Sensor based mattress/seat for monitoring pressure, temperature and sweat concentration to prevent pressure ulcerations
A system for detecting conditions to prevent a bedsore includes a first sensor to detect a first condition that results in the bedsore and to output a first sensor signal from the first sensor indicative of the first condition that results in the bedsore, a controller to receive the first sensor signal and to determine if the condition may result in the bedsore and an alarm responsive to the controller to provide an alarm to indicate that the condition may result in the bedsore.
The present invention is in the field of biotechnology and relates to a method and apparatus for preventing pressure ulcerations, and more particularly, the present invention relates to a sensor system for mattress/seats and other devices which a human may come in contact with to measure pressure, temperature and sweat concentrations to prevent pressure ulcerations.
BACKGROUNDThe development of sol-gel techniques for processing optical-quality thin films of silica glass has been established for various applications. One of the interesting features of the sol-gel application is that it enables one to synthesize inorganic glasses at room temperature without melting. One consideration is that the low temperature sol-gel approach circumvents the inability of the molecules to withstand the high temperatures required in the processing of oxides.
Patient immobility and debilitation are a significant health concern in the world today. This is of significant concern to patients who are suffering from a long-term illness such as trauma victims and spinal cord injury patients and who benefit from a health-care system that in some cases has lengthened and improved the quality of life. However, these patients may not able to move themselves, and consequently, these patients must rely on others for movement. A significant problem that results from this lack of mobility and that plagues these patients and consequently affects the staff of nursing homes and skilled nursing facilities is decubitus ulcers and bedsores. This complication has resulted in the death of one of the most well-known spinal cord injured patients, namely Christopher Reeve. Around-the-clock staffing for the health of the patient is available for only a minority of patients. Most patients will only have the services of a staff member for only short periods of time during the day. Because of the large and ever increasing number of patients assigned to an individual staff member, monitoring of all the needs for these patients is quite challenging. During these short periods of time that is available to each patient, the staff member may overlook the need to move these immobile patients, and the result may be decubitus ulcers or bed sores.
Each year, approximately 2,000,000 bedridden patients develop bedsores or pressure ulcers at an estimated cost of approximately $9 billion in medical expenses to treat these disorders. If vascular and diabetic ulcers are included, the cost can rise by approximately 5 times this amount. This figure does not take into account the number of days of lost productivity from the people suffering these wounds. A significant number of bed sore problems also occur in nursing homes and homes with patients confined to wheelchairs. There are approximately 1.6 million elderly and disabled people in over 17,000 nursing homes in this country alone. Of these nursing home residents, a significant percentage, approximately 13% develop bedsores every year. In 1995, the Department of Health and Human Services issued the toughest nursing home regulations in the history of the Medicare and Medicaid programs and which has led to measurable improvements in the quantity of care but have not completely eliminated the problem of bedsores. Today, there is no automatic system for monitoring pressures in bedridden and wheelchair confined patients. Consequently, patients are turned in their beds systematically and periodically to prevent bedsores.
References
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- 5. Sprigle, Linden, McKenna, Davis and Riordon, “Clinical skin temperature measurement to predict incipient pressure ulcers,” Adv Skin Wound Care, 2001 May-Jun; 14(3):133-7.
- 6. Hickerson, Slugocki, Thaker, Duncan, Bishop and Parks, “Comparison of total body tissue interface pressure of specialized pressure relieving mattresses,” J. Long term Eff Med Implants, 2004; 14(2);81-94.
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A class of environmentally-responsive glasses has been designed to respond to different environmental stimuli. These glasses are prepared by the low temperature, solution based, sol-gel process by using organically-modified bis-[3-(trimethoxysilyl) propyl] ethylendiamine(enTMOS) precursor. Starting from the molecular precursor, the sol-gel reaction yields a solid state glass and a mechanically robust yet elastic material that is capable of generating dynamic responses when subjected to different physicochemical stimuli. These sol-gel glasses exhibit bulk changes in volume and respond to the application of different physicochemical chemical stimuli with the swelling/de-swelling being reversible, consistent and reproducible. The sol-gel undergoes a substantial change in volume when exposed to different stimuli. The change in volume is a result of the amount of liquid that is absorbed or expelled by the sol-gel. Consequently, the amount of liquid affects the electrical properties of the sol-gel. The larger the volume and correspondingly the larger amount of liquid reduce the electrical resistance of the sol-gel, increasing current. Incorporating the sol-gel into a sensor results not only in the ability to determine the presence of the stimuli but to provide a quantitative determination of the amount of stimuli present. The chemical interaction of these sol-gels with different molecules based on the charge, size and hydrophobicity/hydrophilicity can be exploited for separation of these molecules from a mixture. Typically, when the sol-gels are placed in a solution containing a mixture of different molecules, the sol-gels intake preferred species while leaving others out. This feature can be effectively used for the separation of species based on chemical structure of different molecules.
