sensing unit, and the force sensing unit is connectable to the underside of the foot plate. An electronic means is mounted within the cavity and is electrically connected to the at least one strain gage. The electronic means receives electronic signals from the strain gage, the signals in proportion to force applied onto the force sensing unit when the wearer'"'"'s foot applies weight onto the foot plate, with conversion of the signals to output signals for transmission to a signal processing means in a remotely located receiver and display unit. The display unit compares the output signals to upper limits and lower limits, and displays alarms when output signals do not reach lower limits, or exceed upper limits, therefore assisting with therapeutic rehabilitation of an injured lower extremity.

Claims

1. An apparatus for measuring force applied by the weight of a wearer onto a foot of the wearer, said apparatus providing an indication to the wearer when the force is below, or exceeds pre-selected limits, said apparatus comprising:

a body member for attachment to the foot of the wearer, said body member to support at least a portion of the foot, said body member including an upper enclosure, said upper enclosure having an attachment means for contact of said upper enclosure with the sides and top of the foot;

a foot plate removably insertable within said body member, said foot plate having an upper support surface for contact with the bottom of the foot, and having an underside;

a lower sole portion positioned below said foot plate, said lower sole portion having an upper surface, and a lower surface for contact with the support surface;

a cavity within said upper surface of said lower sole portion, said cavity having a front end and a rear end;

a force sensing unit having ends attachable within said cavity, said force sensing unit connectable to said underside of said foot plate, said force sensing unit measures strain in proportion to the force received by said force sensing unit from the foot in contact with said foot plate, said force sensing unit generates strain signals;

an electronic means mounted within said cavity, said electronic means is electrically connected to said force sensing unit, said electronic means receives said strain signals from said force sensing unit and converts said strain signals to output signals for transmission to one or more remote locations;

a power supply connectable to said electronic means;

a signal processing means at a remote location, said signal processing means receives said output signals from said electronic means; and

a display unit coupled with said signal processing means, said display unit displays output signals from said signal processing means;

whereby force placed by the weight of the wearer of said body member onto said foot plate is transmitted through said foot plate to said force sensing unit attachable within said cavity, the force imparts strain on said force sensing unit which is measured as strain signals, said electronic means receives strain signals from said force sensing unit and converts said strain signals to output signals for radio transmission to said signal processing means for indication to the wearer when the force is below or exceeds pre-selected limits.

2. The apparatus of claim 1, wherein said force sensing unit comprises:

at least one beam positioned within said cavity, said beam having a generally rectangular shape, said beam having a forward end slidably supported at said front end of said cavity, and said beam having a rearward end rotatably connected at said rear end of said cavity;

a pair of side rails of said beam, said side rails forming the sides of said generally rectangular shape, said side rails parallel to each other;

a plurality of cross-pins that extend between said side rails of said beam;

a central cross-member of said plurality of cross-members, said central cross-member having a midpoint bridge between said side rails, said central cross-member having an upper surface and a lower surface, said upper surface having a central groove therein, said central groove is perpendicular to the major axis of said beam, said lower surface having a centering axis thereon, said centering axis located at about the midpoint of said beam;

at least one strain gage mounted on said lower surface of said central cross-member, said strain gage produces strain signals in proportion to the force received by said beam, said at least one strain gage mounted at said centering axis at about the midpoint of said beam;

an energizing voltage from a power source, said voltage connectable by electronic wiring to said strain gage and said electronic means; and

at least one output lead, said output lead connecting between said strain gage and said electronic means.

3. The apparatus of claim 2, wherein said plurality of cross-pins further comprises a first pair and a second pair of cross-pins parallel to each other and perpendicular to the major axis of said beam, said cross-pins span said beam between said side rails,

said first pair of cross-pins including a first cross-pin located near said forward end of said beam,

said first pair of cross-pins including a second cross-pin located rearward of said first cross-pin, said second cross-pin located a pre-selected distance forward from said groove in said central cross-member,

said second pair of cross-pins including a third cross-pin located said pre-selected selected distance rearward from said groove in said central cross-member,

said second pair of cross-pins including a fourth cross-pin located near said rearward end of said beam,

said first cross-pin including a front connector detachably attached to said front end of said cavity, said front connector slidably connectable to said first cross-pin,

said second cross-pin including a front support connector detachably attached to said foot plate, said front support connector slidably connectable to said second cross-pin,

said third cross-pin including a rotatable rear support connector detachably attached to said foot plate, and

said fourth cross-pin including a rotatable rear connector detachably attached to said rear end of said cavity,

whereby said foot plate receives forces transferred from the force applied from the foot of the wearer, the forces are transmitted through said front support connector and said second cross-pin, and through said rear support connector and third cross-pin onto said beam for detection of strain over the length of said beam by said strain gage at about the midpoint of said beam.

4. The apparatus of claim 3, wherein said beam includes one or more openings between said plurality of cross-members, said openings capable of containing said electronic means and said power supply.

5. The apparatus of claim 2, wherein said electronic means further comprises:

a microprocessor for analysis of said strain signals, said microprocessor converts said strain signals to output signals in radio frequency form; and

a transmitter circuitry for transmission of output signals in radio frequency form from said microprocessor to said signal processing means at one or more remote locations.

6. The apparatus of claim 5, wherein said signal processing means receives said output signals from said transmitter circuitry, said signal processing means processes said output signals with a second microprocessor for analysis of output signals and notification of the wearer.

7. The apparatus of claim 6, wherein signal processing means further comprises a reporting means, said reporting means includes visual and audible alarms for notification of the wearer of said signal processing means, said alarms notify the wearer if a pre-selected upper threshold weight limit is exceeded, or notify the wearer if a lower threshold weight limit is not achieved.

8. The apparatus of claim 7, wherein said reporting means alarms further comprise a light display, a light display with vibration of said processing means, or a light display and an audible alarm for notification of the wearer if the pre-selected upper threshold weight limit is exceeded, or if the lower threshold weight limit is not achieved.

9. The apparatus of claim 8, wherein said reporting means alarms further comprise a numerical reading for display of output signals.

10. The apparatus of claim 9, wherein said second microprocessor for analysis of said output signals is programable for reset of analysis when the pre-selected upper threshold weight limit is exceeded, or for reset when the lower threshold weight limit is not achieved.

11. The apparatus of claim 10, wherein said second microprocessor is programable for reset to an alternative upper threshold limit below the pre-selected upper threshold weight limit, or for reset to an alternative lower threshold limit below the lower threshold weight limit, said alternative upper or lower threshold weight limit can be set manually by said wearer.

12. The apparatus of claim 11, wherein said reporting means can display a number for each force measured by said strain gage during each step by said wearer.

13. The apparatus of claim 1, wherein said body member and said foot plate can be selected from a plurality of sizes to fit the foot of the wearer.

14. A method of operation of a force monitoring system for measuring force applied to a foot by the weight of a wearer of the force monitoring system, comprising the steps of:

(a) providing an orthopedic shoe for enclosure of the foot of the wearer, said shoe having a foot plate and a sole with an interior cavity;

(b) inserting a beam into said sole cavity, said beam having at least one force measuring strain gage on said beam;

(c) connecting a microprocessor by electrical connectors to said at least one strain gage;

(d) attaching a transmitter by electrical connectors to said microprocessor, said transmitter transmitting signals in proportion to force measured by said strain gage;

(e) placing said orthopedic shoe on the wearer'"'"'s foot;

(f) monitoring the force measured by said strain gage, said strain gage generating electronic signals in proportion to said force applied on said foot plate;

(g) analyzing said electrical signals generated by said monitoring step, said analyzing step generating output signals from said microprocessor;

(h) transmitting said output signals in the form of radio frequency signals to a receiver attachable to said wearer;

(i) processing said output signals in a signal processing means in a display unit at a remote location, said signal processing means receives said output signals from said transmitting step and compares said output signals to pre-selected upper threshold weight limits and lower threshold weight limits; and

(j) displaying to the wearer said output signals if said signals are above the pre-selected maximum weight limits or are below the minimum weight limits.

15. The method of claim 14, wherein said step of analyzing further comprises:

(a) setting a desired range of measured force, said desired range including said pre-selected upper threshold weight limit, and said lower threshold weight limit;

(b) reporting output signals for measured forces outside said desired range of measured force, with no reporting of signals for measured forces below said upper threshold weight limits and above said lower threshold weight limits; and

(c) generating analyzed output signals for transfer to said transmitting step.

16. The method of claim 15, wherein said step of displaying further comprises:

(a) receiving said analyzed output signals in the form of radio frequency signals at said receiver attachable to said wearer;

(b) signaling said received output signals in the form of a light display, a light display with vibration of said processing means, or a light and audible alarm for output signals for measured force outside said desired range;

(c) processing said received output signals as a numerical reading for measured force outside said desired range;

(d) counting the total steps taken by the wearer up to a predetermined step limit;

(e) storing in memory the total steps counted in said counting step; and

(f) displaying said numerical readings and said counted total steps.