BRIEF DESCRIPTION OF THE DRAWINGS
The single conditioning and data transfer unit 114 obtains sufficient information from the patient by the chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110 to determine if bed sores are developing. Other types of sensors are within the scope of the present invention in order to achieve the desired results.
The sheets 102, 104 are shown as rectangles which may be sized to be used with a mattress, but other sizes and shapes for the sheets 102, 104 are possible based on the needs of the patient and the device that the patient is positioned in. The sensors could be directly mounted on the patient for example while lying on the patient's back for example, while in ICU or could used with other applications such as car seats, airplane seats or other applications.
In operation, a patient is positioned between sheet 102 and sheet 104, and the chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110 are positioned on one or both of the sheets 102, 104 but most likely would be located on the bottom sheet. The chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110 continuously or intermittently sense the conditions of the patient and sends a sensor signal along wires 112 to the connector 106 and to the serial connector 116, and the sensor signal reaches the signal conditioner and data transfer unit 114. The signal conditioner and data transfer unit 114 receives the sensor signals from the chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110.
The sensor signals are sent to RAM 208 for storage and then to the controller 206 for evaluation. If the controller 206 determines that conditions are favorable for the development of bed sores for example by determining that the one or more of the sensor signals have exceed a predetermined threshold, then the controller 206 activates the alarm 214. The predetermined threshold is stored in RAM 208 to be accessed by the controller 206 and may be stored for each of the individual patients and for each sensor 108,109,110. The controller 206 may send an alarm and/or the sensor signals to the central monitoring station 140. The controller 206 obtains data from the RAM 208 to evaluate the sensor signals sent from the chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110. If the controller 206 does not for example received a sensor signal from one of the sensors, then the controller 206 activates the alarm 214 so that the defective sensor can be fixed or replaced. The LCD display 210 can display the sensor signals from the chlorine sensor 108 the temperature sensor 109 or/and the pressure sensor 110. Additionally, the LCD display 110 can display the evaluation of the sensor signals by the controller 206 so that the patient or staff member for the patient can determine if conditions favorable for bed sores are being approached. The LED display 212 can display which sensors are active and which sensors are inactive.
The signal conditioning and data transfer unit 114 transmits the sensor signals to the central monitoring station 140 through the input and output unit 130. The central monitoring station 140 may be at a physically different location than the signal conditioning and data transfer unit 114 so that the personnel at the location of the central monitoring station 140 can monitor the patient from a remote location. The signal conditioning and data transfer unit 114 can change the thresholds used by the signal conditioning and data transfer unit 114 in the comparison of the sensor signals from the chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110 for the determination of favorable conditions for the development of bed sores. Consequently, the signal conditioning and data transfer unit 114 can take into account the different tolerances of different patients for favorable conditions for the development of the bed sores. Furthermore, the controller 206 can store the readings from the chlorine sensor 108, the temperature sensor 109 and the pressure sensor 110 in RAM 208 so that evaluations of the patient can be achieved based on previous history sensor readings. The chlorine ion sensor 108 as shown in
The following is a description of one method of the several methods of forming the chlorine sensor 108. The steps of this method are shown in
The thin coating of the sol on the electrodes 402 is achieved with a spin coater. Here, 250 μl of the homogeneous sol is taken and applied to a circular surface of the electrode 402. The electrode 402 is placed on the spin coater, and a homogeneous thin coating is obtained by this process. All the sol-gel electrodes are left to dry under room conditions for approximately 12 hours before use. The electrodes are subsequently washed with water (50 mL) to get rid the electrodes 402 of any Cl− ions.
The steps of electrode preparation are shown in
The sensor may be calibrated by the following electrochemical measurements by which measurements could be taken in a 3-electrode configuration. The electrode is immersed in a given concentration of chloride ions and current is monitored using chromoamperometry. The saturation current is measured at 1 V applied potential or any other appropriate potential. The current is correlated with concentration of the chloride ion in the surrounding liquid.
The pressure sensor 110 can be of many types. One type of pressure sensor 110 is based on converting the pressure exerted on the pressure sensor 110 to an electrical signal which is transmitted to the signal conditioning and data transfer unit 114. Another type of pressure sensor changes color in response to the pressure being exerted on the pressure sensor 110.