17. A force monitoring apparatus for measuring force applied by the weight of a wearer to a foot of the wearer of an orthopedic shoe, the apparatus providing an indication to the wearer when the force is below, or exceeds pre-selected limits, the apparatus comprising:

a base within the orthopedic shoe, said base having an upper sole layer that extends the length of the shoe, and having a lower sole surface for contact with the support surface;

a cavity within said upper sole layer, said cavity having a forefoot end and a heel end;

a foot plate that is attachable over said upper sole layer and said cavity, said foot plate being rigid;

a beam insertable into said cavity, said beam including two side rails, a midpoint cross-member having a midpoint bridge between said side rails, and at least two cross-members on opposite sides of said midpoint cross-member, said cross-members connected between the side rails forming a generally rectangular frame, said beam is connectable underneath said foot plate;

a strain gage positioned under said midpoint cross-member of said beam, said strain gage generates strain signals in proportion to the force placed by the foot of the wearer onto the foot plate;

an electronic processing means located proximal to said strain gage and connected within said side rails of said beam, said electronic processing means generates output signals in proportion to the strain signals generated by said strain gage;

a power supply connectable to said electronic processing means;

a transmitter of output signals from said electronic processing means, said transmitter connectable to the orthopedic shoe, said transmitter emits output signals in proportion to said output signals generated by said electronic processing means;

a receiver of output signals from said transmitter, said receiver located separate from the orthopedic shoe;

a signal processing means within said receiver, said signal processing means receives said output signals from said transmitter;

said signal processing means generates alarm signals if said output signals are below, or exceed pre-selected limits; and

a display unit coupled with said signal processing means, said display unit displays said alarm signals from said signal processing means;

whereby said beam flexes when the wearer places force onto said foot plate, with resultant output signals generated by said electronic processing means, with said output signals transmitted to said receiver of output signals from said transmitter, said receiver displays said alarm signal to notify wearer when the force is below, or exceeds pre-selected limits.

18. The force monitoring apparatus of claim 17, wherein said beam further comprises:

a forefoot section of said beam, said forefoot section having a generally rectangular shape, said forefoot section having a front end and a central cross-member end, said forefoot section including;

a front cross-member positioned near said front end of said forefoot section;

a second cross-member that spans said central cross-member end, said second cross-member forms part of the said midpoint cross-member having said strain gage underneath;

a first cross-pin that spans said front end of said forefoot section, said first cross-pin positioned in front of said front cross-member;

a second cross-pin that spans said front end of said forefoot section, said second cross-pin positioned between said first cross-pin and said front cross-member;

said second cross-pin positioned a pre-selected distance from said strain gage; and

a front beam support connector connectable to said first cross-pin, said front beam support connector is attachable by screws to said forefoot end of said cavity of the shoe;

a heel section of said beam, said heel section having a generally rectangular shape, said heel section having a heel central end and a rear end, said heel section including;

a first heel cross-member that spans said heel section, said first heel cross-member forms part of said midpoint cross-member having said strain gage underneath;

a second heel cross-member that spans a point near said rear end of said heel section;

a third cross-pin that spans said heel section distal said second heel cross-member from said midpoint cross-member, said third cross-pin positioned said pre-selected distance from said strain gage as said second cross-pin of said forefoot section;

a fourth cross-pin that spans said heel section at said rear end of said heel section, said fourth cross-pin distal said third cross-pin; and

a rear beam support connector rotatable around said fourth cross-pin, said rear beam support connector is attachable by screws to said heel end of said cavity of the shoe; and

a central groove at a mid-point of said midpoint cross-member, said central groove reduces the thickness of said mid-point of said midpoint cross-member, said central groove having said strain gage centered underneath;

whereby said beam is insertable into said cavity, said foot plate is placed over said beam and said cavity, said foot plate is attachable over said beam, with force transfer by the foot of the wearer during standing and walking provides variable forces on said foot plate, said strain gage generates strain signals proportional to the force placed on said foot plate.

19. The force monitoring apparatus of claim 18, wherein said electronic processing means further comprises:

a microprocessor connected to said strain gage, said microprocessor generates electrical signals in proportion to the strain signals generated by said strain gage;

a receiver of electrical signals from said strain gage, said receiver channels electrical signals to said electrical circuitry;

an electrical circuitry including electrical components for the analysis of electrical signals from said strain gage;

an analog to digital converter, for converting the electrical signals to output signals; and

a programable computer program including pre-selected upper threshold weight limits and lower threshold weight limits, said computer program reports output signals for measured weights outside said pre-selected upper threshold weight limits and lower threshold weight limits, with no reports of output signals for measured weights below said upper threshold weight limit but above said lower threshold weight limit.

20. The force monitoring apparatus of claim 19, wherein said receiver further comprises:

a receiver having a LED display and a microprocessor having storage memory;

a plurality of LED alarm signals stored in said microprocessor memory;

at least one alarm lower limit stored in said microprocessor memory;

at least one alarm upper limit stored in said microprocessor memory;

a vibrator mechanism triggered to vibrate at said upper threshold weight limit, and at said lower threshold weight limit; and

a calibration connection for external connection with a calibration computer.