With the present invention, elastic sol-gels or silicones are impregnated with conducting particles such as carbon powder or metal particles that are used to change the resistance of the sol-gel and consequently the current varies based on changes of pressure on the pressure sensor 110. These types of gels shrink or contract as pressure is applied to the pressure sensor 110, increasing the density of the conducting particles and lowering the resistance of the sol-gel.
In a similar fashion as the chlorine sensor 108, the pressure sensor 110 is formed as follows as shown in
While the above embodiments of the present invention have been described in a particular manner, one of ordinary skill in the art would recognize that substitutions and modifications would be contemplated with the teachings of the present invention. Thus, other modifications and substitutions are within the scope of the present invention.
Claims
1) A system for detecting conditions to prevent a bedsore, comprising:
- a first sensor to detect a first condition that results in said bedsore and to output a first sensor signal from said first sensor indicative of said first condition that results in said bedsore;
- a controller to receive said first sensor signal and to determine if said condition may result in said bedsore; and
- an alarm responsive to said controller to provide an alarm to indicate that said condition may result in said bedsore.
2) A system for detecting conditions to prevent a bedsore as in claim 1, wherein said first sensor includes a chlorine sensor to detect the presence or absence of chlorine.
3) A system for detecting conditions to prevent a bedsore as in claim 1, wherein said system includes a second sensor to detect a second condition that results in said bedsore and to output a second sensor signal from said second sensor indicative of said second condition that results in said bedsore
4) A system for detecting conditions to prevent a bedsore as in claim 3, wherein said system includes a third sensor to detect a third condition that results in said bedsore and to output a third sensor signal from said third sensor indicative of said third condition that results in said bedsore.
5) A system for detecting conditions to prevent a bedsore as in claim 3, wherein said second sensor includes a pressure sensor to detect pressure.
6) A system for detecting conditions to prevent a bedsore as in claim 4, wherein said third sensor includes a temperature sensor to detect temperature.
7) A system for detecting conditions to prevent a bedsore as in claim 2, wherein said chlorine sensor includes a chlorine sol-gel sensor.
8) A system for detecting conditions to prevent a bedsore as in claim 5, wherein said pressure sensor includes a pressure sol-gel sensor.
9) A system for detecting conditions to prevent a bedsore as in claim 5, wherein said pressure sensor includes a pressure liquid crystal sensor.
10) A system for detecting conditions to prevent a bedsore as in claim 6, wherein said temperature sensor includes a temperature liquid crystal sensor.
11) A method for detecting conditions to prevent a bedsore, comprising the steps of:
- sensing to detect a first condition that results in said bedsore and to output a first sensor signal indicative of said first condition that results in said bedsore;
- receiving said first sensor signal and determining if said condition may result in said bedsore; and
- sending an alarm to indicate that said condition may result in said bedsore.
12) A method for detecting conditions to prevent a bedsore as in claim 11, wherein said sensing said first condition includes sensing to detect the presence or absence of chlorine.
13) A method for detecting conditions to prevent a bedsore as in claim 11, wherein said method includes sensing to detect a second condition that results in said bedsore and to output a second sensor signal indicative of said second condition that results in said bedsore
14) A method for detecting conditions to prevent a bedsore as in claim 13, wherein said method includes sensing to detect a third condition that results in said bedsore and to output a third sensor signal indicative of said third condition that results in said bedsore.
15) A method for detecting conditions to prevent a bedsore as in claim 13, wherein said sensing said second condition includes using a pressure sensor to detect pressure.
16) A method for detecting conditions to prevent a bedsore as in claim 14, wherein said sensing said third condition includes using a temperature sensor to detect temperature.
17) A method for detecting conditions to prevent a bedsore as in claim 12, wherein said sensing said first condition includes using a chlorine sol-gel sensor.
18) A method for detecting conditions to prevent a bedsore as in claim 15, wherein said sensing said second condition includes using a pressure sol-gel sensor.
19) A method for detecting conditions to prevent a bedsore as in claim 15, wherein said sensing said second condition includes using a pressure liquid crystal sensor.
20) A method for detecting conditions to prevent a bedsore as in claim 16, wherein said sensing said third condition includes using a temperature liquid crystal sensor.
Type: Application
Filed: Sep 8, 2005
Publication Date: Mar 15, 2007
Inventors: Ajay Mahajan (Murphysboro, IL), Sumeer Lal (Greenwood, SC), Jayant Nath (Overland Park, KS), Bakul Dave (Carbondale, IL)
Application Number: 11/221,565
International Classification: A47B 71/00 (20060101);